Progress 01/22/10 to 09/30/12
Outputs
OUTPUTS: Clostridium perfringens (CP), Listeria monocytogenes (LM), and Salmonella Typhimurium (ST) were inoculated into bacon brine formulations: natural nitrate with (NNSC) and without starter culture (NN), natural nitrite with a natural cure accelerator (NNNCA), and conventional cure (CC). NN inhibited the growth of LM; NN, NNNCA, and CC control were not different from each other; NN, NNSC, and CC brine reduced all pathogens (24 hours at 35C). Whole broilers from farmers' markets (FM) and supermarkets were evaluated for hygiene indicators, Campylobacter, and Salmonella. 28% and 90% of broilers from FM, 20% and 28% of supermarket organic, and 8% and 52% of supermarket broilers, were positive for Salmonella and Campylobacter, respectively. FM vendors also exhibited critical gaps in food safety knowledge and practices. Shiga toxin-producing E. coli (STEC) O157, O145, O121, O113, O111, O103, O45, and O26 were isolated from carcass swabs, hide swabs, ground beef, and environmental samples from small and very small beef processing plants using a multiplex polymerase chain reaction assay. 35.0% carcass samples, 56.6% environmental samples, 85.2% hide samples, and 17.0% ground beef samples tested positive for STEC. 0.044% of the carcass samples, 0.074% of the environmental samples, 0% of the hide samples, and 0% ground beef samples tested positive for the STEC. A counter top (CT), food safety training was developed for Spanish-speaking employees of carnicerias. to increase retention of food safety knowledge, improve attitude, alter behavior, and increase skills. Twenty carnicerias were assigned: control-no training or CT-training. Assessments were given pre-training, post-training and delayed-post training. ANCOVA for knowledge and skill results demonstrated a significant difference in post-test and delayed post-test scores when controlling for the pre-test scores of the CT-trained group, as compared to the control group. Ground beef was experimentally inoculated with 6 log10 CFU/gram of STEC (see above serogroups) formed into patties and subjected to 4 high pressure processing (HPP) cycles (one cycle = 400 MPa for 1 minute). HPP resulted in a 3 to 4 log10 CFU/gram reduction of the STEC in the ground beef patties. Uninoculated ground beef patties were HPP treated as described above and cooked to 158F. Seventy participants, 79% female and 21%, male compared HPP-treated ground beef to untreated ground beef for overall liking, texture, juiciness, and flavor. Untreated ground beef patties were liked by consumers more than HPP-treated beef. When evaluated for texture and juiciness, HPP-treated products appeared to be slightly chewier and less juicy. Water samples from surface water sources used for irrigation in Southeastern Pennsylvania were collected from 39 farms over a two year period and analyzed for microbes, turbidity, conductivity, pH, dissolved oxygen, air and water temperature, sampling day and accumulated precipitation levels, algae growth, water movement, and sunlight. Samples showed high variability both between and within sampling sites. During the second year of the survey, Salmonella was recovered from 5 water samples. PARTICIPANTS: Drs. Catherine Cutter, Stephanie Doores, Ed Dudley, Lynne Brown, and Luke LaBorde from the Department of Food Science contributed to the project and information provided in this final report. Drs. Ken Kephart, Ed Mills and Chris Raines from Department of Animal Science, Dr. Chobi DebRoy from Veterinary and Biomedical Sciences, Dr. Nancy Ostiguy from Department of Entomology, and Drs. Rama Radhakrishna and Ed Yoder from Department of Agricultural Extension also contributed to the research project. TARGET AUDIENCES: The target audience for this research is the food processing industry, food scientists, academia and government researchers, and general public. Research findings were presented at national and international meetings attended by food safety specialists, food scientists, food microbiologists, and industry personnel. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Following completion of the brine study, additional experiments will determine if similar reductions are obtained in a bacon/meat system.The farmers' market study demonstrates that poultry purchased from farmers' markets in Pennsylvania were more likely to be contaminated with Salmonella spp. and Campylobacter spp., as compared to conventionally-processed poultry sold at supermarkets as well as the need to develop food safety training for poultry vendors at farmers' markets in order to improve the safety of these products for public consumption. Small and very small beef processors may be a source of the various STEC. The information from STEC study may be of interest to regulatory officials, researchers, public health personnel, and the beef industry that are interested in the presence of these pathogens in the beef supply. The findings of the counter-top training demonstrated that food safety attitude and behavior changes were not significant, although numerical improvements were observed. A "counter-top" food safety training program could impact positively on retail establishments to improve food safety practices of their low literacy, Spanish-speaking, employees. Results suggest that HPP may be a suitable intervention for reducing the "big-6" STEC in ground beef products. However, HPP treatments may affect color and eating quality of ground beef products. Further research studies to determine optimal HPP treatments that effectively reduce STEC in ground beef, yet minimize changes to sensory attributes, are warranted. Results from the sensory studies suggest some sensory attributes of ground beef may be impacted negatively by the HPP treatment and that consumers could detect differences. However, it is important to note that sensory evaluation was conducted on "naked" ground beef patties, and not served with buns, seasonings, or condiments. Current standards based on microbial indicator organisms were not shown to be strong predictors of water safety.
Publications
- Cutter, C. N. 2012. Local Foods: Food Safety Risks and Benefits symposium; Microbiological Assessment of Poultry Sold in Farmers' Markets. International Association of Food Protection Annual meeting. Providence, RI, July 22-25, 2012. https://iafp.confex.com/iafp/2012/webprogram/Session1118.html.
- Richard, A. E., J. L. Brown, S. Nieto-Montenegro, C. N. Cutter, R. B. Radhakrishna, and E. P. Yoder. 2011. Development and implementation of a counter-top training program to increase retention of food safety knowledge, alter behavior, improve attitude, and increase skills of Spanish-speaking retail employees. Institute of Food Technologists Annual Meeting. New Orleans, LA. June 11-14, 2011. (Abstract #040-01).
- Richard, A., L. Brown, R. Radhakrishna, E. P. Yoder, S. Nieto-Montenegro, and C. Cutter. 2011. Mystery shopping as a way to collect needs assessment data for food safety training purposes. Presentation 611. Evaluation 2011: Values and Valuing in Evaluation Anaheim, CA. November 2-5, 2011. page 104.
- Cutter, C. N. and C. R. Raines. 2011. High Pressure Processing: Food Safetys Next Big Squeeze. 2011 American Meat Science Association Reciprocal Meat Conference, Kansas State University, Manhattan, KS, June 19-21, 2011. http://www.meatscience.org/Page.aspxID=7497.
- Svoboda, A. M., C. DebRoy, E. W. Dudley, E. W. Mills, and C. N. Cutter. 2012. Presence of Shiga-toxin Producing Escherichia coli in Small and Very Small Beef Processing Plants and Resulting Beef Products Detected by a Multiplex Polymerase Chain Reaction Assay. #P3-16.International Association of Food Protection Annual meeting. Providence, RI, July 22-25, 2012. https://iafp.confex.com/iafp/2012/webprogram/Paper1600.html.
- Cutter, C. N. 2012. Incidence of Shiga-Toxin Producing Escherichia coli in Small and Very Small Beef Processing Plants and Resulting Beef Products Detected by a Multiplex Polymerase Chain Reaction. 2012 IFT Annual Meeting. Las Vegas NV. June 25-28, 2012. Assay. #061-03.
- Gipe, A., E. Mills, K. Kephart, C. Raines, and C. Cutter. 2012. Inhibition of foodborne pathogens in no-nitrate or nitrite-added bacon brine formulations. Poster and oral presentation, L-31. International Congress of Meat Science and Technology (ICOMST), Montreal, Canada; August 12-17, 2012. http://www.icomst2012.ca/wp-content/uploads/2012/08/ICoMST2012_Progra m-FINAL.pdf.
- Yoder, S. F., E. W. Mills, W. R. Henning, N. Ostiguy, S. Doores, and C. N. Cutter. 2012. Investigation of antimicrobial rinses suitable for very small meat establishments to reduce pathogens on beef surfaces. Journal of Food Protection 75:14-21.
- Cutter, C. N., R. N. Senevirathne, V. P. Chang, R. B. Cutaia, K. A. Fabrizio, A. M. Geiger, A. M. Valadez, and S. F. Yoder. 2012. Major microbiological hazards associated with packaged fresh and processed meat and poultry. In Meat, Poultry and Seafood Packaging, J. P. Kerry (ed). Woodhead Publishing, Cambridge, England. pp.3-58.
- Richard, A. E. 2011. Development and implementation of a counter-top training program to increase retention of food safety knowledge, alter behavior, improve attitude, and increase skills of Spanish-speaking retail employees. M.S. Thesis. Pennsylvania State University, University Park, PA. 165 pages. https://etda.libraries.psu.edu/paper/11648/.
- O'Patchen, R. 2011. Fate of Listeria monocytogenes and Salmonella spp. in Sphagnum Peat-Based Casing Soils and Pre-Harvest Food Safety Interventions to Reduce Contamination of Fresh Mushrooms. M.S. Thesis. Pennsylvania State University, University Park, PA. 106 pages. https://etda.libraries.psu.edu/paper/11978/.
- Scheinberg, J. A. August 2012. A Microbiological Comparison of Poultry Products Obtained From Farmers' Markets and Supermarkets in Pennsylvania. M.S. Thesis. Pennsylvania State University, University Park, PA. 170 pages. https://etda.libraries.psu.edu/paper/15223/.
- Svoboda, A. M. August 2012. Presence of Shiga toxin-producing Escherichia coli O-groups in small and very small beef processing plants and resulting beef products detected by a multiplex polymerase chain reaction assay. M.S. Thesis. Pennsylvania State University, University Park, PA. 172 pages. https://etda.libraries.psu.edu/paper/15107/.
- Valderrama, W. B. August 2012. Effect of environmental factors on biofilm formation by Listeria monocytogenes. Ph.D Dissertation. Pennsylvania State University, University Park, PA. 275 pages. https://etda.libraries.psu.edu/paper/15489/.
- Cutter, C., D. Depasquale, J. Hayes, C. Raines, and R. Seniviranthe. 2012. Meat Science Review: HPP, ground beef, and the "Big 6" STEC. National Provisioner. Published: July 5, 2012. http://www.provisioneronline.com/articles/98113-meat-science-review-- hpp--ground-beef-and-the--big-6--stec.
- Draper, A. A., S. Doores, H. Gourama, and L. F. LaBorde. 2012. Microbial Survey of Pennsylvania Surface Waters Used for Irrigation of Fruit and Vegetable Crops. Research poster. International Association for Food Protection annual meeting. Providence, Rhode Island. July 22-23, 2012. Paper #2677. https://iafp.confex.com/iafp/2012/webprogram/Paper2677.html.
- Valderrama, W. B. and C. N. Cutter. 2012. An ecological perspective of Listeria monocytogenes biofilms in food processing facilities. Current Reviews in Food Science and Nutrition. http://www.tandfonline.com/doi/full/10.1080/10408398.2011.561378.
- Scheinberg, J. A., S. Doores, R. Radhakrishna, and C. N. Cutter. 2012. A Microbiological Comparison of Poultry Products Obtained from Farmers' Markets and Supermarkets in Pennsylvania. #T5-06. International Association of Food Protection annual meeting. Providence, RI, July 22-25, 2012. https://iafp.confex.com/iafp/2012/webprogram/Paper1919.html.
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: The objectives of this project are to develop or improve methods for the detection, control, or elimination of pathogens in pre-and post-harvest environments, including meat and poultry, dairy foods, and fruits and vegetables. First, a multiplex PCR (mPCR) assay was developed for the detection of 6 pathogenic E. coli (O26, O45, O103, O111, O113, O121, O145, and O157) and validated in beef environments and products (trim, ground, carcass swabs). In another project, the application of an antimicrobial film, made from pullulan and several other components, including Sakacin A, was found to control Listeria monocytogenes on a ready-to-eat poultry product. Another project addressed the attachment of Listeria monocytogenes and the ability to form biofilms on food surfaces when subjected to a combination of several factors, including water activity, pH, temperature, nutrient availability, and bacterial load. These results may provide understanding of L. monocytogenes ecology for future research and ultimately, could provide practical suggestions for the improvement of L. monocytogenes environmental sampling plans in food processing establishments. Inactivation kinetics of Escherichia coli and L. monocytogenes in phosphate buffer and milk upon ultrasound treatment were determined. Experiments were designed to assess the effect of growth phase of bacteria on inactivation and to investigate the effect of individual milk components such as lactose, casein, and whey proteins, and their interactions on sonoprotection of E. coli and L. monocytogenes and visualize changes in their structures upon sonication using scanning electron microscopy. Data also are being collected that that will contribute to the development of a simple, economical test kit that can be used by produce growers to submit surface water samples for microbial testing to determine optimal holding conditions to minimize microbial changes and design a suitable package that will allow overnight, or longer, shipping of surface water samples to remote testing laboratories. Additional research has revealed that Listeria monocytogenes and Salmonella spp. can be recovered from whole and sliced fresh mushrooms. Along these lines, the fate of Listeria monocytogenes and Salmonella spp. was determined in sphagnum peat-based casing soils as an intervention to reduce contamination of fresh mushrooms. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Research has demonstrated the effectiveness of the mPCR assay for detecting several serogroups in beef products. The findings from this research will assist processors with developing control measures to effectively reduce or eliminate the pathogens in their plant environments and/or beef products. In another experiment, the effects of compounds on film properties were investigated and the characteristics determined. When an antimicrobial, sakacin A, was added to the film mixture, no significant influence on films optical properties was reported. When experimentally inoculated surfaces of turkey breast were treated with these sakacin-A containing films, L. monocytogenes (LM) populations were reduced 3 log10 cfu/g after 3 weeks under refrigerated storage. This project demonstrates the efficacy of an indirect application of an antimicrobial compound to control a foodborne pathogen on a ready-to-eat food. Pickling of hard cooked eggs was evaluated and found to control foodborne pathogens such as E. coli O157:H7, Salmonella spp., LM, and Staphylococcus aureus immediately after treatment. In another experiment, pH, water activity, nutrition level, inoculum size, and incubation temperatures, as well as their combinations were evaluated for biofilm development by LM. Analyses demonstrated that some strains of LM share similar biofilm formation patterns with respect to environmental conditions, suggesting that they share a similar fundamental niche. These findings suggest that variability in biofilm formation may increase the likelihood that the pathogen may evade antimicrobial intervention or routine environmental monitoring. In another experiment, inactivation of EC and LM were investigated in buffer and milk upon treatment with ultrasound waves. Bacterial cells were added to phosphate buffer, whole milk, skim milk, or simulated milk ultrafiltrate. Samples were sonicated with 24 kHz pulse between 30 to 35C. Data suggest that milk exerts a sonoprotective effect on bacteria due to the presence of lactose, casein, or beta lactoglobulin but that ultrasound caused mechanical damage to the cell wall and cell membrane of bacteria, leading to their inactivation. These findings suggest that ultrasound may be employed as a method to control pathogens in milk. In another experiment, multiple hurdles at pre-harvest were investigated as a way to prevent microbial contamination and growth of human pathogens on mushrooms. Results demonstrated that light peat casing soil alone exhibited a suppressive effect on LM and Salmonella spp., and dark peat casing soils also had a suppressive effect on the pathogens. Combinations of peats were used in a model mushroom growing system, pathogen levels were sampled over the course of the growing cycle and emerging mushrooms were tested for presence of pathogens. Pathogen populations were lowest in the 100:0 light:dark peat and were highest in the 60:40 light:dark peat, however, in all three combinations pathogen levels decreased by at least 3.18 logs between inoculation and harvest. These findings are of importance as methods are employed to control LM in fresh and further processed mushroom products.
Publications
- Tobin, D., J. Thomson, and L. LaBorde. 2011. Consumer perceptions of fresh produce safety: A study of Pennsylvania. Presentation. Agricultural Food and Human Values Society (AFHVS) annual meeting. Missoula, MT. June 11. pp. 151 (Abstract).
- LaBorde, L., J. Thomson, and D. Tobin. 2011. Keeping Fresh Produce Safe Using Good Agricultural Practices (GAPs). Produce Safety Alliance - GAPs Education and Training Materials Conference Proceedings. Orlando, FL. June 29-30, 2011. pp. 78-79.
- Phelps, L. L., S. N. Nieto-Montenegro, and L. LaBorde. 2011. Food Safety in the Mushroom Industry. Produce Safety Alliance -GAPs Education and Training Materials Conference Proceedings. Orlando, FL. June 29-30, 2011. pp. 37-38.
- Yoder, S. F., E. W. Mills, W. R. Henning, N. Ostiguy, S. Doores, and C. N. Cutter. 2010. The efficacy of water washes against pathogens associated with beef surfaces processed in very small meat establishments. J. Food Prot. 73:907-915.
- Valadez, A. M., C. DebRoy, E. W. Dudley, and C. N. Cutter. 2011. Multiplex PCR detection of Shiga toxin-producing Escherichia coli strains belonging to serogroups O157, O103, O91, O113, O145, O111, and O26 experimentally inoculated in beef carcass swabs, beef trim, and ground beef. J. Food Prot. 74:228-239.
- Bucknavage, M. W. and C. N. Cutter. 2011. Food safety interventions: reducing risk from farm to table. Food Safety Magazine 17(1):10-15. http://www.foodsafetymag-digital.com/foodsafetymag/20110203folio=10# pg10.
- DebRoy, C., E. Roberts, A. Valadez, E. G. Dudley, and C. N. Cutter. 2011. Detection of Shiga toxin-producing Escherichia coli O26, O45, O103, O111, O113, O121, O145 and O157 serogroups by multiplex PCR of the wzx gene of the O-antigen gene cluster. Foodborne Pathogens and Disease 8(5):651-652.
- Richard, A. E. and C. N. Cutter. 2011. Validation of a pickling process for controlling pathogens associated with hard cooked eggs. J. Food Safety. 31:417-423.
- Trinetta, V., C. N. Cutter, and J. D. Floros. 2011. Effect of ingredient composition on optical and mechanical properties of pullulan film for food food-packaging applications. LWT - Food Science and Technology 44(10):2296-2301.
- Richard, A. E., S. M. Crutchfield, and C. N. Cutter. 2010. Validation of a pickling process for reducing foodborne pathogens associated with hard cooked eggs. Institute of Food Technologists Annual Meeting. Chicago, IL. Abstract #038-14.
- Valderrama, W. B. and C. N. Cutter. 2010. Evaluation of attachment capacity of Listeria monocytogenes isolates in response to different growth conditions using multivariate analysis. International Association of Food Protection Annual Meeting. Anaheim, CA. July 2010. Poster Abstracts P2-129. page 145. http://www.foodprotection.org/files/annual_meeting/iafp-2010-abstract s-posters-2010.pdf
- Gera, N. and S. Doores. 2011. Kinetics and Mechanism of Bacterial Inactivation by Ultrasound Waves and Sonoprotective Effect of Milk Components. J. Food Science 76(2):M11-M19.
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