热稳定脱脂米糠蛋白质碳水化合物酶-蛋白酶分步提取法酶的筛选和条件优化

Screening and Optimization of Carbohydrases and Proteases for Protein Extraction from Heat-Stabilized Defatted Rice Bran

热稳定脱脂米糠(HDRB)中蛋白质已严重变性,采用常规方法很难提取其中蛋白质。本研究其目的在于评价不同碳水化合物酶和蛋白质水解酶组合在HDRB蛋白质提取的作用,以及利用响应曲面方法优化蛋白质提取组合条件。结果发现使用果胶酶P-Ⅱ处理HDRB,继后对其残渣进行蛋白酶P处理,蛋白质提取率可达到80%。采用中心成分回归设计进一步对果胶酶P-Ⅱ、蛋白酶P、水糠比、温度、pH、提取时间进行RSM优化,最大蛋白质提取率可达到89%。本研究为合理利用米糠蛋白及利用米糠蛋白制备功能性短肽提供了可靠的方法。

Sequential uses of carbohydrases and proteases were evaluated for maximum protein extraction from heat-stabilized defatted rice bran （HDRB）. Combined use of Pectinase P-Ⅱ and Protease P extracted the highest amounts .of protein （80%） among the varying combinations. The conditions for Pectinase P- Ⅱ and Protease P were optimized with response surface methodology. The optimal conditions for Peetinase P- Ⅱ were： water to bran ratio 20：1, pH 3.55, 3346.3 units, and 59.8 oC, time 4.33 h; and for Protease P were water to bran ratio 20：1, pH 10, 22138 units, 45 oC, and time 3.1 h. Under these conditions, 89.6% protein was extracted experimentally, Furthermore, data were also processed with Hsu＇s MCB test for the maximum and minimum values of protein extraction. The results suggest that sequential use of carbohydrase and proteasc can maximally increase the extracted protein from HDRB.