化学法提取脱油米糠中蛋白质的研究

以脱油米糠为原料，采用碱法、酸法、盐法依次分步对米糠蛋白质进行提取，以蛋白质提取率为指标，通过单因素试验确定这3种方法中料液比、pH值、温度、时间以及盐溶液的浓度对其提取率的影响，再通过正交试验确定各方法的最优条件。试验结果表明，碱法最佳提取条件:时间3 h，pH值13，温度35 ℃，料液比1∶10，提取率为24.3%；酸法最佳提取条件:时间3.5 h，pH值0.5，温度40 ℃，料液比1∶8，提取率为18.18%；盐法最佳提取条件:NaCl浓度0.6 mol/L，温度45 ℃，料液比1∶10，时间2.5 h，提取率为7.86%。最后依次采用碱法、酸法和盐法的最优参数对脱油米糠蛋白进行分步提取，提取率为48.23%。 

Study on Extraction of Deffatted Rice Bran Protein by Chemical Methods

Defatted rice bran was used to extract protein by alkali method,acid method and salt method,orderly.The yield of protein in defatted rice bran extracted was a key index.The optimal extraction processing parameters were determined by orthogonal experiments through evaluating the effects of material-liquid ratio,pH value,extraction time,temperature,salt concentration of each method on the yield of protein.The results from the alkali method indicated showed that the optimal parameters of defatted rice bran were 3 h,pH 13,35 ℃,material-liquid ratio of 1:10,and the yield of protein was 24.3%.For the acid method used,the best extraction parameters was 3.5 h,pH 0.5,40 ℃,material-liquid ratio of 1:8,and the best yield of protein was 18.18%.For the salt extraction method,the optimal NaCl level,temperature,material-liquid ratio of defatted rice bran were respectively 0.6 mol L,45 ℃,material-liquid ratio of 1:10,2.5 h,and the yield of protein was 7.86%.For the total yield of protein in rice bran extracted was 48.23% under the optimal parameters of alkali method,acid method and salt method,orderly.