Reaction kinetics in food-processing engineering

Abstract Deteriorative reactions occur throughout the food chain comprising harvesting/production, processing, and subsequent storage and distribution up to the point of final use. In order to produce food items of high quality, one should be able to investigate and control changes in major constituents and implement optimal conditions during processing, distribution, and storage that minimize the prevailing chemical, microbiological, or physical reactions. Due to all these reactions, quality is bound to decrease during the product life cycle, even if microbial action is effectively controlled by applying selected preservation techniques. Consequently, in order to control and minimize such degradation, it is necessary to understand and quantify, through appropriate mathematical equations, the effect of the main parameters, intrinsic and/or extrinsic to the food, that influence product gradual deterioration. The purpose of this chapter is to provide an overall view of food reaction kinetics, during processing and in the postprocess chain, present a methodology of describing reaction rates, in terms of appropriate mathematical relations, and quantifying the effect of rate-determining extrinsic factors, on quality-related phenomena, mostly referring to chemical reactions, occurring in foods. This will be accomplished by reviewing current use of food modeling, focusing mainly on quality degradation, and by indicating directions for the use of alternative methodologies that integrate knowledge on food properties, kinetics, and statistics; the ultimate scope is to provide the possibility to predict changes occurring in food attributes during processing and during shelf life in the postprocess handling and storage, using reliable mathematical models. These models can be used as an important tool that will also allow for the control and the optimization of process/storage conditions, in order to minimize food deterioration.