复合酶催化强化浸提桑叶黄酮类物质研究

Enhancing Extraction Flavonoids from Mulberry Leaves by Compound Enzyme

应用复合酶(漆酶、纤维素酶、半纤维素酶、木瓜蛋白酶)催化提取桑叶异槲皮苷、紫云英苷、芦丁等黄酮类物质,以异槲皮苷溶浸量为响应值,采用均匀设计法优化获得酶解时间、酶解活化温度、复合酶投加量及pH等提取桑叶黄酮类物质的适宜条件,解析适宜条件间交互作用。结果表明:当桑叶质量为2 g时,复合酶投加量0.675 g、固液比为1∶30时,在pH为4.3、35℃水浴温度下催化酶解30 min后,可提取桑叶异槲皮苷3.45 mg、芦丁1.45 mg、紫云英苷1.58 mg,分别比同条件下乙醇浸提提高60.37%、42.42%、24.74%;红外光谱分析酶解后桑叶植物组织结构发现C-H、木聚糖分子的-CH 2和O-H,以及-C≡C-、>C=C<等官能团加强,表明复合酶有助于破坏桑叶植物组织交联结构,SEM分析可见酶解促使桑叶表面形成不规则空隙,有助于黄酮类物质溶出。

In this study,extraction of isoquercitrin,astragaloside and rutin from mulberry leaves by enzymatic hydrolysis with compound enzymes(laccase,cellulase,hemicellulase and papain)were studied.Taking isoquercetin as the response value,the optimal conditions of extracting flavonoids from mulberry leaves,such as enzymolysis time,enzymolysis activation temperature,compound enzyme dosage and pH were optimized by uniform design method,and the interaction among the appropriate conditions was analyzed.The results showed that when the mass of mulberry leaves was 2 g,the dosage of complex enzyme was 0.675 g,the ratio of solid to liquid was 1∶30,the isoquercetin 3.45 mg,rutin 1.45 mg and astragaloside 1.58 mg of mulberry leaves could be extracted at the pH value of 4.3 and 35℃water bath temperature for 30 min,which was 60.37%,43.42% and 24.74% higher than alcohol extraction under the same conditions,respectively.It was found that the functional groups of C-H,-CH 2 and O-H of xylan,-C≡C-,>C=C<and so on were strengthened by IR analysis of the tissue structure of mulberry leaves.The results of SEM analysis showed that enzymatic hydrolysis promoted the formation of irregular pores on the surface of mulberry leaves,which contributed to the dissolution of flavonoids.