龙眼、枸杞和红枣多糖的理化性质及其协同益生活性

Physicochemical Properties and Synergistic Prebiotic Activities of Polysaccharides from Longan Fruits, Goji Berries, and Jujube Fruits

摘要:

为了比较龙眼多糖（LP）、枸杞多糖（GP）和红枣多糖（JP）的理化特性及其益生活性差异，探究其是否具有协同增效作用，本文分析了三种多糖的基本成分、分子量分布、单糖组成、显微结构、溶解性、粒径、溶液电位等理化特性，以及三种多糖单独作用或复合作用对益生菌增殖的影响。结果表明LP、GP和JP主要含有中性糖、少量糖醛酸和蛋白质，其中中性糖含量分别为86.25%、72.36%、82.98%；LP和JP的Mw分别是70.73 ku、185.93 ku；GP的Mw为120.61 ku、4.53 ku；LP和GP主要由阿拉伯糖、葡萄糖、半乳糖组成，其摩尔比分别为22.49:56.81:10.18和16.84:62.05:11.08，JP主要由阿拉伯糖、葡萄糖、半乳糖醛酸组成，其摩尔比为10.63:70.05:10.88；三种多糖的微观结构有较大差异，LP为碎片化聚集体，GP呈片状，JP为网状结构；三种多糖的粒径、粒度分散系数、溶液电位均不同；三种多糖均能显著促进益生菌增殖，并呈现剂量依赖效应，在浓度为30 mg/mL时，三者的益生活性为JP>GP>LP；当LP、GP和JP以质量比2:3:1复配时，其益生活性最强，且远好于相同浓度下三种多糖单独作用的益生效果。由此表明，龙眼、枸杞和红枣三种多糖复配后，对益生菌的增殖具有协同增效作用。

Abstract:

The physical and chemical properties and prebiotic activities of polysaccharides from longan fruits, goji berries, and jujube fruits, hereafter referred to as longan polysaccharide (LP), goji berry polysaccharide (GP) and jujube polysaccharide (JP), respectively, were studiedand the existence of their synergistic effects was explored. For this, several features of the polysaccharides, such as the basic composition, molecular weight distribution, monosaccharide composition, microstructure, solubility, particle size and solution potential, were measured, and the effects of the polysaccharides, alone or in combination, on the proliferation of the probiotics were analyzed. The results show that the three polysaccharides mainly contain neutral sugars and a small amount of proteins and uronic acids. More specifically, the neutral sugar contents of LP, GP, and JP are 86.25%, 72.36%, and 82.98%, respectively. The Mw values of LP and JP are 70.73 ku and 185.93 ku, respectively, while the Mw of GP is 120.61 ku and 4.53 ku. Furthermore, LP and GP mainly consist of arabinose, glucose, and galactose in molar ratios of 22.49:56.81:10.18 and 16.84:62.05:11.08, respectively, while JP is mainly composed of arabinose, glucose, and galacturonic acid in a molarratio of 10.63:70.05:10.88. The microstructures of the three polysaccharides are significantly different. LPs were observed as fragmented aggregates, while GPs and JPs showed lamellar and mesh structures, respectively. The particle size, particle size dispersion index, and Zeta potential of the three polysaccharides are different. All the three polysaccharides promoted the proliferation of probiotics significantly and their effectiveness was dose dependent. In particular, at a concentration of 30 mg/mL, the probiotic activities of the three polysaccharides followed the order of JP>GP>LP. The highest probiotic activity was observed when the three polysaccharides, LP, GP, and JP, were used in a mass ratio of 2:3:1, respectively, and this joint effect was far greater than that observed when the three polysaccharides were used alone at the same concentration. The results showed that the mixture of LP, GP, and JP has a synergistic effect on the proliferation of probiotics. Key words: