Stability of microwaved-heated rice bran during 12 weeks of storage under ambient and refrigerated condition

Abstract

This project is aimed to stabilize Free Fatty Acid (FFA) by using microwave heating method to inactivate the lipase enzyme and microorganism growth, thus the formation of FFA will be retarded during storage condition. Rice bran (RB) will be stabilized using microwave heating method at different power level and residence time. The rice bran were packed in the zip lock bag and stored in a cold room (5°C), and at ambient temperature (37°C) for a period of twelve weeks. The effect of microwave heating and storage temperature on the production of FFA, moisture content and pH in RB were examined. For FFA content of rice bran was measured at 2 week intervals. Total FFA decrease rapidly over 12 week period from initial value raw bran at ambient temperature (37°C) in zip lock begs. However, total FFA of RB stored at cool room (5°C) decrease at a slower rate from the initial value. After 12 weeks of storage, total FFA microwaved-heated bran stored at 37°C were decrease while for total FFA microwaveheated sample stored at 5°C was not change significantly with storage time. Result showed that hydrolytic rancidity of rice bran can be prevented by microwave heating using optimum power level and recommended storage condition for microwaved RB is refrigerated (5°C) in zip lock bag.