Role of Aging Temperature on Lipid Components, Physical Properties and Physicochemical Behaviour of Brown Rice cv. Khaw Dok Mali 105

Abstract

Changes in the extent of rice lipids are associated with the storage of rice. Knowledge of thelipid components is essential to an understanding of rice functionality. This study presents data on thelipid, fatty acid contents and pasting properties of brown rice flour following storage of the rice cv.Khaw Dok Mali for up to 7 months. Two storage temperatures, 25 °C and 37 °C were examined asaging process. In this study, the newly harvested paddy was dried to reduce the moisture content to15.23% and packed in polypropylene bags. The results show that the significant increase between thecolor of the brown rice and decrease in gel consistency. The fatty acid content of storage rice at37 °C was lower than that of storage rice at 25 °C in brown rice. Storage produced changes in theRVA pasting properties of the flour as time and temperature dependent phenomenon. The significantchange in the pasting property was the decrease in pasting temperature over time of the samplesstored at 25 °C while pasting temperature of the samples stored at 37 °C was increase over thestorage time. The notable effect was produced by storage temperature treatment which increased PV(peak viscosity) of sample stored at 25 °C and decreased PV of flours from aged (higher temperaturestorage) rice samples. From the results it was shown the relationship between the total free fatty acidcontent and PV and this condition tended to cause the changes in viscosity properties of the flourduring storage. Aged samples treated in this way suggested that fatty acid and lipid compositionsappear as component involved in the aging process.