柚皮多糖提取分级及分子质量的分布

The extraction of polysaccharide from pomelo peel and its molecules weight distribution

为了探讨柚皮多糖提取工艺和分级多糖分子质量差异,以蜜柚果皮为材料,采用正交试验优化了复合酶提取工艺,通过低温醇沉制备不同溶剂分级的柚皮多糖,并采用凝胶色谱研究了分级多糖分子质量分布差异。结果表明:复合酶提取柚皮多糖的优化工艺为,酶用量1.5%、酶解时间120 min、料液比1∶25、酶解温度50℃。柚皮多糖提取率为10.39 g/100 g柚粉,其中分级后a粗多糖为5.61 g/100 g柚粉,b粗多糖为1.94 g/100 g柚粉,c粗多糖为1.82 g/100 g柚粉,不同分级的柚皮粗多糖纯度也不同。不同分级的多糖分子质量测定表明:不同溶剂分级的多糖分子质量有显著差异,其中a粗多糖的峰1的重均分子质量Mw为24 100 Da,b粗多糖的峰1的重均分子质量Mw为11 700 Da,c粗多糖的峰1的重均分子质量Mw为2 130 Da。表明乙醇浓度越低,沉淀多糖的分子质量越大。

To discuss the extraction technology and classified polysaccharide molecular weight distribution,pomelo peel polysaccharide was extracted by enzyme extraction and organic solvent. Distribution of molecules weight was carried out by GPC chromatogram. The optimization of polysaccharides from pomelo peel by the enzyme extraction was: enzyme dosage 1. 5%,reaction time 120 min,solid to liquid ratio of 1∶ 25,enzymolysis temperature 50 ℃. The total polysaccharide content of pomelo peel was 10. 39 g /100 g powder. The crude polysaccharide was then separated into 3 grades based on its content: grade A was 5. 6 g /100 g powder,grade B was 1. 9 g /100 g powder and grade C was 1. 8 g /100 g powder. The purity of coarse polysaccharide of different grades was different. The molecular weight distribution tests showed that the lower the ethanol concentration,the higher the molecular weight. Polysaccharide( a)molecular weight in different grades were: 24 100 Da in grade A,11 700 Da for grade B and 2 130 Da for grade C.