Heat Transfer to Foods: Ensuring Safety and Creating Microstructure

Abstract

Heat transfer in foods is commonplace in the home and restaurant, but is also the basis for a very large industry. Foods are complex non-Newtonian soft solids or structured liquids whose thermal behavior is difficult to model; engineering understanding is needed to develop processes that are safe and products that are attractive to the consumer. The increasing incidence of obesity in the developed world, and of food shortage elsewhere, demands that the industry adopts processes that give nutritious products in environmentally acceptable ways. Heat transfer is often limited by the low thermal conductivity of foods and increasing heating and cooling rates is critical in maximizing product quality. This paper briefly reviews the heat transfer problems found in food processing, with particular reference to the modeling of heating to ensure safety, problems found in the fouling and cleaning and process plant, and how heating and cooling are used to generate food microstructure. Research challenges for the future are outlined.