Study On The Preparation Of Rice Protein Using Enzyme From Rice Dregs And Development Of Related Products

Rice protein is recognized the high quality frumentaceous protein, which has some characters, such as reasonable amino acid compositions, low hypoallergenic character. It is very suitable for infants and babies and other special crowds as nutritious food. In this paper, the rice dreg, which was a by-product from rice starch syrup manufacture, was studied for obtain high quality rice dreg protein (RDP) and improve its applicable properties by enzyme. Then the industrial design was discussed. It provides technological bases for the further development of rice dreg resources. The main results are as follows:1. Cellulase and thermo-stable a-amylase were used to study on the method of removal of impurity to prepare rice dreg protein. The results show that thermo-stable α-amylase had better effect on removing impurity. The purity (70.9%) and extraction ratio (79.0%) of the rice dreg protein product was high, but the solubility of it was poor.2. Alcalase, Neutrase, Flavourzyme, Trypsin and Papain were used to study on the method of protease extraction. The results show that the types of protease affected protein extraction greatly in enzyme extraction. Overall, the protein extraction ratio was low by the method, but the excellent solubility and the acceptable flavor and appearance characters by some proteases of the rice dreg protein product showed that protease could modify the property of protein.3. Eligible rice dreg protein product could be prepared if the removal of impurity method combined with multiple proteases extraction. And the whole best preparation technology line of rice dreg protein included:Raw material of rice dregâ†' crushing and screening through 80meshâ†' thermo-stable α-amylase 85℃,time 1.5hâ†' centrifuged to the deposit(15min)â†'combine Neutrase(1.0%)and Flavourzyme(0.2%) 50℃, time 4hâ†' inactivate enzyme 80℃,time 10minâ†' centrifuged to the clear supernatantâ†' freeze-dryingâ†' rice dreg protein product. Under the above conditions, the whole recovery ratio and content of protein was 53.5% and 86.4% with the yield of rice dreg protein product was 37.0%. The product was white powder with both good flavor and excellent solubility.4. The above experimental production was analyzed summarily. Based on this, some problems about industrial design were studied. The results showed that the process was simple and fast, fewer waste emissions, and environment friendly. The rice dreg protein product has excellent sensory qualities on flavor and appearance characters and high content of soluble protein. Finally, a production workshop of rice dreg protein product which had 1000t annual output was designed. It shows that it would achieve a large-scale industrial production.