Progress 10/01/11 to 09/30/16
Outputs
Target Audience:Students, Professional Associations such as the International Association for Food Protection, Wintergarden Spinach Producers Board. Texas Vegetable Association, Nation-wide stakeholders such as United Fresh, International organizations such as University of Guadalajara (Mexico) which included colleagues for collaborative work and students, for teaching/training] Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Graduate students had the opportunity to present their data for industry professionals and for other professionals in different meetings. As a result, two students were able to obtain jobs after graduation. How have the results been disseminated to communities of interest?By peer-reviewed articles, a book chapter and multiple invited presentations in professional conferences. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
2 papers published in peer-reviewed journals and one abstract published in conference proceedings for an International Conference. These addressed Objectives 4 and 5. IN these studies we were able to develop a protocol for inoculating bacteria on produce hat would simulate nqatural contanmination occuring during postharvest especially during produce washing. Also, in these studies we were able to determine potential effects of the normal biota on the ability of pathogens to colonize produce. This will be followed by studies of the microbiome depending on funding.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Cabrera-Díaz, E., L. Martínez-Chávez, J. Sánchez-Camarena, J. A. Muñiz-Flores, A. Castillo, P. Gutiérrez González, S. M. Arvizu-Medrano, D. G. González-Aguilar and N. E. Martínez-Gonzáles. 2018. Simultaneous and Individual Quantitative Estimation of Salmonella, Shigella and Listeria monocytogenes on Inoculated Roma Tomatoes (Lycopersicon esculentum var. Pyriforme) and Serrano peppers (Capsicum annuum) using an MPN technique. Food Microbiology 73:282-287.
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Perez-Lewis, K., Y. Yegin, L. Cisneros-Zevallos, A. Castillo, C. Kerth, M. Akbulut, T. M. Taylor. 2018. Geraniol-Loaded Polymeric Nanoparticles Inhibit Enteric Pathogens on Spinach During Post-Treatment Refrigerated and Temperature Abuse Storage. Frontiers in Sustainable Food Systems. 2:Article 4. https://doi.org/10.3389/fsufs.2018.00004.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Villarreal, M. 2014. Surface-related factors of produce that affects its contamination with pathogens. 2nd. GAP Food
Safety Conference. August 28, 2014. Seguin, T
|
Progress 10/01/13 to 09/30/14
Outputs
Target Audience: The produce industry from Texas was reached by our efforts during two GAP FFood safety Conferences, one in College Station, Texas in July of 2014 and the other in Seghuin, Texas in August 2014. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Graduate students had the opportunity to present their data for industry professionals and for other professionals in two different meetings. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? Prepare peer-reviewed manuscripts for publication. Write news articles for the general public Publish notes in Agricultural publications targeting the produce industrty Organize and/or participate nin workshops and conferences to disseminate results of this project.
Impacts
What was accomplished under these goals?
one abstract published in conference proceedings for an International Conference.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
KEILA PEREZ, Mariana Villarreal-Silva, Mustafa Akbulut, Luis Cisneros-Zevallos, Matthew Taylor, Alejandro Castillo. 2014. Identification of Leafy Green Recovered Bacteria with Antagonistic Activity against Enteric Bacterial Pathogens. Anual Meeting International Association for Food Protection. August 3-6. Indianapolis, IN
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Villarreal, M. 2014. Surface-related factors of produce that affects its contamination with pathogens. 2nd. GAP Food Safety Conference. August 28, 2014. Seguin, TX.
|
Progress 01/01/13 to 09/30/13
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? OUTPUTS: Farms growing spinach and other leafy greens, tomatoes and cantaloupes were selected for sample collection during two seasons: Spring (March/May) and Fall (August/October). For each typoe of crop, two farms were selected in the State of Texas. At each farm and at each season, 25 samples of each of the following produce were collected in the field: spinach, lettuce, parsley, tomatoes, and cantaloupes. Samples were tested for microbial content by firmly rubbing 100 cm2 of product surface with a sterile sponge (bioPro Sampling System), previously moistened with 25ml of 0.1% sterile peptone water kept in a sterile plastic bag, then the sponge will be placed in the plastic bag with the remaining diluents, and gently massaged to release the microorganisms. For leafy greens, the weigth that correlated with a 100 cm2 area was obtained and mixed with diluent. For each sample, aerobic mesophilic and psychrotrophic bacteria, coliforms, and lactic acid bacteria were enumerated. Ten microbial isolates were obtained from the various plating media and screened for inhibitory action against E. coli O157:H7 and Salmonella Saintpaul using the agar spot test onto a lawn plate with the particular pathogen, incubated at 37 ?C for 24h and examined for zones of inhibition surrounding each isolate colony. Isolates exhibiting antagonistic (inhibitory) activity were further characterized based on their morphological and biochemical properties using a Vitek microbiological identification system. As a result, a collection of bacteria showing antagonism against bacterial patghogens was obtained and will be used for further in-vivo studies. PARTICIPANTS: Alejandro Castillo (Project Director) Keila Perez (Ph. D. candidate), Mariana Villarreal (Ph. D. student), Wendy Alvarez (Undergraduate Student Intern) How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? Prepare peer-reviewed manuscripts for publication. Write news articles for the general public Publish notes in Agricultural publications targeting the produce industrty Organize and/or participate nin workshops and conferences to disseminate results of this project.
Impacts
What was accomplished under these goals?
One M. Sc. thesis published, one abstract published in conference proceedings for an International Conference.
Publications
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Onafowokan, Ayoola A (2013). Quantitative Assessment of the Presence of Salmonella and Fecal Indicators in Mexican Tomatoes for Export to the United States. Master's thesis, Texas A&M University. Available electronically from http : / /hdl .handle .net /1969 .1 /149273.
Villarreal-Silva, M., Anciso, J.R., Cisneros-Zevallos L., Kakani, G., Murano, E.A.,
P�rez-Flores, K.L., Taylor, T.M., Castillo, A. 2013. Ocurrence and identification of lactic acid bacteria isolated from spinach, showing antagonistic activity against Salmonella Saintpaul and Escherichia coli O157:H7. 15th. International Food Safety Conference. 31 Oct-1 Nov, 2013. Guadalajara, Mexico.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2013
Citation:
Villarreal-Silva, M., Anciso, J.R., Cisneros-Zevallos L., Kakani, G., Murano, E.A., P�rez-Flores, K.L., Taylor, T.M., Castillo, A. 2013. Ocurrence and identification of lactic acid bacteria isolated from spinach, showing antagonistic activity against Salmonella Saintpaul and Escherichia coli O157:H7. 15th. International Food Safety Conference. 31 Oct-1 Nov, 2013. Guadalajara, Mexico.
|
Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: A tomato packing operation was tested in two consecutive years. For each visit, sampling was conducted on 3 processing days. For each sampling, 20 samples of tomato were collected at 15 minutes interval during work hour at the plant. Each set of sample contains 4 processed tomatoes that were aseptically collected on the conveyor prior to packaging. These tomato samples were rinsed with 250 ml of Universal pre-enrichment broth, shaking and massaging inside a sterile plastic bag for 2 min. These tomato rinse samples were then allowed to stand in the rinse liquid inside the bag at room temperature for 60 minutes. Also, 100 liter of wash water was collected from the tomato wash tank at the end of each shift. This volume was separated in 4 25-liter subsamples and each subsample was sampled by filtering it through a Modified Moore's Swab (MMS) with peristaltic pump. At the end of the sampling, all the MMS were harvested placed in sterile polyethylene bags. All samples were packed in refrigerated containers and shipped to the laboratory in College Station, TX for testing for the presence of Salmonella on both types of samples, and also for E. coli as a fecal indicator for the tomato samples. No Salmonella or E. coli was found in any of the 144 tomato samples or the 600 liters of tomato wash water. The activities resulting form this project included visiting foreign tomato producing facilities and collaborating with scientists from Colorado State University and the University of Guadalajara in Mexico. These results were disseminated as a form of a Thesis and are being prepared for publication in a scientific journal. PARTICIPANTS: Alejandro Castillo (Project Director), Ayoola Onafowokan, Mariana Villarreal and Zahra Mohammed (graduate students). TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A graduate student obtained his Master's degree
Publications
- No publications reported this period
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Extracts of serrano, jalapeno and bell peppers were prepared at various concentrations and separately inoculated with Salmonella Saintpaul and a cocktail of Salmonella serotypes Agona, Gaminara, Michigan, Montevideo, Poona and Typhimurium. The inoculated extracts were stored at 35C and Salmopnella counts were conducted at various intervals during storage. The type of pepper did not affect the ability of Salmonella to survive or grow in the extracts. No effect of the parts of the pepper used to prepare the extracts (skin only vs skin + seed), or whether the extract was sterilized by autoclaving or membrane filtration was observed. The concentration of pepper in the suspension, and the time of storage affected the ability of Salmonella to grow in the suspension. The activities resulting form this project included receiving a foreign visiting scientist and mentoring students participating in this project. These results have not been disseminated but a thesis is being prepared with these data. PARTICIPANTS: Alejandro Castillo (Project Director), Ana Mercado (visiting scientist), Mariana Villarreal, Zahra Mohammed and Ayoola Onafowokan (graduate students), Lisa Lucia (Research Associate) TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Nothing significant to report at this time
Publications
- No publications reported this period
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Activities included the irradiation of romaine lettuce, baby spinach, diced tomato, and cut cantaloupe, inoculated with a mixture of strains of Salmonella and Escherichia coli O157:H7. The inoculated produce was exposed to electron beam (e-beam) irradiation at doses of 0.2, 0.4, 0.6, 0.8 and 1.0 kGy. At all doses, both pathogens were significantly reduced in comparison to non-irradiated controls. The D10-value for Salmonella on irradiated cut cantaloupe, cut roma tomatoes, baby spinach, and romaine lettuce was found to be 0.71 kGy, 0.64 kGy, 0.19 kGy, and 0.23 kGy respectively. The D10-value for E. coli O157:H7 on the produce listed above was found to be 0.73 kGy, 0.54 kGy, 0.18 kGy, and 0.20 kGy respectively. Another series of experiments during this project included testing the ability of Salmonella to survive and/or grow on jalapeno peppers. A 5-strain cocktail was inoculated onto fresh jalapenos. The inoculated jalapenos were stored under cold (4 and 10C) or warm (25 and 44C) temperatures. At 4C Salmonella decreased slowly but steadily, whereas at 10C no decrease or growth was observed (Figure 1). At 25C this pathogen showed a survival trend, whereas at 44C the trend indicated a slow reduction by 2 log cycles over 144 (6 days) of storage. This may indicate that under field conditions, when air temperatures can be as high as 40-45C, Salmonella may not be able to survive for long periods of time. PARTICIPANTS: Participants: Alejandro Castillo (Project Director) Megha Adavi (Graduate Research Assistant) Josue Morales (Graduate Research Assistant) Mary Pia Cuervo: Technical assistance Mayra Marquez: Provided technical assistance Lisa Lucia (Research Associate) TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Nothing significant to report
Publications
- No publications reported this period
|
Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Activities included the irradiation of lettuce, spinach, tomato, and cantaloupe inoculated with a mixture of strains of Salmonella and Escherichia coli O157:H7. The inoculated produce were exposed to electron beam irradiation at doses of 0.2, 0.5, 0.6, 0.8 and 0.9 kGy. The reduction in populations of both bacteria ranged between 0.7 and 1.9 log cycles when exposed to the maximum dose (0.9 kGy). A reduction of this magnitude was again observed in a second trial where the inoculated produce commodities were irradiated at .2 and 0.7 kGy. In a third trial, spinach leaves were inoculated with Salmonella and E. coli O157:H7 and were subjected to e-beam comparatively using the linear accelerator of the electron beam center and the Van de Graaff accelerator of the Department of Biological Engineering. The doses applied during the third trial were 0.2 and 0.8 kGy. The reductions obtained by 0.8 kGy were 3.6-3.7 log cycles with the Van de Graaff accelerator and 3.9-4.1 log cycles with the accelerator at the e-beam center. Because of the discrepancy between the reductions obtained in trials 1-2 and trial 3, it was determined that these studies were to be repeated after verifying equipment performance at the e-beam center. 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
No outcomes can be described yet due to the need for verification of the results obtained during 3 different trials.
Publications
- No publications reported this period
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: During this year a great understanding of the applicability of electron beams (e-beams) for eliminating pathogens in spinach and almonds was gained through our research. D-values for Salmonella and Escherichia coli O157:H7 were determined and will help in designing treatments for electronic pasteurization of these commodities. D-values for E. coli O157:H7 in spinach and for Salmonella Enteritidis PT 30 in almonds were 0.18 kGy and 0.78 kGy, respectively. The association between E. coli O157:H7 and Salmonella cells, and spinach surfaces was also studied. By using Confocal Laser microscopy it was possible to study the attachment of these pathogens. Multiple imaging permitted to visualize the incorporation of these pathogens to intenal fluids after being internalized via cut edges and other openings. PARTICIPANTS: Alejandro Castillo, Project Director. Joseph Maxim, from the National Center for Electron Beam Research at Texas A&M. His role was fundamental in designing experiments and determining dose mapping, which ensured a low dose variation. Jack A. Neal, Ph. D. student. Mary-Pia Cuervo, Ph. D. student. Wintergarden Spinach Producers Board. California Almond Board. TARGET AUDIENCES: Students. Professional Associations: International Association for Food Protection. Industry associations: Wintergarden Spinach Producers Board and California Spinach Board. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Information collected during this study supports current regulation allowing irradiation of spinach and iceberg lettuce. Also, this information is being used in teaching activities for a change in attitude among students towards food safety in general and food irradiation for food safety purposes. In addition, we have been working with professional groups in promoting electron beam irradiation as an environment-friendly, safe alternative for improving food safety without damaging food products, especially fresh and fresh-cut fruits, vegetables and nuts.
Publications
- Neal, J. A., E. Cabrera-Diaz, M. Marquez-Gonzalez, J. E. Maxim and A. Castillo. 2008. Reduction of Escherichia coli O157:H7 and Salmonella on Baby Spinach Using Electron Beam Irradiation. Journal of Food Protection. 71:2415-2420.
- Cuervo-Pliego. M. P., J. E. Maxim and A. Castillo. 2008. Electron beam irradiation as an alternative method for almond pasteurization (trans). p. 45. Memorias del 10. Congreso Internacional Inocuidad de Alimentos, XXV Reunion Nacional de Microbiologia, Higiene y Toxicologia de Alimentos (Proceedings of the 10th International Food Safety Conference). Puerto Vallarta, Mexico, November 6-8.
|
Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Spinach disinfection. The effect of different sanitizers on the reduction of Escherichia coli O157:H7 and Salmonella on baby spinach leaves was studied. Fresh spinach was obtained directly from growers and transported to the Food Microbiology Laboratory at Texas A&M. Spinach leaves were inoculated with Escherichia coli O157:H7 and Salmonella Agona, Gaminara, Michigan, Montevideo, Poona and Typhimurium. Inoculated spinach leaves were subjected to a water wash followed by treatment of one of the following sanitizers: 2% lactic acid at 55 C, calcium hypochlorite, peroxyacetic acid, ozonated water, or chlorine gas. The reductions of E. coli O157:H7 and Salmonella on spinach leaves were similar to each other and the sanitizers had an average log reduction of 1.1 CFU/g. The treatment that produced the greatest bacterial reduction was lactic acid. This treatment significantly reduced E. coli O157:H7 by 2.7 and Salmonella by 2.3 log cycles. If used as part of a holistic approach for
food safety which includes good agricultural practices as well as good manufacturing practices, the use of a disinfection treatment may contribute to the overall safety of fresh spinach. Irradiation of spinach. The reduction of inoculated E. coli O157:H7 and Salmonella on baby spinach by the application of e-beam irradiation was tested in this study. Fresh spinach was inoculated with a bacterial cocktail containing rifampicin resistant (Rif+) E. coli O157:H7 and Rif+ Salmonella Agona, Gaminara, Michigan, Montevideo, Poona and Typhimurium. Inoculated samples as well as controls were exposed to 0.79, 1.16 or 2.48 kGy electron beam irradiation from a linear accelerator. Reductions in populations were determined by plate counting. Irradiated spinach was also stored for 8 days at 4 C and counting was done at 2-day intervals to determine if there was any effect of irradiation on the survival of both pathogens. For E. coli O157:H7, the log reduction was 4.1, 6.3 and 6.4 log CFU/g when
irradiated at 0.79, 1.16 and 2.48 kGy, respectively. For Salmonella, the log reduction was 4.0 at 0.79 kGy. For samples irradiated at 1.16 or 2.48 kGy, initial counts of 7.3 log CFU/g were reduced to below the detection limits (< 10 CFU/g). Irradiation did not affect the survival of the remaining microorganisms stored over eight days (P < 0.05). These results suggest that electron beam irradiation may be a viable tool for reducing microbial populations or eliminating E. coli O157:H7 and Salmonella from fresh bagged spinach. We have been working with the Wintergarden Spinach Producers Board and the Texas Produce Association.
PARTICIPANTS: Alejandro Castillo (Project Director) Jay Neal (Ph D student) Joe Maxim (collaborator) Wintergarden Spinach Producers Board
TARGET AUDIENCES: Students Professional Associations such as the International Association for Food Protection Wintergarden Spinach Producers Board
Impacts
Knowledge generated from tgius study is being used in teaching activities for a change in attitude among students towards food safety in general and food irradiation for food safety purposes. In addition, we have been working with professional groups in promoting electron beam irradiation as an environment-friendly, safe alternative for improving food safety without damaging food products, especially fresh and fresh-cut fruits and vegetables.
Publications
- Neal, J., Maxim, J., Castillo, A. 2007. Reduction of Escherichia coli 0157:H7 and Salmonella Species on Baby Spinach Using Electron Beam Irradiation. IAFP Program and Abstract Book Annual Meeting. Orlando, FL. T2-03
|
|