Abstract: Stabilized treatment was conducted on rice bran through twin-screw extrusion. The effects of water consumption, extrusion temperature and feeding rate on residual peroxidase activity of rice bran were explored. Response surface methodology was applied to optimize extrusion parameters and explore optimal processing parameters and quadratic regression model equations. The results indicated that the optimal twin-screw extrusion conditions were water consumption of 12%, extrusion temperature of 143 ℃and feeding rate of 220 g/min. Under the optimal process conditions, the residual peroxidase activity was 3.081%, which was less than 5% of maximum permissible value. Therefore, the extrusion treatment can largely improve the stability of rice bran and is suitable for the extraction of rice bran oil and other functional components.

Key words: rice bran, twin-screw extrusion, peroxidase, activity