Donald W. Schaffner Extension Specialist Rutgers University Dept. of Food Science School of Env & Biol Sciences Food Science Building 65 Dudley Rd. New Brunswick. NJ 08901-8520 (732) 932-9611. x 214 FAX - 6776 schaffner@aesop.rutgers.edu Visit Dr. Schaffner's Homepage!

Predictive food microbiology and quantitative microbial risk assessment

Our applied research program is focused on the use of mathematics and statistics to understand and control foodborne microbes. Our research currently has two separate but interrelated thrust areas: predictive microbiology and quantitative microbial risk assessment.

We currently have two on-going predictive microbiology research projects. The first project evaluates existing mathematical models for the growth of Clostridium spp. in meat products under changing temperatures. We have recently developed a new model for Clostridium perfringens. and are validating this model for it's suitability for predicting C. botulinum growth. The second project seeks to model the growth of pathogens and spoilage bacteria on raw poultry.

Our quantitative microbial risk assessment thrust area currently has one risk assessments underway. The risk assessment compares the risk reductions achieved through seed sanitation treatments and through testing of sprout irrigation water for pathogens.

We are also involved in a number of applied food microbiology projects including a survey of the microbiological quality of apple ciders produced in New Jersey.

Selected Publications

Dominguez SA, Schaffner DW. (2008) Modeling the growth of Salmonella in raw poultry stored under aerobic conditions. J Food Prot. 71(12):2429-35.

Liu B, Schaffner DW. (2007) Mathematical modeling and assessment of microbial migration during the sprouting of alfalfa in trays in a nonuniformly contaminated seed batch using Enterobacter aerogenes as a surrogate for Salmonella Stanley. J Food Prot. 70(11):2602-5.

Dominguez SA, Schaffner DW. (2007) Development and validation of a mathematical model to describe the growth of Pseudomonas spp. in raw poultry stored under aerobic conditions. Int J Food Microbiol. 120(3):287-95.

Smith-Simpson S, Corradini MG, Normand MD, Peleg M, Schaffner DW. (2007) Estimating microbial growth parameters from non-isothermal data: a case study with Clostridium rfringens. Int J Food Microbiol. 118(3):294-303.

Ingham SC, Fanslau MA, Burnham GM, Ingham BH, Norback JP, Schaffner DW. (2007) Predicting pathogen growth during short-term temperature abuse of raw pork, beef, and poultry products: use of an isothermal-based predictive tool. J Food Prot. 70(6):1446-56.

Rho MJ, Schaffner DW. (2007) Microbial risk assessment of staphylococcal food poisoning in Korean kimbab. Int J Food Microbiol. 116(3):332-8.

Liu B, Schaffner DW. (2007) Quantitative analysis of the growth of Salmonella stanley during alfalfa sprouting and evaluation of Enterobacter aerogenes as its surrogate. J Food Prot. 70(2):316-22.

Schaffner DW, Schaffner KM. (2007) Management of risk of microbial cross-contamination from uncooked frozen hamburgers by alcohol-based hand sanitizer. J Food Prot. 70(1):109-13.

De Siano T, Padhi S, Schaffner DW, Montville TJ. (2006) Growth characteristics of virulent Bacillus anthracis and potential surrogate strains. J Food Prot. 69(7):1720-3.

Danyluk MD, Harris LJ, Schaffner DW. (2006) Monte Carlo simulations assessing the risk of salmonellosis from consumption of almonds. J Food Prot. 69(7):1594-9.

Montville TJ. Dengrove R. De Siano T. Bonnet M. Schaffner DW. (2005) Thermal resistance of spores from virulent strains of Bacillus anthracis and potential surrogates. J Food Prot. 68(11):2362-6.

Montville. R. I. and Schaffner. D.W. (2005). Monte Carlo simulation of pathogen behavior during the sprout production process. Applied and Environmental Microbiology. 71(2): 746-753.

Smith-Simpson. S. and Schaffner. D.W. (2005). The development of a model to predict growth of Clostridium perfringens in cooked beef during cooling. Journal of Food Protection. 68(2): 336-341.

Stewart. C.M.. Cole. M.B. Legan. J.D. Slade. L and Schaffner. D.W. (2005). Solute-specific effects of osmotic stress on Staphylococcus aureus. Journal of Applied Microbiology. 98: 193-202.

Schaffner. D.W. (2004). Mathematical frameworks for modeling Listeria cross-contamination in food processing plants. Journal of Food Science 69(6):R155-159.

Smith. S.. Juneja. V. and Schaffner. D.W. (2004). The influence of several methodological factors on the growth of Clostridium perfringens in cooling rate challenge studies. Journal of Food Protection 67(6): 1133-1137.

Smith. S. and Schaffner. D.W. (2004). Evaluation of predictive models for Clostridium perfringens growth during cooling. Journal of Food Protection 67(6): 1128-1132.

Smith. S. and Schaffner. D.W. (2004). Evaluation of a Clostridium perfringens predictive model developed under isothermal conditions in broth to predict growth in ground beef during cooling. Applied and Environmental Microbiology 70(5): 2728-2733.

Montville. R. I. and Schaffner. D.W. (2004). Analysis of published sprout seed disinfection studies shows treatments are highly variable. Journal of Food Protection. 67(4):758-765.

Schaffner. D.W.. Sithole. S.. R. Montville. (2004). Use of microbial modeling and Monte Carlo simulation to determine performance criteria for bacterial populations on plastic cutting boards in use in foodservice kitchens. Food Protection Trends. 24(1): 14-19.

Montville. R. and Schaffner. D.W. (2004). Statistical distributions describing microbial quality of surfaces and foods in foodservice operations. Journal of Food Protection. 67(1): 162-167.

Stewart. C.M.. Cole. M.B. and Schaffner. D.W. (2003). Managing the risk of Staphylococcal food poisoning from cream-filled baked goods using food safety objectives. Journal of Food Protection. 66(7) 1310-1325.

Mattick. K. Durham. K.. Domingue. G.. Jørgensen. F. Sen. M.. Schaffner D.W. and Humphrey. T. (2003). The survival of foodborne pathogens during domestic washing-up and subsequent transfer onto washing-up sponges. kitchen surfaces and food. International Journal of Food Microbiology. 85: 213-226.

Vora. P.. Senecal. A. and Schaffner. D.W. (2003). Survival of Staphylococcus aureus ATCC 13565 in intermediate moisture foods is highly variable. Risk Analysis 23(1): 229-236.

Zhao. L. Montville. T.J. and Schaffner. D.W. (2003). Computer simulation of the behavior of Clostridium botulinum 56A spores at low spore concentrations. Applied and Environmental Microbiology 69(2): 845-851.

Ng. T.M. Viard. E.. Caipo. M.L. Duffy. S and Schaffner. D.W. (2002). Expansion and validation of a predictive model for the growth of Bacillus stearothermophilus in military rations. Journal of Food Science 67(5): 1872-1878.

Duffy. S and Schaffner. D.W. (2002). Monte Carlo simulation of the risk of contamination of apples with Escherichia coli O157:H7. International Journal of Food Microbiology 78(3): 245-255.

Zhao. L. Montville. T.J. and Schaffner. D.W. (2002). Time-to-detection. percent-growth-positive and maximum growth rate models for Clostridium botulinum 56A at include multiple temperatures. International Journal of Food Microbiology 77(3): 187-197.

Caipo. M.L.. Duffy. S. Zhao. L. and Schaffner. D.W. (2002). Bacillus megaterium spore germination is influenced by inoculum size. Journal of Applied Microbiology. 92(5): 879-884.

Battey. A.S.. Duffy. S. and Schaffner. D.W. (2002). Modeling yeast spoilage in cold-filled ready to drink beverages by Saccharomyces cerevisiae. Zygosaccharomyces bailii and Candida lipolytica. Applied and Environmental Microbiology. 68(4): 1901-1906.

Stewart. C.M.. Cole. M.B.. Legan. D.. Slade. L.. Vandeven. M.H. and Schaffner. D.W. (2002). Staphylococcus aureus growth boundaries: Moving towards mechanistic predictive models based on solute-specific effects. Applied and Environmental Microbiology. 68(4): 1864-1871.

Montville. R.. Chen. Y. and Schaffner. D.W. (2002). Risk assessment of handwashing efficacy using literature and experimental data. International Journal of Food Microbiology 73: 305-313.

Zhao. L.. Chen. Y.. and Schaffner. D.W. (2001)Comparison of logistic and linear regression in modeling percentage data. Applied and Environmental Microbiology. 67(5) 2129-2135.

Montville. R.. Chen. Y.. and Schaffner. D.W. (2001) Glove barriers to bacterial cross-contamination. Journal of Food Protection. 64(6). 845-849.

Duffy. S and Schaffner. D.W. (2001) Modeling the survival of Escherichia coli O157:H7 in apple cider using probability distribution functions for quantitative risk assessment. Journal of Food Protection. 64(5): 599-605.

Chen. Y.. Jackson. K.M. Chea. F.P. and Schaffner. D.W. (2001) Quantification and variability analysis of bacterial cross-contamination rates in the kitchen. Journal of Food Protection. 64(1):72-80.

Stewart. C.M. Cole. M.B.. Legan J.D. Slade. L.. Vandeven. M.H. and Schaffner. D.W. (2001) Modeling the growth boundary of Staphylococcus aureus for risk assessment purposes. Journal of Food Protection. 64(1):51-57.

Uljas. H.E.. Schaffner. D.W. Duffy. S.M.. Zhao. L. and Ingham. S.C. (2001) Modeling of combined processing steps for reducing Escherichia coli O157:H7 populations in apple cider. Applied and Environmental Microbiology. 67(1):133-141.

Zhao. L.. Montville. T.J.. and Schaffner. D.W. (2001) Inoculum size of Clostridium botulinum 56A spores influences time-to-detection and percent growth-positive samples. Journal of Food Science. 65(8):1369-1375.