46G-3 |
Thermal reduction and outgrowth of Clostridium sporogenes spores in vacuum packaged cooked beef and cooked pork held at 4.4° and 10°C |
R. J. Danler, E. A. E. BOYLE, C. L. Kastner, H. Thippareddi, D. Y. C. Fung, J. F. Gosch, and R. K. Phebus. Department of Animal Sciences and Industry, Kansas State University, Weber Hall, Manhattan, KS 66506 Heat treatment for extended shelf-life refrigerated foods is less than that required for commercial sterility. Vegetative cells are destroyed but spores survive. Little or no preservatives are used in the manufacture of these products and refrigeration is required to ensure product safety. However, refrigeration alone cannot be relied upon to keep foods safe. Potential temperature abuse along with vacuum packaging to create an anaerobic environment make these types of foods a potential risk from spore forming bacteria such as Clostridium botulinum. C. sporogenes is the organism most frequently used for conducting inoculated pack studies in low acid foods. The purpose of this study was to determine the thermal reduction and outgrowth of C. sporogenes spores in vacuum packaged cooked beef and cooked pork held at 4.4° and 10°C for up to 150 days. Beef and pork were inoculated with 106 Colony Forming Unit/g (CFU/g) C. sporogenes spores, vacuum packaged and cooked to 82.2°C with a dwell time of 7 h and 4 h, respectively, chilled to 4.4°C within 4 h, then stored at 4.4°C or 10°C for 150 d. Samples were tested for aerobic, anaerobic, and C. sporogenes counts every 30 d during storage. Cooking significantly reduced aerobic, anaerobic, and C. sporogenes counts from 4.07 to <1 Log CFU/g, 3.74 to <1 Log CFU/g, and 6.19 to 3.90 Log CFU/g, respectively for beef and 3.49 to <1 Log CFU/g, 3.25 to <1 Log CFU/g, and 6.28 to 4.73 Log CFU/g, respectively for pork. Aerobic, anaerobic, or C. sporogenes counts did not change during refrigerated storage cooked beef or pork. C. sporogenes spores were significantly reduced during initial cooking and no significant increase in numbers was found during refrigerated storage. These heat treatments would greatly reduce the risk of food poisoning caused by sporeforming microorganisms provided products are handled safely.
Session 46G, Muscle Foods I
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