ABSTRACT
The application in food processing is one of the most important and promising uses of membrane separation processes. Especially, in the process of concentrating liquid food, many volatile food flavors escape by the conventional method of evaporation, whereas in the membrane process, those flavor components are preserved in the food because no heat needs to be supplied in the latter process. Moreover, because it involves no phase change, the membrane process is intrinsically an energy-saving process compared with the evaporation process. Though the experimental testing of membrane food processing, such as in fruit juice concentration, cheese whey concentration, egg white concentration, and treatment of alcoholic beverages, is well documented in the literature, very little work has been performed to elucidate the fundamental principles involved therein. In this chapter, the fundamental aspects of membrane food processing have been particularly emphasized including the Transport Theories: Preferential sorption of water at the membrane-solution interface; Surface force-pore flow model, generation of interfacial surface force parameters, and their Application; Enumeration of Problems involved in Membrane Separation and Concentration of Liquid Foods: Application of water preferential sorption model; Application of transport equations to real fruit juice concentration; Application of transport equations for the concentration of green tea juice; Some illustrative examples of the surface force-pore flow model; Some data on the ultra-filtration of proteins; Application of pervaporation in the recovery and concentration of food flavors; and Recent Literature on Membrane Applications: Dairy product industry; Beverage industry; Edible oil industry; and Miscellaneous food products.
