分级醇沉香菇多糖益生活性研究

Studies on the prebiotics characteristic of lentinan with gradient ethanol precipitation

目的比较分级醇沉香菇多糖的益生活性差异。方法采用20%、50%和80%乙醇对香菇多糖进行分级醇沉,并研究分级醇沉香菇多糖对植物乳杆菌的增殖作用和体外耐受模拟胃肠液性能。结果在发酵48 h时,以80%醇沉香菇多糖为碳源时,植物乳杆菌活菌数可达到9.62 log CFU/mL;50%醇沉(9.21 log CFU/mL)、20%醇沉(9.07 log CFU/mL)和菊粉组(8.67 log CFU/mL)无显著差异,但都显著高于葡萄糖组的活菌数(8.35 log CFU/mL,P<0.05)。发酵液pH表明,在发酵48 h时,80%醇沉香菇多糖组的pH降低至3.23,显著低于其他组(P<0.05)。体外模拟胃肠液结果表明,以80%醇沉香菇多糖为碳源培养120 min时,植物乳杆菌在模拟胃液和肠液中的存活率分别为63.37%和96.37%,显著高于葡萄糖组和菊粉组(P<0.05)。结论以80%醇沉香菇多糖为碳源可以促进植物乳杆菌的增殖,并提高植物乳杆菌在模拟胃肠液环境中的存活率,具有一定的益生元活性。

Objective To compare the difference of prebiotic activities of lentinan precipitated by ethanol concentration gradients. Methods Lentinan were precipitated with 20%, 50% and 80% ethanol, respectively, and the prebiotic activity of lentinan with gradient ethanol precipitation were evaluated by the proliferation of Lactobacillus plantarum and the tolerance to simulated digestive fluid in vitro. Results The viable number of Lactobacillus plantarum reached 9.62 log CFU/mL while lentinan precipitated with 80% alcohol was used as carbon source after fermentation for 48 h. There was no significant difference on viable number among 50% ethanol precipitation gradient(9.21 log CFU/mL), 20% ethanol precipitation gradient(9.07 log CFU/mL) and inulin group(8.67 log CFU/mL), but each of them was significantly higher than that of glucose group(8.35 log CFU/mL, P<0.05).The pH of fermentation broth showed that the pH of 80% alcohol precipitated lentinan decreased to 3.23 after 48 h of fermentation, which was significantly lower than that of other groups(P<0.05). The results of simulated gastrointestinal fluid in vitro showed that the survival rates of Lactobacillus plantarum in simulated gastric fluid and intestinal fluid were 63.37% and 96.37%, respectively, while lentinan with 80% alcohol precipitation gradients was used as carbon source for 120 min, which was significantly higher than that of glucose group and inulin group(P<0.05). Conclusion The 80% alcohol precipitation gradients of lentinan can promote the proliferation of Lactobacillus plantarum and improve the survival rate of Lactobacillus plantarum in simulated gastrointestinal fluid,indicating that it has certain prebiotic activity.