Alterations of polysaccharides, starch gelatinization, and retrogradation

Polysaccharides are natural biopolymers present in almost all living organisms and used extensively in various industrial applications such as food and pharmaceuticals. Starch is the most important polysaccharide in foods. Most starch consumed by humans has undergone some form of processing or cooking, which causes native starch granules to gelatinize, followed by retrogradation on cooling. The extent of gelatinization and retrogradation are major determinants of the susceptibility of starch to enzymatic digestion and its functional properties for food processing. In many cases, starch modification is used to improve the functional properties of starch and widen its potential applications. This chapter provides a comprehensive review consisting of current knowledge on the structure of polysaccharides; definition of modification, gelatinization; and retrogradation of starch; molecular mechanisms of the processes; influencing factors; and implications on food quality and human health.