化学法提取脱油米糠中蛋白质的研究

Study on Extraction of Deffatted Rice Bran Protein by Chemical Methods

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3h,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3.5h,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0.6molL,温度45℃,料液比1:10,时间2.5h,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%。

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.