ABSTRACT
High Pressure .............................................................................................. 416 15.3 Chemical Reaction Kinetics ........................................................................ 419 15.4 Temperature Prediction Models .................................................................. 426
15.4.1 Thermal Properties under Pressure................................................ 427 15.4.2 Temperature Prediction Models for High-Pressure Processes ...... 429
15.5 Recommendations for Proper Experimental Procedures ............................ 434 15.6 Final Remarks ............................................................................................. 435 References .............................................................................................................. 435
The exponential growth of the pressure-processing industry and the many products found all over the world illustrate the commercial success of the high pressure processing (HPP) technology. The previous chapter described the essential elements of pressure processing including the mechanisms and inactivation kinetics of microorganisms and enzymes. A new equipment generation is expected in the near future to allow the commercial application of pressure-assisted thermal processing (PATP) research. Moderate-temperature PATP will be used when HPP is not commercially feasible due long processing times when using pressure alone, for example,
pasteurized milk. PATP at higher temperatures will deliver shelf-stable, low-acid foods with higher quality than the conventional thermal treatments used today for the commercial sterilization of foods. In this chapter, a reaction kinetics approach will be followed to explain PATP effects on food composition as compared to conventional thermal treatments. The design of PATP processes will require knowledge of the temperature distribution in the high-pressure vessel and the food being processed. Also important will be to ensure homogenous temperature pro le to ensure that all foods are subjected to treatments that are not dependent upon location within the vessel. Modeling approaches proposed to explore solutions to these two technological challenges are presented in this chapter.
