Progress 11/01/99 to 12/31/05

Outputs
A cocktail of five Salmonella or five Listeria monocytogenes strains were used for inoculation of Prosciutto ham. The curing and heat treatment reduced Salmonella spp. by an average of 7.7 log CFU/cm2 and Listeria monocytogenes by 6.8 log CFU/cm2, therefore, meeting USDA reduction standards. The GrovacTM (Pine Bluff, AR) was evaluated for its effectiveness in reducing E. coli O157:H7 and Salmonella spp. inoculated onto the surfaces of raw beef trimmings. Pathogen reductions were modest. PathatrixTM an immuno- capture system increased the concentration of Escherichia coli O157:H7 in analytical units, and a same day protocol for detection of E.coli O157:H7 from 25 and 375 g ground beef samples was established. PCR was more sensitive in detecting E. coli O157:H7 as compared to plating and ColortrixTM, an enzyme-linked immunoassay, after running the sample on the PathatrixTM. Pathatrix/Colortrix provides same day results for the 25 g ground beef sample (5.25 hr), 375 g (6.50 hr). When combined with the PCR, results are obtained in 8 hrs for the 25 g and 9 hrs for the 375 g ground beef sample. Dried plum mixtures were able to increase the microbial shelf life of ground beef. Additionally, fresh plum juice concentrate is able to prevent and decrease E. coli O157:H7 and S. Typhimurium growth in liquid systems. In a liquid system a honey and tea extract combination was effective in reducing L. monocytogenes and E. coli O157:H7. The application of this treatment is currently being investigated with positive results as a surface wash. The strongest candidates as ideal indicator of fecal contamination are Escherichia coli, enterococci, and Clostridium perfringens. C. perfringens gives an acceptable correlation to fecal contamination, and can be enumerated in 8-9 hours. Therefore, it should be considered a viable alternative to current fecal indicators. A new method for the recovery of E. coli, clostridia, and Yersinia enterocolitica from animal confinement air samples was devised with Tryptic Soy Agar plates using an impaction air sampler. The formation of 2-DCB as indicator of irradiation exposure was evaluated in fresh irradiated ground beef patties at two fat levels.

Impacts
Our results show that 2-DCB can be used to monitor fresh irradiated beef and approximate the dose applied to it. Natural antioxidants found in some spices have been demonstrated to decrease the levels of HCAs, carcinogenic compounds and mutagens present at part per billion levels in cooked meat products. Origanox, a natural water soluble extract of oregano, may be effective in reducing certain HCAs. Epidemiology is being added to the list of food safety related courses offered via the Internet (K-State Online). Existing distance education courses and modules are being evaluated for their use in food safety and security curricula and others are being identified for development. It would have cost about $640 million to test all cattle slaughtered in the United States in 2004 for BSE. The revenue gain would equal testing costs with 25 percent of the Japanese and South Korean markets recovered and testing performed on 75 percent of commercial cattle slaughtered.

Publications

• Retzlaff, D., R. Phebus, C. Kastner and J. Marsden. 2005. Establishment of minimum operational parameters for a high-volume static chamber steam pasteurization system 9SPS-400SC-trademark) for beef carcasses to support HACCP programs. Foodborne Pathogens and Disease. Vol 2, No. 2:146-151.
• Capellas, M., D.Y.C. fung and J. Yuste. 2005. meodes rapids i automatizacio en microbiolgia alimentaria. Vetenineris. 84:16-17.
• Fox, J.A., B. Coffey, J. Mintert, T. Schroeder and L. Valentin. 2005. The U.S. repsonse to BSE. Choices. 20:1-5.
• Fung, D.Y.C. 2005. Molecular food microbiology: modern tools for food safety. U.S. Food Safety. 3:1-4.
• Gadgil, P., J.S. Smith, K.A. Hachmeister and D.H. Kropf. 2005. Evaluation of 2-dodecylcyclobutanone as an irradiation dose indicator in fresh irradiated ground beef. J. Agriucltural and Food Chemistry. 53:1890-1893.
• Kim, S., and D.Y.C. Fung. 2005. Modified microtiter count method for viable cell counts from pure cultures and food model samples. Food Microbiology. 22:595-599.

Progress 01/01/04 to 12/31/04

Outputs
A novel controlled phase carbon dioxide (cpCO2) antimicrobial decontamination system was tested against a multiple-strain cocktail of Listeria monocytogenes, Salmonella spp., generic E. coli, and E. coli O157:H7 inoculum on sterile 5.5 cm filter paper #1 disks. Log10 CFU/cm2 reductions ranged from 5.4 to 6.0 for Salmonella spp., 2.7 to 5.2 for Listeria monocytogenes, 1.9 to 5.8 for generic E. coli, and 4.4 to 6.4 for E. coli O157:H7 in four replications. The use of cpCO2 as an antimicrobial intervention system for food products appears promising in the case of low organic loads. Non-inoculated ground meat samples were exposed to supercritical CO2 inside an extractor at 1470, 2000, 3000 and 5000 psi for 5, 7.5 and 15 min. Meat cubes inoculated with E. coli O157:H7 were tested inside a controlled phase carbon dioxide (cpCO2) antimicrobial decontamination system at 1000 psi for 5, 10 and 240 min. The greatest reductions of E. coli O157:H7 (1.9 Logs) and generic E. coli (1.2 Logs) populations were achieved by 1600 psi for 7 min and 2400 psi for 3 min, respectively. Other research showed that the most recovered microbial genus in the air from the dairy facility was Staphylococcus, Aerococcus from the swine unit, and Corynebacterium from the poultry unit. Overall, the most common organism recovered was Corynebacterium. The majority of identified organisms were found to be Gram-positive. Some Gram- negative organisms identified in this study include Escherichia, Klebesiella, Proteus, Shigella, and Yersenia; The effect of rosmarinic acid and a rosemary extract antioxidant powder (24-26% of carnosic acid as main component) on Heterocyclic amines (HCAs) in fried beef patties at two variable temperatures was investigated. The rosemary compounds were able to decrease HCAs formation and overall mutagenic activity in the beef patties. We also evaluated the mutagenic potential of fusaproliferin using the Ames Salmonella/microsome assay. Our results suggest that fusaproliferin with S9 activation is a weak mutagen in S. typhimurium TA98. Supercritical fluid extraction (SFE) coupled with gas- chromatography/mass spectroscopy (GC-MS) was found to be an effective method for evaluating 2-dodecylcyclobutanone (2-DCB) formation in fresh irradiated ground beef. Three-food safety and security distance education courses (Principles of HACCP, Applied Microbiology for Meat & Poultry Processors, Fundamentals of Communication for the Agriculture and Food Science Community) were offered via the Internet (K-State Online) A survey in California, New York and Kansas found that consumers would be significantly more likely to reduce beef consumption in response to multiple cases of BSE than to a single additional case. Numerous HACCP and related programs training workshops were held for industry groups and more than 200 food products were evaluated for safety and shelf-life.

Impacts
The work has resulted in significant methods development for the isolation, detection, and quantification of microbial and chemical hazards and the elimination of those hazards. Also significant information and technology transfer and risk assessment information was developed and has laid the foundation for expansion on those areas. Furthermore, our food safety work has prepared us to address food security that may be a result of bioterrorism and/or natural disasters.

Publications

• No publications reported this period

Progress 01/01/03 to 12/31/03

Outputs
Beef heifers were fed dried distiller's grains with solubles (DDGS), at 0, 15, 30, 45, 65, and 75% on a dry matter basis. DDGS did not affect acid resistant E. coli and coliforms in the feces or in the rumen fluid. Vibrio parahaemolyticus counts declined due to pressure-induced inactivation from 4 to 0.5 log CFU/mL at 200 MPa for 5 min, and were nondetectable at 300 MPa for 5 min. Bacillus cereus vegetative cells were reduced from 4 to 2.5 log CFU/mL at 300 MPa for 1 min and were nondetectable at 300 MPa for 5 min. Decon Foam-100 (DF-100) was used against Listeria monocytogenes and Pseudomonas putida containing biofilms resulting in 4-6 log reductions for all treatment times. Exposure to ozone on a 24 hour bio-film of Listeria monocytogenes and Pseudomonas putida grown on Nylon (NYL), Buna-n Nitrile Rubber (BUN), Stainless Steel type 304 #2b finish (STS), and Ultra High Molecular Weight polyethylene (POL) after 1 min. reduced counts by 0.6, 0.7, 1.0 and 1.3 log CFU/cm2 for STS, POL, NYL, and BUN, respectively for L. monocytogenes and by 0.3, 2.1, 2.1 and 2.5 log CFU/cm2 for P. putida. Sodium citrate (0, or 2% w/w) reduced the C. perfringens population in vacuum-packaged beef samples in the range of 0.38 to 1.14 log. There were neither antagonisms nor synergisms between sodium citrate and any of the spices used in this study. The addition of 2% sodium lactate prevented C. perfringens from exceeding 1 log. Frankfurters, polish sausage, and roast beef were inoculated with L. moncytogenes and sprayed with 1% cetylpyridinium chloride CPC and CPC followed by a water spray treatment. 1% CPC inhibited growth of L. monocytogenes on those products surfaces after storage for up to 42 days at 0 and 4 C. Sterilized cardboard samples were inoculated with a cocktail of E. coli O157:H7 or Salmonella spp and sprayed with a 500 ppm chlorine dioxide solution for 30 min. The number of E. coli 0157:H7 strains and Salmonella spp. was reduced below detection level. Treating beef flank with 32 ppm colloidal silver (Ag) solution had a bactericidal affect on Salmonella spp. and Escherichia coli O157:H7, resulting in a greater than 90% reduction after 240 min. The efficiency of Tryptic Soy Agar (TSA), Tryptone-Glucose Extract Agar, Brain Heart Infusion Agar, and Plate Count Agar for the recovery of heat-injured Escherichia coli O157:H7, Listeria moncytogenes, Salmonella Typhimurium, and Yersinia enterocolictica) were evaluated. TSA was the most effective. Oxyrase(registered trademark) was found to enhance recovery. The 5'-nuclease TaqMan) assay had reliable sensitivity with a detection limit of 3 to 4 log CFU/ml or gram for Yersinia enterocolitica O:8 in pure culture system and spiked ground pork samples. The acute toxicity of 2-dodecylcyclobutanone (2-DCB) was evaluated by the Microtox acute toxicity system and mutagenicity by the Ames assay. The potential risk from 2-DCB, if any, was very low. Applied Microbiology for Meat and Poultry Processors was developed as a Distance Education Course. Dr. Fung's Automated and Rapid Methods workshop continued for the 23rd year. The safety of >200 food products was evaluated and HACCP training provided.

Impacts
A variety of strategies for detection and control of pathogens provide industry with more options to enhance food safety. Extension and outreach efforts are means of providing critical assistance to processors and farmers to help them comply with food safety regulations and ultimately result in safer foods for consumers.

Publications

• Crozier-Dodson, B.A., and D.Y.C. Fung. 2002. Comparison of recovery of airborne microorganisms in a dairy cattle facility using selective agar and thin agar layer resuscitation media. Journal of Food Protection, 65 (9):1488-1492.
• Danler, R.J., E.A.E. Boyle, C.L. Kastner, H. Thippareddi, D.Y.C. Fung, and R.K. Phebus. 2003. Effects of chilling rate on outgrowth of Clostridium perfringens spores in vacuum-packaged cooked beef and pork. Journal of Food Protection, 66:501-503.
• Fotso, J., J.F. Leslie, and J.S. Smith. 2002. Production of beauvericin, moniliformin, fusaproliferin and fumonisins B1, B2 and B3 by fifteen ex-type strains of fusarium species. Applied and Environmental Microbiology, 68:5195-5197.
• Fotso, J., and J. S. Smith. 2003. Evaluation of beauvericin toxicity with the bacterial bioluminescence assay and the Ames mutagenicity bioassay. Journal of Food Science, 68:1938-1941.
• Fox, J.A. Influences on purchase of irradiated foods. 2002. Food Technology , 56 (November 2002):34-37.
• Gadgil, P., K.A. Hachmeister, J.S. Smith and D. H. Kropf. 2002. 2-alkylcyclobutanones as irradiation dose Indicators in irradiated ground beef patties. Journal of Agricultural and Food Chemistry, 50:5746-5750.
• Gadgu, P., K.A. Hachmeister, J.S. Smith, and D.H. Kropf. 2002. 2-Alkylcyclobutanones as irradiation dose indicators in irradiated ground beef patties. Journal of Agricultural and Food Chemistry, 50:5746-5750.
• Hayes, D.J., J.A. Fox and J.F. Shogren. 2002. Experts and advocates: How information affects the demand for food irradiation. Food Policy, 27:185-193.
• Hunt, M.C., J.J. Schoenbeck, E.J. Yancey, M.E. Dikeman and P.B. Addis. 2002. Effects on meat display-color stability of postexsanguination vascular infusion of cattle with calcium chloride or a solution of saccharides, sodium chloride, phosphates. Journal of Animal Science, 81:669-675.
• Lawrence, T.E., M.C. Hunt and D.H. Kropf. 2002. Surface roughening of precooked, cured beef round muscles reduces iridescence. Journal of Muscle Foods, 13:69-73.
• Lien, R., M.C. Hunt, S. Anderson, D.H. Kropf, T.M. Loughin, M.E. Dikeman and J. Velazco. 2002. Effects of endpoint temperature on the internal color of pork loin chops of different quality. Journal of Food Science, 67(3):1007-1010.

Progress 01/01/02 to 12/31/02

Outputs
No significant effect of higher amounts of dried distillers grain on the log CFU/g of acid-resistant E. coli and coliforms was observed at 2 and 20 h post-feeding (P>0.05); however, the time at which samples were taken had a tendency to affect acid-resistant E. coli and coliforms (P<0.10) in feeder cattle. The efficacy of a unique quaternary/peroxide foaming sanitizer developed by Sandia National Laboratories was evaluated and found to be effective against common foodborne pathogens and spoilage. A microbiological validation study evaluated the safety of a cook-in-bag process for a precooked lamb in curry sauce product. Cooking at the optimum temperature and time for quality (90 degrees C for 2 h), reduced counts by ca. 5 log CFU/g, and C. sporogenes populations by 1.38 log CFU/g. Chilling product inoculated with C. perfringens (ca. 3 log CFU/g) according to USDA recommendations (1.5 h from 54.4 to 26.7 degrees C and 5 h from 26.7 to 4.4 degrees C reduced (P<.05) C. perfringens populations by 1 log CFU/g compared to heat shocked controls. The efficacy of a saturated steam-based post-process pasteurization system to reduce/eliminate L. monocytogenes on frankfurters and restructured hams was evaluated. Pasteurization of inoculated single layer franks to target surface end point temperatures of 160, 170, and 180 degrees F resulted in L. monocytogenes reductions (P<.05) of .92, 1.44 and 2.89 log CFU/frank, respectively. Pasteurization of hams (half) for 2 and 4 min resulted in L. monocytogenes reductions (P<.05) of 2.03 and 4.14 log CFU/g., respectively. When cooking at 375 degrees F, spices added to ground beef at the .5 percent level decreased heterocyclicamines formation. Garlic (21 percent reduction), basil (79 percent), dried plums (74 percent) and rosemary (67 percent) were the best inhibitors. A survey of Kansas consumers indicated that 47 percent were willing to pay more for irradiated hamburger. Providing information to consumers had a significant impact on their choice (55 percent versus 39 percent). No significant differences in the enumeration of Clostridium perfringens were found between Fung's Double Tube (FDT) system using Tryptose Cycloserine without egg-yolk (TSC) versus Shadidi-Ferguson perfringens (SFP) agar in three typical meat products and peptone water using a three-strain cocktail inoculum of the bacterium spores in each food system. The formation of 2-dodecylcyclobutanone (2-DCG) and 2-tetradec-5' enylcyclobutanone (2-TDCB) in irradiated ground beef patties from commercial and non commercial sources was investigated. The 2-DCB was detected in all the irradiated samples and its concentration increased with the irradiation dose. The safety and shelf-life of 191 food products manufactured by local companies were evaluated and potential problems addressed. One-on-one consultations and company specific training for on-site assistance in HACCP implementation and maintenance and related pre-requisite programs were performed. Several workshops on HACCP, Sanitation and GMPs and Good Agricultural Practices were conducted for food/meat processors and fruits/vegetable growers.

Impacts
A variety of strategies for detection and control of pathogens provide industry with more options to enhance food safety. Extension and outreach efforts are means of providing critical assistance to processors and farmers to help them comply with food safety regulations and ultimately result in safer foods for consumers.

Publications

• Fox, J.A., D.J. Hayes, and J.F. Shogren. 2002. Consumer preferences for food irradiation: how favorable and unfavorable descriptions affect preferences for irradiated pork in experimental auctions. Journal of Risk and Uncertainty, 24:75-95.
• Fung, D.Y.C. 2002. Critical review of rapid methods and automation in microbiology. Comprehensive Reviews in Food Science and Food Safety (IFT Electronic Journal), 1:3-22.
• Fung, D.Y.C. 2002. Predictions for the future of rapid methods. Journal of AOAC International, 85(4):1-3.
• Fung, D.Y.C. 2002. Where are we now? On the fast tract with rapid and automated methods. Food Safety, 8(3):18-26.
• Brashears, M., Burson, D., Boyle, E., Aramouni, F., Mann, J. and Murphy, M. 2002. Development and Evaluation of an Advanced HACCP Workshop for Meat Processors. Dairy, Food and Environmental Sanitation. 22(12). 976-984.

Progress 01/01/01 to 12/31/01

Outputs
There was a 1 to 2 log CFU/ml reduction of pathogens with both plum juice concentrate and dried plum puree compared with the control after 5 days. All inoculated pathogens in ground beef decreased by 1-2 log CFU/g. The liquid media with prune puree or plum juice caused a 2.5 log or greater reduction of total count, S. typhimurium, L. monocytogenes, E. coli O157:H7, Y. enterocolitica, and S. aureus at a concentration greater than 2.5%. Addition of garlic into ground beef patties had synergistic effect of E. coli O157:H7 during cooking. The Thin Agar Layer method provided a good combination of TSA and selective media to enumerate and isolate injured pathogens. Our research established the susceptibility of Listeria monocytogenes to heat and established the efficacy of an in-package pasteurization treatment to reduce risk of surface contamination of hard salami and kielbasa. We validated the effectiveness of a saturated steam based post-processing system for reducing or eliminating L. monocytogenes on surfaces of RTE deli meat products. Stork RMS-Protecon system can be integrated into the RTE meat product manufacturing process as a Critical Control Point to reduce or eliminate the risk of Listeria monocytogenes in these products. The risk of L. monocytogenes on frankfurters can be reduced by incorporation of processing steps such as post-process, in-package pasteurization to eliminate Listeria monocytogenes surface recontamination of RTE products. Even though the blade tenderized prime rib preparation process utilizes very low cooking temperatures, long cooking time and tempering period (accompanied by a significant post-cook temperature rise) results in substantial process lethality and a safe final product. When the product was cooked to the optimum temperature for quality (90 C for 2 h), anaerobic and APC were reduced by 5 log CFU/g. Lactic acid bacteria and C. sporogenes populations were reduced by 5.08 and 1.38 log CFU/g, respectively. Chilling the C. perfringens inoculated product according to the USDA recommendations (1.5 h from 54.4 C to 26.7 C and 5 h from 26.7 to 4.4 C) reduced C. perfringens population 1 log CFU/g compared to heat shocked controls. Chilling of the product according to industry conditions of 2 h through the first temperature phase and 5 h through the second phase resulted in no growth or reduction of C. perfringens. Effective treatments for the reduction of bacteria were 2% lactic acid (80 C) dipped for 2 sec, vacuum packaging, and microwave treatment of 70 sec. This method is an effective terminal treatment to reduce bacteria and prevent re-contamination on beef subprimals. Several workshops on HACCP implementation, Advanced HACCP, Recalls, Sanitation and GMPs, and Good Agricultural Practices were conducted for food/meat processors, and fruits/ vegetable growers. One-on-one consultations and company specific training for on-site assistance in implementation and maintenance of HACCP and related pre-requisite programs were performed. The shelf-life and safety of dozens of food products manufactured by local companies were evaluated and potential problems addressed.

Impacts
The variety of pathogen control strategies provide the industry with a variety of options to enhance food safety. Extension and Outreach efforts are a venue of assistance for companies and farmers to help them comply with food safety regulations and ultimately result in safer foods for consumers.

Publications

• Thompson, L.K. and D.Y.C. Fung. 2001. Effects of dried prune purees on suppression of growth of foodborne pathogens in uncooked ground beef. The Food Safety Consortium Annual Meeting, pp. KSU 1-10, Ames, IA.
• Thompson, L.K., D.Y.C. Fung and B.A. Crozier-Dodson. 2001. Effects of dried plum purees on suppression of foodborne pathogens in liquid medium. The Food Safety Consortium Annual Meeting, pp. KSU 11-17, Ames, IA.
• Ceylan, E., D.Y.C. Fung, M.C. Hunt and C.L. Kastner. 2001. Synergistic effect of garlic, cold storage and heating in controlling Escherichia coli O157:H7 in ground beef patties. The Food Safety Consortium Annual Meeting, pp. KSU 18-22, Ames, IA.
• Wu, V.C.H. and D.Y.C. Fung. 2001. Evaluation of thin agar layer method for recovery of cold-injured foodborne pathogens. The Food Safety Consortium Annual Meeting, pp. KSU 39-59, Ames, IA.
• Mancini, R.A., M.C. Hunt, C.L. Kastner and D.H. Kropf. 2001. The effects of lean level, storage temperature, storage time, and display temperature on aerobic plat counts and lactic acid bacteria counts of ground beef. The Food Safety Consortium Annual Meeting, pp. KSU 60-68, Ames, IA.
• Gill, V.S., H. Thippareddi, R.K. Phebus, J.L. Marsden and C.L. Kastner. 2001. Steam based post-process pasteurization of beef salmi and turkey kielbasa for control of Listeria monocytogenes. The Food Safety Consortium Annual Meeting, pp. KSU 69-73, Ames, IA.
• Gill, V.S., H. Thippareddi, R.K. Phebus, J.L. Marsden and C.L. Kastner. 2001. Validation of a steam based post-process pasteurization system for control of Listeria monocytogenes in ready-to-eat deli meats. The Food Safety Consortium Annual Meeting, pp. KSU 74-78, Ames, IA.
• Gill, V.S., H. Thippareddi, R.K. Phebus, J.L. Marsden and C.L. Kastner. 2001. Steam based post-process pasteurization of frankfurters for control of Listeria monocytogenes. The Food Safety Consortium Annual Meeting, pp. KSU 79-83, Ames, IA.
• Wendelburg, J.W., D.L. Lambert, C.L. Kastner, R.K. Phebus, H. Thippareddi and J.L. Marsden. 2001. Salmonella spp. risk assessment for production and cooking of blade tenderized prime rib. The Food Safety Consortium Annual Meeting, pp. KSU 84-88, Ames, IA.
• Vander Wal, L.S., C.L. Kastner, H. Thippareddi, R.J. Danler, P. Udomvarapont, R.K. Phebus and D.H. Kropf. 2001. Microbial validation of sous vide-like cooking process for lamb in curry sauce. The Food Safety Consortium Annual Meeting, pp. KSU 111-114, Ames, IA.
• Crozier-Dodson, B.A., D.Y.C. Fung, J.M. Kim and L.K. Thompson. 2001. Combined treatments of 2 pct lactic acid (80degreesC), and microwaves for the reduction of natural microflora and Escherichia coli O157:H7 on vacuum packaged beef subprimals. The Food Safety Consortium Annual Meeting, pp. KSU 150-164, Ames, IA.
• Aramouni, F.M., and Lindquist, T.B. Current Good Manufacturing Practices (cGMPs) in Manufacturing, Packing, or Holding Human Foods. 2001. Kansas State University Agricultural Experiment Station and Cooperative Extension Service. MF-2505.
• Recall Workshop Manual. 2001. Burson, D., Boyle, E. Breshears, M. and Aramouni. F. Kansas State University Agricultural Experiment Station and Cooperative Extension Service and University of Nebraska, Lincoln.
• GMPs and Sanitation Workshop Manual. 2001. Boyle, E, Aramouni, F., Burson, D., and Breshears, M. Kansas State University Agricultural Experiment Station and Cooperative Extension Service and University of Nebraska, Lincoln.
• Advanced HACCP Workshop Manual. 2001 Breshears, M., Burson, D., Boyle, E. and Aramouni, F. University of Nebraska, Lincoln and Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Progress 01/01/00 to 12/31/00

Outputs
Inoculation studies showed that post-process pasteurization of some packaged meat products with steam can control 3-5 logs of listeria without negatively impacting product quality. Of 23 spices tested, garlic, clove, cinnamon, oregano, and sage were all shown to control bacteria. The thin-layer agar method (TAL) has been developed to detect injured cells. It is more rapid and may be more sensitive than previous methods. Myoglobin denaturation in pork patties was affected by endpoint temperature, quality level, myoglobin form and whether the patty was cooked from a frozen or thawed state. The combination of oxymyoglobin and PSE patties predisposed myoglobin to denature at lower temperatures. Mechanical tenderization and needle injection resulted in translocation of surface Salmonella typhimurium to the interior of pork loin muscle, with progressively decreasing levels with penetration of the blades or needles. Cooking of 1.0 in. thick non-intact pork loin chops to 1600 F resulted in 4.0 log CFU/g reduction of Salmonella spp. obtained from blade tenderized or needle inject pork. Sixty percent of consumers were willing to purchase irradiated beef products, with older consumers, family with children under 18 at home, and people who have an education level of college and beyond more inclined to buy these products. HACCP, sanitation and GMPs assistance was provided to tens of meat and food processing operations and food service establishments through on-site visits, workshops, a toll free telephone number, a world wide web site, and a variety of printed and audio visual materials. 139 products from small and medium size food companies were analyzed for safety and compliance with low-acid canned food regulations.

Impacts
Steam is proving effective in pasteurizing the surface of final-packaged products (i.e., hams) that may have been contaminated after processing. Spices provide another important hurdle that microorganisms must overcome. Ongoing research on the safety of non-intact products is helping USDA-FSIS make preparation recommendations relative to these products. Beef processors may receive a small price premium to cover the cost of irradiation. Food Safety and HACCP assistance programs are enabling meat and food processors to comply with regulations and improve their products.

Publications

• Kang, D.H. and D.Y.C. Fung. 2000. Stimulation of starter culture for further reduction of foodborne pathogens during salami fermentation. Journal of Food Protection 63(5).
• Mark, D., M.A. Boland, and J.A. Fox. 2000. Pork producers cost estimates of on-farm Salmonella testing. American Journal of Agricultural and Applied Economics 31(2):388.
• Schmidt, K.A., R.H. Thakur, G. Jiang, and D.Y.C. Fung. 2000. Application of a double tube system for the enumeration of Clostridium typobutyricum. Journal of Rapid Methods and Automation in Microbiology 8(1):21-30.
• Vichicnroj, K. and D.Y.C. Fung. 2000. Growth of pathogenic bacteria in Universal Preenrichment Broth supplemented with Oxyrase and Ferrioxamine E. Journal of Rapid Methods and Automation in Microbiology 8:41-51.
• Zhang, P., J.A. Fox, and M.A. Boland. 2000. Consumer valuation of antimicrobial: An application to beef. American Journal of Agriculture Economics 82:5.