Heat Transfer to Foods: Safety and Structure

Heat transfer in foods is a commonplace operation 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 behaviour is difficult to model; but 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. This paper reviews the heat transfer problems that are found in food processing, with particular reference to the modelling of heating operations to ensure safety, problems that are found in the fouling and cleaning and process plant, and how heating and cooling are used to generate structure. Research challenges for the future are outlined.