34-6 |
High pressure processing of low acid foods |
V. M. BALASUBRAMANIAM, Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007 High-pressure processing (HPP) of low-acid foods is of interest because of its ability to inactivate harmful bacterial spores at moderate temperatures and without the use of chemical preservatives. Successful HPP validation will require a multidisciplinary approach integrating basic microbiological, physical, chemical, and engineering principles to demonstrate the uniformity and sterility of the process. The presentation will provide an overview on current research status on high pressure sterilization of low-acid foods. Both process time and temperature are factors in HPP sterilization, but the unique contribution of pressure must also be considered. Product characteristics such as composition, pH, and water activity may affect the physical sterilization process and the microbial inactivation kinetics. Significant questions remain unanswered as to the mechanism of action of the pressure, spore injury, and uniformity of the treatment delivered. Much of the initial pasteurization work did not consider the thermal component of high pressure processing. As a food is pressurized, compression of the food results in heating of the product. To date, water seems to be the slowest heating component under pressure and fats seem to have highest compression heating (up to 9°C per 100 MPa). Presence and distribution of fat and water among other food components clearly affect the compression heating values of different foods during high pressure processing. These differences should be considered during HPP product development as well as in spore inactivation studies.
Session 34, Applications of high pressure processing technology in the food industry: Case study
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