ABSTRACT
The extent of denaturation of proteins in a food milieu depends on the susceptibility of intra-molecular interactions that hold the compact native protein structure to temperature, pressure (shear), pH, ionic strength, types of ions, and specific and non-specific interactions with other food components such as sugars, polysaccharides, lipids, and other additives. It should be recognized, however, that from a food application standpoint, protein denaturation during processing is not always undesirable. In fact, in some cases it is highly desirable. For instance, partial denaturation of proteins at the air-water and oil-water interfaces improve their foaming and emulsifying properties (2, 3), whereas excessive thermal denaturation of soy proteins diminishes their foaming and emulsifying properties (4). In protein beverages, where high solubility and dispersibility of proteins is a necessity, even partial denaturation of protein during processing may cause flocculation and precipitation during storage and thus may adversely affect the sensory attributes of the product. Thus, to develop appropriate processing strategies, a basic understanding of the environmental and other factors that affect structural stability of proteins in food systems is imperative.
