Changes in Lipid Colour of Grain and Pasting Properties of Brwon Rice cv. Khao Dok Mail 105 during Storage

Abstract

This research was to find out the changes of the total lipid, fatty acid contents, the colour of brown rice, gel consistency and pasting properties during storage of the rice for 0-7 months at 25˚C and 37˚C. The experiment was designed as a factorial in CRD with two storage conditions, eight times of storages and conducted at the Laboratory of the School of Bioresources and Technology, King Monkut’s University of Technology, Thonburi during 2000-2003. Storage produced changes in the total free fatty acid, the colour of the brown rice, gel consistency and RVA pasting properties as a varietal, times and temperatures dependent phenomenon. The significant difference between the colour of the brown rice, total free fatty acid contents and the pasting behavior of brown rice flour was shown in the rice stored at 25 and 37˚C. Aging had no apparent effect on the levels of total lipid contents during storage. Free fatty acid contents dereased from 5.31 to 3.70% and 5.31 to 2.09% of total lipids for rice stored at 25 and 37˚C. respectively. There was the negative correlation between total fatty acid contents and colour of brown rice at 37˚C. The relationship between pasting properties and total free taffy acid contents of rice storage at 25 and 37˚C. also represented the linear regression. This study indicated the changes of free faffy acid contents, physical and physicochemical properties on rice during aging were functionality of the storage temperatures and times.