Abstract: Using radio frequency heating system to treat fresh rice bran, taking the relative activity of rice bran lipase as an indicator, on the basis of single factor test, using response surface method to optimize the conditions of radio frequency rice bran treatment. The results showed that the optimal conditions for radiofrequency treatment of rice bran were 10.5cm RF plate spacing, 92 ℃ RF temperature, and 5.3 min RF time. Under these conditions, the relative activity of rice bran lipase decreased to 18.25%. When rice bran was stored at 35 ℃ for 6 weeks, the relative activity of lipase increased only from 18.35% to 22.63%, the acid value was only 22.32% of untreated rice bran in the same period, and the peroxide value remained within the threshold of less than 10 meq/kg. The rice bran protein content decreased slightly during storage time, but the change was not significant; The Rice bran protein water holding capacity reached its maximum in the first week, and the treated rice bran increased by 37% compared with the untreated rice bran. Therefore, Rice bran can not only improve the storage time after radio frequency treatment, but also the application of rice bran protein in function can be increased, which provides a good theoretical basis for the expansion of rice bran.

Key words: radio frequency heating, rice bran, Lipase relative activity, storage stability, rice bran protein