桑枝多糖酶法脱蛋白工艺优化及理化特性研究

Optimization of enzymatic deproteinization and study on physicochemical property of polysaccharides from Ramulus mori L.

为优化桑枝多糖酶法脱蛋白工艺及对其特性理化进行分析。在对不同种类蛋白酶筛选的基础上,以桑枝多糖提取物为原料,采用木瓜蛋白酶进行脱蛋白,研究酶的用量、酶解时间、酶解温度和pH对蛋白脱除率的影响,通过响应面实验优化脱蛋白工艺条件,并对脱蛋白前后桑枝多糖的热稳定性及其表面形貌进行分析。结果表明:优化的桑枝多糖脱蛋白工艺为添加多糖质量2.5%的木瓜蛋白酶,在pH 7.0、60℃条件下酶解2.5h;该条件下蛋白脱除率为78.75%。脱蛋白后的多糖易溶于热水,具有较好的乳化性,脱蛋白后热稳定性增加,表面形貌较为均匀,球状聚集体结构致密。表明桑枝多糖酶法脱蛋白是一种适宜的方法,脱蛋白对改善桑枝多糖的特性具有重要作用。

In order to optimize the process of enzymatic deproteinization of Ramulus mori polysaccharides(RMP)and analyze its physicochemical property,RMP was used as raw material.The protein was hydrolyzed by Papain after screening different kinds of protease.The effects of enzyme amount,enzymolysis time,enzymolysis temperature and pH on protein removal rate were studied.The deproteinization conditions were optimized by response surface method.The thermal stability,surface morphology of RMP before and after deproteinization were analyzed.The results showed that the optimum deproteinization process was:enzyme dosage 2.5%,enzymolysis time 2.5h,enzymolysis temperature 60℃and pH 7.0.Under the above conditions,the protein removal rate was 78.75%.The deproteinized polysaccharide was easy to dissolve in hot water and had good emulsifying property.After deproteinization,the heat stability of RMP increased,the surface morphology was uniform and the spherical aggregate structure was compact.Therefore enzymatic deproteinization of RMP is an appropriate method,and deproteinization plays an important role in improving the properties of RMP.