Abstract
During the last few decades, the food industry is moving towards improved thermal and novel processing technologies as well as non-thermal processing techniques, owing to the associated high quality loss involved in conventional thermal processing. Among these are the novel agitation systems which permit forced convention in canned particulate fluids to improve heat transfer, reduce process time and minimize heat damage to processed products. These include the traditional rotary agitation systems involving end-over-end, axial or biaxial rotation of cans and the more recent reciprocating (lateral) agitation. However, the invention of agitated systems has made the heat transfer studies more difficult due to problems in tracking the temperature of particles in dynamic motion during processing and complexities produced by the effect of forced convection due to agitation. This has prompted active research to model and characterize the heat transfer phenomena in such systems. This review brings to perspective, the current status on thermal processing of particulate foods with respect to the lethality requirements from safety view point, available techniques of data collection, heat transfer coefficient evaluation and the critical processing parameters which affect these heat transfer coefficients, especially under agitation processing conditions.