Effect of defatting of rice on the gelatinization

Abstract

This chapter discusses the consequence of defatting of rice on the process of gelatinization and explores an experimental study to explain the same. According to the study, rice grains are defatted by methanol-chloroform for five periods. Total fat and free content in rice reduce with increasing defatting time while the fat-by-hydrolysis content is not much changed. Heating DSC curves for the rice grains water system shows two endothermic peaks around 60°C∼90°C (peak l and peak 2) and third endothermic peak around 90°C∼120°C (peak 3). The decrease in total fat content lowers the temperature of peak 2, increases the enthalpy of peak 1, and decreases the enthalpy of peak 2. It is discovered that fat content has a drastic effect on the gelatinization of rice grains Total fat and free fat content decrease with increasing defatting time, while the fat-by-hydrolysis content doesn't change much less even after 24 hours. In heating DSC curves of both varieties, the temperatures of Peaks 1 and 2 shift slightly to lower temperatures with the defatting time. However, the results show that the amylose–lipid complex in rice grains is not influenced by defatting, because fat-by-hydrolysis in rice grains was not removed..