100A-12 |
Lethality determinations of surface pasteurization in a heat shrink steam tunnel |
F. M. Steele, A. D. ZAMORA, S. Frewing, and E. J. Hancock. Food Science and Nutrition, Brigham Young University, S-131 ESC, Provo, UT 84602 The potential for post-process contamination in ready-to-eat (RTE) turkey products exists as the product is handled for further processing. The product undergoes a mild heat treatment in a shrink-wrapping process as it is packaged for shipping. This heat shrink process should possess some degree of lethality to any potential surface contaminants although the lethality has not been determined. It would be significant to know what level of surface pasteurization is achieved in this packaging process. This study was designed to determine the degree of lethality achieved in the current shrink-wrap steam tunnel used in packaging of RTE products in a local turkey processing facility. Temperature monitoring thermocouples were placed at the surface of the products and a time temperature profile of the process was determined. Thermal Death Time curves were then obtained by inoculating 2.54 cm diameter portions of RTE turkey with a cocktail of Salmonella derby and S. typhimurium at 108 cfu/20 gram sample. Inoculated samples were submerged in either a 76.6C or 87.7C for between 20 and 140 seconds. Samples were plated and the lethality was determined. Results showed that an excess of 6-log reduction of the target microorganisms was obtained from the steam tunnel thermal processing of the RTE turkey products with a minimum temperature of 87.7C for at least a 100 second exposure. These results suggest that the process is adequate. However, the inability of different regions of the samples analyzed to uniformly reach the required heat exposure indicates a need for design modifications in the heat tunnel. These modifications could include complete submersion in hot water instead of exposure to steam because of complete heat penetration.
Session 100A, Food Microbiology: General II
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