Progress 10/01/02 to 09/30/07
Outputs
OUTPUTS: Inactivation kinetics of a food-borne pathogen, Escherichia coli O157:H7 has been established in various food products subjected to electron beam (e-beam). Inactivation kinetics of food-borne pathogens is expressed as a D-value. The D-value determines the e-beam dose (kGy) required to inactivate (kill) 1-log (90%) of a target microorganism. We determined D-value for E. coli in the most representative meat products, ground beef, chicken breast meat, and fish fillets. Depending on the conditions in a food product and the type of a food product, it takes between 0.22-0.64 kGy of e-beam to inactivate 1-log (equivalent of 90%) of the initial microbial population of E. coli. Our laboratory has also established inactivation kinetics for another very common food-borne pathogen, Salmonella in tomatoes. Since tomatoes are naturally acidic foods, our studies determined D-value for Salmonella in tomatoes as a function of pH. The D-value for Salmonella in tomatoes ranged between
1.07-1.50 kGy depending on the pH.
PARTICIPANTS: Graduate students: Jennifer L. Black (MS student) Leah Levanduski (MS student) Deborah James (MS student) Visiting Professor: Dr. Priya R. Chalise (Department of Electronic and Electrical Engineering, Loughborough University, the U.K.) Research collaborators: Dr. Eiki Hotta, Department of Energy Sciences, Tokyo Institute of Technology, Japan Dr. Kristen E. Matak, Division of Animal and Nutritional Sciences, West Virginia University
TARGET AUDIENCES: food scientists and technologists, regulatory agencies, food industry and academia
PROJECT MODIFICATIONS: We added a new aspect of compact electron beam that was developed by Dr. Hotta's laboratory in Japan. This new e-beam device has a great potential to be integrated with a microwave oven. This new device would be targeted at increased food safety at a house hold level in a non-thermal fashion. Therefore, it this new device would be applicable to fresh food products such as fresh greeen vegetables. This modification was added in a response to the recent outbreaks implicating E. coli O157:H& in leafy greens.
Impacts
Escherichia coli O157:H7 is commonly associated with food products, especially ground meat products. However, more recently E. coli O157:H7 has also been implicated in outbreaks associated with fresh green vegetables that resulted in confirmed deaths. E-beam effectively inactivates this pathogen. Our studies demonstrated that the D-value for E. coli varies depending on a food product. Not only does the D-value differ for various food products, but it also changes depending of the water activity, ionic strength, and temperature of a food product during e-beam processing. In our studies we demonstrated that lowering water activity and ionic stress suppress growth of E. coli; however, at the same time E. coli becomes more radio-resistant to e-beam and survives e-beam processing better (i.e., higher D-value). Our food science laboratory was also the first one to demonstrate that E. coli has a capability to develop an significantly increased resistance to e-beam if the
microorganism is repetitively exposed to e-beam at sublethal doses. This phenomenon is similar to the increased microbial resistance to various antibiotics. Salmonella has been recently implicated in several outbreaks in fresh tomatoes that resulted in numerous law suits. Fresh food products such as tomatoes of fresh green vegetables simply cannot be thermally processed. However, as evidenced by recent outbreaks involving E. coli and Salmonella, these food products should also be considered vehicles for pathogen transmission. Therefore, in order to maintain high food safety/security standards for the fresh food products (especially "ready-to-eat" ot RTE), non-thermal processing should be developed and implemented. As demonstrated in our studies, e-beam efficiently inactivates common food-borne pathogens such as E. coli and Salmonella in a non-thermal fashion; and therefore, the quality attributes of the processed food products are not affected by heat. Research in my laboratory at WVU
with food-borne pathogens and e-beam has led me to believe that a key to further increase microbial safety of our food supply is the development of a non-thermal device at the end of the food distribution chain - the household level, immediately preceding consumption of the food. My belief was confirmed by the recently publicized outbreaks implicating fresh vegetables (spinach, lettuce) and peanut butter contaminated by E. coli and Salmonella, respectively; which resulted in confirmed deaths. Therefore, I initiated research collaboration with a plasma physicist specializing in compact e-beam linear accelerators, Dr. Eiki Hotta from the Department of Energy Sciences (Tokyo Institute of Technology, Japan) and an electrical engineer specializing in design of e-beam linear accelerators, Dr. Priya Raj Chalise from the Department of Electronic and Electrical Engineering (Loughborough University, the U.K.). Under my leadership we submitted a proposal to the USDA-NRI for the 2008 funding
cycle. The long-term aim of the submitted proposal was to develop a compact e-beam device integrated with a microwave oven for the purpose of increased microbial food safety at a household and food service level.
Publications
- Black JL, Jaczynski J. 2007. Effect of ionic strength on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. International Journal of Food Science and Technology 42:894-902.
- Chalise PR, Hotta E, Matak KE, Jaczynski J. 2007. Inactivation kinetics of Escherichia coli by pulsed electron beam. Journal of Food Science 72(7):M280-285.
- Black JL, Jaczynski J. 2008. Effect of water activity on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. International Journal of Food Science and Technology. In Press doi:10.1111/j.1365-2621.2006.01480.
- Levanduski L, Jaczynski J. 2008. Increased resistance of Escherichia coli O157:H7 to electron beam following repetitive irradiation at sub-lethal doses. International Journal of Food Microbiology. In Press doi: 10.1016/j.ijfoodmicro.2007.11.009.
- Chalise PR, Hotta E, Matak KE, Jaczynski J. 2007. Low-energy pulsed electron beam technique for microbial inactivation. The 34th IEEE International Conference on Plasma Science and the 16th IEEE International Pulsed Power Conference, Albuquerque, NM. June 17-22, 2007.
- Conference Abstracts: aczynski J, Park JW, Zinn CA. 2002. Non-thermal electron beam affects gelation properties of fish proteins. Abstract # 44-2. Institute of Food Technologists, Anaheim, CA.
- Jaczynski J, Park JW, Zinn CA. 2002. Electron beam penetration in seafood. Abstract # 76E-1. Institute of Food Technologists, Anaheim, CA.
- Jaczynski J, Black J. 2005. Assurance of food safety/security and shelf-life extension of aquatic foods using non-thermal electron beam. Abstract # 190. World Aquaculture Society, New Orleans, LA.
- Jaczynski J, Black J. 2006. Temperature effect on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. Abstract # 0391I-23. Institute of Food Technologists, Orlando, FL.
- Jaczynski J, Black J. 2006. Effect of water activity on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. Abstract # 0391I-24. Institute of Food Technologists, Orlando, FL.
- James DL, Jaczynski J, Matak KE. 2007. Effect of electron beam irradiation on acid-resistant Salmonella enterica subsp. enterica serotype Montevideo in tomato. Abstract # P1-41. International Association for Food Protection, Lake Buena Vista, FL.
- Levanduski L, Jaczynski J. 2007. Increased resistance of Escherichia coli O157:H7 to electron beam following repetitive irradiation at sub-lethal doses. Abstract # 189-06. Institute of Food Technologists, Chicago, IL.
- Lansdowne L, Beamer S, Jaczynski J, Matak KE. 2008. The survivability of Listeria innocua in rainbow trout filets (Oncorhynchus mykiss) processed using isoelectric solubilization/precipitation. Abstract #. Institute of Food Technologists, New Orleans, LA.
- Book Chapters: Jaczynski J, Park JW. 2004. Application of Electron Beam to Surimi Seafood. In: Komolprasert V, Morehouse K, editors. Irradiation of Food and Packaging: Recent Developments. Washington, DC: American Chemical Society. p 165-79.
- Su YC, Daeschel MA, Frazier J, Jaczynski J. 2005. Microbiology and Pasteurization of Surimi Seafood. In: Park JW, editor. Surimi and Surimi Seafood, 2nd ed. Boca Raton: CRC Press. p 583-648.
- Jaczynski J, Hunt A, Park JW. 2005. Safety and Quality of Frozen Fish, Shellfish and Related Products. In: Sun DW, editor. Handbook of Frozen Food Processing and Packaging. Boca Raton: CRC Press. p 341-377.
- Peer-Reviewed Publications: Jaczynski J, Park JW. 2003. Physicochemical properties of surimi seafood as affected by electron beam and heat. Journal of Food Science 68(5):1626-1630.
- Jaczynski J, Park JW. 2003. Microbial inactivation and electron penetration in surimi seafood during electron beam processing. Journal of Food Science 68(5):1788-1792.
- Jaczynski J, Park JW. 2004. Physicochemical changes in Alaska pollock surimi and surimi gel as affected by electron beam. Journal of Food Science 69(1):53-57.
- Black JL, Jaczynski J. 2006. Temperature effect on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. Journal of Food Science 71(6):M221-227.
- James DL, Jaczynski J, Matak KE. 2008. Effect of electron beam irradiation on nalidixic acid resistant Salmonella Montevideo in cooked tomato puree of various pH values. LWT - Food Science and Technology. Under review.
- Chalise PR, Hotta E, Matak KE, Jaczynski J. 2008. Electron beam techniques in microbial inactivation. IEEE Transactions on Plasma Science. Under review.
- Invited Keynote Lectures: Jaczynski J, Le Formal G, Park JW. 2003. Application of electron beam to surimi seafood and salmon. National Fisheries Institute Annual Meeting, Long Beach, CA. Oct. 9-11, 2003.
- Jaczynski J, Park JW. 2003. Application of electron beam to surimi seafood and smoked salmon. National Fisheries Institute Seafood Technology Innovations Conference, Orlando, FL. Feb. 4-7, 2003.
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Progress 01/01/06 to 12/31/06
Outputs
Progress report Inactivation kinetics of Escherichia coli and acid-resistant Salmonella ssp. Montevideo subjected to e-beam has been investigated. The D10-value is a decimal reduction of microbial population expressed as e-beam dose required to inactivate 1-log of initial microbial population. Fresh meat products such as ground beef, chicken meat, and fish fillets usually do not use a pasteurization step to inactivate microorganisms such as E. coli O157:H7. Recent outbreaks of E. coli in spinach and lettuce as well as Salmonella in tomatoes indicate a need for microbial inactivation in these fresh ready-to-eat (RTE) foods in a non-thermal manner. Electron beam (e-beam) inactivates microorganisms without heat, instead e-beam generates radiation from ordinary electricity. Therefore, e-beam could be applied to fresh meat products as well as RTE products including fresh leafy vegetables. D10-values ranged from 0.22 to 0.35 kGy for E. coli in trout at 4C and chicken at
-20C, respectively. Regardless of temperature, chicken had highest D10-value followed by beef and trout. D10-values of frozen samples were higher than D10-values of samples irradiated at 4 and 22C regardless of species. These data indicate that microbial inactivation depends on the temperature of the food during irradiation; the lower the temperature, the less efficient microbial inactivation. Water activity (Aw) of ground beef, chicken breast meat, and trout fillets was adjusted to 1.00 (control), 0.98, and 0.96 by partial vacuum drying. Water activity (Aw) is the amount of water in food available for microbial growth, chemical reaction, etc. D10-values ranged from 0.22 to 0.35 kGy for E. coli in trout (Aw=1.00) and chicken (Aw=0.96), respectively. D10-values for samples with Aw=1.00, 0.98, and 0.96 were 0.254, 0.317, and 0.319, respectively. These data indicate that microbial resistance increases as the amount of available water in food decreases. Acid-resistant Salmonella was
inoculated in tomato and pH was adjusted to 4.4 and 4.9. The D10-value was 1.07 and 1.50 kGy for Salmonella in tomato at pH = 4.4 and 4.9, respectively. These values are relatively high likely due to resistance that Salmonella developed to acid. Collaboration with Tokyo Institute of Technology Department of Energy Sciences has been initiated. Our collaborators have developed a compact e-beam device that utilizes secondary emission electron gun (SEEG) for surface decontamination. Some experiments have been conducted to inactivate E. coli with SEEG e-beam. A visiting scientist has come to our laboratory to initiate our collaborative study. Due to its compact and innovative design, the SEEG e-beam can be developed into a household device and likely may be combined with an existing appliance such as a microwave oven. This is our mutual goal and focus of our research collaboration. This household device could work in two modes: microwave - whenever heat is needed and e-beam - whenever
non-thermal microbial inactivation is desired. Non-thermal inactivation of food-borne pathogens by the SEEG e-beam could be used for RTE foods such as fresh leafy vegetables.
Impacts
Electron beam (e-beam) inactivates microorganisms without heat (i.e., non-thermally), instead e-beam generates ionizing radiation from ordinary electricity. Therefore, e-beam could be applied to fresh meat products as well as RTE products including fresh leafy vegetables to maintain high standards of microbial safety while maintaining the "fresh" symbol of identity of those products. Our research indicates that microbial inactivation using e-beam depends on the temperature of the food during irradiation; the lower the temperature, the less efficient microbial inactivation. It also depends on the water availability in a food product measured as water activity (Aw). Our studies demonstrated that microbial resistance increases as the amount of available water in food decreases (lower Aw). E-beam also efficiently inactivates Salmonella in tomato. However, acid-resistant strain has higher microbial resistance to e-beam.
Publications
- Publications in 2006:
- Book chapters: Jaczynski J, Chen YC, Velazquez G, Torres JA. 2006. Procesamiento de Productos Pesqueros Con Haz de Electrones (Application of Electron Beam to Fish and Crustacean Processing). In: Legarreta IG, Rosmini MR, Armenta Lopez RE, editors. Tecnologia De Pescado (Fish and Crustacean Technology). Mexico City: Editorial Limusa, S.A. de C.V. In Press.
- Peer-reviewed articles: Chalise PR, Hotta E, Matak KE, Jaczynski J. 2007. Inactivation kinetics of Escherichia coli by low-energy high-power pulsed electron beam. J Food Protect. Under review.
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Progress 01/01/05 to 12/31/05
Outputs
The D10-value is a decimal reduction of microbial population expressed as e-beam dose required to inactivate 1-log (equivalennt of 90%) of initial microbial population. Fresh meat products such as ground beef, chicken meat, and fish fillets usually do not use a pasteurization step to inactivate microorganisms such as Escherichia coli O157:H7 (E. coli). Electron beam (e-beam) inactivates microorganisms in a non-thermal manner. Therefore, e-beam could be applied to fresh meat products to maintain high standards of microbial safety while maintaining the fresh symbol of identity of those products. The objective of this study was to determine D10-values for E. coli subjected to e-beam at three different temperatures in ground beef, chicken meat, and trout fillets. E. coli was inoculated in ground beef, boneless skinless chicken breast meat, and boneless skinless trout fillets. Sample temperature was equilibrated to -20, 4, and 22C. Samples were subjected to e-beam at 0
(control), 0.5, 1.0, 2.0, 2.5, and 3.0 kGy. Survivors were enumerated using standard spread-plating method. Survivor curves were plotted on logarithmic scale as a function of e-beam dose for each meat sample at different temperature. The D10-values were calculated as an inverse reciprocal of the slope of the survivor curves. The results were analyzed by analysis of variance for a completely random design model. D10-values ranged from 0.22 to 0.35 kGy for E. coli in trout at 4C and chicken at -20C, respectively. Regardless of temperature, chicken had highest D10-value followed by beef and trout. D10-values of frozen samples were higher than D10-values of samples irradiated at 4 and 22C regardless of species. Although there were differences between D10-values for samples at 4 or -20C, they were statistically insignificant. The objective of this study was to determine D10-values for Escherichia coli O157:H7 (E. coli) subjected to e-beam at three different water activities (Aw) in fresh
meats. Aw of ground beef, boneless skinless chicken breast meat, and boneless skinless trout fillets was adjusted to 1.00 (control), 0.98, and 0.96 by partial vacuum drying. E. coli was inoculated in meat samples and temperature was adjusted to 4C. Samples were subjected to e-beam and survivors were enumerated. Survivor curves were plotted and D10-values were calculated. Results were analyzed by analysis of variance for a completely random design model. D10-values ranged from 0.22 to 0.35 kGy for E. coli in trout (Aw=1.00) and chicken (Aw=0.96), respectively. Regardless of Aw, chicken had highest D10-value followed by trout and beef. Although D10-values for trout and beef were numerically different, the difference was insignificant. D10-values for samples with Aw=1.00, 0.98, and 0.96 were 0.254, 0.317, and 0.319, respectively. D10-values for samples with Aw=1.00 were significantly lower than those with reduced Aw. Shouldering of survivor curve was observed in reduced Aw samples.
E-beam effectively reduced E. coli O157:H7 in meat products even at reduced Aw.
Impacts
Water radio-lysis is considered as an in-direct mechanism for microbial inactivation. Therefore, while the physical state of water (frozen or un-frozen) in foods seems major contributor to microbial inactivation by e-beam due to water radio-lysis, water temperature most likely plays minor role. Due to significant effect of Aw on D10-values, e-beam could be applied to the products before Aw-reducing techniques are employed. However, this would require stringent control following irradiation.
Publications
- Technical non-refereed article: Jaczynski J. 2005. E-beam treatments could improve seafood safety, shelf life. Global Aquaculture Advocate 8(3):34-6.
- Refereed article: Black JL, Jaczynski J. 2005. Temperature effect on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. J Food Sci. Under review.
- Refereed article: Black JL, Jaczynski J. 2005. Effect of ionic strength on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. J Food Sci. Under review.
- Refereed article: Black JL, Jaczynski J. 2005. Effect of water activity on inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets. J Food Sci. Under review.
- Poster at national meeting: Jaczynski J, Black J. 2005. Assurance of food safety/security and shelf-life extension of aquatic foods using non-thermal electron beam. Abstract # 190. Aquaculture America, New Orleans, LA.
- Book chapter: Su YC, Daeschel MA, Frazier J, Jaczynski J. 2005. Microbiology and Pasteurization of Surimi Seafood. In: Park JW, editor. Surimi and Surimi Seafood, 2nd ed. Boca Raton: CRC Press. p 583-648.
- Book chapter: Jaczynski J, Hunt A, Park JW. 2005. Safety and Quality of Frozen Fish, Shellfish and Related Products. In: Sun DW, editor. Handbook of Frozen Food Processing and Packaging. Boca Raton: CRC Press. p 341-377.
- Book chapter: Jaczynski J, Chen YC, Velazquez G, Torres JA. 2005. Application of Electron Beam to Fish and Crustacean Processing. In: Legarreta IG, Rosmini MR, Armenta Lopez RE, editors. Fish and Crustacean Technology. Mexico City: Editorial Limusa, S.A. de C.V. In Press.
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Progress 01/01/04 to 12/31/04
Outputs
Inactivation kinetics using electron beam (e-beam) for E. coli O157:H7 inoculated in fresh ground beef, fresh boneless skinless chicken breast, and fresh trout fillets as a function of temperature, ionic strength (IS) and water activity (Aw) has been determined. The IS was adjusted to 0.05 (control), 0.44, and 0.76 by adding NaCl at 0.0, 3.5 and 7.0% (w/w), respectively. The Aw was adjusted to 1.0 (control), 0.99, and 0.96 by freeze-drying. The following e-beam doses were applied: 0 (control), 0.5, 1.0, 2.0, 2.5, and 3.0 kGy with e-beam energy fixed at 10 MeV. The experimental design was 3 x 3 factorial. The E. coli survivors were enumerated by spread-plating on E. coli petrifilms using 10-fold serial dilution procedure. The survivor counts were used to plot a survivor curve to determine the D-values. The D-values indicated that E. coli inoculated in trout were least resistant to e-beam radiation, followed by beef and chicken. Regardless of the species, the meat
temperature during e-beam processing was critical; the lower meat temperature during e-beam processing, the higher resistance of E. coli to radiation. Lowering the Aw by freeze-drying in the tested meat samples increased resistance of E. coli to e-beam radiation. Increasing the IS by addition of NaCl to the tested meat samples induced shoulder effect in microbial survival. The D-value ranged from 0.19-0.37 kGy depending on what species the meat was derived from and the experimental treatment. Therefore, to obtain a 12-D safety level for E.coli, the e-beam dose of 2.2-4.4 kGy would be required. Irradiation of poultry is currently approved up to 3.0 kGy. Irradiation of red meats is approved up to 4.5 kGy for fresh and 7.0 kGy for frozen products. The approval of aquatic foods irradiation currently has a pending status.
Impacts
E.coli has caused a record-breaking 25 mln pound recall of ground beef in 2002 from a single national-scale operation. This was a very significant monetary loss as well as it has increased consumer doubt in microbial safety of food products. E.coli was a reason for the USDA to make a HACCP plan mandatory for meat and poultry processing facilities in 1996. The purpose of this mandatory action was to reduce incidence of E.coli contamination. Despite this preventive measure, E.coli proved its prevalence in 2002 with the largest-ever food recall. Ground beef cannot be thermally processed to assure reduction of E.coli. Therefore, non-thermal electron beam can potentially be used as a critical control point (CCP) to reduce E.coli in ground beef, and thus prevent further monetary losses as well as increase consumer confidence in microbial safety of food products.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
During the first year of the project one graduate student at MS level was hired to conduct the project. The student has been taking courses and laboratory training necessary to carry out the analyses. The laboratory equipment necessary to conduct the project has been acquired, certified (if required), and set up. The equipment includes microbiological bio-safety cabinet, stationary incubator, incubator-shaker, colony counter, refrigerator, freezer, and ultra-low temperature (-80C) freezer. An Escherichia coli O157:H7 have been purchased from American Type Culture Collection (ATCC). Along with the equipment, the disposable supplies necessary for microbial growth, enumeration, and analyses have been purchased as well. The microbiological laboratory procedures to safely handle food-borne human pathogens have been developed and approved by the WVU Institutional Bio-safety Committee (WVU-IBC, notice IBC# 2003IBC009) at bio-safety level BSL2. It is anticipated that
microbial inactivation data using electron beam in muscle foods will be generated in 2004.
Impacts
E.coli has caused a record-breaking 25 mln pound recall of ground beef in 2002 from a single national-scale operation. This was a very significant monetary loss as well as it has increased consumer doubt in microbial safety of food products. E.coli was a reason for the USDA to make a HACCP plan mandatory for meat and poultry processing facilities in 1996. The purpose of this mandatory action was to reduce incidence of E.coli contamination. Despite this preventive measure, E.coli proved its prevalence in 2002 with the largest-ever food recall. Ground beef cannot be thermally processed to assure reduction of E.coli. Therefore, non-thermal electron beam can potentially be used as a critical control point (CCP) to reduce E.coli in ground beef, and thus prevent further monetary losses as well as increase consumer confidence in microbial safety of food products.
Publications
- Jaczynski J, Park JW. 2003. Physicochemical properties of surimi seafood as affected by electron beam and heat. J Food Sci 68(5):1626-30.
- Jaczynski J, Park JW. 2003. Microbial inactivation and electron penetration in surimi seafood during electron beam processing. J Food Sci 68(5):1788-92.
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