Effects of Proteins and Lipids of Rice Starch on Gelatinization and Viscosity

Abstract

　We examined the effects of components of starch surface granule (included lipids and proteins) on the gelatinization and viscosity properties of rice starch. In water absorbing and solubility test, lipids and proteins inhibited the water absorption power and solubility of starch granule. There effect was stronger for proteins than lipids. The viscosity profile showed that lipids and proteins in the starch granule increased pasting temperature of starch granule. In addition, proteins decreased swelling power of starch granule. The viscosity behavior of gelatinized starch paste showed lipids and proteins promoted retrogradation of starch. These data were suggested promotion of retrogradation of starch was due to interaction with hydrophobicity protein such as glutelin and prolamiin in the rice starch granule. These data were suggested component of starch granule such as lipids and proteins are also significant in determining the characteristics of starch granules. It can be valuable in developing novel technologies for starch processing.