Thermal Food Processing

178 Thermal Food Processing: New Technologies and Quality Issues
FIGURE 6.10 Townsend condensing steam postprocess surface pasteurization system.
(From Townsend Engineering, Des Moines, IA. With permission.)
6.7 THERMAL DESTRUCTION KINETICS
OF MICROORGANISMS
Thermal processes are designed to provide characteristic properties to food products.
However, the main target of these processes is to eliminate the risk of pathogens in
the product to ensure safety to consumers. Therefore, the higher the initial microbial
population in a product, the longer the processing/heating time or temperature required
to achieve the same degree of microbial reduction. 1 Heat penetration in meat products
occurs from the outside to the inside. Due to the high water content of meat, the
conditions within the muscle fibers or comminuted particles are similar to the heating
of water; therefore, they cannot reach temperatures above 100°C unless heated in a
pressured environment. 2 The rate of heating depends on the thermal conductivity of
the product and the surface temperature of the heating source.