紫苏叶多糖的提取工艺优化及理化特性分析

Optimization of Extraction Technology of Polysaccharide from Perilla frutescens var.frutescens and Its Physicochemical Properties

以紫苏叶为原料,对紫苏叶多糖的提取工艺及理化特性进行研究。通过单因素试验探究料液比、提取时间和醇沉浓度对紫苏叶多糖得率的影响,在单因素试验基础上进行响应面优化试验后对紫苏叶粗多糖进行分离纯化,纯化后得到均一组分多糖并命名为PFP(Perilla frutescens var.frutescens polysaccharide),其总糖含量为(89.73±0.23)%。通过热重分析仪、差示扫描量热仪、X-射线衍射仪对PFP的理化特性进行分析。结果表明,最佳提取工艺条件为料液比1∶30(g/mL)、提取时间4 h、醇沉浓度60%。此时,紫苏叶多糖得率达到(5.22±0.17)%。理化特性分析结果表明,紫苏叶多糖在200℃以下有较好的热稳定性,其热解过程主要分为2个阶段,无结晶现象,是一种无定型结构。

With Perilla frutescens var.frutescens as raw material,the extraction technology of polysaccharide from P.frutescens leaves and its physicochemical properties were studied.The effects of solid-liquid ratio,extraction time and alcohol precipitation concentration on the yield of polysaccharide from P.frutescens leaves were investigated by single factor experiment.On this basis,the response surface optimization experiment was carried out.Then,the crude polysaccharide from P.frutescens leaves was separated and purified to obtain the homogeneous polysaccharide,which was named as PFP(P.frutescens var.frutescens polysaccharide),and its total sugar content was(89.73±0.23)%.Additionally,the physicochemical properties of PFP were analyzed by thermogravimetric analyzer,differential scanning calorimeter,and X-ray diffractometer.The results showed that the optimal extraction conditions were as follows:solid-liquid ratio of 1∶30(g/mL),extraction time of 4 h,and alcohol precipitation concentration of 60%.Under the above conditions,the yield of PFP reached(5.22±0.17)%.The physicochemical properties analysis revealed that PFP had good thermal stability below 200℃,and its pyrolysis process was mainly divided into two stages,showing an amorphous structure without crystallization.