Dr. Elliot T. Ryser

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Michigan State University
College of Agriculture and Natural Resources
Food Science and Human Nutrition
ProfessorAppointed: 2008
Michigan State University
College of Agriculture & Natural Resources
Food Science & Human Nutrition
Associate ProfessorAppointed: 2003
Michigan State University
College of Agriculture & Natural Resources
Food Science & Human Nutrition
Assistant ProfessorAppointed: 1998
Professional Headshot of Elliot T. Ryser

Mailing Address

334A G.M. Trout
Department of Food Science and Human Nutrition
Michigan State University
East Lansing, Michigan 48824
United States

Contact Information

Phone: (517) 355-8474, ext. 185
Fax: (517) 353-8963
ryser@msu.edu

Qualifications

Ph.D., University of Wisconsin-Madison, Food Safety, 1990.
M.S., University of Wisconsin-Madison, Food Microbiology, 1982.
B.S., University of Wisconsin-Madison, Bacteriology, 1980.
B.S., Carroll College, Biology, 1979.

Expertise and Research Interests

1. Transfer of E. coli O157:H7 during processing of leafy greens.
2. Transfer coefficients for Listeria monocytogenes in delicatessen settings.
3. Inactivation of microorganisms in blueverries using chlorine dioxide gas
4. Transfer of bacterial pathogens from conveyor belts to foods and efficacy of current cleaning/sanitizing methods for conveyors.
5. Development of an antilisterial hot dog casing from whey protein.
6. Incidence, behavior and reduction of Listeria monocytogenes, Salmonella Typhimurium DT104 and Escherichia coli O157:H7 in dairy products, poultry, deli meats and fresh produce.
7. Fate of L. monocytogenes and other milkborne pathogens during manufacture and storage of fermented and unfermented dairy products.
8. Sensitivity/inclusivity of the FDA and USDA methods for detecting specific strains of healthy and sublethally injured L. monocytogenes in food and environmental samples.
8. Effectiveness of various sanitizer treatments in eliminating Escherichia coli 0157:H7 and other bacterial foodborne pathogens from fresh produce and meat.

Other Expertise

Expert witness in cases of foodborne listeriosis

Future Research

Develop a series of transfer coefficients for the spread of Listeria and E. coli O157:H7 that can be used to fill critical data gaps in current risk assessments for deli meats and leafy greens.

Industrial Relevance

A fatty acid solution examined in our laboratory has proven to effectively reduce populations of E. coli O157:H7, Salmonella and Listeria > 5 logs on inoculated alfalfa seeds and is currently being adopted by the industry.

A chlorine dioxide gassing procedure has been partially adopted for decreasing microbial counts on fresh bluebberries before processing.

Current work is showing the superiority of a non-interlocking conveyor belt in terms of bacterial pick up during processing as well as cleaning and sanitizing.

Keywords

COS Keywords:

Dairy Products, Dairy Science, Food Safety, Food Sciences.

Additional Terms:

E. Coli, Food Safety, Foodborne Pathogens, Listeria.

Memberships

American Society for Microbiology
Institute of Food Technologists
International Association for Food Protection

Honors and Awards

1999, Book Award, Michigan State University Library, Michigan State University, 'Listeria, Listeriosis and Food Safety', 2nd edition
2007, Elmer Marth Educator Award, International Association for Food Protection

Previous Positions

1994-1998, Research Associate, University of Vermont
1992-1993, Research Project Manager, Silliker Laboratories Group, Inc.
1990-1991, Research Scientist, Institute National de la Recherche Agronomique,

Patents

Novel Culture and Transfer device for Enhanced Recovery and isolation of Microorganisms., Patent Number: 5616499, 1997, , United States of America.

Publications

  • Moorman, M., C. Thelemann, J. Pestka, J. Linz, E.T. Ryser (2008) Altered hydrophobicity and membrane composition in stress-adapted Listeria innocua, J. Food Prot., 71, 182-185
  • Keskinen, L.A., E.C.D. Todd, E.T. Ryser (2008) Impact of bacterial stress and biofilm formation on Listeria monocytogenes transfer during slicing of deli meats., Int. J. Food Microbiol., 127, 298-304
  • Keskinen, L.A., E.C.D. Todd, E.T, Ryser (2008) Transfer of surface-dried Listeria monocytogenes from stainless steel knife blades to roast turkey breast., J. Food Prot., 71, 176-181
  • Warsow, C.R, A. Orta-Ramirez, B.P. Marks, E.T. Ryser, A.M. Booren (2008) Unidirectional penetration of Salmonella spp. into marinated whole muscle turkey breast., J. Food Prot., 71, 153-156
  • Ryser, E.T., E.C.D. Todd, K.L. Vorst (2007) Bacterial transfer during slicing of delicatessen meats, New Food, 10 (3), 52-56
  • Popa, I., E.J. Hanson, A. Schilder, E.C.D. Todd, E.T, Ryser (2007) Efficacy of chlorine dioxide gas sachets for enhancing the microbiological quality and safety of blueberries., J. Food Prot., 70, 2084-2088
  • Yan, Z, K.L. Vorst, L. Zhang, E.T. Ryser (2007) Use of 1-ply composite tissues in an optical automated assay for recovery of Listeria from food contact surfaces and poultry- processing environments, J. Food Prot., 70, 1263-1266
  • Ryser, E.T., E.H. Marth (2007) Listeria, Listeriosis and Food Safety, 3rd Edition, Boca Ratan, FL, Taylor and Francis
  • Ryser, E.T, (2007) Incidence and behavior of Listeria monocytogenes in poultry and egg products., Listeria, Listeriosis and Food Safety, 3rd edition, Boca Ratan, FL, Taylor and Francis (bookchapter)
  • Ryser, E.T, (2007) Incidence and behavior of Listeria monocytogenes in unfermented dairy products., Listeria, Listeriosis and Food Safety, 3rd edition, Boca Ratan, FL, Taylor and Francis (bookchapter)
  • Ryser, E.T (2007) Incidence and behavior of Listeria monocytogenes in fermented dairy products, Listeria, Listeriosis and Food Safety, 3rd edition, Boca Ratan, FL, Taylor and Francis (bookchapter)
  • Pierre, P.M., J.N. Cash, E.T. Ryser (2006) Efficacy of an FDA approved peroxyacid-based sanitizer for inactivating Escherichia coli O157:H7, Salmonella Typhimurium DT104 and Listeria monocytogenes on artificially contaminated alfalfa seeds., J. Food Prot., 69, 582-590
  • Vorst, K.L., E.C. D. Todd, E.T. Ryser (2006) Transfer of Listeria monocytogenes during slicing of turkey breast, bologna, and salami using kitchen knives., J. Food Prot., 69, 2939-2946
  • Zhang, L, Z. Yan, E.T. Ryser (2006) Comparison of the RevealTM test, the U.S. Food and Drug Administration culture method, and selective media for recovery of Salmonella Enteritidis from commercial egg layer flock environments, J. Food Prot., 69, 2766-2769
  • Vorst, K.L., E.C.D. Todd, E. T. Ryser (2006) Transfer of Listeria monocytogenes during mechanical slicing of turkey breast, bologna, and salami., J. Food Prot., 69, 619-626
  • Wesche, A.M, B.P. Marks, E.T. Ryser (2005) Thermal resistance of heat-, cold-, and starve-injured Salmonella in irradiated comminuted turkey., J. Food Prot., 68, 942-948
  • Limjaroen, P, E.T. Ryser, H. Lockhart, B. Harte (2005) Inactivation of Listeria monocytogenes on beef bologna and Cheddar cheese using polyvinylidene chloride films containing sorbic acid., J. Food Sci., 70, M267-271
  • Orta-Ramirez, A, B.P. Marks, C.R. Warsow, A.M. Booren, E.T. Ryser (2005) Enhanced thermal resistance of Salmonella in whole muscle compared to ground beef., J. Food Sci., 70, M359-362
  • Carlson, T.R, B.P. Marks, A.M. Booren, E.T. Ryser, A. Orta-Ramirez (2005) Effect of water activity on thermal inactivation of Salmonella in ground turkey., J. Food Sci., 70, M363-366
  • Moorman, M, W. Nettleton, E.T. Ryser, J. Linz, J. Pestka (2005) Altered sensitivity of a quaternary ammonium sanitizer in stressed Listeria innocua., J. Food Prot., 68, 1659-1663
  • Rodgers, S.L., J.N. Cash, E.T. Ryser (2004) Reduction of microbial pathogens during apple cider production using sodium hypochlorite, copper ion and sonication., J. Food Prot., 67, 766-771
  • Cagri, A, Z. Ustunol, E.T, Ryser (2004) Antimicrobial edible films and coatings: A review, J. Food Prot., 67, 833-848
  • Rodgers, S.L, J.N. Cash, M. Siddiq, E.T. Ryser (2004) A comparison of different chemical sanitizers for inactivating Escherichia coli O157:H7 and Listeria monocytogenes in solution and on apples, strawberries, lettuce and cantaloupe., J. Food Prot., 67, 721-731
  • Harris, K.L., B.P. Marks, T.A. Ten Eyck, A.M. Booren, E.T. Ryser (2004) Line-level training needs related to commercial production of fully-cooked meat and poultry products., Food Prot. Trends, 24, 946-952
  • Vorst, K, E.C.D. Todd, E.T. Ryser (2004) Improved quantitative recovery of Listeria monocytogenes from stainless steel surfaces using a 1-ply composite tissue., J. Food Prot., 67, 2212-2217
  • R.S. Flowers, R. Reiser, E.T. Ryser (2004) Pathogens in milk and milk products. In Henning, D (eds), Standard Methods for the Examination of Dairy Products, 17th Edition, Washington, DC, American Public Health Assoc. (bookchapter)
  • Cagri, A., Z. Ustunol, W.N. Osburn, E.T. Ryser (2003) Inhibition of Listeria monocytogenes on hot dogs using antimicrobial whey protein-based edible films., J. Food Sci., 68, 291-299
  • Limjaroen, P., E.T. Ryser, H. Lockhart, B. Harte (2003) Development of a food packaging coating material with antimicrobial properties., J. Plastic Film and Sheeting, 19, 95-109
  • Ryser, E.T, (2003) Pasteurisation of liquid milk products: Principles, public health aspects, Encyclopedia of Dairy Sciences., London, Academic Press (bookchapter)
  • Ryser, E.T, (2003) Listeria monocytogenes, Encyclopedia of Dairy Sciences, London, Academic Press (bookchapter)
  • Mathew, F.P., E.T. Ryser (2002) Competition of thermally injured Listeria monocytogenes with a mesophilic lactic acid starter culture in milk of various heat treatments., J. Food Prot., 65, 643-650
  • Smith, S.E., A. Orta-Ramirez, R.Y. Ofoli, E.T. Ryser, D.M. Smith (2002) Phycoerythrin as a time-temperature integrator to verify the thermal processing adequacy of beef patties., J. Food Prot., 68, 814-819
  • Cagri, A., Z. Ustunol, E.T. Ryser (2002) Inhibition of three pathogens on bologna and summer sausage using antimicrobial edible films., J. Food Sci., 67, 2317-2324
  • Smith, S.E., J.L. Maurer, A. Orta-Ramirez, E.T. Ryser, D.M. Smith (2001) Thermal inactivation of Salmonella spp., Salmonella Typhimurium DT104, and Escherichia coli O157:H7 in ground beef., J. Food Sci., 66, 1164-1168
  • Cagri, A., Z. Ustunol, E.T. Ryser (2001) Mechanical, barrier, and antimicrobial properties of low pH whey protein isolate edible films containing para-aminobenzoic or sorbic acid., J. Food Sci., 66, 665-670
  • Ryser, E.T,, C.W. Donnelly (2001) Listeria, Compendium of Methods for the Microbiological Examination of Foods, 4th edition, Washington, DC, American Public Health Assoc. (bookchapter)
  • Ryser, E.T, (2001) Public Health Concerns, Applied Dairy Microbiology, 2nd edition, New York, Marcel Dekker (bookchapter)
  • Issa, M.A., E.T. Ryser (2000) Fate of Listeria monocytogenes, Salmonella typhimurium DT104 and Escherichia coli O157:H7 in Labneh as a pre- and post-fermentation contaminant., J. Food Prot., 63, 608-612
  • Abou-Eleinin, A.M, E.T. Ryser, C.W. Donnelly (2000) Incidence and seasonal variation of Listeria species in bulk tank goat's milk., J. Food Prot., 63, 1208-1212
  • Ryser, E.T., Pathogens in milk and milk products, Standard Methods for the Examination of Dairy Products, Amer, 17th Edition, 1999
  • Donnelly, C.W., and E.T. Ryser, Listeria, Compendium of Methods for the Microbiological Examination of Foods, 4th Edition, 1999
  • Ryser, E.T,, E.H., Marth, Listeria, Listeriosis and Food Safety, 1999
  • Ryser, E.T., E.H. Marth (1999) Listeria, Listeriosis and Food Safety, Marcel Dekker, Marcel Dekker
  • Ryser, E.T., Ryser, E.T., and E.H. Marth (eds), Incidence and behavior of Listria monocytogenes in unfermented dairy products, Listeria, Listeriosis and Food Safety, 1998
  • Ryser, E.T., Ryser. E.T., and E.H. Marth (eds), Incidence and Behavior of Listeria monocytogenes in fermented dairy products, Listeria, Listeriosis and Food Safety, 1998
  • Cox, N.A., S.S. Bailey, and E.T. Ryser, Ryser, E.T. and E.H. Marth (eds), Incidence and Behavior of Listeria monocytogenes in poultry and egg products, Listeria, Listeriosis and Food Safety, 1998
  • Ryser ET, Arimi SM, Donnelly CW, Effects of pH on distribution of Listeria ribotypes in corn, hay, and grass silage, Applied and Environmental Microbiology, 63(9), 3695-7, September 1997 Abstract
  • Silk, T.M., E.T. Ryser, and C.W. Donnelly, Comparison of methods for determining coliform and Escherichia coli levels in apple cider, Journal of Food Protection, 60, 1302-1305, 1997
  • Arimi, S.M., Ryser, E.T., and C.W. Donnelly, Dairy cattle and silage as potential sources of Listeria ribotypes common to dairy processing facilities, Journal of Food Protection, 60, 811-816, 1997
  • Ryser ET, Arimi SM, Bunduki MM, Donnelly CW, Recovery of different Listeria ribotypes from naturally contaminated, raw refrigerated meat and poultry products with two primary enrichment media, Applied and Environmental Microbiology, 62(5), 1781-7, May 1996 Abstract
  • Ryser ET, Maisnier-Patin S, Gratadoux JJ, Richard J, Isolation and identification of cheese-smear bacteria inhibitory to Listeria spp, International Journal of Food Microbiology, 21(3), 237-46, February 1994 Abstract
  • Ryser, E.T., and E.H. Marth, Listeria, Listeriosis and Food safety, Marcel Dekker, Inc., New York, 1991
  • E.T. Ryser, E.H. Marth (1991) Listeria, Listeriosis and Food Safety, New York, Marcel Dekker, Out of Print
  • Ryser ET, Marth EH, New food-borne pathogens of public health significance, Journal of the American Dietetic Association, 89(7), 948-54, July 1989 Abstract
  • Ryser ET, Marth EH, Behavior of Listeria monocytogenes during manufacture and ripening of brick cheese, Journal of Dairy Science, 72(4), 838-53, April 1989 Abstract
  • Yousef AE, Ryser ET, Marth EH, Methods for improved recovery of Listeria monocytogenes from cheese, Applied and Environmental Microbiology, 54(11), 2643-9, November 1988 Abstract
  • Ryser ET, Marth EH, Growth of Listeria monocytogenes at different pH values in uncultured whey or whey cultured with Penicillium camemberti, Canadian Journal of Microbiology, 34(6), 730-4, June 1988 Abstract

Profile Details

Last Updated: 1/16/2009

COS Expertise ID #444802
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