分级醇沉兰州百合多糖体外消化耐受及益生活性比较

Comparison of Lanzhou Lily Polysaccharides with Gradient Ethanol Precipitation and Their in vitro Digestive Tolerance and Prebiotic Activity

摘要:

兰州百合是中国药食同源甜百合，为深入分析其主要功能成分之一百合多糖的益生潜力，提升百合资源利用率，该文采用超声波复合酶提取法，体积分数分别为60%、80%和95%乙醇提取获得3种百合多糖（LLP），研究其体外消化耐受性和益生活性。结果显示，随乙醇体积分数增加，兰州百合多糖可溶性总糖、提取率、蛋白质和模拟胃肠液耐受性均有提高，其中LLP-95%的可溶性总糖质量分数、提取率分别高达19.83%和23.77%，模拟胃液中6 h水解度仅为5.90%，蛋白质质量分数较少仅4.09%。以其作为碳源，植物乳杆菌发酵48 h时益生指数PI、pH值和OD600分别为0.96、4.73和0.75，显著优于低聚果糖组和其他多糖组；在模拟胃液和肠液培养40 min，LLP-95%处理菌液存活率分别为25.89%和56.00%，与其他几组相比显著提高了菌株存活率。该研究证明，LLP-95%具有良好消化耐受性，可以促进植物乳杆菌的增殖并提高菌株在模拟胃肠液环境中的存活率，具有较好的益生元潜力，为功能性食品和药品研发提供了科学依据。

Abstract:

Lanzhou lily (Lilium davidii var. unicolor Salisb. ), a medicinal and edible plant in China, is commonly referred to as sweet lily. To further investigate the prebiotic potential of one of its major bioactive components, lily polysaccharides, and enhance the utilization of lily resources, a study was conducted using ultrasonic-assisted enzymatic extraction with volume fractions of 60%, 80%, and 95% ethanol to obtain three types of lily polysaccharides (LLP). Their in vitro digestive tolerance and prebiotic activity were examined. The results demonstrated that as the ethanol volume fraction increased, the soluble total sugar content, extraction yield, protein content, and tolerance to simulated gastric and intestinal fluids of Lanzhou lily polysaccharides were all improved. Notably, LLP-95% exhibited a soluble total sugar content and extraction yield of 19.83% and 23.77%, respectively, while the hydrolysis degree in simulated gastric juice after 6 hours was only 5.90%. Additionally, the protein content was relatively low at just 4.09%. When used as a carbon source, Lactobacillus plantarum fermentation for 48 hours resulted in a prebiotic index (PI) of 0.96, pH value of 4.73, and OD600 of 0.75, significantly outperforming the fructooligosaccharides and other polysaccharide groups. Furthermore, after 40 minutes of incubation in simulated gastric and intestinal fluids, the survival rates of bacterial suspensions treated with LLP-95% were 25.89% and 56.00%, respectively, significantly enhancing bacterial survival compared to the other groups. This study demonstrated that LLP-95% possesses good digestive tolerance, promotes the proliferation of Lactobacillus plantarum, and enhances bacterial survival in simulated gastrointestinal environments, indicating strong prebiotic potential. These findings provide scientific evidence for the development of functional foods and pharmaceuticals.