Changes In The Main Components Of Rice Bran Under Heat Processing And Their Application In Bread Processing

China is a big country of rice,and rice bran is a by-product in the process of rice processing.Rice bran is rich in high-quality protein,dietary fiber,a variety of essential amino acids,oryzanol,sterols and other nutritional elements.As rice bran products need to be processed,how to maintain the nutritional and functional active components in rice bran is a subject that must be studied in the development of rice bran industry.In this paper,fresh rice bran is used as raw material and processed by five different methods and conditions,in order to explore their effects on the nutritional components and functional active components of rice bran,and to apply those effects to the production of rice bran bread,which can provide reference for the in-depth development and utilization of rice bran.The main research contents and results are as follows:(1)In this experiment,fresh rice bran was used as raw material to explore the effects of microwave,baking,frying,atmospheric pressure steaming and high-pressure steaming on moisture,fat,ash,protein and dietary fiber of rice bran.The results showed that: under better conditions,microwave treatment,baking treatment and frying can better preserve and increase the nutrients in rice bran,while steaming treatment will lead to the loss of nutrients in rice bran.Under atmospheric steaming-10 min and high-pressure steaming-15 min conditions,the crude fat content is up to 18.370% and 17.215%,and under atmospheric steaming-15 min and high pressure steaming-25 min conditions,the protein content is up to14.887% and 15.237%.(2)In this experiment,fresh rice bran was used as raw material to investigate the effects of microwave,baking,frying,atmospheric steam and high pressure steam on sterol and vitamin in rice bran.The results showed that microwave and baking treatments did not destroy the oryzanol in rice bran,while stir-frying and steaming treatments decreased the oryzanol in rice bran.Sterol was well preserved under the condition of 420 W microwave.Stir-frying had little effect on sterol in rice bran.Baking and steaming could lead to a large loss of sterol content in rice bran.(3)Comprehensively considering to preserve the nutritional components and functional active ingredients of rice bran,the better treatment conditions are:Microwave420W-5min,490W-3min,560W-1min,630W-1min and 700W-1min;Baking100℃-25 min,105℃-20 min,110℃-25 min,115℃-20 min and 120℃-10min;Stir-fry-7min;Atmospheric steaming-10 min and High pressure steaming-10 min.(4)In order to develop a rice bran bread that integrates taste and nutrition,the rice bran bread formula was optimized.Sensory score was used as evaluation index,single factor test and orthogonal test were conducted to determine the best formula of rice bran bread: Salt 0.9%,water 10%,oil 9%,rice bran 2%,milk powder 4.5%,sugar 9%,Bread improver 0.5%(by weight of flour).Compared with ordinary bread,rice bran bread has higher nutritional value under this formulation.