Characterization of starch-water interactions and their effects on two key functional properties: starch gelatinization and retrogradation

The complex and unique structure of starches is associated to the conditions existing during processing and storage and contribute to specific interactions with water. These interactions can lead to starch transitions such as gelatinization and retrogradation, which have key importance in food and non-food applications. Water content plays a critical role in the structure-function capacity of starches, which depend on starch granules capacity to adsorb water and disperse in aqueous media. The presence of salt, sugars, non-starch polysaccharides, proteins, and lipids influences starch behavior in aqueous media, affected by competitive interactions of starch with these constituents. Gelatinization and retrogradation are associated to the interaction of starches with water. The first phenomenon describes water absorption by the starch molecules in the presence of shear and temperature and under excess of water whereas the second phenomenon describes the interaction of starch molecules under limited water availability. (AU)