The Fundamentals of Rate Processes

Abstract

Any analysis of the processing of foods must be based on a thorough understanding of the transfer of heat, of momentum and of mass. It is self-evident that a knowledge of heat transfer to and within foods (both solids and fluids) is vitally important; simply consider the following list of common processing operations, all of which involve the transfer of heat: sterilisation, evaporation, freezing, drying. The theory of heat transfer will be developed in Chapter 7. Momentum transfer will be developed into a treatment of fluid flow in Chapter 6 where the concern is the behaviour of both Newtonian and non-Newtonian fluids (amongst the latter may be numbered very many foodstuffs), especially in pipe flow. Mass transfer (Chapter 8) is very much underused in the study of food processing. Many operations, of which drying is a good example, involve both heat and mass transfer and an analysis of both is needed for a full understanding of such processes.