Inactivation of lipase enzyme of locally produced rice bran using microwave heating

Abstract

This research is carried out due to the development of rice bran, the by-product of rice which is applicable in a wide range in various industries. There are serious rancidity problem inside rice bran that affect its quality. Therefore, rancidity problem which caused by reaction of lipase enzyme must be solve. In this study, locally produced rice bran was treated with microwave heating at different power level and time to inactivate lipase enzyme that contained inside the rice bran. Several test had been conducted to investigate the effect of microwave on the establishment of physiochemical properties of the rice bran which is moisture content (MC), oil yield, Free Fatty Acid (FFA) and pH. The optimum result obtained was treatment T9 (800W/3min). It recorded the lowest moisture content (17.69%), the highest oil yield (0.5731g), the lowest FFA (8.19%), and highest pH (6.97) after 30 days storage. However, this result it is not very ideal as the oil sample obtained had exceed FFA limit advised (5%). From this study, the microwave powers (300W, 600W and 800W) used are not sufficient to inactivate the lipase enzyme. Further study can be carried out to improve the research results.