Investigation on rice bran and its oil: storage of rice bran and evaluation of lipase activity on hydrolysing rice bran oil

摘要

Seven varieties of rice bran were collected from the automatic rice mills of different parts of Bangladesh and were subjected to analysis for moisture, protein, oil, free fatty acids (FFAs), Peroxide value and iodine value. Determinations of the formation of FFAs after storing the bran at different temperatures (0 deg C, 10 deg C, 20 deg C, 25 deg- 28 deg C and 35 deg-38 deg C) and heat treatments at higher temperatures (100 deg C and 110 deg C) for various time intervals of 1 hr, 3hrs and 5hrs were taken into consideration. After 60 days storage at 0 deg C, 10 deg C, 20 deg C, 25 deg-28 deg C (room temp.) and 35 deg-38 deg C (optimum temp.) the FFAs among the 7 varieties were found to be varied from 22.88% to 30.74%, 31.48% to 40.57%, 51.66% to 64.20%, 53.81% to 68.29% and 55.95% to 69.48% respectively. On heating the bran at 100 deg C and 110 deg C for 5 hrs, the oil hydrolysed only 6.32-7.47% and 2.32-3.13% respectively after 60 days of storage.