龙眼果肉多糖超微粉碎-酶解提取工艺优化及其免疫活性

依据Box-Benhnken中心组合原则,分别选取超声时间、酶添加量和提取时间3个因素对超微粉碎纤维素酶辅助提取工艺进行优化。通过分析多糖基本成分、分子质量、黏度、溶解度等比较热水浸提法、超微粉碎辅助法和超微粉碎纤维素酶辅助法3种方法制得的龙眼果肉多糖(LP、LP-S、LP-SE)的理化特性。通过分析对巨噬细胞分泌细胞因子的刺激作用,比较3种龙眼果肉多糖的免疫活性。结果表明:①最佳的提取工艺参数为:超微时长2 min,酶添加量140 U/g,pH值5,料液比1∶40,提取温度50℃,提取时长90 min,在此条件下,多糖提取率为38.49%;②LP-SE与LP和LP-S相比,具有得率高,分子质量小,糖醛酸含量低,鼠李糖和阿拉伯糖含量高,低黏度和高溶解性的特性;③LP-SE激活巨噬细胞分泌NO、TNF-α、IL-6、IL-1β的能力显著高于LP和LP-S。不同提取工艺制备的龙眼果肉多糖的理化性质和免疫活性存在显著性差异,超微粉碎-纤维素酶辅助提取法制备的龙眼果肉多糖表现出较好的免疫调节活性。

Optimization of Extraction of Polysaccharides from Longan Pulp by Superfine Grinding and Enzymatic Hydrolysis and Its Immune Activity

In this paper,response surface experiments according to the Box-Benhnken center combination principle was applied to optimize the extraction of polysaccharides from longan pulp by superfine grinding and enzymatic hydrolysis and the influencing factors as ultrasonic time,enzyme dosage and extraction time were evaluated;through the analysis of the basic composition,viscosity,polysaccharides solubility and molecular weight,physicochemical properties of longan polysaccharides(LP,LP-S,LP-SE)extracted by traditional hot water extraction,superfine grinding auxiliary extraction,superfine grinding and enzymatic hydrolysis auxiliary extraction were compared;the immune activity of longan polysaccharides(LP,LP-S,LP-SE)was compared by detecting the cytokines expression of macrophage.The results showed that①The optimal technological parameters were conformed as follows:superfine grinding time 2 min,enzyme dosage 140 U/g,pH value 5,ratio of solid to liquid 1∶40,extraction temperature 50℃.Under these conditions,the experimental yield of polysaccharides was 38.49%;②Compared to LP and LP-S,LP-SE had obvious differences including the higher yield,smaller molecular weight,lower viscosity and higher solubility,lower uronic acid,higher rhamnose and arabinose content;③The ability of LP-SE to activate macrophages to secrete NO,IL-6,TNF-α,IL-1β,was significantly higher than that of LP and LP-S.The results indicated that the superfine grinding and enzymatic hydrolysis extraction can effectively change the physicochemical properties of polysaccharides and it showed the best immunoregulatory activity.