Study on the Extraction Technology of Rice Starch

[Objective]The purpose was to optimize the technology of extracting rice starch with higher purity by the enzyme method of Alcalase proteinase so as to solve the problem of severe waste of stock grains.[Method] With rice as raw material,the rice starch was extracted by the enzyme method of Alcalase proteinase and the extraction technology was optimized by orthogonal design with 3 factors.The protein content was determined by kjeldahl GB5511285 and the starch content was determined by Anthrone colorimetry method.[Result] The order of the influence factors on protein removal and starch yield was reaction temperature enzyme addition quantity reaction time.The optimum combination of technology conditions for protein removal was as follows:temperature of 50 ℃,enzyme addition quantity of 0.3% and reaction time of 6 h.The optimum combination of technology conditions for extracting starch was as follows:temperature of 50 ℃,enzyme addition quantity of 0.2% and reaction time of 5 h.[Conclusion] Considering comprehensively,with rice as raw material,the optimum technology of removing protein and extracting rice starch by the enzyme method of Alcalase proteinase was as follows:temperature of 50 ℃,enzyme addition quantity of 0.2% and reaction time of 5 h,under which,the protein content in the rice starch was 0.39% and the extraction rate of starch was 89.53%.