Progress 09/01/10 to 08/31/15
Outputs
Target Audience:The target audiences for this project include: growers, producers, and processors of organic leafy greens; manufacturers of natural antimicrobials and organic sanitizers; and consumers of organic leafy greens. Leafy green producers, manufacturers of natural antimicrobials, organic sanitizers have been involved in this project by providing in-kind support. Duncan Family farms, Buckeye, AZ and JV Farms, Yuma, AZ provided lab equipment and organic leafy greens. CreAgri Inc., Hayward, CA and Apple Poly, LLC., Morrill, NE provided antimicrobial plant extracts and Spectral Imaging, Tucson, AZ provided imaging equipment. The following companies provided organic sanitizers: GTX Technologies, Amarillo, TX; E3 Organics, Inc., CA; Summerdale, Inc., Verona, WI; ASC Agrecom, Inc., Tucson, AZ; Arch Chemicals, Inc., Charleston, TN; and BioSafe Systems, East Hartford, CT. They have been informed periodically on the project results through various forums such as seminars, reports, talks and demonstrations. For growers, information about the project results was shared at meetings, conferences, seminars and via demonstrations. Meetings such as the Arizona Produce Research Priorities meeting organized by the Center for Produce Safety, Food Safety Summit (2011-2015), Southwest Agricultural Summit (2011-2015), and Lettuce days (2011-2015) provided Drs. Sadhana Ravishankar, Kelly Bright, Charles Gerba, Kurt Nolte, Jorge Fonseca and Divya Jaroni an opportunity to present their research findings and develop a deeper insight about food safety challenges faced by the growers. Dr. Ravishankar and Gerba have served as panel members in food safety panels at the Southwest Agricultural Summits in Yuma, AZ. Dr. Ravishankar serves in the Food Safety Advisory Board for Duncan Family Farms. Visits to farms and meetings with growers nurtured an efficient channel of communication between stakeholders and researchers. Visits to farms such as JV Farms, Dole Fresh Produce, Pasquinelli Produce Company, Fresh Express, Taylor Farms, Duncan Family Farms and Foxy Fresh Produce by research team helped understand current issues associated with safety of organic leafy greens. Farms were also advised on water sampling techniques and frequency based on results obtained about water quality and pathogen surveillance conducted during the project. The research team often exceeded the scope of the project to improve food safety knowledge and awareness by testing the role of dust in pathogen transfer, an issue of concern for AZ leafy green growers, and testing biofilm formation by E. coli on leafy green wash water contact surface. The initiative to test different viruses as reliable indicators of fecal contamination was also done to help growers develop robust biomarkers for environmental contamination. Research data was presented at international conferences, academic meetings, professional associations and for students. These included the Annual Meetings of the following: American Society for Horticultural Sciences (2012-2014), International Association for Food Protection (2011-2015), Institute of Food Technologists (IFT; 2011-2015), University of Arizona Food Safety Consortium (2012-2015), Yuma Fresh Vegetable Association (2012), Arizona Iceberg Lettuce Research Council (2012-2015) and Yuma Safe Produce Council (2015). Demonstrations on use of plant antimicrobials for produce washing and safe handling of produce was conducted at the Youth Biotechnology Career Expo in Tucson, AZ (2013); Science City, Tucson Festival of Books (2012-2015); Cactus IFT meeting, Phoenix & Tucson (2014 & 2015); Career Day at Summit View Elementary School, Tucson (2015); and the Clean and Green Produce Safety Workshop, Tucson, AZ (2015). A total of 27 presentations/demonstrations were conducted by Dr. Ravishankar and her team during the grant duration. The audiences at these conference and meetings included food safety professionals, produce growers, produce industry professionals and students. Research was also presented to elementary, middle, and high school, undergraduate and graduate students to develop awareness about organic agriculture, food safety, produce handling, and sanitizers. The initiative to develop an interest in research and analytical thinking was catered to by developing activities and demonstrations that involved active learning. Biophotonic imaging was used to develop awareness of cross contamination and sanitizer efficacy. Glitter contaminated cutting boards were used to demonstrate cross contamination to younger children. These activities were well received by the audience. Three workshops with hands on demonstrations were conducted for University of AZ and AZ Western College, Yuma, AZ students (27 participants) on organic leafy green safety. Dissemination of information to the public occurred through radio shows, news coverage and USDA blogs. Dr. Ravishankar was interviewed by Phoenix Public Radio KJZZ 91.5 FM, "Agronomically Speaking" Radio 710 KURV, Texas, and Arizona Public Media (Tucson section NPR). News coverage also included print media- Fresh Cut Magazine, California Farmer Magazine "Compendium" by the UA College of Agriculture and Life Sciences. Interviews with the Daily Wildcat, Packer magazine and UA News were also published. These were well received by both industry and consumers who contacted Dr. Ravishankar via emails for more information or to foster collaborations. Two national level webinars hosted by E3 Organics and eOrganics were also presented by Dr. Ravishankar. The webinars were attended by students, produce industry personnel and state regulatory agencies. Dr. Ravishankar presented the results via seminars at the Western Regional Research Center, Albany, CA; Texas A&M University, College Park, TX; Arizona Senior Academy, Tucson, AZ; Microbiology Club, Tucson, AZ; and the Annual Registered Sanitarians Conference, Phoenix, AZ. The extension team at Yuma developed effective and innovative methods to disseminate information to growers that continue to be a source of applicable data for stakeholders. Dr. Nolte and his team developed a website, created and uploaded YouTube videos, developed training DVDs and has made information accessible over Facebook, Pinterest and Twitter. Apart from improving the accessibility to latest research in food safety and good agricultural practices, he has also conducted seminars and training series in different parts of Arizona addressing pressing issues in food safety. A unique feature of his efforts has been the bilingual mode of instruction in order to reach a larger target audience and non-English speaking minorities. Dr. Jaroni spoke at 2 workshops in Opelousas, LA and 2 field-days in Baton Rouge, LA. These were designed to increase knowledge of growers in food safety, agricultural practices and nutritional properties of crops grown in LA. The workshops and field days were attended by at least 50 & 100 farmers, respectively. Dr. Jaroni also presented results at 3 Plant Biosecurity symposiums held at Southern University attended by about 200 fresh produce industry and academia professionals and consumers. Dr. Brandenberger and Dr. McGlynn carried out a total of 24 presentations to several groups of fresh produce growers and processors in Oklahoma related to fresh produce safety. These are generally small-scale producers who sell their products at the local grocery stores or farmer's markets. The PIs from Oklahoma State University have also finalized and made public a website related to fresh produce safety, which is intended to provide Oklahoma growers, processors, and interested consumers with single-source access to relevant research results. A total of 20 abstracts were submitted by Dr. Jaroni's group and accepted for oral and poster presentations at various meetings. Dr. Jitu Patel of USDA-ARS shared results on internalization and natural antimicrobials with the largest organic growers in the mid-Atlantic region. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?All postdoctoral fellows, technicians and students hired to work on this project have received training in good laboratory practices, including pathogen safety precautions, media preparation, product sampling, field sampling and other laboratory activities related to the project. Dr. Sadhana Ravishankar's lab had 23 undergraduate students, 8 graduate students, 1 research specialist and 2 postdoctoral research associates involved with organic leafy greens research. All students have been trained in bacterial inoculation & enumeration, environmental isolation of pathogens, soil, organic composts and compost teas evaluation and have been involved with conducting experiments under the guidance of Drs. Ravishankar and Dev Kumar. Students have been trained to analyze and present data and have presented research posters at Food Safety Conferences in University of Arizona and at the Cactus Institute of Food Technologists regional meeting. Dr. Dev Kumar was trained in confocal microscopy at the USDA, Beltsville facility in Maryland by Dr. Patel. Dr. Ralph Meer and research specialist Libin Zhu were trained in confocal microscopy and a graduate student Arlette Schneider in fluorescent microscopy (for investigating mechanism of action of clove bud oil) at the University of Arizona. Three graduate students were trained to design primers, develop master mixes for polymerase chain reaction (PCR) and perform PCR for the identification of foodborne pathogens. These students were also trained in antibiotic resistance testing for bacteria. Dr. Ravishankar's team offered hands on organic leafy greens safety training workshop covering various topics to undergraduate and graduate students from Tucson and Yuma and industry in August 2015. Dr. Ravishankar also trains local elementary, middle and high school students in microbiological techniques and allows them to work on produce safety projects using non-pathogenic bacterial strains. Four high school students, two middle school students and two elementary school students conducted their research projects in Dr Ravishankar's lab for science fairs. Three high school students won awards at the school and regional levels (Southern Arizona Science and Engineering Fair) and got the opportunity to participate at the Intel International Science and Engineering Fair, where two high school students won special awards. Two elementary school and one middle school students won awards at the school and regional levels. Produce safety demonstrations were conducted by Dr. Ravishankar's research team during lab tours for local school students Dr. Ravishankar's students and postdoctoral research associate (Dr. Dev Kumar) had the opportunity to present research results at various occasions. Dr. Dev Kumar presented a seminar on biofilms on leafy green wash water equipment surfaces at the Fall seminar series of the School of Animal and Comparative Biomedical Sciences, University of Arizona. He also presented the research results in the form of oral presentations at the quarterly meetings of the Arizona Iceberg Lettuce Research Council in November 2013, July 2014 and 2015. These meetings were attended by leafy green growers and industry professionals from Yuma, AZ and California. Dr. Dev Kumar also had the opportunity to present the research results as a technical oral presentation at the Annual Meeting of the International Association for Food Protection in Indianapolis and the Yuma Fresh Produce Council meeting. Dr. Ravishankar's students and postdoctoral research associate presented their research results in the form of posters at the Annual Food Safety Conference hosted by the University of Arizona Food Safety Consortium in 2012, 2013, 2014 and 2015. Dr. Ravishankar's graduate student Xeeroy Rada and Arlette Schneider won the third place and first place respectively in the student poster competition at this conference. Dr. Ravishankar's students and postdoctoral research associate had the opportunity to participate in food safety demonstrations about natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination at the following events: for the local high school students at the at the Youth Biotechnology Career Expo in October 2013, Tucson, AZ; for the local high school students at the Southwest Ag Summit in February 2014, and 2015 at Yuma, AZ; for the local community at the Tucson Festival of Books in March 2012, 2013, 2014, and 2015 at Tucson, AZ; for the local community at the Lettuce Days in February 2014 and 2015, Yuma, AZ. In the Yuma Agricultural Center, 5 research technicians and 1 undergraduate student were trained in laboratory work for analyzing the safety and quality aspects of organic leafy greens; organic composts and compost teas production; investigating the survival of non-pathogenic E.coli and background microflora in compost teas; cross-contamination potential of original and modified design coring tools; field work involving organic leafy greens production, application of compost teas with and without E.coli; harvesting leafy greens and analyzing them for quality and market attributes. One media specialist assisted Dr. Kurt Nolte in the production of audiovisual material, YouTube videos and other social media networking. She interviewed few project members and produced YouTube videos on specific topics concerning organic leafy greens production. Dr. Nolte also trained one undergraduate student in outreach material production. In Dr. Patel's lab, two postdoctoral fellows, 1 graduate, and 2 undergraduate students were trained in food microbiology under the research project to determine attachment and internalization of E. coli O157:H7 on organic leafy greens. In Dr. Jaroni's lab 3 postdoctoral fellows, 8 graduate and 16 undergraduate students were trained as food microbiologists to evaluate the efficacies of various approved organic sanitizers/antimicrobials against E.coli O157:H7 on organic leafy greens. The students and postdocs also had opportunities to present their research (oral and poster) at several venues for their professional development; at the Annual meeting of International Association for Food Protection (IAFP), the Oklahoma State University (OSU) Research Week, the annual FAPC Research Symposium, the Dept. of Animal Science (ANSI) Seminar series, and the FAPC Seminar series. 12 graduate and 11 undergraduate students were also trained during the FDSC 4253/5120 Preharvest Food Safety course offered in Spring Semesters through the ANSI Food Science Program at OSU. Dr. Kelly Bright trained Sheri Carlino, research specialist and two graduate students to perform environmental field sampling for bacterial pathogens and the culture and isolation of bacterial foodborne pathogens from irrigation waters. Also, Dusty Tyree, part-time research technician was trained to perform environmental field sampling for bacterial and viral pathogens, the concentration of viruses from water, and quantitative PCR for the detection of viruses in water. The use of mass media for the propagation of food safety information to stakeholders has given students and other researchers in the Ravishankar lab and the Yuma Agricultural Center an opportunity to participate in interviews about their research for Youtube videos. The new forum helps students and researchers present their findings in a succinct and easily accessible format. Drs. Ravishankar, Jaroni, Gerba, Bright, Patel and Nolte's students and team members have had the opportunity to present their research findings at international and state level conferences such as the Annual Meetings of the International Association for Food Protection, the Institute of Food Technologists and the American Society for Horticultural Sciences, as well as the food safety summits in Yuma, AZ, Annual Food Safety Conference and PI meetings in Tucson, AZ, through poster and oral presentations. How have the results been disseminated to communities of interest?The extension teams at the Yuma Agricultural Center, Oklahoma State University, Dr. Nolte and Dr. Ravishankar's team have been involved in dissemination of information to communities of interest. Seminars, training sessions, conferences, demonstrations, videos, internet based communications and print media have all been used. Overall Extension/ Outreach Summary- Dr. Nolte, University of Arizona- 06/2012-05/2015: 1. Arizona Organic Food Safety Workshops, Target Trainings and Demonstrations: Since initiating Organic Fresh Produce USDA GHP/GAP targeted trainings, tours, workshops in 2012, the total number of Organic Safety training participants was 3,474. During this period, the number of Arizona specific, USDA GHP/GAP certified growers has increased 3-fold. Initiated the first Arizona Group USDA GHP/GAP effort and submitted a Quality Management System to USDA-AMS for external review and approval. With USDA approval, Arizona Group GAP effort will be the first University/State Department of Agriculture/Local Grower Network fresh produce collaboration in the US. 2. Internet Video Outreach Developed and published a collection of 31 (19 in English, 12 in Spanish) Extension and targeted training videos which provides research outcomes to users. Total viewership includes 10,470 individual views from among 12 countries. Video modules can be viewed on the Fresh Produce Safety Channel (http://www.youtube.com/user/FreshProduceSafety/featured). A portion of this video series is also available in a DVD format for use when an internet connection is not available. 3. Social Media Interfacing Extension also included programming that utilized a dedicated web interface, Facebook, Twitter, and Pinterest. Since the live release in early 2013, the sites have generated over 11,170 global interactions and fresh produce safety communication continues to grow daily. Workshops have been conducted throughout the state to provide content detailed training involving the safe production of organically grown leafy greens. In 2015, the following workshops were conducted: Tucson (March, 2015): A GHP/GAP training workshop was provided to 125 attendees during the Greenhouse Crop Production and Engineering Design Short Course Phoenix (March, 2015) 23 participants Phoenix (Spring, 2015): Initiated an Arizona Group USDA GHP/GAP effort to be organized in Central Arizona (Phoenix), and being facilitated by Stewart Jacobson (Arizona Department of Agriculture) and Kurt Nolte (University of Arizona). The Central Arizona Group USDA GHP/GAP, Quality Management System was submitted to the USDA-AMS for review. With USDA approval, the Arizona Group GAP effort will be the first University/State Department of Agriculture/Local Grower Network fresh produce collaboration in the US. Specific regulatory and grower related training was provided to educate clientele or third party auditors about research outcomes to gain greater insight on industry needs. Fresh Produce Safety Tour Series in Yuma (Jan. - Mar., 2015) included 880 participants. Extension Videos covering the following topics were developed: edible films; microbial internalization; organic sanitizers, compost teas; reducing contamination in irrigation water; safe management practices for composted manures. Also a 4-part, video series of field worker training modules (English and Spanish) covering hand washing, field sanitization, bodily fluid discharge and field etiquette were developed for field workers. Growers found these very useful. Dr. Ravishankar and her team attended the Annual Food Safety Conferences in Tucson, AZ where project results were shared with stakeholders and posters were presented. Dr. Ravishankar's graduate student presented a poster on the efficacy of plant antimicrobial combinations at the University of Arizona Student Poster Competition to inform the university community about the efforts associated with making produce safer. Dr. Ravishankar's team conducted food safety demonstrations on natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination for local high school students at the Youth Biotechnology Career Expo (2013) in Tucson, AZ and Southwest Ag Summit (2014, 2015) in Yuma, AZ; for local community at Science City, Tucson Festival of Books (2012-2015) and Lettuce Days (2014, 2015) at Yuma, AZ; for food professionals at Cactus IFT meeting, Phoenix and Tucson (2014, 2015); for students Career Day at Summit View Elementary School (2015); and for college students and industry at the Clean and Green Produce Safety Workshop, Tucson, AZ (2015). Dr. Dev Kumar presented the work on biofilm based attachment of E. coli to washing equipment surfaces at the University of Arizona (2013) and the Arizona Iceberg Lettuce Research Council Quarterly meeting (2013, 2014) in Yuma, AZ. Dr. Ravishankar and her graduate student attended the Food Systems Network meetings during January-March 2014 at Tucson, Arizona to discuss produce safety issues. Dr. Ravishankar presented the results of her research at 2 National Webinars conducted by E3 Organics and the eOrganic in 2013 and 2014. The project team attended the Southwest Agricultural Summit (2012-2015) at Yuma, Arizona to provide information to stakeholders on produce safety issues. Dr. Ravishankar discussed research on produce safety and novel interventions at the Food Systems Network conference in April, 2014. She participated in the Foodborne Task Force Meeting in August 2014, organized by the Arizona Department of Health Services where some findings from the project were shared. A total of 27 presentations/demonstrations were conducted by Dr. Ravishankar and her team. Dr. Dev Kumar presented research on Salmonella internalization in spinach at the IAFP annual conference and the Yuma Safe Produce Council Executive Breakfast in 2015. Dr. Ravishankar presented the results via seminars at the Western Regional Research Center, Albany, CA; Texas A&M University, College Park, TX; Arizona Senior Academy, Tucson, AZ; Microbiology Club, Tucson, AZ; and the Annual Registered Sanitarians Conference, Phoenix, AZ. Dr. Ravishankar was interviewed by Phoenix Public Radio KJZZ 91.5 FM, "Agronomically Speaking" Radio 710 KURV, Texas, and Arizona Public Media (Tucson section NPR). News coverage also included print media- Fresh Cut Magazine, Packer magazine, California Farmer Magazine, Daily Wildcat and "Compendium" by the UA College of Agriculture and Life Sciences. Oklahoma state University team also participated in various talks, presentations and website development for information dissemination. Drs. Brandenberger and McGlynn carried out a total of 24 presentations to several groups of fresh produce growers and processors in Oklahoma related to fresh produce safety. These are generally small-scale producers who sell their products at the local grocery stores or farmer's markets. The PIs from Oklahoma State University have also finalized and made public a website related to fresh produce safety titled: Fresh Produce Safety (www.freshproducesafety.okstate.edu). This website is intended to provide Oklahoma growers, processors, and interested consumers with single-source access to relevant research results, Extension outreach materials, and a calendar of upcoming events related to fresh produce food safety. A total of 20 abstracts were submitted by Dr.Jaroni's group and accepted for Oral and Poster presentations between 2012 and 2015 for the following: IAFP Annual Conferences; OSU Research Week, FAPC Research Symposia; Plant Biosecurity Symposia at Southern University. Dr. Jitu Patel of the USDA-ARS shared the results of his research on internalization and natural antimicrobials with the largest organic growers in the mid-Atlantic region. A video on 'pathogen internalization in leafy greens' was prepared by Dr. Patel's group in collaboration with University of Arizona Extension for dissemination of science to growers. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 1: Factors causing attachment and internalization of E.coli O157:H7 and Salmonella in organic leafy greens were explored. Strains that expressed curli and were more hydrophobic attached at higher numbers compared to weak/non-expressing strains. E.coli O157:H7 internalized into hydroponically grown intact spinach plants through root. Internalization was dependent on bacterial population, not curli production. Internalized pathogen reached the phylloplane. Cellulose-deficient and wild E.coli O157:H7 strains persisted for 14 days on young spinach plant shoots when sprayed with droplets of phosphate buffered saline, irrespective of cultivar. Rapid attachment of all E.coli O157:H7 (~3.5-4 logs) was observed on intact and cut leafy green surfaces within 5 min. Internalization of Salmonella was observed in spinach plants developing from contaminated seed and spinach sprouts germinated using contaminated water. Salmonella was isolated from leaves, shoots and roots of spinach plants when grown from contaminated seed or with contaminated water during seed germination. Soil and water runoff were positive for Salmonella. Coring tool design was modified and evaluated for ability to reduce cross contamination to lettuce. Removal of welding from original tool resulted in the highest reduction of E.coli transfer, 44% positives lettuce heads compared to the original tool with 91% positives. Organic matter and iceberg lettuce debris in sanitizing dips promoted attachment of Salmonella to coring tool surface. The ability of E.coli to form biofilms on wash water contact surface and synergistically with leafy green native microbiota was studied. Biofilms formed on unfiltered baby spinach wash water contact surface after one wash (light reuse) by E.coli O157:H7, curli-deficient E.coli O157:H7 and E.coli K12 resulted in OD600 of 0.49, 0.57 and 0.31, respectively, while on stomached (extensive reuse) unfiltered spinach wash water contact surface, OD600 of 1.38, 2.59 and 2.08 resulted. Wash water reuse, curli production by E.coli and synergy with leafy green native microbiota contributed towards biofilm formation. Objective 2: A study on survival of E.coli K12 in homemade compost teas revealed that compost tea made with vegetables allowed E.coli to survive over 4 weeks with 0.5 log reduction. Horse and sheep compost tea with and without E. coli showed longer survival on all crops. E. coli O157:H7 populations fell below levels of detection within 3 days in steer manure compost. For Salmonella, compost tea using Alpaca manure and steer manure based composts with an alkaline pH resulted in highest reduction. Background microflora did not affect pathogen survival in composts. Field studies showed that foliar application of sheep compost tea on iceberg and romaine lettuce resulted in highest recovery of E.coli while cow compost tea showed the fastest reduction. Side dress application was determined as the safer application route. Compost teas with fertilizer application in field improved leafy green crop yield and quality attributes. Analysis of irrigation water samples from Yuma and Maricopa revealed that E.coli was isolated from 9.3% water and 8.1% sediment samples. Salmonella was isolated from 14% water and 22.6% sediment samples. Both E.coli and Salmonella were isolated from 3% water and 0.9% sediment samples from both irrigation systems. All confirmed E.coli isolates were non-pathogenic. A subset of 25% samples from Yuma and 33.3% samples from Maricopa were assayed for the Salmonella invA and himA genes and tested positive. Pepper Mild Mottle virus was isolated from 22% and 80% irrigation water samples from Yuma and Maricopa, respectively. No (0/231) samples were positive for human norovirus, hepatitis A, or Aichi virus. The physico-chemical characteristics and microbial quality of irrigation waters from Yuma and Maricopa did not differ significantly. Quantitative Microbial Risk Assessment could not be done because no E.coli O157:H7 was detected and data collected for Salmonella was qualitative. Objective 3: Plant extracts (olive, apple, grapeseed), essential oils (oregano, clove bud, lemon grass, cinnamon), their active components (carvacrol, eugenol, citral, cinnamldehyde), and combinations were tested against Salmonella, E.coli O157:H7, E.coli K12, murine norovirus and spoilage organisms (Pseudomonas, Lactobacillus) as alternatives to oxidizing sanitizers. Plant based sanitizers were effective in reducing pathogens and spoilage organisms on leafy greens when added to wash water. Antimicrobial effect was concentration and storage time dependent. Plant antimicrobials had residual activity during storage at 4 and 8°C for 3 days. All essential oils at 0.5% were effective showing no recovery of pathogens immediately upon exposure or by day 1. Olive extract was the most effective among plant extracts with a maximum 5.3 log reductions. Plant extracts were also tested for their activity against background microflora of organic leafy greens and reductions ranged from 0-2.8 logs; effectiveness of olive extract was comparable to that of hydrogen peroxide, while the activity of all plant antimicrobials was better than that of hydrogen peroxide for pathogens. Some combination treatments showed synergistic activity with >4 logs reduction. Plant antimicrobials and their combinations were tested against starved Salmonella and were effective. Starvation stress rendered Salmonella more susceptible to antimicrobials compared to non-starved cells. Efficacy of plant antimicrobials was evaluated during recycling of wash water for five batches of organic leafy greens both in the laboratory and large scale. Plant antimicrobials maintained their effectiveness during 5 times recycling of wash water and were better at inactivating Salmonella and E.coli K12 than hydrogen peroxide and 50 ppm chlorine. No survivors were detected from any of the treatment wash waters. Apple, carrot and hibiscus films containing antimicrobials were tested against Salmonella, E.coli O157:H7 and Pseudomonas on organic leafy greens in sealed plastic bags during 7 day storage at 4°C. On all produce, 3% carvacrol films were most effective. The films showed a concentration and storage time dependent activity. The efficacy of organic sanitizers (fulvic acid, citric acid, and peracetic acid based, C8C10, CG100, CDG3000, calcium hypochlorite) was also evaluated against pathogens. Chico Wash, C8C10 and CG100 reduced E.coli O157:H7 on organic leafy greens by upto 3.4 logs. For Salmonella Chicowash was the most effective with upto 2.87 log reductions. Carvacrol, cinnamon oil, cinnamaldehyde and olive extract were effective against murine norovirus within six hrs of exposure. Chicowash yielded >4.56 log reductions within 30 min of exposure. Scanning electron microscopy was used to understand the antiviral mechanism of action. Oregano oil and carvacrol caused viral capsid to expand in size and lose structural integrity. Allspice and clove bud oils appear to break down the virus capsid. Lemongrass oil and citral appear to coat virus capsid and prevent the virus adsorbing to host cell. Organoleptic quality of leafy greens after wash treatments was evaluated by sensory analysis and ranged from acceptable to detection of strong aftertastes. Objective 4: Extension activities in AZ included statewide organic food safety workshops, training seminars, video training series, development of online content (website, social media) and bilingual videos for effective dissemination of research results useful for stakeholders. In Oklahoma, results on fresh produce safety were disseminated to growers and processors. Drs. Ravishankar, Jaroni, Bright, Gerba, Fonseca and Nolte conducted presentations, demonstrations and seminars to growers, students and general public. PIs have also presented results at international professional meetings and published manuscripts in scientific journals to reach both academia and industry.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Dusty Winchester, Rachael Zinn, Jonathan Sexton, Jason Torrey, Kelly Bright. Occurrence of Pathogenic (Disease-Causing) Foodborne Viruses In Irrigation Waters in the Southwest . University of Arizona Student Showcase. November 2012.
Friedman, M. Plant Food Constituents that Inactivate Pathogens and Reduce Formation of Heterocyclic Amines. Northern California Chapter, Genetic and Environmental Toxicology Association Symposium Food Safety and Health in a Global Setting: The Good, the Bad, and the Ugly, Oakland, California. June 7, 2012.
Jason Torrey, Jonathan Sexton, Rachael Zinn, Dusty Winchester, Jerry Lopez, Kelly Bright. Prevalence of Pathogenic Organisms in Irrigation Waters of the Southwest. University of Arizona Annual Food Safety Conference. October 2012.
Macarisin, D., Darlington, K., Chauhan, P., Patel, J. 2012. Role of Curli and Host Cultivar on Uptake and Movement of Escherichia coli O157:H7 in Organic Spinach. International Association for Food Protection annual conference, Providence, RI.
Moore-Neibel, K., Patel., J., Friedman, M. and Ravishankar, S. 2012. Antimicrobial activity of oregano oil against Salmonella enterica on organic leafy greens at varying exposure times and storage temperatures. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Patel, J., Macarisin, D., Bauchan, G. 2012. Effect of Spinach Cultivar and Strain Variation on Survival of Escherichia coli O157:H7 on Spinach Leaves. International Association for Food Protection annual conference, Providence, RI.
Patel, J., Macarisin, D., Bauchan, G. 2012. Influence of curli expression on biofilm formation and attachment to plant surface by shiga toxigenic E. coli. Annual Institute of Food Technologist Annual Conference, Las Vegas, NV.
Ravishankar, S. Food Safety & Control of Foodborne Pathogens Using Natural Antimicrobials. Seminar to Microbiology Club, Dept. of Vet. Sci. & Microbiology, University of Arizona. March 19, 2012.
Reyna-Granados, J., Joens, L., Friedman, M. and Ravishankar, S. 2012. Concentration and time-dependent inactivation of Escherichia coli O157:H7 by plant extracts. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Rojas, D., Todd, J.L., Friedman, M., Jaroni, D. and Ravishankar, S. 2012. Antimicrobial activity of hibiscus tea and grapeseed and green tea extracts against antibiotic-resistant Salmonella Newport on organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2012, Las Vegas, NV.
Todd, J. L. and Ravishankar, S. 2012. Survival of Escherichia coli O157:H7 and Salmonella Newport in various commercial organic composts. Poster presented at the Institute of Food Technologists Annual Meeting 2012, Las Vegas, NV.
Zhu, L. and Ravishankar, S. 2012. Efficacy of sanitizers approved for organic use against Salmonella enterica on organic leafy greens. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Ravishankar, S. 2012. Safer salads: Clean and green approaches. Invited featured speaker at the Yuma Fresh Vegetable Association Annual Meeting, Yuma, AZ.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2011
Citation:
Ravishankar, S. Control of Foodborne Pathogenic Bacteria Using Natural Antimicrobials. Seminar presented at the Food Safety Retreat, Tucson, AZ. November 4, 2011.
Ravishankar, S. Organically Grown Leafy Greens and the Control of Foodborne Pathogens Using Natural Antimicrobials. Fresh Produce Safety: Research Update. Yuma, AZ. December 16, 2011.
Ravishankar, S., Bright, K., Fonseca, J., Gerba, C., Knolte, K., Jaroni, D., Patel, J., and Friedman, M. 2011. Improving the safety and post-harvest quality of field grown organic leafy greens: assessment of good agricultural/production practices along the farm to fork continuum. Poster presented at the USDA-National Institute of Food & Agriculture (NIFA)-Organic Program Project Directors Meeting, USDA-NIFA Waterfront Center, Washington, D.C.
Kelly Bright and Channah Rock. The Impact of Irrigation Water Quality on Food Safety . University of Arizona Annual Food Safety Conference. November 4, 2011.
Bright, K. Assessing irrigation water quality. Fresh Produce Safety: Research Update. Yuma, AZ. December 16, 2011.
Fonseca, J and Nolte, K. Compost teas and coring tools: Research Update. Fresh Produce Safety: Research Update. Yuma, AZ. December 16, 2011.
Gerba, C. Microbial Risk Assessment: A tool for determining Whats important and Whats not. Fresh Produce Safety: Research Update. Yuma, AZ. December 16, 2011.
Jaroni, D. Farm-to-Fork Fresh Produce Safety. Plant Bio-security Symposium, Southern University and A&M Colleges, Baton Rouge, LA. Nov. 9-12, 2011.
Jaroni, D. Use of natural antimicrobials to reduce foodborne pathogens in leafy greens. Workshop for Fresh Produce Growers in Louisiana. St. Landry Parish Extension Office, Opelousas, LA. Oct. 13, 2011.
Masaaki Kitajima, Brandon Iker, Kelly Bright, Ian Pepper, Charles Gerba. Molecular Detection of Enteric Viruses in Water . University of Arizona Annual Food Safety Conference. November 4, 2011.
Moore, K., Patel, J., Jaroni, D., Friedman, M. and Ravishankar, S. 2011. Antimicrobial activity of plant extract/concentrate rinses against Salmonella enterica on organic leafy greens. Poster presented at the International Association for Food Protection Annual Meeting 2011, Milwaukee, WI.
Fonseca, J and Nolte, K. Compost teas and coring tools: Research Update. Fresh Produce Safety: Research Update. Yuma, AZ. December 16, 2011.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2010
Citation:
Jaroni, D. and S. Ravishankar. 2010. Inactivation of foodborne pathogens in vitro and on romaine lettuce and alfalfa sprouts by roselle (Hibiscus sabdariffa). Abstract. Annual IAFP Meeting, Anaheim, CA. Aug 1-4, 2010.
- Type:
Book Chapters
Status:
Awaiting Publication
Year Published:
2015
Citation:
Bright KR, Gilling DH. (2015) Chapter 16. Natural virucidal compounds in foods. In Cannon JL, Goyal SM (Eds.), Viruses in Foods, 2nd Ed. Springer Science: New York, NY. In Press.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2015
Citation:
Gilling DH, Kitajima M, Torrey JT, Bright KR. (2015) Evaluation of antiviral efficacy of cinnamon plant compounds against murine norovirus, a human norovirus surrogate. Submitted to Food Environ Virol.
Divya Jaroni, Buddhini Jayasundera, Jordan Denton and Sadhana Ravishankar. Antibacterial Efficacy of Roselle (Hibiscus sabdariffa) Calyx Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens Stored at 4�C. Quality Assurance and Safety of Crops & Foods. Submitted
Jordan J. Denton, Mendel Friedman, Sadhana Ravishankar, and Divya Jaroni. Antimicrobial Efficacy of Plant-Derived Compounds against Escherichia coli O157:H7 on Organic Leafy Greens under Refrigeration Temperatures. J. of Food Science and Preservation. Submitted
Jordan J. Denton, Buddhini, P. K. Jaysundera, Sadhana Ravishankar, and Divya Jaroni. Evaluation of Antibacterial Effects of Plant-Derived Essential Oils against Escherichia coli O157:H7 on Organic Leafy Greens. J. of Food Protection. Submitted.
Pushpinder Litt, Sadhana Ravishankar, and Divya Jaroni. Use of Fulvic Acid Formulations as Flume-Wash Treatments for Reduction of Escherichia coli O157:H7 on Organic Leafy Greens. Food Protection Trends. Submitted.
Jaroni, Divya; Kakani, Radhika; Ravishankar, Sadhana; Jadeja, Ravirajsinh, Efficacy of roselle (Hibiscus sabdariffa) calyx formulations against Escherichia coli O157:H7 during flume-washing of organic leafy greens. Quality Assurance and Safety of Crops & Foods. Submitted.
Schneider, A. and Ravishankar, S. Investigating the mechanism of action of clove bud oil against non-pathogenic Escherichia coli using fluorescent microscopy and morphological profiling. Journal of Applied Microbiology. submitted.
Rada,X., Todd-Searle, T., Friedman,M., Patel, J., Jaroni, D. and Ravishankar, S. Combining essential oils and olive extract for control of multi-drug resistant Salmonella enterica on organic leafy greens.Journal of Food Processing and Preservation. Submitted.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Friedman, M., Henika, P. R., and Levin, C. E. 2015. Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157: H7 and Salmonella enterica serovar Hadar. Food Control 50, 652-658.
Denton, J., S. Ravishankar, M. Friedman and D. Jaroni. 2015. Efficacy of Plant-derived Compounds against Escherichia coli O157:H7 during Flume-washing and Storage of Organic Leafy Greens. J. Food Process. Preserv. doi:10.1111/jfpp.12523
- Type:
Websites
Status:
Other
Year Published:
2012
Citation:
Social Media Networking: Extension at the University of Arizona includes programming that uses a dedicated web interface, Facebook, Twitter, and Pinterest. Since their release the sites have generated over 8,650 client interactions which and continues to grow daily.
o Fresh Produce Safety Website (8,850 views): A safe organic training website has been created for producers. The site contains key information about the USDA Good Handling and Agricultural Practices program, as well as the online, bilingual version of the training materials (http://cals.arizona.edu/fps/).
o Facebook (1,247 fans): Built to accomplish a social mission to make the world more open and connected, the Fresh Produce Safety Facebook page provides networked followers tips, tends and key information about the practices involving fresh produce safety (https://www.facebook.com/FoodSafety101).
o Twitter (961 followers): Followers receive instant updates related to fresh produce safety production practices, research developments, workshops, demonstrations. A key to this outreach is presence, in which a mobile, lightweight method allows a seamless way to keep updated (https://twitter.com/FreshFoodSafety).
o Pinterest (106 subscribers): 'Pinning' Fresh Produce Safety Materials allowing fresh produce safety materials to be shared with others and has become a leader in creating referral traffic (http://www.pinterest.com/producesafety).
The PIs from Oklahoma State University have also finalized and made public a website related to fresh produce safety titled: Fresh Produce Safety (www.freshproducesafety.okstate.edu). This website is intended to provide Oklahoma growers, processors, and interested consumers with single-source access to relevant research results, Extension outreach materials, and a calendar of upcoming events related to fresh produce food safety.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Zhu, L., Olsen, C., McHugh, T., Friedman, M., Jaroni, D. and Ravishankar, S. 2014. Apple, Carrot, and Hibiscus Edible Films Containing the Plant Antimicrobials Carvacrol and Cinnamaldehyde Inactivate Salmonella Newport on Organic Leafy Greens in Sealed Plastic Bags. J. Food Sci. 79:M61-M66.
Buddhini, P. K., Jones, J., Ravishankar, S. and Jaroni, D. 2014. Evaluating the Efficacy of Olive, Apple and Grape Seed Extracts in Reducing Escherichia coli O157:H7 Contamination on Organic Leafy Greens during the Wash Process. Int. J. Food Sci. Nutr.Diet. 3 (10):1-7.
Gilling DH, Kitajima M, Torrey JT, Bright KR. 2014. Antiviral efficacy and mechanisms of action of oregano essential oil and its primary component carvacrol against murine norovirus. J Appl Microbiol 116(5): 1149-1163.
Gilling DH, Kitajima M, Torrey JT, Bright KR. 2014. Antiviral efficacy and mechanisms of action of plant antimicrobials against murine norovirus. Appl Environ Microbiol 80(16): 4898-4910.
Friedman, M. 2014. Antibacterial, antiviral, and antifungal properties of wines and winery byproducts in relation to their flavonoid content. Journal of Agricultural and Food Chemistry 62, 6025-6042.
Friedman, M. 2014. Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices. Journal of Agricultural and Food Chemistry 62, 7652-7670.
Macarisin, D., Patel, J. R., and Sharma, V.K. Role of curli and plant cultivation conditions on Escherichia coli O157:H7 internalization into spinach grown on hydroponics and in soil. 2014. Int. J. Food Microbiol. 173, 48-53.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2013. The antimicrobial effects of cinnamon leaf oil against multi-drug resistant Salmonella Newport on organic leafy greens. International Journal of Food Microbiology. 166:193-199.
Moore-Niebel, K. , Gerber, C., Patel, J., Friedman, M., Jaroni, D. and Ravishankar, S. 2013. Antimicrobial activity of oregano oil against antibiotic-resistant Salmonella enterica on organic leafy greens at varying exposure times and storage temperatures. Food Microbiology. 34:123-129.
Yossa, N., Patel, J., Millner P., Ravishankar S. and Lo, Y. M. 2013. Antimicrobial activity of plant essential oils against Escherichia coli O157:H7 and Salmonella on lettuce. Foodborne Pathogens and Disease. 10:87-96.
Macarisin, D., Patel, J. R., Bauchan, G., Giron, J., and Ravishankar, S. 2013. Effect of spinach cultivar and bacterial adherence factors on survival of Escherichia coli O157:H7 on spinach leaves. J. Food Protect. 76:1829-1837.
Patel, J.R., Singh, M., Macarisin, D., Sharma, M., and Shelton, D. 2013. Differences in biofilm formation of produce and poultry Salmonella enterica isolates and their persistence on spinach plants. Food Microbiol., 36:388-394.
Friedman, M. 2013. Rice brans, rice bran oils, and rice hulls: compositions, food and industrial uses, and bioactivities in humans, animals, and cells. Journal of Agriculture and Food Chemistry. 61: 10626-10641.
Friedman, M., Henika, P. R. and Levin, C. E. 2013. Bactericidal activities of health-promoting, food-derived powders against the foodborne pathogens Escherichia coli, Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus. Journal of Food Science. 78: M270-M275.
Friedman, M. and Rasooly, R. 2013. Review of the inhibition of biological activities of food-related selected toxins by natural compounds. Toxins. 5: 743-775.
Kim, S. P., Park, S. O., Lee, S. J., Nam, S. H. and Friedman, M. 2013. A polysaccharide isolated from the liquid culture of Lentinus edodes (Shiitake) mushroom mycelia containing black rice bran protects mice against a Salmonella lipopolysaccharide-induced endotoxemia. Journal of Agriculture and Food Chemistry. 61:10987-10994
- Type:
Journal Articles
Status:
Published
Year Published:
2011
Citation:
Nolte K. D., C. A. Sanchez, and J. M. Fonseca. 2011. Assessing the Culture of Fresh Produce Safety within a Leafy Green Producing Community. Journal of Extension. 49(6), Article Number 6IAW4.
Nolte K. D., and S. R. Bealmear. 2011. Fresh Produce Safety Includes Small Acreages and Home Gardens. Backyards and Beyond. 5(2):4-5.
Fonseca J. M., S. D. Fallon, C. A. Sanchez, and K. D. Nolte. 2011. Escherichia coli survival in lettuce fields following its introduction through different irrigation systems. Journal of Applied Microbiology. 110(4):893-902.
Kim, S. P., J. Y. Yang, M. Y. Kang, J. C. Park, S. H. Nam, and M. Friedman. 2011. Composition of Liquid Rice Hull Smoke and Anti-Inflammatory Effects in Mice. Journal of Agricultural and Food Chemistry. 59:4570-4581.
Patel, J., Sharma, M. and Ravishankar, S. 2011. Effect of curli expression and hydrophobicity of Escherichia coli O157:H7 on attachment to fresh produce surfaces. J. Appl. Microbiol. 110: 737-745.
Moore, K., Patel, J., Jaroni, D., Friedman, M., and Ravishankar, S. 2011. Antimicrobial activity of apple, hibiscus, olive, and hydrogen peroxide formulations against Salmonella enterica on organic leafy greens. Journal of Food Protection. 74:1676-1683.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Brooks, J. S. Ravishankar, D. Jaroni. 2015. Evaluating the Re-usability of Organic Sanitizers in Reducing Escherichia coli O157:H7 on Organic Leafy Greens. Poster Presentation. Annual Meeting of International Association for Food Protection, 2015. Portland, OR.
Brooks, J., Jaroni, D. 2015. Reusability of Organic Sanitizers against Escherichia coli O157:H7 on Organic Leafy Greens. Oral Presentation. Annual FAPC Research Symposium, 2015, Stillwater, OK.
Kakani, R., S. Ravishankar, and D. Jaroni. 2015. Inhibitory Activity of Plant-derived Antimicrobials against Lactobacillus brevis on Organic Leafy Greens. Annual Meeting of International Association for Food Protection, 2015. Portland, OR.
Harrison, L., D. Jaroni. 2015. Inhibitory Effects of Organic Sanitizers against Pathogenic and Spoilage Microorganisms on Baby Spinach. Poster Presentation. Annual OSU Research Symposium, 2015. Stillwater, OK.
Zhu, L., Mild, R. and Ravishankar, S. 2015. Efficacy of a Citric Acid based Organic Sanitizer against Salmonella enterica and Escherichia coli K-12 on organic leafy greens during wash water recycling. Poster presented at Annual Meeting of the International Association for Food Protection (IAFP). Portland, OR, 2015.
Schneider, A. Freidman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2015. Clove Bud Oil, Its Active Component, and Combination Treatments with Plant Extracts Inactivate Multi-Drug Resistant Salmonella Newport on Organic Leafy Greens. Poster presented at Annual Meeting of the International Association for Food Protection (IAFP). Portland, OR, 2015.
Dev Kumar, G., Patel, J. and Ravishankar, S. 2015. Persistence and internalization of Salmonella on/in organic spinach sprout: Exploring the contamination route. Oral presentation at Annual Meeting of the International Association for Food Protection (IAFP). Portland, OR, 2015.
Ravishankar, S. 2015. Safer salads and grilled meats: Clean and green approaches. Invited talk at the USDA-Western Regional Research Center, Albany, CA.
Ravishankar, S. 2015. Safer salads: clean and green approaches. Invited seminar at the Department of Horticultural Sciences, Texas A & M University, College Station, TX.
Ravishankar, S. 2015. Safer salads and grilled meats: Clean and green approaches. Invited talk at the Annual Registered Sanitarians Conference, Phoenix, AZ.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
Jaroni, D., and S. Ravishankar. 2012. Bactericidal effects of roselle (Hibiscus sabdariffa) against foodborne pathogens in vitro and on romaine lettuce and alfalfa sprouts. Quality Assurance and Safety of Crops & Foods. 4: 33-40.
Moore-Neibel, K., C. Gerber, J. Patel, M. Friedman, and S. Ravishankar. 2012. Antimicrobial activity of lemongrass oil against Salmonella enterica on organic leafy greens. Journal of Applied Microbiology. 112:485-492.
Kim, S. P., M. Y. Kang, J. C. Park, S. H. Nam, and M. Friedman. 2012. Rice Hull Smoke Extract Inactivates Salmonella Typhimurium in Laboratory Media and Protects Infected Mice against Mortality. Journal of Food Science. 77:M80-M85.
Kim, S. P., E. Moon, S. H. Nam, and M. Friedman. 2012. Hericium erinaceus Mushroom Extracts Protect Infected Mice against Salmonella Typhimurium-Induced Liver Damage and Mortality by Stimulation of Innate Immune Cells. Journal of Agricultural and Food Chemistry. 60:5590-5596.
Du, W.-X., Avena-Bustillos, R. J., Woods, R. D., Breksa, A., McHugh, T. H., Friedman, M., Levin, C. E. and Mandrell, R. 2012. Sensory evaluation of baked chicken wrapped with antimicrobial apple and tomato edible films formulated with cinnamaldehyde and carvacrol. Journal of Agriculture and Food Chemistry. 60: 7799-7804.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Jaroni D., P. K. Jayasundera, and S. Ravishankar. 2013. Efficacy of Roselle (Hibiscus sabdariffa) Calyx Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens. Abstract. Poster Presentation. Annual IAFP, 2013. Charlotte, NC.
Jayasundera, P. K., S. Ravishankar, L. M. Ramirez-Lopez and D. Jaroni. Antibacterial Effects of Olive, Apple and Grapeseed Extracts against Escherichia coli O157:H7 on Organic Leafy Greens Stored at 4� C. Abstract. Annual IAFP, 2013. Charlotte, NC.
Kelly Bright, Charles Gerba. Pathogen Sources, Fate, and Transport in Constructed Irrigation Systems Used for Food Crop Production . University of Arizona Watershed Workshop. May 2013.
Macarisin, D. Patel, J., Sharma, V. 2013. Role of Curli and Contamination Level on Escherichia coli O157:H7 Internalization into Organic Spinach Plants grown on hydroponics and in Soil. International Association for Food Protection annual conference, Charlotte, NC.
Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2013. The antimicrobial effects of cinnamon oil against multi-drug resistant Salmonella Newport on organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2013, Chicago, IL.
Tollerson, R., Dev Kumar, G. and Ravishankar, S. 2013. Role of environmental factors in the transfer of Salmonella enterica to iceberg lettuce leaves and biophotonic imaging of transfer sites. Poster presented at the 2013 Food Safety Conference, University of Arizona Food Safety Consortium, Tucson, AZ.
Nolte, K.D. 2013. The Track and Scat Fresh Produce Safety Handbook for Southwest, Arizona. Abstract published in the proceedings at the 2013 American Society for Horticultural Science Annual Meeting, Palm Desert, CA. URL: http://ashs.org/abstracts/2013/abstracts13/abstract_id_15926.html
Rada, X., Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2013. Synergistic effects of combination treatments of essential oils and a plant extract against multi-drug resistant Salmonella enterica on organic leafy greens. Poster presented at the 2013 Food Safety Conference, University of Arizona Food Safety Consortium, Tucson, AZ.
Reyes Murrieta, Masaaki Kitajima, Damian Gilling, Jason Torrey, Laura Sifuentes, Kelly Bright. Effectiveness of Plant Antimicrobials Against Hepatitis A Virus . University of Arizona Student Showcase. November 2013.
Ravishankar, S. 2013.Chico Wash- An Organic Sanitizer Effective Against Foodborne Pathogens on Fresh Produce. National Webinar hosted by the E3 Organics, Inc. December 2013.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Jaroni, D., P. K. Litt, S. Ravishankar, and J. Brooks. Inhibitory Activity of Hydrogen Peroxide, Water and Organic Sanitizers against Escherichia coli O157:H7 on Organic Leafy Greens. Annual Meeting of International Association for Food Protection, 2014. Indianapolis, IN.
Jason Torrey, Jonathan Sexton, Dusty Tyree, Kelly Bright. Prevalence of Foodborne Pathogenic Organisms in Irrigation Waters of the Southwest United States . Water and Environmental Technology Conference. Tokyo, Japan, June 2014.
Bevington, R., K.D. Nolte and S. Ravishankar. 2014. Best Methods to Present Research Information via Video Formats to a Public Audience. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL. URL: https://www.google.com/?gws_rd=ssl#q=Ashs+horticulture+pdf+nolte+2014+orland
Brandenberger, L. 2014. Basic Good Agricultural Practices for Fresh Produce. Oral presentation, handouts, and hands-on demonstration given on February 19 to the Otoe-Missouria / Ponca tribes as part of a community garden project. Red Rock, OK.
Brandenberger, L. 2014. GAPs for fresh produce. Presentation and handouts given on February 28 at the Statewide Organic Production Conference, Oklahoma City, OK.
Brandenberger, L. and McGlynn, W. 2014. Food Safety 101. Presentation given on March 6 at: Oklahoma Market Gardening School. Oklahoma Cooperative Extension Offices, Norman, OK.
Brandenberger, L. and McGlynn, W. 2014. Food Safety for Fresh Produce. Poster presented on January 22 at the Oklahoma Cooperative Extension Service State Conference. Stillwater, OK.
Brandenberger, L., McGlynn, W., Bihn, E., and Wall, G. 2014. Food Safety Training & the Produce Safety Alliance (PSA) Curriculum. Presentation given and abstract published in 2014 Horticulture Industries Show Book of Proceedings and presentation given on January 11 in vegetable session, Tulsa, OK.
Damian Gilling, Masaaki Kitajima, Jason Torrey, Kelly Bright. Mechanisms of Action of Plant Antimicrobials against Murine Norovirus . International Association for Food Protection Annual Meeting. Indianapolis, IN, August 2014.
Dev Kumar, G. and Ravishankar, S. 2014. Detection of stressed Salmonella enterica from Iceberg lettuce irrigation and processing water. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
Dev Kumar, G. and Ravishankar, S. 2014. Efficacy of sequential dual hurdle treatments- ozone and plant antimicrobials in reducing Salmonella enterica on iceberg lettuce. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
Dev Kumar, G., Patel, J. and Ravishankar, S. 2014. Comparative Evaluation of Factors Affecting Escherichia coli Biofilms on Organic Leafy Green Wash Water Contact Surface. Annual Meeting of the International Association for Food Protection (IAFP). Indianapolis, Indiana. 2014.
Dusty R. Tyree, Jason R. Torrey, Jonathan Sexton, Rachael Zinn, Masaaki Kitajima, and Kelly R. Bright.The Occurrence of Bacterial and Viral Foodborne Pathogens in Irrigation Waters in Southern Arizona. Presented at the International Association for Food Protection annual meeting, August 2014.
Litt, P. K., S. Ravishankar and D. Jaroni. 2014. Antimicrobial Efficacy of Fulvic Acid Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens at Refrigeration Temperatures. Annual Meeting of the International Association for Food Protection, 2014. Indianapolis, IN.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Presentation given and abstract published in 2014 Horticulture Industries Show Book of Proceedings and presentation given on January 11 in fruit session, Tulsa, OK.
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on March 13 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Oklahoma City, OK.
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on May 8 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Stillwater, OK.
McGlynn, W., Brandenberger, L. and Young, J. 2014. Creating and Using a Basic GAP/GHP Food Safety Plan Checklist. Handout and presentation given on January 27th at: Regional grower/supplier meeting sponsored by Reasors. Tulsa, OK.
McGlynn, W.G. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on February 13 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Weatherford, OK.
Wilson, R., R. Bevington, Nolte, K.D., and S. Ravishankar 2014. Extending Research Impacts to a General Audience Via Video: The Good, The Bad, And The Ugly. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL. URL: https://www.google.com/?gws_rd=ssl#q=Ashs+horticulture+pdf+nolte+2014+orland
Young, J, Brandenberger, L, and McGlynn, W. 2014. Preparing a Basic GAP/GHP Food Safety Plan. Oral presentations and handouts given on March 19 to the Hmong growers group. Rose/Leach, OK.
Schneider, A. and Ravishankar, S. 2014. Antimicrobial Activity of Essential Oil X Against Multi-Drug Resistant Salmonella enterica on Organic Leafy Greens. Annual Food Safety Conference, Tucson, AZ.
Nolte, K.D. and S. Ravishankar. 2014. The 5 Year Anniversary of the Arizona Leafy Green Marketing Agreement: What Works and What Doesnt. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL. URL: https://www.google.com/?gws_rd=ssl#q=Ashs+horticulture+pdf+nolte+2014+orland
Patel, J., Macarisin, D. 2014. Escherichia coli O157:H7 Biofilm Formation by MBEC" Assay: Effect of Curli Expression on its Resistance to Natural Antimicrobials. International Association for Food Protection annual conference, Indianapolis, IN.
Rada, X., Todd, J., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2014. Synergistic Effects of Combination Treatments of Essential Oils and a Plant Extract Against Multi drug Resistant Salmonella Newport on Organic Leafy Greens. Annual Meeting of the International Association for Food Protection, 2014. Indianapolis, IN.
Ravishankar, S. 2014. Improving the safety and quality of organic leafy greens. National Webinar hosted by the eOrganic. February 2014.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Bevington, R, Ravishankar, S. and Nolte, K. 2013. How to: making an informative video from start to finish. Poster presented at the Annual Meeting of the American Society for Horticultural Sciences (ASHS), Palm Desert, CA.
Zhu, L., Friedman, M., Olson, C., McHugh, T., Jaroni, D. and Ravishankar, S. 2013. Use of edible films containing plant antimicrobials to inhibit Pseudomonas fluorescens in bagged organic lettuce. Poster presented at the International Association for Food Protection Annual Meeting 2013, Charlotte, NC.
Zhu, L., Olson, C., McHugh, T., Friedman, M., Jaroni, D. and Ravishankar, S. 2013. Apple, carrot, and hibiscus edible films containing plant antimicrobials inactivate Salmonella Newport in packaged organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2013, Chicago, IL.
Denton, J. J., P. K. Jayasundera, S. Ravishankar and D. Jaroni. 2013. Antimicrobial Activity of Cinnamon, Oregano and Lemongrass Essential Oils against Escherichia coli O157:H7 on Organic Leafy Greens Stored at Refrigeration Temperatures. Poster Presentation. Annual IAFP, 2013. Charlotte, NC.
Denton, J. J., S. Ravishankar and D. Jaroni. 2013. Antimicrobial Efficacy of Cinnamaldahyde, Carvacrol and Citral against Escherichia coli O157:H7 on Organic Leafy Greens Held at 4�C. Poster Presentation. Annual IAFP, 2013. Charlotte, NC.
Dev Kumar, G. and Ravishankar, S. 2013. Effectiveness of Antimicrobials and Saponins in Reducing Biofilm Formation on Wash Water Equipment Surfaces. Arizona Iceberg Lettuce Council Meeting. Yuma Arizona.
Dev Kumar, G. and Ravishankar, S. 2013. Effects of environmental conditions on transfer rates of Salmonella enterica and Escherichia coli O157:H7 from soil, dust and irrigation water to iceberg lettuce surfaces. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
Dev Kumar, G., Ravishankar, S. and Patel, J. 2013. Comparative Evaluation of Factors Affecting Escherichia coli Biofilms on Organic Leafy Green Wash Water Contact Surfaces. Presented at Special Seminar Series, School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
Dusty Tyree, Rachael Zinn, Jonathan Sexton, Jason Torrey, Masaaki Kitajima, Kelly Bright Occurrence of Pathogenic (Disease-Causing) Foodborne Viruses In Irrigation Waters in the Southwest . University of Arizona Annual Food Safety Conference. October 2013.
|
Progress 09/01/13 to 08/31/14
Outputs
Target Audience: The target audiences for this project include: growers, producers, and processors of organic leafy greens; manufacturers of natural antimicrobials and organic sanitizers; and consumers of organic leafy greens. Leafy green producers and manufacturers of natural antimicrobials and organic sanitizers have been involved in this project by providing in-kind support to the project. They have been informed periodically on the results of this project through various forums such as seminars, talks and demonstrations. Information about the results from the project was shared with stakeholders at the Food Safety Consortium at the University of Arizona in October 2014, where posters were presented. The audience in these meeting included produce growers, students and other faculty involved in food safety research. Dr. Ravishankar presented the research results generated from this project at the Annual Meetings of the International Association for Food Protection and Institute of Food Technologists in 2014 in the form of posters. The audiences at these conference included food safety professionals, produce growers, produce industry executives and students. Dr. Ravishankar's research team conducted food safety demonstrations about natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination at the following events: for the local high school students at the Youth Biotechnology Career Expo in Tucson, AZ in October 2013; for the local high school students at the Southwest Agricultural Summit in Yuma, AZ, in February 2014; for the local Yuma community at the Lettuce Days in March 2014; and for the local Tucson community at the Science City, Tucson Festival of Books in March 2014. Dr. Nolte of the Yuma Agricultural Center has used multiple communication strategies towards knowledge dissemination. His team has developed a website, uploaded YouTube videos, developed training DVDs and has made information accessible over Facebook, Pinterest and Twitter. Apart from improving the accessibility to the latest research in food safety and good agricultural practices he has also conducted seminars and training series in different parts of Arizona addressing pressing issues in food safety. A unique feature of his efforts has been the bilingual mode of instruction in order to reach a larger target audience. Dr. Nolte's team presented posters related to this project at the 2014 Annual Meeting of the American Society for Horticultural Sciences in Orlando, FL. At the University of Oklahoma, Dr. Lynn Brandenberger and Dr. William McGlynn are the co-investigators on this project, responsible for carrying out the extension activities related to the project. In 2014, Dr. Brandenberger and Dr. McGlynn carried out a total of eleven presentations to several groups of fresh produce growers and processors in Oklahoma related to fresh produce safety. These are generally small-scale producers who sell their products at the local grocery stores or farmer's markets. These presentations have incorporated the results of the studies carried out in Dr. Jaroni's lab, typically in the form of research updates. The PIs from Oklahoma State University have also finalized and made public a website related to fresh produce safety titled: Fresh Produce Safety which is intended to provide Oklahoma growers, processors, and interested consumers with single-source access to relevant research results, Extension outreach materials, and a calendar of upcoming events related to fresh produce food safety. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? All post-doctoral fellows, technicians and students hired to work on this project have received training on good laboratory practices, including pathogen safety precautions, media preparation, product sampling, field sampling and other laboratory activities related to the project. In 2014, Dr. Sadhana Ravishankar's lab had 7 undergraduate students, 4 graduate students and a postdoctoral research associate involved with organic leafy greens research. Undergraduate and graduate students have been trained in bacterial inoculation & enumeration, environmental isolation of pathogens, soil evaluation and have been involved with conducting experiments under the guidance of Drs. Ravishankar and Dev Kumar. Undergraduate and graduate students have been trained to analyze and present data and have presented research posters at the Food Safety Conference in the University of Arizona. One graduate student was trained to design primers, develop master mixes for PCR and perform PCR for the identification of foodborne pathogens. The student was also trained in antibiotic resistance testing for bacteria. Dr. Sadhana Ravishankar also trains high school students in microbiological techniques and allows them to work on produce safety projects using non-pathogenic bacterial strains. Two high school students, one middle school student and one elementary school student conducted their research projects in Dr Ravishankar' lab for science fair this year. Dr. Ravishankar's students and postdoctoral research associate (Dr. Dev Kumar) had the opportunity to present research results at various occasions. Dr. Dev Kumar presented a seminar on the biofilms on leafy green wash water equipment surfaces at the Fall seminar series of the School of Animal and Comparative Biomedical Sciences, University of Arizona. He also presented the research results in the form of oral presentations at the quarterly meetings of the Arizona Iceberg Lettuce Research Council in Nov. 2013 and July 2014. These meetings were attended by leafy green growers and industry professionals from Yuma, AZ and California. Dr. Dev Kumar also had the opportunity to present the research results as a technical oral presentation at the Annual Meeting of the International Association for Food Protection in Indianapolis. Dr. Ravishankar's students and postdoctoral research associate presented their research results in the form of posters at the Annual Food Safety Conference hosted by the University of Arizona Food Safety Consortium in October 2013. Dr. Ravishankar's graduate student Xeeroy Rada won the third place in the student poster competition at this conference. Dr. Ravishankar's students and postdoctoral research associate had the opportunity to participate in food safety demonstrations about natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination at the following events: for the local high school students at theYouth Biotechnology Career Expo in October 2013, Tucson, AZ; for the local high school students at the Southwest Ag Summit in February 2014, Yuma, AZ; for the local community at the Tucson Festival of Books in March 2014, Tucson, Arizona; for the local community at the Lettuce Days in March 2014, Yuma, AZ. The use of mass media for the propagation of food safety information to stakeholders has given students and other researchers in the Ravishankar lab and at the Yuma Agricultural Center an opportunity to participate in interviews about their research for Youtube videos. The new forum helps students and researchers present their findings in a succinct and easily accessible format. Drs. Ravishankar, Jaroni, Gerba, Bright, Patel and Nolte's students and team members have had the opportunity to present their research findings at international and state level conferences such as the Annual Meetings of the International Association for Food Protection, the Institute of Food Technologists and the American Society for Horticultural Sciences, as well as the Annual Food Safety Conference in Tucson, AZ, through poster and oral presentations. How have the results been disseminated to communities of interest? The extension teams at the Yuma Agricultural Center, Oklahoma State University, Dr. Nolte and Dr. Ravishankar's laboratory groups have been involved with the dissemination of information to communities of interest. Seminars, training sessions, conferences, demonstrations, videos, internet based communication and print media have all been used. Workshops have been conducted throughout the state to provide content detailed training involving the safe production of organically grown leafy greens in Prescott (February, 2014), 25 participants; Phoenix (March, 2014), 30 participants; Yuma (June, 2014), 10 participants; Tucson (July, 2014), 22 participants; Prescott (July, 2014), 12 participants; Parker (July, 2014), 11 participants; Phoenix (August, 2014), 22 participants. Specific regulatory and grower related training was provided to educate clientele or third party auditors about research outcomes to gain greater insight on industry needs. This year's trainings include: Safe Organic Production Practices-Yuma (February, 2014), 74 participants; Safe Organic Production Safety Meeting-UC Davis, CA (May, 2014), 65 participants; Farm to School Training-Tucson (October, 2014), 30 participants; Farm to School Training-Yuma (August, 2014), 35 participants. Recent interest in the organic leafy green training segments has prompted greater bilingual interest with Spanish viewership increasing 55% during the last 12 months. These videos topics, viewership (as of June, 2014) and the date of publication include: December 5: Fresh Produce Safety: Equipment Hazards - 91 views December 13: Water Sampling Recommendations - 48 views December 16: Peligros Equipos - 72 views December 23: Muestreo de Agua - 193 views February 3 - Fresh Produce Safety Commercial - 126 views February 5: Agrochemical Storage and Fresh Produce Safety - 84 views Feb 24: Sanitizing with Chlorine - 83 views March 7: Cleaning Harvest Equipment Prior to Sanitizing - 83 views March 28: Inocuidad de Alimentos Frescos: Desinfeccion con cloro - 149 views April 17: Inocuidad de Alimentos Frescos: Almacenamiento de Agroquimicos - 123 views April 17: Pets and Produce Don't Mix - 121 views April 24: Las Mascotas 7 Los Productos Frescos no se Mezclan - 48 views April 30: Inocuidad de Alimentos Frescos: Limpieza Equipo Cosecha antes de Desinfeccion - 116 views June 20: Assessing Microbial Contamination Risk Among Different Irrigation Systems - 50 views June 26th: Evaluar Riesgo de Contaminacion Microbiana Entre Diferentes Sistemas de Riego - 48 views. Extension also includes programming that uses a dedicated web interface, Facebook, Twitter, and Pinterest. Since their release the sites have generated over 5,900 client interactions which continue to grow daily. Compared to last year, the viewers for Fresh Produce Safety website increased 72% (http://cals.arizona.edu/fps/); Facebook fans increased 436% (https://www.facebook.com/FoodSafety101); Twitter followers increased 58% (https://twitter.com/FreshFoodSafety); Pinterest subscribers increased 73% (http://www.pinterest.com/producesafety ) . Our team from the Oklahoma state University has also participated in various talks, presentations and has developed a website for information dissemination. In 2014, Dr. Brandenberger and Dr. McGlynn carried out a total of eleven presentations to several groups of fresh produce growers and processors in Oklahoma related to fresh produce safety. These are generally small-scale producers who sell their products at the local grocery stores or farmer's markets. These presentations have incorporated the results of the studies carried out in Dr. Jaroni's lab, typically in the form of research updates. The PIs from Oklahoma State University have also finalized and made public a website related to fresh produce safety titled: Fresh Produce Safety (www.freshproducesafety.okstate.edu). This website is intended to provide Oklahoma growers, processors, and interested consumers with single-source access to relevant research results, Extension outreach materials, and a calendar of upcoming events related to fresh produce food safety. Dr. Jaroni and her graduate students presented the research results generated from this project at the 2014 Annual Meeting of the International Association for Food Protection (IAFP) in Charlotte, NC in the form of posters. Dr. Jitu Patel of the USDA-ARS shared the results of his research on internalization and natural antimicrobials with the largest organic growers in the mid-Atlantic region. Dr. Ravishankar and her team attended the Annual Food Safety Conference of the Food Safety Consortium in Tucson, AZ in October, 2013 where information about the results from the project was shared with stakeholders. At this conference posters on efficacy of plant antimicrobial combinations, biofilm formation by E. coli on produce wash water contact surfaces and attachment and cross transfer of Salmonella from soil to produce surfaces were presented by Dr. Ravishankar's students and postdoctoral research associate. Dr. Ravishankar's graduate student presented a poster on the efficacy of plant antimicrobial combinations at the University of Arizona Student Poster Competition to inform the university community about the efforts associated with making produce safer and the novel strategies implemented to achieve this goal. The audience in these meetings included produce growers, students and other faculty involved in food safety research. Dr. Ravishankar's research team conducted food safety demonstrations about natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination for the local high school students at the Youth Biotechnology Career Expo in October 2013, hosted by the BIO5 Institute, University of Arizona. Dr. Ravishankar's postdoctoral Research Associate, Dr. Dev Kumar presented the work on biofilm based attachment of E. coli to washing equipment surfaces in seminar presentations at the University of Arizona (October 2013) and the Arizona Iceberg Lettuce Research Council (AILRC) Quarterly meeting attended by the produce growers (November 2013 and July 2014) in Yuma, AZ. Dr. Ravishankar and her graduate student attended the Food Systems Network meetings during January to March 2014 at Tucson, Arizona to discuss produce safety issues. Dr. Ravishankar presented the results of her research at a National Webinar conducted by the eOrganic in February, 2014. She attended the Southwest Agricultural Summit during February 2014 in Yuma, Arizona to provide information to stakeholders on produce safety issues and interventions. A food safety demonstration was conducted for local high school students at the Southwest Agricultural Summit by Dr. Ravishankar's lab group in Yuma, Arizona. Dr. Ravishankar's lab group also conducted similar food safety demonstrations at the Lettuce Days event in March, 2014 for the Yuma community in Yuma, AZ and at the Tucson Festival of Books for the local Tucson community at Tucson, AZ. Dr. Ravishankar attended the Food Systems Network conference in April, 2014 to discuss a synopsis of her research work on produce safety and novel interventions. Results of this research project were also presented in the form of oral and poster presentations in August 2014 at the Annual Meeting of the International Association for Food Protection at Indianapolis, Indiana. Dr. Ravishankar participated in the Foodborne Task Force Meeting in August 2014, organized by the Arizona Department of Health Services where some findings from the project were shared. What do you plan to do during the next reporting period to accomplish the goals? In objective 1, internalization of Salmonella on to lettuce plants will be studied and confocal images will be taken. The role of environmental factors such as soil quality and humidity in bacterial cross contamination of leafy greens from soil will be evaluated. In objective 2, presumptive positives from irrigation water samples will be further confirmed. A risk assessment model based on irrigation water results will be developed. The potential of coring tools of various designs in cross contaminating lettuce heads will be studied. In objective 3, studies on the efficacy of plant antimicrobials and organic sanitizers as well as edible films will be continued. Sensory evaluations on the most effective treatments will be conducted. In objective 4, outreach activities will be continued through meetings, seminars, conference presentations, demonstrations and social media.
Impacts
What was accomplished under these goals?
For Objective 1: Effects of contaminated seed and water, on the persistence and internalization of Salmonella in organic spinach cultivars were studied. Contaminated seeds and irrigation water had S. Newport populations of 7.64±0.43 log CFU/g and 7.12±0.04 log CFU/ml, respectively. Sprouts germinated using contaminated water and seeds had S. Newport populations of 8.09±0.04 and 8.08±0.03 log CFU/g, respectively. Populations of S. Newport in leaves, stem and roots of spinach plants were as follows: contaminated seed- 2.82±1.69, 1.69±0.86, and 4.41±0.62 log CFU/ml; contaminated water- 3.56±0.90, 3.04±0.31, and 4.03±0.42 log CFU/ml of macerated tissue suspension, respectively. Internalization occurred in plants developing from contaminated seed and sprouts germinated using contaminated water. S. Newport was recovered from soil and water runoff. The results indicate that contamination during germination can result in persistence, internalization and environmental reintroduction of Salmonella For Objective 2: A study on survival of E. coli K-12 in homemade compost teas revealed that compost tea made with vegetables allowed E. coli to survive well over 4 weeks with 0.5 log reduction (6 logs in vegetable only tea compared to 4 logs in all other teas). Horse and sheep compost tea with and without E. coli showed longer survival on all crops in both applications. Foliar application of sheep compost tea on iceberg and romaine lettuce resulted in highest recovery of E. coli while cow compost tea showed the fastest reduction. Side dress applications showed reduction after 5 days without added E. coli and after 8 days with E. coli and were determined as the safer application route. Environmental evaluation of irrigation water samples from Yuma and Maricopa revealed that E. coli was isolated from 22/236 (9.3%) water and 19/235 (8.1%) sediment samples. Salmonella was isolated from 33/236 (14.0%) water and 53/235 (22.6%) sediment samples. Both E. coli and Salmonella were isolated from 7/236 (3.0%) water and 2/235 (0.9%) sediment samples in total from both irrigation systems. All of the confirmed E. coli isolates were non-pathogenic. For Salmonella isolates, a subset of 17/68 (25%) samples from Yuma and 6/18 (33.3%) samples from Maricopa were assayed for the Salmonella invA and himA genes and tested positive. No (0/231) samples were positive for human norovirus (either GI or GII serotypes), hepatitis A virus, or Aichi virus. For Objective 3 Clove bud oil or eugenol (0.1, 0.3 or 0.5%), 5% grape seed extract with 0.1% clove bud oil (combination A), and 5% olive extract with 0.1% clove bud oil (combination B) were tested against S. Newport on organic leafy greens. Reductions in Salmonella populations after 3 days of storage ranged from 0.5-3.7 and 0.4-3.7 log CFU/g for clove bud oil and eugenol treatments, respectively. Eugenol (0.5%) reduced Salmonella population below detection limit by day 3. Combination A reduced Salmonella populations from 0.3-1.2 log CFU/g and was the most effective on romaine lettuce with a reduction of 1.23 log CFU/g by day 3. Combination B had reductions ranging from 1.3-3.6 log CFU/g and was most effective on mature spinach with a reduction of 3.6 log CFU/g by day 3 demonstrating synergistic activity. Individual and combined use of oregano oil and olive extract against starved S. Newport indicated that 0.5% oregano oil was the most effective on all leafy greens, and 0.3% oregano oil was effective on baby spinach, iceberg and romaine lettuce. No survivors were detected immediately upon exposure. The 5.0% olive extract was the most effective on romaine lettuce, and the hydrogen peroxide treatment was comparable to 0.1% oregano oil and 1.0 and 3.0% olive extract. Starvation stress did not cross-protect Salmonella against antimicrobials. Apple, carrot and hibiscus films (control; 0.5, 1.5 and 3% carvacrol; 0.5, 1.5 and 3% cinnamaldehyde for each type of film) were tested against E. coli O157:H7 on organic leafy greens in sealed plastic bags. On all produce, 3% carvacrol films were the most effective. All 3 types of 3% carvacrol films reduced E.coli O157:H7 to below detection limit at day 0, 3 and 7 on iceberg and romaine lettuce. Carrot and hibiscus films with 1.5% carvacrol reduced E.coli O157:H7 to below detection limit at day 7 on iceberg lettuce. In general, carvacrol films were more effective than cinnamaldehyde films. Edible films were most effective on iceberg lettuce. In a large scale study, nonpathogenic E. coli K-12 inoculated iceberg lettuce was treated with 0.5% oregano oil, 5% olive extract and a 3.0% olive extract+1.0% oregano oil combination. The large scale study yielded an initial 2.3-3.7 log CFU/g reduction on organic iceberg lettuce which remained constant after three days of storage. These studies indicate that combination treatments are potential sanitizers for washing organic produce. Organic sanitizers Chico Wash, C8C10 and CG100 reduced E. coli O157:H7 on baby spinach by 2.6 logs by day 3, while other organic sanitizers showed reduction between 1-2 logs. Chico wash resulted in a reduction in microbial counts of 2.0 logs by day 3, while 1.5-2.0 log reductions resulted from other organic sanitizers. Romaine lettuce treated with CG100 and Chico Wash showed reductions of 3.4 and 2.6 logs, respectively, by day 3. Chico Wash and CG100 treatment of iceberg lettuce caused 2.4 log reduction by day 3 while other organic sanitizers showed 1.5-2.5 log reductions in pathogen counts Carvacrol, cinnamaldehyde, oregano and cinnamon oils were tested at 0.5% concentration for their reusability against E. coli O157:H7 on organic leafy greens. Oregano oil was the most effective, reducing E. coli O157:H7 populations to undetectable levels after initial application. Carvacrol performed similarly except on mature spinach where undetectable levels were achieved on day 3. Cinnamaldehyde showed a significant reduction in pathogen population, 2.1-3.7 logs on day 0 and undetectable growth on days 1 & 3. Cinnamon oil reduced pathogen by 2.2-3.7 logs after initial application and achieved undetectable levels by day 3 on organic mature spinach and iceberg lettuce. No growth was detected from the treatment wash waters. Carvacrol, cinnamaldehyde, oregano and cinnamon oils were tested at 0.5% against Lactobacillus brevis on organic leafy greens. Carvacrol and oregano oil reduced L. brevis populations to undetectable levels immediately upon exposure. Cinnamon oil reduced populations by 1.0-1.5 logs by day 3. On leafy greens washed with cinnamaldehyde or hydrogen peroxide, reduction was seen on day 0 and 1, but by day 3, an increase in population was observed, except in baby spinach where a 1.0 log reduction was observed on all three days. These studies showed that plant antimicrobials and organic sanitizers are effective in reducing bacterial populations on organic leafy greens and are a viable option for the organic produce industry. For Objective 4: Extension activities included statewide organic food safety workshops in Arizona, training seminars, development of online content (social media) and bilingual videos for effective dissemination of research results for stakeholders. In Oklahoma, fresh produce safety related presentations incorporating results from studies carried out in Dr. Jaroni's lab were disseminated to growers and processors. A produce safety website with relevant research outcomes has been finalized. Drs. Ravishankar, Jaroni, Bright and Nolte have also conducted presentations, demonstrations and seminars to growers, students and the general public. The PIs have also presented research results generated from this project at the Annual Meetings of the International Association for Food Protection, Institute of Food Technologists and the American Society of Horticultural Sciences in 2014 in the form of oral and poster presentations to both academia and industry.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Zhu, L., Olsen, C., McHugh, T., Friedman, M., Jaroni, D. and Ravishankar, S. (2014). Apple, Carrot, and Hibiscus Edible Films Containing the Plant Antimicrobials Carvacrol and Cinnamaldehyde Inactivate Salmonella Newport on Organic Leafy Greens in Sealed Plastic Bags. J. Food Sci. 79:M61-M66.
Buddhini, P. K., Jones, J., Ravishankar, S. and Jaroni, D. (2014). Evaluating the Efficacy of Olive, Apple and Grape Seed Extracts in Reducing Escherichia coli O157:H7 Contamination on Organic Leafy Greens during the Wash Process. Int. J. Food Sci. Nutr.Diet. 3 (10):1-7.
Macarisin, D., Patel, J. and Sharma, V. (2014). Role of curli and plant cultivation conditions on Escherichia coli O157:H7 internalization into spinach grown on hydroponics and in soil. Int. J. Food Microbiol. 173:48-53.
Gilling DH, Kitajima M, Torrey JT, Bright KR. (2014) Antiviral efficacy and mechanisms of action of oregano essential oil and its primary component carvacrol against murine norovirus. J Appl Microbiol 116(5): 1149-1163.
Gilling DH, Kitajima M, Torrey JT, Bright KR. (2014) Antiviral efficacy and mechanisms of action of plant antimicrobials against murine norovirus. Appl Environ Microbiol 80(16): 4898-4910.
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Friedman, M. Antibacterial, antiviral, and antifungal properties of wines and winery byproducts in relation to their flavonoid content. Journal of Agricultural and Food Chemistry 62, 6025-6042, 2014.
Friedman, M. Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices. Journal of Agricultural and Food Chemistry 62, 7652-7670, 2014.
- Type:
Journal Articles
Status:
Published
Year Published:
2015
Citation:
Friedman, M., Henika, P. R., and Levin, C. E. Antimicrobial activities of red wine-based formulations containing plant extracts against Escherichia coli O157: H7 and Salmonella enterica serovar Hadar. Food Control 50, 652-658, 2015.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2014
Citation:
Gilling DH, Kitajima M, Torrey JT, Bright KR. (2014) Evaluation of antiviral efficacy of cinnamon plant compounds against murine norovirus, a human norovirus surrogate. Submitted to Food Environ Virol.
Divya Jaroni, Buddhini Jayasundera, Jordan Denton and Sadhana Ravishankar. Antibacterial Efficacy of Roselle (Hibiscus sabdariffa) Calyx Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens Stored at 4�C. Quality Assurance and Safety of Crops & Foods. Submitted
Jordan J. Denton, Mendel Friedman, Sadhana Ravishankar, and Divya Jaroni. Antimicrobial Efficacy of Plant-Derived Compounds against Escherichia coli O157:H7 on Organic Leafy Greens under Refrigeration Temperatures. J. of Food Science and Preservation. Submitted
Jordan J. Denton, Buddhini, P. K. Jaysundera, Sadhana Ravishankar, and Divya Jaroni. Evaluation of Antibacterial Effects of Plant-Derived Essential Oils against Escherichia coli O157:H7 on Organic Leafy Greens. J. of Food Protection. Submitted.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Ravishankar, S. 2014. Improving the safety and quality of organic leafy greens. National Webinar hosted by the eOrganic. February 2014.
Dev Kumar, G., Patel, J. and Ravishankar, S. 2014. Comparative Evaluation of Factors Affecting Escherichia coli Biofilms on Organic Leafy Green Wash Water Contact Surface. Annual Meeting of the International Association for Food Protection (IAFP). Indianapolis, Indiana. 2014.
Damian H. Gilling, Masaaki Kitajima, Jason R. Torrey, and Kelly R. Bright. Mechanisms of Action of Plant Antimicrobials against Murine Norovirus. Presented at the annual meeting of the International Association for Food Protection, August 2014.
Rada, X., Todd, J., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2014. Synergistic Effects of Combination Treatments of Essential Oils and a Plant Extract Against Multi drug Resistant Salmonella Newport on Organic Leafy Greens. Annual Meeting of the International Association for Food Protection, 2014. Indianapolis, IN.
Schneider, A. and Ravishankar, S. 2014. Antimicrobial Activity of Essential Oil X Against Multi-Drug Resistant Salmonella enterica on Organic Leafy Greens. Annual Food Safety Conference, Tucson, AZ.
Jaroni, D. P. K. Litt, S. Ravishankar, and J. Brooks. 2014. Inhibitory Activity of Hydrogen Peroxide, Water and Organic Sanitizers against Escherichia coli O157:H7 on Organic Leafy Greens. Annual Meeting of the International Association for Food Protection, 2014. Indianapolis, IN.
Litt, P. K., S. Ravishankar and D. Jaroni. 2014. Antimicrobial Efficacy of Fulvic Acid Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens at Refrigeration Temperatures. Annual Meeting of the International Association for Food Protection, 2014. Indianapolis, IN.
Dusty R. Tyree, Jason R. Torrey, Jonathan Sexton, Rachael Zinn, Masaaki Kitajima, and Kelly R. Bright.The Occurrence of Bacterial and Viral Foodborne Pathogens in Irrigation Waters in Southern Arizona. Presented at the International Association for Food Protection annual meeting, August 2014.
Dev Kumar, G. and Ravishankar, S. 2014. Detection of stressed Salmonella enterica from Iceberg lettuce irrigation and processing water. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
Dev Kumar, G. and Ravishankar, S. 2014. Efficacy of sequential dual hurdle treatments- ozone and plant antimicrobials in reducing Salmonella enterica on iceberg lettuce. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2014
Citation:
Nolte, K.D. and S. Ravishankar. 2014. The 5 Year Anniversary of the Arizona Leafy Green Marketing Agreement: What Works and What Doesnt. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL.
Wilson, R., R. Bevington, Nolte, K.D., and S. Ravishankar 2014. Extending Research Impacts to a General Audience Via Video: The Good, The Bad, And The Ugly. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL.
Bevington, R., K.D. Nolte and S. Ravishankar. 2014. Best Methods to Present Research Information via Video Formats to a Public Audience. Abstract published in the proceedings at the 2014 American Society for Horticultural Science Annual Meeting, Orlando, FL.
Brandenberger, L., McGlynn, W., Bihn, E., and Wall, G. 2014. Food Safety Training & the Produce Safety Alliance (PSA) Curriculum. Presentation given and abstract published in 2014 Horticulture Industries Show Book of Proceedings and presentation given on January 11 in vegetable session, Tulsa, OK.
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Presentation given and abstract published in 2014 Horticulture Industries Show Book of Proceedings and presentation given on January 11 in fruit session, Tulsa, OK.
Brandenberger, L. and McGlynn, W. 2014. Food Safety for Fresh Produce. Poster presented on January 22 at the Oklahoma Cooperative Extension Service State Conference. Stillwater, OK.
McGlynn, W., Brandenberger, L. and Young, J. 2014. Creating and Using a Basic GAP/GHP Food Safety Plan Checklist. Handout and presentation given on January 27th at: Regional grower/supplier meeting sponsored by Reasors. Tulsa, OK.
McGlynn, W.G. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on February 13 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Weatherford, OK.
Brandenberger, L. 2014. Basic Good Agricultural Practices for Fresh Produce. Oral presentation, handouts, and hands-on demonstration given on February 19 to the Otoe-Missouria / Ponca tribes as part of a community garden project. Red Rock, OK.
Brandenberger, L. 2014. GAPs for fresh produce. Presentation and handouts given on February 28 at the Statewide Organic Production Conference, Oklahoma City, OK.
Brandenberger, L. and McGlynn, W. 2014. Food Safety 101. Presentation given on March 6 at: Oklahoma Market Gardening School. Oklahoma Cooperative Extension Offices, Norman, OK.
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on March 13 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Oklahoma City, OK.
Young, J, Brandenberger, L, and McGlynn, W. 2014. Preparing a Basic GAP/GHP Food Safety Plan. Oral presentations and handouts given on March 19 to the Hmong growers group. Rose/Leach, OK.
McGlynn, W. and Brandenberger, L. 2014. Good Agricultural Practices Basic Principles. Handouts disseminated and discussion session led on May 8 at: ODAFF / FAPC Advanced Farm Food Safety Workshop, Stillwater, OK.
- Type:
Websites
Status:
Published
Year Published:
2014
Citation:
Fresh Produce Safety Website: http://cals.arizona.edu/fps/
Fresh Produce Safety Facebook page: https://www.facebook.com/FoodSafety101
Twitter: https://twitter.com/FreshFoodSafety
Pinterest: http://www.pinterest.com/producesafety
Fresh Produce Safety :http://www.freshproducesafety.okstate.edu
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2013
Citation:
Dev Kumar, G., Ravishankar, S. and Patel, J. 2013. Comparative Evaluation of Factors Affecting Escherichia coli Biofilms on Organic Leafy Green Wash Water Contact Surfaces. Presented at Special Seminar Series, School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
Dev Kumar, G. and Ravishankar, S. 2013. Effectiveness of Antimicrobials and Saponins in Reducing Biofilm Formation on Wash Water Equipment Surfaces. Arizona Iceberg Lettuce Council Meeting. Yuma Arizona.
Dev Kumar, G. and Ravishankar, S. 2013. Effects of environmental conditions on transfer rates of Salmonella enterica and Escherichia coli O157:H7 from soil, dust and irrigation water to iceberg lettuce surfaces. Arizona Iceberg Lettuce Council Meeting, Yuma, Arizona.
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Progress 09/01/12 to 08/31/13
Outputs
Target Audience: Target Audiences The target audiences for this project include: growers, producers, and processors of organic leafy greens; manufacturers of natural antimicrobials and organic sanitizers; and consumers of organic leafy greens. Leafy green producers and manufacturers of natural antimicrobials and organic sanitizers have been involved in this project by providing in-kind support to the project. They have been informed periodically on the results of this project through various forums such as seminars, talks and demonstrations. Dr. Ravishankar visited fresh produce growers and industry personnel in Goodyear, AZ and Yuma, AZ in May 2012 and December 2012, respectively, to discuss research needs. She was invited as the featured speaker at the Yuma Fresh Vegetable Association Annual Meeting in December 2012 in which she provided an overview of the organic leafy greens project and an update on the project progress to the attendees that included fresh produce professionals. Dr. Ravishankar attended the Food Safety Research Update Meeting with the Yuma Fresh Produce Growers in September 2013 and gave the most recent update on the results from this project. Information about the results from the project was also shared with stakeholders at the Food Safety Consortium at the University of Arizona in October 2013, where posters on efficacy of plant antimicrobial combinations, biofilm formation by E. coli on produce wash water contact surfaces and attachment and cross transfer of Salmonella from soil to produce surfaces were presented. The audience in these meeting included produce growers, students and other faculty involved in food safety research. Dr. Ravishankar also presented the research results generated from this project at the Annual Meetings of the International Association for Food Protection (IAFP; Charlotte, NC) and Institute of Food Technologists (IFT; Chicago, IL) in 2013 in the form of posters. The audiences at these conference included food safety professionals, produce growers, produce industry executives and students. Dr. Ravishankar’s research team conducted food safety demonstrations about natural antimicrobial/organic sanitizers for washing produce, safe produce handling and cross contamination for the local Tucson community at the Science City, Tucson Festival of Books in March 2013 and for the local school students at the Youth Biotechnology Career Expo in October 2013, hosted by the BIO5 Institute, University of Arizona. Dr. Ravishankar’s postdoc, Dr. Dev Kumar presented the work on biofilm based attachment of E. coli to washing equipment surfaces in seminar presentations at the University of Arizona (October 2013) and the Arizona Iceberg Lettuce Research Council (AILRC) Quarterly meeting attended by produce growers (November 2013) in Yuma, AZ. Dr. Ravishankar’s graduate student presented a poster on the efficacy of plant antimicrobial combinations at the University of Arizona Student Poster Competition in November 2013 to inform the university community about the efforts associated with making produce safer and the novel strategies implemented to achieve this goal. Dr. Nolte of the Yuma Agricultural Center has used multiple communication strategies towards knowledge dissemination. His team has developed a website, uploaded YouTube videos, developed training DVDs and has made information accessible over facebook.com, Pintrest and Twitter. Apart from improving the accessibility to the latest research in food safety and good agricultural practices he has also conducted seminars and training series in different parts of Arizona addressing pressing issues in food safety. A unique feature of his efforts has been the bilingual mode of instruction in order to reach a larger target audience. Dr. Nolte’s team presented posters related to this project at the 2013 Annual Meeting of the American Society for Horticultural Sciences in Palm Desert, CA. At the University of Oklahoma, Dr. Brandenberger has given four talks to several fresh produce farmers in Oklahoma, related to fresh produce safety. Dr. William McGlynn has incorporated the results of the studies carried out in Dr. Jaroni’s lab in five workshops. He also attended the Center for Produce Safety Produce Research Symposium in June 25 and 26 in Rochester, NY where he participated in discussions and planning sessions related to implementing Good Agricultural Practice (GAP) programs designed to allow smaller-scale, local fresh produce growers and processors to safely supply produce to local and regional retail outlets. He also gathered information about emerging microbial threats and potential mitigation strategies. The Principal Investigators from Oklahoma State University have also established a website related to fresh produce safety. Dr. Jaroni and her graduate students presented the research results generated from this project at the 2013 Annual Meeting of the International Association for Food Protection (IAFP) in Charlotte, NC in the form of posters. Dr. Friedman of the USDA and Dr. Ravishankar participated with Marcia Wood (ARS) in drafting an article for April 2013 issue of Agricultural Research. The article and press release resulted in numerous exchanges of information with reporters of health magazines. Dr. Friedman is also a member of the W3122 Multistate Research Project entitled "Beneficial and Adverse Effects of Natural Chemicals on Human Health and Food Safety" for which he exchanged ideas with members (university professors and ARS scientists) to facilitate progress associated with food safety and human health. Dr. Jitu Patel of the USDA-ARS shared the results of his research on internalization and natural antimicrobials with the largest organic growers in the mid-Atlantic region. All post-doctoral fellows, technicians and students hired to work on this project have received training on good laboratory practices, including pathogen safety precautions, media preparation, product sampling, field sampling and other laboratory activities related to the project. Dr. Dev Kumar received training in PCR and use of confocal scanning laser microscopy to study the attachment/internalization of bacteria on/in organic leafy greens from the Palanivelu lab, School of Plant Sciences, University of Arizona, Tucson. Over the past year numerous media outlets have provided coverage/stories on the organic leafy greens research project (see publication list) to reach a wide variety of audience. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? All post-doctoral fellows, technicians and students hired to work on this project have received training on good laboratory practices, including pathogen safety precautions, media preparation, product sampling, field sampling and other laboratory activities related to the project. Dr. Sadhana Ravishankar’s lab currently has 6 undergraduate students, 3 graduate students and a postdoctoral research associate involved with organic leafy greens research. Undergraduate and graduate students have been trained in bacterial inoculation & enumeration, environmental isolation of pathogens, soil evaluation and have been involved with conducting experiments under the guidance of Drs. Ravishankar and Dev Kumar. Undergraduate and graduate students have been trained to analyze and present data and have presented research posters at the Food Safety Conference in the University of Arizona. Dr. Sadhana Ravishankar also trains high school students in microbiological techniques and allows them to work on produce safety projects using non-pathogenic bacterial strains. She currently has 2 high school students conducting their science fair projects in her lab. The use of mass media for the propagation of food safety information to stakeholders has given students and other researchers in the Ravishankar lab and at the Yuma Agricultural Center an opportunity to participate in interviews about their research for youtube videos. The new forum helps students and researchers present their findings in a succinct and easily accessible format. Dr. Dev Kumar received training in PCR and use of confocal scanning laser microscopy to study the attachment/internalization of bacteria on/into organic leafy greens from the Palanivelu lab, School of Plant Sciences, University of Arizona, Tucson. Dr. Dev Kumar presented the work on biofilm based attachment of E. coli to washing equipment surfaces in seminar presentations at the University of Arizona (October 2013) and the Arizona Iceberg Lettuce Research Council (AILRC) Quarterly meeting attended by produce growers (November 2013) in Yuma, AZ. Dr. Ravishankar’s graduate student presented a poster on the efficacy of plant antimicrobial combinations at the University of Arizona Student Poster Competition in November 2013 to inform the university community about the efforts associated with making produce safer and the novel strategies implemented to achieve this goal. Drs. Ravishankar, Jaroni, Gerba, Bright, Patel and Nolte’s students have had the opportunity to present their research findings at international and state level conferences such as the Annual Meetings of the International Association for Food Protection (IAFP), the Institute of Food Technologists (IFT) and the American Society for Horticultural Sciences (ASHS), as well as the Annual Food Safety Conference in Tucson, AZ, through posters. How have the results been disseminated to communities of interest? The extension teams at the Yuma Agricultural Center, Oklahoma State University and Dr. Ravishankar’s laboratory groups have been involved with the dissemination of information to communities of interest. Seminars, training sessions, conferences, demonstrations, videos, internet based communication and print media have all been used. Workshops have been conducted throughout the state to provide content detailed training involving the safe production of organically grown leafy greens in Flagstaff (December, 2012), 35 participants; Phoenix (January, 2013), 18 participants; Maricopa (February, 2013), 22 participants; Flagstaff (March, 2013), 28 participants; Snowflake (April, 2013), 22 participants; Yuma (May, 2013), 7 participants; and Nogales (October, 2013), 18 participants. Extension Videos were developed covering the following topics: Edible Films, Microbial Internalization & Surface Adhesion in Leafy Greens, Organic Sanitizers, Compost Teas, Reducing Contamination in Irrigation Water, Safe Management Practices for Using Composted Manures. A 4-part, video series of field worker training modules (English and Spanish) was developed. Bilingual production of training modules has provided an additional avenue of outreach that includes a clientele base that could not necessarily be otherwise reached. While total viewership has reached 2,100 views (February 2012) since the release of the Fresh Produce Safety Channel in April, 2013, user testimonials have been extremely positive. These training segments cover topical areas that include: Hand Washing, Field Sanitation, Bodily Fluid Discharge, and Field Etiquette. Extension also includes programming that uses a dedicated web interface, Facebook, Twitter, and Pinterest. Since their release the sites have generated over 3,300 client interactions (February 2012) which continue to grow daily. Details Fresh Produce Safety Website (2,700 views). A Safe Organic Training website has been created for producers, and progress is being made to integrate this into eXtension. The site contains key information about the USDA Good Handling and Agricultural Practices (GAP/GHP) program, as well as the online, bilingual version of the training materials (http://cals.arizona.edu/fps/). Facebook (102 fans). The Fresh Produce Safety Facebook page provides networked follower’s tips, trends and key information about the practices involving fresh produce safety (https://www.facebook.com/FoodSafety101). Twitter (377 followers). Followers receive instant updates related to fresh produce safety production practices, research developments, workshops, and demonstrations. Allows a seamless way to keep updated (https://twitter.com/FreshFoodSafety). Pinterest (56 subscribers). Allows fresh produce safety materials to be shared with others, a leader in creating referral traffic (http://www.pinterest.com/producesafety). Our team from the Oklahoma state University also participated in various talks, presentations and has developed a website for information dissemination. Dr. Brandenberger has carried out four talks to several fresh produce farmers in Oklahoma, related to fresh produce safety. Dr. William McGlynn has incorporated the results of the studies carried out in Dr. Jaroni’s lab in five workshops. Presentations McGlynn, W.G. & Brandenberger, L. 2013. Food Safety 101, presentation given on March 12 at: Oklahoma Market Gardening School. Oklahoma Cooperative Extension Offices, Tulsa, OK. McGlynn, W.G. 2013. Good Agricultural Practices (GAPs): an Introduction. Oral presentation, handouts, given on March 13 to the Otoe-Missouria tribes / Ponca as part of a Plasticulture Market Garden demonstration project. McGlynn, W.G. 2013. Good Agricultural Practices (GAPs): an Introduction. Oral presentation, handouts, given on April 9 to the Otoe-Missouria tribes / Ponca as part of a Plasticulture Market Garden demonstration project. Brandenberger, L.; McGlynn, W.G. 2013. Basic Good Agricultural Practices for Fresh Produce. Oral presentation, handouts, and hands-on demonstration given on May 8 to the Hmong people as part of a Plasticulture Market Garden demonstration project. Brandenberger, L. 2013. Safe Use of Pesticides for Produce Production. Oral presentation, handouts, and hands-on demonstration given on July 2 to the Hmong people as part of a Plasticulture Market Garden demonstration project. Brandenberger, L.; McGlynn, W.G. 2013. Basic Good Agricultural Practices for Fresh Produce. Oral presentation, handouts, and hands-on demonstration given on July 24 to the Otoe-Missouria / Ponca tribes as part of a Plasticulture Market Garden demonstration project. The PIs from Oklahoma State University have also established a website related to fresh produce safety titled: Fresh Produce Safety (www.freshproducesafety.okstate.edu). Dr. Jaroni and her graduate students presented the research results generated from this project at the 2013 Annual Meeting of the International Association for Food Protection (IAFP) in Charlotte, NC in the form of posters. Dr. Jitu Patel of the USDA-ARS shared the results of his research on internalization and natural antimicrobials with the largest organic growers in the mid-Atlantic region. Dr. Sadhana Ravishankar has also been involved with multiple demonstration based activities to educate the public about plant antimicrobials, safe produce handling and the risk of cross contamination in the kitchen. She and her team conducted Food Safety Demonstrations on these topics for the local Tucson community at the Science City, Tucson Festival of Books; for the local school students at the Youth Biotechnology Career Expo, hosted by the BIO5 Institute, University of Arizona. Models were created to demonstrate cross contamination from cutting board to produce surfaces. Biophotonic images of pathogens on produce surfaces before and after antimicrobial treatments were also used to demonstrate the effectiveness of plant based antimicrobials. Dr. Ravishankar was invited as the featured speaker at the Yuma Fresh Vegetable Association Annual Meeting in December 2012 in which she provided an overview of the organic leafy greens project and an update on the project progress to the attendees that included fresh produce professionals. She attended the Food Safety Research Update Meeting with the Yuma Fresh Produce Growers in September 2013 and gave the most recent update on the results from this project. Information about the results from the project was also shared with stakeholders at the Food Safety Consortium at the University of Arizona in October 2013, where posters on efficacy of plant antimicrobial combinations, biofilm formation by E. coli on produce wash water contact surfaces and attachment and cross transfer of Salmonella from soil to produce surfaces were presented. The audience in these meetings included produce growers, students and other faculty involved in food safety research. Dr. Ravishankar also presented the research results generated from this project at the Annual Meetings of the International Association for Food Protection (IAFP; Charlotte, NC) and Institute of Food Technologists (IFT; Chicago, IL) in 2013 in the form of posters. The audiences at these conference included food safety professionals, produce growers, produce industry executives and students. Dr. Dev Kumar presented the work on biofilm based attachment of E. coli to washing equipment surfaces in seminar presentations at the University of Arizona (October 2013) and the Arizona Iceberg Lettuce Research Council (AILRC) Quarterly meeting attended by produce growers (November 2013) in Yuma, AZ. Dr. Ravishankar’s graduate student presented a poster on the efficacy of plant antimicrobial combinations at the University of Arizona Student Poster Competition in November 2013 to inform the university community about the efforts associated with making produce safer and the novel strategies implemented to achieve this goal. What do you plan to do during the next reporting period to accomplish the goals? Objective 1 To study the fate of Salmonella on organic leafy greens we plan to grow spinach sprouts that have been challenged with the pathogen through Salmonella contaminated seed or contaminated water in organic soil. Once the plant reaches the 4 leaf stage, the leaves, stem and roots will be sampled for the presence of surface attached and internalized Salmonella to understand distribution of pathogen after contamination event during germination. To understand the effect of soil contamination by Salmonella on organic leafy greens, we plan to grow spinach in soil contaminated by the pathogen. We will also study fate of pathogen on organic leafy greens when irrigation water is contaminated. The effect of these conditions when root damage occurs will be studied. Both surface contamination and possible internalization by the pathogen will be accounted for. Objective 2 Studies to understand the impact of compost teas on the survival of non-pathogenic Escherichia coli on plants and the benefits of the application of compost teas on plant yield will continue. Survival times and safest methods of compost tea application will be evaluated. Studies on the survival of E. coli in composts will continue to determine raw materials most suitable and safe for composting. Dr. Bright will continue her survey of Arizona irrigation water and sediments for norovirus and hepatitis A virus. A microbial risk assessment of irrigation water will be done. Objective 3 Efficacy of combinations of plant based antimicrobials will be evaluated against Salmonella on organic leafy greens to gauge antimicrobial activity of the combinations at the lowest concentrations. The effectiveness of edible film based antimicrobial delivery in salad packaging in reducing pathogen survival and growth will be evaluated against E. coli O157:H7. The use of plant based antimicrobials to enhance the safe reuse of produce wash water will further be pursued to develop a viable alternative to chlorination for the fresh cut produce industry. Efficacy of antimicrobials and their combinations as determined from our data will be tested in a pilot scale. Our team at the University of Arizona will conduct a sensory evaluation to determine acceptance of organic leafy greens sanitized by plant antimicrobials. Continuation of the antiviral efficacy of plant based antimicrobials will occur to determine most effective concentrations and understand mechanisms of antiviral activity. Our team at Oklahoma state University will complete their evaluation of plant based antimicrobials and commercial sanitizers against spoilage lactic acid bacteria and E. coli O157:H7. Objective 4 Our outreach team will continue their efforts towards education of growers on safe produce handling practices and good agricultural practices. We plan to disseminate the information we have gathered to our stakeholders through conference presentations, meetings, farm visits and consultations. Our efforts to make information more accessible will continue through the development of bilingual training DVD’s, youtube videos and classes. Information access through social networking websites has been extremely popular and we will continue to add content to our facebook page, twitter accounts and pinterest. The University of Oklahoma will continue their outreach and extension efforts to inform growers about safe organic leafy green handling and on farm strategies. The team will make information more accessible through the development of their website and conducting training modules and classes for our stakeholders. Dr. Ravishankar and other investigators will be continuing their efforts to provide growers with information and guidance regarding produce safety through seminars, webinars, farm visits and guest lectures. The courses taught by Dr. Ravishankar at the University of Arizona focus on produce safety and information about her research extensively, and are a primer for students interested in food safety and food microbiology. She will also continue conducting her demonstrations on natural interventions, safe produce handling and cross contamination risks at the Science City- Tucson Festival of Books and other educational fairs. All investigators will be presenting their research and findings at various international conferences such as the Annual Meetings of the International Association for Food Protection (IAFP), Institute of Food Technologists (IFT), the American Society for Horticultural Sciences (ASHS) and others.
Impacts
What was accomplished under these goals?
The influence of organic leafy greens wash water reuse on biofilm formation by curli producing Escherichia coli O157:H7, curli deficient E. coli O157:H7 and non-pathogenic E. coli K12 on baby spinach, mature spinach, romaine lettuce and iceberg lettuce wash water contact surfaces was evaluated. Increased reuse of wash water resulted in increased generation of biofilm. Organic leafy green native microbiota along with E. coli increased biofilm formation indicating a possible synergistic activity. The use of S. Newport contaminated water (8 log CFU/ml) and S. Newport contaminated seed (8 log CFU/g) resulted in presence of the pathogen 6 days after germination on sprouts. Microbiological analysis of surface sterilized tissue indicated presence of internalized S. Newport (3 log CFU/ml) in all 4 spinach cultivars tested. Transfer of S. Newport from soil to leaf surface could depend on multiple factors such as the type of soil and humidity of the environment. The amount of transfer of Salmonella from soil to leaf surface was the highest in compost amended soil, followed by soil from an organic farm. Study of homemade compost tea native microbiota revealed that horse manure compost tea had 5.5 Log CFU/ml of microbiota. By week 2 homemade horse manure tea showed a 3 Log CFU/ml reduction of E. coli. Horse and vegetable tea showed a 2 Log CFU/ml reduction at week 2. Vegetable tea increased by 1 Log from week 1 to 2. Study of E. coli survival on organic leafy greens after foliar and side dress application of compost teas indicated that romaine lettuce that had commercial compost teas applied foliarly showed E. coli counts up to day 23 whereas iceberg lettuce showed reduction after day 13. Sheep compost tea had the highest recovery and cow compost tea had the lowest recovery of E. coli foliarly on both iceberg and romaine lettuce. Side dress applications of compost tea showed a reduction in E. coli counts much faster than foliar applications. Analysis of yields and quality parameters of organic leafy greens after compost tea application indicated that the yields of Iceberg lettuce with compost tea had more weight (g) and diameter (cm) compared to the control. In spinach, the addition of fertilizers fulvic and humic acids along with compost teas resulted in better crop yield than in the controls that did not contain the fertilizers. Environmental evaluation of waters from the Yuma and Maricopa regions revealed that the two regions were fairly comparable; the only major difference was in water turbidity of water from Yuma. Both E. coli and Salmonella were isolated from 7 of the 236 (3.0%) water and 2 of the 235 (0.9%) sediment samples in total from both irrigation systems. None of the E. coli isolates possessed stx1 and stx2 and eae genes. All of these isolates were confirmed as Salmonella species. No human norovirus (either GI or GII serotypes), hepatitis A virus, or Aichi virus were detected in any of the 231 large volume irrigation water samples from Yuma or Maricopa. Nineteen of 66 samples (28.8%) that were positive for pepper mild mottle virus (PMMV) also had Salmonella spp. in either the water (12 samples) or the sediment (7 samples) samples. Evaluation of Fulvic acid as a sanitizer for coring tools indicated that Fulvic Acid #2 performed the best in reducing E. coli counts on both tool types; Fulvic Acid #3 also performed well at reducing E. coli. Re-designed tool treated with Fulvic Acid #2 showed a 2 log reduction of E. coli. Hibiscus concentrates (10-30%) reduced the Pseudomonas population on leafy greens by 0.7-4.2 log CFU/g, and 1-5% olive extract showed 0.6-4.1 log CFU/g reductions. For essential oils, 0.1-0.5% oregano oil reduced the bacterial population by 0.3-2.5 log CFU/g, and 0.1-0.5% lemongrass oil decreased 0.4-3.1 log CFU/g Pseudomonas. Cinnamon oil was the most effective essential oil tested. At day 3, 0.3% cinnamon oil reduced the bacterial population by 4.3-4.4 log CFU/g. There were 2-3 log reductions at day 0 for 0.5% cinnamon oil treatment, and no survivors were detected at day 3. Evaluation of the effectiveness of plant based sanitizers in increasing the recyclability of wash waters indicated that the 5-time reuse of 3% olive and apple extracts didn’t reduce their antimicrobial effects. At day 3 oregano oil reduced the Salmonella population to below detection limit on romaine lettuce after 1st and 2nd washes. Salmonella cells couldn’t survive in 3% olive extract, 0.3% oregano and cinnamon oil wash liquids, while there were 0.5-2.1 log CFU/ml surviving cells in 3% apple extract wash liquids. The use of plant based antimicrobial combinations resulted in baby spinach showing 3.5 logs and 4.0 logs CFU/g reductions for S. Newport on day 3 for the cinnamon oil and olive extract, and oregano oil and olive extract combination treatments, respectively. Mature spinach resulted in a 3.0 log CFU/g reduction for both combination treatments. For romaine lettuce, there was a 3.0 log CFU/g S. Newport reduction for the cinnamon oil and olive extract combination, and a 4.0 log CFU/g reduction for the oregano oil and olive extract combination. For E. coli O157:H7 on organic leafy greens, carvacrol at 0.3 and 0.5%, and cinnamaldehyde at 0.5% concentrations inhibited growth to non-detectable levels, while citral at 0.5% decreased E. coli O157:H7 population by 3.8-4.9 log CFU/g. Of the three compounds, carvacrol provided the most effective reduction in pathogen populations among all four leafy greens. Assay of the antimicrobial efficacy of commercial sanitizer CHICO wash indicated that both wash times displayed distinct reduction of the E. coli O157:H7 population. The two minute wash had a remaining population log value of 0.6 logs lower than that of the one minute. Fulvic acid washes resulted in reductions in E. coli O157:H7 population in adult spinach. Fulvic acid # 2 and 3 at 3% were the two most effective treatments showing approximately 3 logs reduction on Day 0. In baby spinach, 3% Fulvic acid #1 reduced E. coli O157:H7 growth by 2.3 logs by day 3. Carvacrol, cinnamon oil, cinnamaldehyde and olive extract were highly effective against murine norovirus within six hours of exposure. CHICO Wash was quite effective, yielding >4.56–log reductions within 30 minutes of exposure. Oregano oil and carvacrol caused the viral capsid to expand in size and lose structural integrity. Allspice oil and clove bud oil appear to break down the virus capsid. Lemongrass oil and citral appear to coat the virus capsid and prevent the virus adsorbing to its host cell. Evaluation of novel antimicrobial agents revealed that at pH 7.0, red wine plus oregano oil and red wine plus Hidrox-12 and oregano oil exhibited the highest inhibition of E. coli O157:H7, S. enterica, Listeria monocytogenes, and Staphylococcus aureus. Also, a new polysaccharide was identified as a potential antimicrobial as it protected mice against Salmonella induced sepsis. Extension activities included statewide safety workshops in Arizona and Oklahoma, training seminars, development of online content (social media) and videos for effective dissemination of research results useful for stakeholders. Bilingual training videos were developed by the University of Arizona, covering the following topics; Hand Washing, Field Sanitation, Bodily Fluid Discharge and Field Etiquette. The Oklahoma extension team conducted training programs where the audience belonged to the Otoe-Missouria / Ponca tribes, Hmong people and the Otoe-Missouria tribes. They have established a website on fresh produce safety. Drs. Ravishankar, Jaroni, Bright and Nolte have also conducted presentations, demonstrations and seminars to growers, students and the general public. The PIs have also presented research results generated from this project at the Annual Meetings of the International Association for Food Protection and Institute of Food Technologists in 2013 in the form of posters to both academia and industry.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2013
Citation:
Macarisin, D., Patel, J., Bauchan, G., Giron, J. A. and Ravishankar, S. (2013). Effect of spinach cultivar and bacterial adherence factors on survival of Escherichia coli O157:H7 on spinach leaves. Journal of Food Protection. 76:1829-1837
Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. (2013). The antimicrobial effects of cinnamon leaf oil against multi-drug resistant Salmonella Newport on organic leafy greens. International Journal of Food Microbiology. 166:193-199.
Moore-Niebel, K., Gerber, C., Patel, J., Friedman, M., Jaroni, D. and Ravishankar, S. (2013). Antimicrobial activity of oregano oil against antibiotic-resistant Salmonella enterica on organic leafy greens at varying exposure times and storage temperatures. Food Microbiology. 34:123-129
- Type:
Journal Articles
Status:
Accepted
Year Published:
2012
Citation:
Jaroni, D. and Ravishankar, S. (2012). Bactericidal effects of roselle (Hibiscus sabdariffa) against foodborne pathogens in vitro and on romaine lettuce and alfalfa sprouts. Quality Assurance and Safety of Crops & Foods. 4:33-40.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2013
Citation:
Dev Kumar, G., Patel, J. and Ravishankar, S. 2013. Comparative evaluation of factors affecting Escherichia coli biofilms on organic leafy green wash water equipment surfaces. Poster presented at the 2013 Food Safety Conference, University of Arizona Food Safety Consortium, Tucson, AZ.
Tollerson, R., Dev Kumar, G. and Ravishankar, S. 2013. Role of environmental factors in the transfer of Salmonella enterica to iceberg lettuce leaves and biophotonic imaging of transfer sites. Poster presented at the 2013 Food Safety Conference, University of Arizona Food Safety Consortium, Tucson, AZ.
Rada, X., Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2013. Synergistic effects of combination treatments of essential oils and a plant extract against multi-drug resistant Salmonella enterica on organic leafy greens. Poster presented at the 2013 Food Safety Conference, University of Arizona Food Safety Consortium, Tucson, AZ.
Zhu, L., Friedman, M., Olson, C., McHugh, T., Jaroni, D. and Ravishankar, S. 2013. Use of edible films containing plant antimicrobials to inhibit Pseudomonas fluorescens in bagged organic lettuce. Poster presented at the International Association for Food Protection Annual Meeting 2013, Charlotte, NC.
Todd, J. L., Friedman, M., Patel, J., Jaroni, D. and Ravishankar, S. 2013. The antimicrobial effects of cinnamon oil against multi-drug resistant Salmonella Newport on organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2013, Chicago, IL.
Zhu, L., Olson, C., McHugh, T., Friedman, M., Jaroni, D. and Ravishankar, S. 2013. Apple, carrot, and hibiscus edible films containing plant antimicrobials inactivate Salmonella Newport in packaged organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2013, Chicago, IL.
Jayasundera, B. P. K., Denton,J. J., Ravishankar, S. and Jaroni, D. 2013. Antibacterial Effects of Olive, Apple and Grape Seed Extracts Against Escherichia coli O157:H7 on Organic Leafy Greens Stored at 4�C. Poster presented at the Annual Meeting of International Association of Food Protection, July 27-August 1, 2013, Charlotte, NC.
Jaroni, D., Jayasundera, B. P. K., Denton, J. and Ravishankar, S. 2013. Efficacy of Roselle (Hibiscus sabdariffa) Calyx Formulations against Escherichia coli O157:H7 on Bagged Organic Leafy Greens. Poster presented at the Annual Meeting of International Association of Food Protection, July 27-August 1, 2013, Charlotte, NC.
Denton, J., Ravishankar, S. and Jaroni, D. 2013. Antimicrobial Efficacy of Cinnamaldehyde, Carvacrol, and Citral against Escherichia coli O157:H7 on Organic Leafy Greens Held at 4�C. Poster presented at the Annual Meeting of International Association of Food Protection, July 27-August 1, 2013, Charlotte, NC.
Denton, J., Jayasundera, B. P. K., Ravishankar, S. and Jaroni, D. 2013. Antimicrobial Activity of Cinnamon, Oregano, and Lemongrass Essential Oils against Escherichia coli O157:H7 on Organic Leafy Greens Held at Refrigeration Temperatures. Poster presented at the Annual Meeting of International Association of Food Protection, July 27-August 1, 2013, Charlotte, NC.
Bevington, R., S. Ravishankar and K.D. Nolte. 2013. How To: Making an Informative Video from Start to Finish. Abstract published in the proceedings at the 2013 American Society for Horticultural Science Annual Meeting, Palm Desert, CA. URL: http://ashs.org/abstracts/2013/abstracts13/abstract_id_15934.html
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2012
Citation:
Reyna-Granados, J., Joens, L., Friedman, M. and Ravishankar, S. 2012. Concentration and time-dependent inactivation of Escherichia coli O157:H7 by plant extracts. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Zhu, L. and Ravishankar, S. 2012. Efficacy of sanitizers approved for organic use against Salmonella enterica on organic leafy greens. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Moore-Neibel, K.�, Patel., J., Friedman, M. and Ravishankar, S. 2012. Antimicrobial activity of oregano oil against Salmonella enterica on organic leafy greens at varying exposure times and storage temperatures. Poster presented at the International Association for Food Protection Annual Meeting 2012, Providence, RI.
Todd, J. L. and Ravishankar, S. 2012. Survival of Escherichia coli O157:H7 and Salmonella Newport in various commercial organic composts. Poster presented at the Institute of Food Technologists Annual Meeting 2012, Las Vegas, NV.
Rojas, D., Todd, J.L., Friedman, M., Jaroni, D. and Ravishankar, S. 2012. Antimicrobial activity of hibiscus tea and grapeseed and green tea extracts against antibiotic-resistant Salmonella Newport on organic leafy greens. Poster presented at the Institute of Food Technologists Annual Meeting 2012, Las Vegas, NV.
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2013
Citation:
Zhu, L., Olsen, C., McHugh, T., Friedman, M., Jaroni, D. and Ravishankar, S. (2013). Apple, carrot, and hibiscus edible films containing the plant antimicrobials carvacrol and cinnamaldehyde inactivate Salmonella Newport on organic leafy greens in sealed plastic bags. Journal of Food Science. In press.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2013
Citation:
Nolte, K.D. 2013. The Track and Scat Fresh Produce Safety Handbook for Southwest, Arizona. Abstract published in the proceedings at the 2013 American Society for Horticultural Science Annual Meeting, Palm Desert, CA. URL: http://ashs.org/abstracts/2013/abstracts13/abstract_id_15926.html
- Type:
Journal Articles
Status:
Accepted
Year Published:
2013
Citation:
Yossa, N., Patel, J., Millner P., Ravishankar S. and Lo, Y. M. (2013). Antimicrobial activity of plant essential oils against Escherichia coli O157:H7 and Salmonella on lettuce. Foodborne Pathogens and Disease. 10:87-96.
Friedman, M. (2013). Rice brans, rice bran oils, and rice hulls: compositions, food and industrial uses, and bioactivities in humans, animals, and cells. Journal of Agriculture and Food Chemistry. DOI: 10.1021/jf403635v. (Review). Includes antibiotic effects.
Friedman, M., Henika, P. R. and Levin, C. E. (2013). Bactericidal activities of health-promoting, food-derived powders against the foodborne pathogens Escherichia coli, Listeria monocytogenes, Salmonella enterica, and Staphylococcus aureus. Journal of Food Science. 78: M270-M275.
Friedman, M. and Rasooly, R. (2013). Review of the inhibition of biological activities of food-related selected toxins by natural compounds. Toxins. 5: 743-775. Covers fungal, microbial, and plant toxins.
Kim, S. P., Park, S. O., Lee, S. J., Nam, S. H. and Friedman, M. (2013). A polysaccharide isolated from the liquid culture of Lentinus edodes (Shiitake) mushroom mycelia containing black rice bran protects mice against a Salmonella lipopolysaccharide-induced endotoxemia. Journal of Agriculture and Food Chemistry. Online November 8. DOI: 10.10.21/jf40317k.
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Progress 09/01/11 to 08/31/12
Outputs
OUTPUTS: The potential for internalization and consequential phylloplane transfer of shiga-toxigenic Escherichia coli through the root system of hydroponically grown organic spinach (cultivars Waitiki and Space) was studied. Hydrophobicity and curli production ability of Salmonella Newport were tested along with the proclivity of organic leafy greens wash water in aiding S. enterica biofilm formation. Hydrophobicity of organic leafy green microflora isolated from wash water was measured. Survival of S. Newport and E. coli O157:H7 in 8 different commercial organic composts and that of S. Newport in 7 compost teas was determined. Iceberg and romaine lettuces were irrigated with compost teas with and without E. coli K12 to understand risks associated with compost tea application on organic leafy greens in organic plots at the Yuma Agricultural Center. Effect of 3 coring tool designs was evaluated for risk of contamination during coring of lettuce. Comparison was made with a current tool used commercially in reducing the risk of lettuce contamination in the field. Organic leafy green wash waters were analyzed for changes in pH, turbidity and microbial counts with reuse. Irrigation water and sediments were sampled from Maricopa and Yuma agricultural systems during and after growing season and from Yuma region after rainfall events. These samples were analyzed for Salmonella, and E. coli. These are also being processed for hepatitis A, noroviruses and other viruses that could serve as indicators of fecal contamination of water. Hydrogen peroxide, olive, grapeseed and apple extracts were tested against E. coli O157:H7 on organic romaine and iceberg lettuces and mature and baby spinaches and Pediococcus damnosus on baby spinach. Hibiscus tea, hydrogen peroxide, carvacrol (CAR), citral, and essential oils of oregano, cinnamon, and lemongrass were evaluated against E. coli O157:H7 on organic leafy greens. Antimicrobial properties of oregano, cinnamon and lemongrass essential oils, CAR, cinnamaldehyde (CIN), hibiscus tea, green tea and grapeseed extract were explored against S. Newport on organic leafy greens. Hibiscus concentrate, olive and apple extracts, oregano, cinnamon and lemongrass oils were tested against Pseudomonas fluorescens on organic iceberg lettuce. Dietary supplements, mushroom extracts and rice hull liquid smoke were tested against S. enterica. Antimicrobial activities of apple skin polyphenols against L. monocytogenes, E. coli O157:H7, and S. enterica and bactericidal activities of 10 nutraceuticals against E. coli O157:H7, S. enterica, L. monocytogenes, and Staphylococcus aureus were tested. Oregano oil, CAR, cinnamon oil, CIN, lemongrass oil, citral, allspice oil and olive extract were tested in vitro against murine norovirus. Three commercial organic sanitizers and calcium hypochlorite were tested on organic leafy greens inoculated with S. Newport. Antibacterial activities of apple-based edible films containing apple polyphenols were evaluated. Apple, carrot, and hibiscus-based edible films with CIN and CAR were tested for physico-chemical properties and ability to inactivate S. Newport and P. fluoresens in organic leafy green salad bags. PARTICIPANTS: Project Director: Sadhana Ravishankar, Ph.D. Dept. of Veterinary Science & Microbiology, University of Arizona (UA), Tucson, AZ. Staff in Dr. Ravishankar's group: a post-doctoral fellow, research technician, graduate and 5 undergraduate students. She oversees all microbiological work related to attachment and internalization of Salmonella enterica on/in leafy greens, and pre- and post-harvest interventions against S.enterica and Pseudomonas spp. on leafy greens. She is involved in education and outreach. The postdoctoral fellow in Dr. Ravishankar's lab received training in sample preparation and use of confocal scanning laser microscopy to study the attachment/internalization of bacteria on/in organic leafy greens from the USDA, ARS, BARC research facility in Beltsville, MD. Dr. Ravishankar has been involved with organic leafy green safety knowledge dispersion in classrooms, conferences, book fairs and symposiums. Co-Project Directors: Charles Gerba, Ph.D. & Kelly Bright, Ph.D. Dept. of Soil, Water & Environmental Sciences, UA. Staff in their group: 3 grad. students and one research technician. Dr. Gerba assists with data analysis and performs quantitative microbial risk assessment for test pathogens. Dr. Bright conducts field sampling and laboratory testing of irrigation water samples for bacterial and viral pathogens and evaluates post-harvest interventions against viruses. Jorge Fonseca, Ph.D. Vegetable & Post-harvest Specialist, Yuma Agricultural Center, UA-Yuma, AZ. Dr. Fonseca has 2 research technicians and plans to hire a post-doctoral fellow. Dr. Fonseca investigates attachment of non-pathogenic E.coli on harvesting equipment, and conducts assessment of compost teas/biostimulants and their effects on nonpathogenic E.coli in organic leafy green fields. He is involved in outreach. Kurt Nolte, Ph.D. Director, Yuma County Coop. Extension, Yuma, AZ. Dr. Nolte has a student worker to assist with extension and outreach. He is responsible for all extension activities of this project. Divya Jaroni, Ph.D. Department of Animal Science, Oklahoma State University. Dr. Jaroni has 1 graduate student and one postdoctoral fellow. Dr. Jaroni oversees all microbiological work related to interventions for E.coli O157:H7 and Lactococcus spp. She is involved in education and outreach along with Drs. McGlynn and Brandenberger. Dr. Jitendra Patel, Ph.D. Lead Scientist, Environmental Microbiology & Food Safety Laboratory, USDA-ARS, Beltsville, MD. Dr. Patel has a post-doctoral fellow and 1 research technician. Dr. Patel investigates attachment and internalization of E.coli O157:H7 on/in organic leafy greens. Mendel Friedman, Ph.D. USDA-ARS WRRC, Produce Safety & Microbiology Research, Albany, CA. Dr. Friedman is a consultant, providing expertise on plant antimicrobials. JV Farms, Yuma, AZ provided organic leafy greens. CreAgri Inc., Hayward, CA and Apple Poly, LLC., Morrill, NE provided antimicrobial plant extracts. The following companies provided organic sanitizers: GTX Technologies, Amarillo, TX; E3 Organics, Inc., CA; Summerdale, Inc., Verona, WI; ASC Agrecom, Inc., Tucson, AZ; Arch Chemicals, Inc., Charleston, TN; and BioSafe Systems, East Hartford, CT. TARGET AUDIENCES: Target audiences for these projects include: growers, producers, and processors of organic leafy greens; manufacturers of natural antimicrobials and organic sanitizers; and consumers of organic leafy greens. Leafy green producers and manufacturers of natural antimicrobials and organic sanitizers have been involved in this project by providing in-kind support to the project (see participants). They have been informed periodically on the results of this project and Drs Nolte and Ravishankar have been involved with creating online and mobile application versions of Fresh Organic Produce safety training, aimed towards meeting needs of commercial producers and direct marketers. Drs. Bright, Gerba and Ravishankar have had multiple interactions with growers and producers in the Yuma, AZ region. Discussion with growers and food safety managers (JV Farms, Dole Fresh Produce, Pasquinelli Produce Company, Fresh Express, Taylor Farms, Duncan Family Farms and Foxy Fresh Produce) were conducted to understand current issues associated with safety of organic leafy greens. Drs. Bright, Ravishankar and Gerba attended the Food Safety Summit at the Yuma Agricultural Center (attended by 65 industry personnel, researchers from University of Arizona, UA Cooperative Extension). Dr. Bright traveled to Yuma, AZ to meet growers and discuss current irrigation water sampling methods and Drs. Bright, Gerba and Ravishankar attended the Yuma Ag Summit that included a panel discussion entitled, "Quality Standards and Sampling of Irrigation Water for Food Safety". Drs. Bright, Gerba, Meer and Ravishankar attended a meeting with Dr. Michelle Russell from U.C. Davis and the President and Food Safety Managers of JV Farms in Yuma, AZ to discuss research needs and possible research collaborations with UC Davis scientists. Drs. Bright, Dev Kumar, Ravishankar and Nolte toured and visited Duncan Family Farms in Goodyear, AZ to discuss food safety concerns and best management practices. Drs. Bright, Ravishankar, Nolte and Gerba currently have ongoing research projects in the Yuma, AZ region. Many of these involve cooperation with stakeholders. Dr. Nolte was involved in conducting Arizona outreach food safety workshops with a goal to increase the applied knowledge in specific areas within the production of safe organically grown leafy greens. Dr. Ravishankar and Dr. Dev Kumar conducted a seminar for local high school students about approaches for antimicrobial applications on leafy greens and laboratory techniques involved. Demonstration of safe produce handling practices was performed at the University of Arizona book fair by Drs. Ravishankar and Dev Kumar. Dr. Ravishankar gave a seminar on natural antimicrobials and organic leafy greens to undergraduate microbiology majors. Drs. Ravishankar and Nolte conducted a seminar for students in the University of Arizona on organic leafy green contamination, issues for farmers and steps taken towards contamination mitigation. Dr. Jaroni spoke at workshops held in Opelousas, LA and focus groups in Baton Rouge, LA for fresh produce farmers. These activities were designed to increase food safety knowledge of organic fresh produce farmers in LA. PROJECT MODIFICATIONS: Dr. Divya Jaroni transferred from the Southern University Agricultural Research & Extension Center (SUAREC), Baton Rouge, Louisiana, to Oklahoma State University, Stillwater, Oklahoma. She is currently an Assistant professor in the Department of Animal Sciences at the Oklahoma State University, Stillwater, Oklahoma. She has included Dr. William McGlynn, Horticultural Products Processing Specialist, and Dr. Lynn Brandenberger, Professor, Department of Horticulture & Landscape Architecture at the Oklahoma State University to conduct the extension and outreach activities of this project. Project funds have been transferred to the Oklahoma State University for Dr. Jaroni's work in the project. No significant project modifications with regard to the goals of the project have been made.
Impacts
E. coli O157:H7 internalized into hydroponically grown intact spinach plants through root. Internalization was dependent on bacterial population, not curli production. Internalized pathogen reached the phylloplane. S. Newport strains had varying hydrophobicities and were curli positive. S. Newport produced biofilms in produce wash waters. Natural microbiota in wash water had varying hydrophobicities depending on produce. Composts 4 and 5 had reduced populations of both S. Newport and E. coli O157:H7 with no recovery of E. coli after day 3 in composts 1,2,3,4,5 and S. Newport after day 3 in compost 5. S. Newport reduction varied in the compost teas. Compost teas enhanced E. coli K12 attachment to lettuce leaves and increased their survival. Coring tool design significantly affected contamination risk of lettuce, with modified design reducing the risk significantly. Tool with angled core end resulted in 56% of E.coli positive lettuces, compared to 100% from original design. Reused wash waters had increased turbidity and decreased pH. Salmonella and E. coli were detected in 8.7% and 8% water samples and 16.8% and 13.6% of sediment samples, respectively, from Yuma. From Maricopa, Salmonella and E. coli were detected in 18.8% and 25% water samples and 37.5% and 6.3% sediment samples, respectively. Carvacrol (CAR) 0.3%, 0.5%, oregano 0.5%, cinnamon 0.5%, and lemongrass 0.5% oils reduced E. coli O157:H7 on organic baby spinach. On organic iceberg lettuce, 0.1, 0.3 % and 0.5% CAR, 0.3 and 0.5% citral, oregano, lemongrass and cinnamon essential oils reduced pathogen counts significantly at day 0. Hibiscus tea reduced E. coli O157:H7 by 2-4 logs on leafy greens. On day 0, 3% and 5% olive extracts reduced E. coli O157:H7 populations by 2 logs in adult spinach and 3% and 5% olive extracts reduced P. damnosus by upto 4 logs in baby spinach. Salmonella reduction by lemongrass oil directly correlated with exposure time and concentration. Oregano oil proved effective against S. Newport at all levels. Concentration dependent reductions (0.7-2.3 log CFU/g, 0.4-2.0 log CFU/g, and 0.2-1.6 log CFU/g, respectively) were observed in S. Newport on organic leafy greens by hibiscus tea, grapeseed and green tea extracts. CAR at 0.5% showed no survivors of Salmonella by day 1 on organic leafy greens. Cinnamon oil reduced P. fluorescens below detection levels and lemongrass oil by 1 log at day 1 on iceberg. Olive pomace, olive powder and oregano leaves were active against E. coli O157:H7, S. enterica, L. monocytogenes, and S. aureus. Rice hull liquid smoke had antibacterial activity in vitro. Mushroom extracts and rice hull liquid smoke improved recovery in mice from Salmonella infection. CAR, cinnamon oil, cinnamaldehyde, olive extract were effective against murine norovirus showing upto 4 log reductions within 6 h. CHICO wash caused up to 2.5 log Salmonella reduction in 3 days in lettuces. Polyphenol containing apple edible films were highly effective against L. monocytogenes. Edible films with carvacrol reduced Salmonella by 5 logs at day 0 and were also effective against P. fluorescens on organic leafy greens. The pH, color and thickness of the edible films varied.
Publications
- 1) Nolte K. D., C. A. Sanchez, and J. M. Fonseca. 2011. Assessing the Culture of Fresh Produce Safety within a Leafy Green Producing Community. Journal of Extension. 49(6), Article Number 6IAW4. 2) Nolte K. D., and S. R. Bealmear. 2011. Fresh Produce Safety Includes Small Acreages and Home Gardens. Backyards and Beyond. 5(2):4-5. 3) Fonseca J. M., S. D. Fallon, C. A. Sanchez, and K. D. Nolte. 2011. Escherichia coli survival in lettuce fields following its introduction through different irrigation systems. Journal of Applied Microbiology. 110(4):893-902. 4) Moore-Neibel, K., C. Gerber, J. Patel, M. Friedman, and S. Ravishankar. 2012. Antimicrobial activity of lemongrass oil against Salmonella enterica on organic leafy greens. Journal of Applied Microbiology. 112:485-492. 5) Kim, S. P., M. Y. Kang, J. C. Park, S. H. Nam, and M. Friedman. 2012. Rice Hull Smoke Extract Inactivates Salmonella Typhimurium in Laboratory Media and Protects Infected Mice against Mortality. Journal of Food Science. 77:M80-M85. 6) Kim, S. P., E. Moon, S. H. Nam, and M. Friedman. 2012. Hericium erinaceus Mushroom Extracts Protect Infected Mice against Salmonella Typhimurium-Induced Liver Damage and Mortality by Stimulation of Innate Immune Cells. Journal of Agricultural and Food Chemistry. 60:5590-5596. 7) Kim, S. P., J. Y. Yang, M. Y. Kang, J. C. Park, S. H. Nam, and M. Friedman. 2011. Composition of Liquid Rice Hull Smoke and Anti-Inflammatory Effects in Mice. Journal of Agricultural and Food Chemistry. 59:4570-4581. Outreach Presentations: Friedman, M. Plant Food Constituents that Inactivate Pathogens and Reduce Formation of Heterocyclic Amines. Northern California Chapter, Genetic and Environmental Toxicology Association Symposium Food Safety and Health in a Global Setting: The Good, the Bad, and the Ugly, Oakland, California. 6/7/2012. Ravishankar, S. Organically Grown Leafy Greens and the Control of Foodborne Pathogens Using Natural Antimicrobials. Fresh Produce Safety: Research Update. Yuma, AZ. 12/16/2011. Ravishankar, S. Control of Foodborne Pathogenic Bacteria Using Natural Antimicrobials. Seminar presented at the Food Safety Retreat, Tucson, AZ. 11/4/2011. Ravishankar, S. Food Safety & Control of Foodborne Pathogens Using Natural Antimicrobials. Seminar to Microbiology Club, Dept. of Vet. Sci. & Microbiology, University of Arizona. 3/19/2012. Bright, K. Assessing irrigation water quality. Fresh Produce Safety: Research Update. Yuma, AZ. 12/16/2011. Gerba, C. Microbial Risk Assessment: A tool for determining Whats important and Whats not. Fresh Produce Safety: Research Update. Yuma, AZ. 12/16/2011. Fonseca, J and Nolte, K. Compost teas and coring tools: Research Update. Fresh Produce Safety: Research Update. Yuma, AZ. 12/16/2011. Jaroni, D. Use of natural antimicrobials to reduce foodborne pathogens in leafy greens. Workshop for Fresh Produce Growers in Louisiana. St. Landry Parish Extension Office, Opelousas, LA. 10/13/2011. Jaroni, D. Use of natural antimicrobials to reduce foodborne pathogens in leafy greens. Workshop for Fresh Produce Growers in Louisiana. St. Landry Parish Extension Office, Opelousas, LA. 10/13/2011.
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Attachment of Escherichia coli O157:H7 isolates to organic romaine and iceberg lettuce and green cabbage was studied. Curli expression, hydrophobicity, and biofilm formation by these strains were evaluated as potential virulence factors. Persistence of wild type and curli and celluose mutant E.coli O157:H7 strains on 4 organic spinach cultivars (Lazio, Waitiki, Emilia, and Space) for 14 days was studied. Effect of natural hormones (growth regulators) on the ability of E.coli to form biofilms and have better survival opportunities in field conditions was investigated. Irrigation water sampling from Yuma, AZ; 15 samples/month are collected and analyzed for indicator organisms, quality parameters, and E.coli O157:H7, Salmonella, hepatitis A virus, and norovirus surveillance. Presumptive positives are analyzed for confirmation. Romaine and iceberg lettuce were planted in semi-commercial fields in Yuma, AZ. One field was planted in October and harvested in January, the other in December and harvested in March, respectively. Both fields are part of the Organic Parcel of the Yuma Agricultural Center managed by Dr.Fonseca, and are used for quality and microbial risk tests of foliar application of organic biostimulants and compost teas. Parallel to first phase of these trials, the survival of E.coli in different compost teas and biostimulants was studied in the lab and in the field being incorporated through foliar application using different spray systems (providing different solution drop sizes). Studies were conducted to determine the risk impact of using a contaminated tool to core iceberg lettuce destined to the fresh-cut industry. Efficacy of low levels of chlorine washes to prevent cross-contamination from field-contaminated lettuce to non-contaminated lettuce was evaluated. Plant compounds (green tea and olive extracts, cinnamaldehyde, citral, and oils of allspice, clove. lemongrass, cinnamon) were tested in vitro against E.coli. Cinnamaldehyde, carvacrol and grapeseed extracts were tested for their activity in vitro against S.typhimurium and E.coli O157:H7. Effects of hibiscus concentrate and tea, olive extract, carvacrol, cinnamldehyde, citral and oils of cinnamon, clovebud, allspice and lemongrass were evaluated on MS-2 bacteriophage. The bactericidal effects of aqueous extracts of roselle calyces and leaves against E.coli O157:H7, Salmonella enterica and Listeria monocytogenes were evaluated. Roselle calyx concentrate and tea were also tested against E.coli O157:H7 on romaine lettuce and Salmonella on sprouts. The antimicrobial effects of plant extracts (olive, apple, 1-5%; hibiscus, 10-30%) and five organic sanitizers (fulvic acid-based, 1-3%; citric acid-based, 0.05%) against S.Newport on organic romaine and iceberg lettuce, and adult and baby spinach stored at 4C for 3 days were investigated. Plant extracts were also tested against background flora of all 4 organic leafy greens. Effects of carvacrol and cinnmaldehyde (1.5 and 3%) containing edible apple, carrot and hibiscus films against S.Newport in bagged iceberg lettuce, baby spinach and spring mix, and against E.coli O157:H7 in bagged spinach stored at 4C for 7 days were evaluated. PARTICIPANTS: Project Director: Sadhana Ravishankar, Ph.D. Dept. of Veterinary Science & Microbiology, University of Arizona, Tucson, AZ. Staff in Dr. Ravishankar's group involved in this project include: 1 post-doctoral fellow, 1 technician, 1 grad. Student and 2 undergrad. students. She oversees all microbiological work related to attachment and internalization of Salmonella enterica on/in leafy greens, and pre- and post-harvest interventions against S.enterica and Pseudomonas spp. on leafy greens. She is involved in education and outreach. Co-Project Directors: Charles Gerba, Ph.D. & Kelly Bright, Ph.D. Dept. of Soil, Water & Environmental Sciences, University of Arizona, Tucson, AZ. Staff in their group involved in this project include: 3 grad. students and one research technician. Dr. Gerba assists with data analysis and performs quantitative microbial risk assessment for test pathogens. Dr. Bright conducts field sampling and laboratory testing of irrigation water samples for bacterial and viral pathogens, and evaluates post-harvest interventions against hepatitis A and murine norovirus. Jorge Fonseca, Ph.D. Vegetable & Post-harvest Specialist. Yuma Agricultural Center, University of Arizona-Yuma, AZ. Dr. Fonseca has 2 research technicians involved in this project and plans to hire a post-doctoral fellow. Dr. Fonseca investigates the attachment of non-pathogenic Escherichia coli on harvesting equipment, and conducts assessment of compost teas/biostimulants and their effects on non pathogenic E.coli in organic leafy green fields. He is involved in outreach activities. Kurt Nolte, Ph.D. Director, Yuma County Coop. Extension, Yuma, AZ. Dr. Nolte expects to hire a grad. student this summer to assist with extension and outreach. He is responsible for all extension activities of this project. Divya Jaroni, Ph.D. Southern University Agricultural Research & Extension Center (SUAREC), Baton Rouge, LA. Dr. Jaroni has 1 grad. student involved in the project and plans to hire a post- doctoral fellow. Dr. Jaroni oversees all microbiological work related to interventions for E.coli O157:H7 and Lactococcus spp. She is involved in education and outreach. Jitendra Patel, Ph.D. Lead Scientist, Environmental Microbiology & Food Safety Laboratory, USDA-ARS, Beltsville, MD. Dr. Patel has a post-doctoral fellow and 1 research technician involved in the project. Dr. Patel investigates the attachment and internalization of E.coli O157:H7 on/in organic leafy greens. Mendel Friedman, Ph.D. USDA-ARS Western Regional Research Center, Produce Safety & Microbiology Research, Albany, CA. Dr. Friedman is a consultant, providing expertise on plant antimicrobials and is involved in education and outreach. JV Farms, Yuma, AZ provides in-kind support in the form of organic leafy greens. CreAgri Inc., Hayward, CA and Apple Poly, LLC., Morrill, NE provide in-kind support in the form of antimicrobial plant extracts. The following companies provide in-kind support in the form of organic sanitizers. GTX Technologies, Amarillo, TX.; E3 Organics, Inc., CA; Summerdale, Inc., Verona, WI.; ASC Agrecom, Inc., Tucson, AZ; Arch Chemicals, Inc., Charleston, TN; and BioSafe Systems, East Hartford, CT. TARGET AUDIENCES: The target audiences for this project include: growers, producers, and processors of organic leafy greens; manufacturers of natural antimicrobials and organic sanitizers; and consumers of organic leafy greens. Leafy green producers and manufacturers of natural antimicrobials and organic sanitizers have been involved in this project by providing in-kind support to the project (see participants). They have been informed periodically on the results of this project. Drs. Ravishankar, Gerba and Bright attended the Arizona Produce Research Priorities meeting organized by the Center for Produce Safety, September 2010 to discuss our fresh produce/leafy greens research. They also visited Yuma in December 2010 to meet leafy greens producers, discuss their research needs and provide an introduction to the organic leafy greens grant. Dr. Ravishankar presented an overview of the grant and some results at the Food Safety Summit in Yuma, January 2011, attended by 65 fresh produce industry professionals. In March 2011, Drs. Ravishankar, Bright, and Jaroni traveled to Yuma, Arizona to attend the Southwest Agricultural Summit. They along with Drs. Nolte and Fonseca discussed this project with agricultural professionals attending the meeting. In April 2011, Drs. Ravishankar, Bright, Gerba, and Meer traveled to Yuma to meet with growers and University of California, Davis researchers, to discuss the research needs of the producers and to develop future plans, including additional collaborations between the growers and researchers at the University of Arizona, Tucson, AZ, and the University of California, Davis, CA. In microbiology classes, at the University of Arizona, for undergraduate and graduate students Dr. Ravishankar has incorporated laboratory exercises to isolate the background microflora, spoilage and pathogenic microorganisms from organic leafy greens. In collaboration with the Joint Institute of Food Safety and Applied Nutrition, Dr. Fonseca offered 2 courses on Good Agricultural Practices at Costa Rica and Mexico for produce exported to the U.S. He plans to offer an on-line course this summer on post-harvest physiology, technology and produce safety for undergrad./grad. students and industry professionals at the University of Arizona. Dr. Ravishankar will offer a course on food microbiology and biotechnology in spring 2012 which will cover organic leafy greens safety and quality aspects. Information generated from this project was/will be used in all these courses. All post-doctoral fellows, technicians and students hired to work on this project have received training on good laboratory practices, including pathogen safety precautions, media preparation, product sampling, field sampling and other laboratory activities related to the project. Dr. Meer received training in sample preparation and use of confocal scanning laser microscopy to study the attachment/internalization of bacteria on/in organic leafy greens from the USDA, ARS, BARC research facility in Beltsville, MD. Over the past year numerous media outlets have provided coverage/stories on the organic leafy greens research project (see publication list) to reach a wide variety of audience. PROJECT MODIFICATIONS: We have not made any significant project modifications with regard to the goals of the project. However, we intend to request a no-cost extension for the first year of this project since there was a significant delay in the transfer of funds to the subcontracts, and the process of hiring technical assistance (e.g., graduate and undergraduate students, postdoctoral fellows, research technicians, etc.) took longer than anticipated.
Impacts
Rapid attachment of E.coli O157:H7 (3.5-4 logs) was seen on intact and cut leafy green surfaces within 5 min. Attachment to intact and cut cabbage increased with time. Cut surfaces had greater attachment than intact surfaces. Strains that expressed curli and were more hydrophobic, attached at higher numbers compared to weakly or non-expressing strains. Attachment strength may be associated with production of surface appendages and subsequent binding to produce. Attachment strength of E.coli O157:H7 was higher on romaine lettuce than cabbage surfaces. Wild type and cellulose deficient strains persisted better than curli deficient and curli and cellulose deficient mutants on spinach cultivars, with Waitiki cultivar supporting higher bacterial levels. In vitro studies showed that growth regulators may interfere with bacterial biofilm formation. Presumptive positives for E.coli O157:H7 were identified in 6 analyzed irrigation water samples from Yuma and will be confirmed. Salmonella was detected in 2 sediment samples. Generic E.coli (<1-27.2 MPN/100ml) and coliforms (131.4->2419.6 MPN/100 ml) were identified. The pH, conductivity, total dissolved solids in irrigation water were 7.2-8.5, 1.0-1.2 mS/cm, 0.5-0.6 g/L, respectively. Most of the biostimulants and compost teas tested had pH levels too low for bacterial survival, one product with a higher pH, showed bacterial survival of 1 week. No difference in leafy green quality due to foliar application of organic products was seen. Different spray applicators showed that big drops held higher bacterial numbers up to 24 h; however, no organisms were detected after day 10. We found that a contaminated tool may contaminate as many as 75 lettuce heads. Most contamination was in the welding area. Chlorine (1.3 ppm free chlorine) washes prevented cross-contamination from field-contaminated lettuce. In vitro studies with plant antimicrobials showed no survivors for E.coli and S.Typhimurium with 0.2% cinnamaldehyde (CIN) at 1 min and 0.05% carvacrol (CAR) at 3 min. Reductions observed for E.coli in vitro tests; >5.7 logs with 0.2% CIN at 30 min, 6.1 logs with 1% allspice oil at 10 min, 5.2 logs with 1% clove oil at 25 min, >6 logs with 1.5% cinnamon oil at 30 min, 5 logs with 0.05% citral at 15 min, 4.7 logs with 2.5% olive extract at 30 min. Reductions for MS2 bacteriophage were >4 logs with olive extract, CIN, cinnamon oil; >3 logs with hibiscus tea, CAR; about 2 logs with citral, clove oil at 24h. No survivors of E.coli O157:H7 or Salmonella were detected in 24h in vitro and on lettuce and sprouts, and L.monocytogenes in 48h with hibiscus extracts. Olive, apple, hibiscus extracts and hydrogen peroxide showed 1-3 log reductions of S.Newport/background on organic leafy greens. The fulvic and citric acid based sanitizers showed 2-3 log reductions of S.Newport on leafy greens by day 3. Apple, carrot, hibiscus films (3% CAR) were very effective with immediate reductions (at least 5 log) of S.Newport on iceberg lettuce. Reductions of 3.5-4 logs were seen on spring mix and baby spinach with 3% CAR apple, hibiscus films. Apple films (3% CAR) showed about 3 logs reduction of E.coli O157:H7 in bagged baby spinach.
Publications
- The New Southwest, Jan. 15-Feb. 15, 2011, page 20. http://thenewsouthwest.com/2011/improving-safety-quality-of-organic-l eafy-greens/
- The college of Agriculture and Life Sciences Compendium, Spring 2011, Vol. 31, Issue 1. http://www.cals.arizona.edu/alumni/pdfs/FINALCompendiumSP2011.pdf
- Southern University Systems Magazine, "Ovations", Spring 2011, Page 32. http://issuu.com/susystempublications/docs/2011_spring_ovations
- JOURNAL ARTICLES: Patel, J., Sharma, M. and Ravishankar, S. 2011. Effect of curli expression and hydrophobicity of Escherichia coli O157:H7 on attachment to fresh produce surfaces, Journal of Applied Microbiology, 110: 737-745.
- Moore, K., Patel, J., Jaroni, D., Friedman, M. and Ravishankar, S. 2011. Antimicrobial Activity of Apple, Hibiscus, Olive, and Hydrogen Peroxide Formulations against Salmonella enterica on Organic Leafy Greens. Journal of Food Protection (accepted).
- Jaroni, D. and Ravishankar, S. 2011. Bactericidal effects of roselle (Hibiscus sabdariffa) against foodborne pathogens in vitro and on romaine lettuce and alfalfa sprouts. Quality Assurance and Safety of Crops & Foods (accepted).
- Du, W.-X., Olsen, C. W., Avena-Bustillos, R. J., Friedman, M. and McHugh, T. H. 2011. Physical and antibacterial properties of edible films formulated with apple skin polyphenols. Journal of Food Science, 76: 149-155.
- Sirk, T. W., Friedman, M. and Brown, E. F. 2011. Molecular binding of black tea theaflavins to biological membranes: Relationship to bioactivities. Journal of Agricultural and Food Chemistry, 59: 3780-3787.
- ABSTRACTS: Moore, K., Patel, J., Jaroni, D., Friedman, M. and Ravishankar, S. 2011. Antimicrobial Activity of Apple, Hibiscus, Olive, and Hydrogen Peroxide Formulations against Salmonella enterica on Organic Leafy Greens. Abstract for presentation at the International Association for Food Protection (IAFP) Annual Meeting, Milwaukee, Wisconsin.
- Macarisin, D., Bauchan, G., Giron, J. and Patel, J. 2011. Role of Curli Expression by Escherichia coli O157:H7 on the Cells Ability to Attach to Spinach. Abstract for presentation at the IAFP Annual Meeting, Milwaukee, Wisconsin.
- Du, W.-X., Olsen, C. W., Avena-Bustillos, R. J., Friedman, M. and McHugh, T. H. 2010. Physical and antibacterial properties of edible films formulated with apple skin polyphenolics. Abstract presented at the Institute of Food Technologists Annual Meeting, Chicago, Illinois
- Du, W.-X., Avena-Bustillos, R. J., Friedman, M. and McHugh, T. H. 2011. Antimicrobial volatile essential oils in edible films and pouches for produce safety. Abstract presented at the fifth International Functional Food Symposium, Hong Kong.
- Friedman, M. and Levin, C. E. 2010. Review of antimicrobial activities of plant-derived edible compounds against susceptible and antibiotic-resistant foodborne pathogens. Abstract presented at the National Meeting of the American Chemical Society, San Francisco.
- NEWSLETTERS/EXTENSION PUBLICATIONS: Organic Leafy Greens Research awarded by USDA-NIFA-OREI was featured in the following: UA now and UA news.org Nov. 2011. http://www.uanews.org/node/35363
- Channel 13 KOLD local Tucson Nov. 2011. http://www.kold.com/Global/story.aspS=13515749
- Bites (the worldwide food safety news listserv) Nov. 2011. http://bites.ksu.edu/news/145094/10/11/14/arizona-improving-safety-an d-quality-organic-leafy-greens
- Food Chemical News. Nov. 19, 2010. http://www.foodchemicalnews.com
- Growing produce.com Nov. 11, 2010. http://www.growingproduce.com/news/storyid=4621
- Fresh Cut Magazine, Jan. 2011. Page 12. http://freshcut.com/index.php/magazine/issue/january-2011
- California Farmer, Jan. 2011, page 13. http://www.FarmProgress.com
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