本研究旨在研究碱提取果胶多糖(AkPP)的结构和理化特性,并评估其益生元效应。AkPP是使用碱性提取方法从南瓜果肉中获得的。AkPP,其分子量(Mw)主要为13.67kDa,酯化度为9.60%,主要由半乳糖醛酸(GalA)组成,鼠李糖(Rha),半乳糖,和阿拉伯糖。AkPP中高半乳糖醛酸(HG)区与鼠李糖半乳糖醛酸-I(RG-I)区的比率为48.74:43.62。在核磁共振谱中,指示α-1,4-连接的D-GalA的信号,α-1,2-连接的L-Rha,α-1,2,4-连接的L-Rha残基被很好地拆分,证明其分子结构中存在HG和RG-I区。总的来说,AkPP是富含具有短侧链的RG-I区的低甲氧基果胶并且具有低Mw。热分析表明AkPP具有良好的热稳定性。与菊粉相比,AkPP更有效地促进嗜酸乳杆菌的增殖,鼠李糖乳杆菌GG,干酪乳杆菌,和副干酪乳杆菌和乳酸的生产,乙酸,和丙酸.这项研究展示了AkPP独特的结构特征,为进一步研究AkPP作为一种有前途的益生元的潜力提供了科学依据。
The present study aimed to investigate the structural and physicochemical characteristics of alkali-extracted pectic polysaccharide (AkPP) and to evaluate its prebiotic effects. AkPP was obtained from pumpkin pulp using an alkaline extraction method. AkPP, which had a molecular weight (Mw) of mainly 13.67 kDa and an esterification degree of 9.60%, was composed mainly of galacturonic acid (GalA), rhamnose (Rha), galactose, and arabinose. The ratio of the homogalacturonan (HG) region to the rhamnogalacturonan-I (RG-I) region in AkPP was 48.74:43.62. In the nuclear magnetic resonance spectrum, the signals indicating α-1,4-linked D-GalA, α-1,2-linked L-Rha, α-1,2,4-linked L-Rha residues were well resolved, demonstrating the presence of the HG and RG-I regions in its molecular structure. Collectively, AkPP was low methoxyl pectin rich in the RG-I region with short side chains and had a low Mw. Thermal analysis revealed that AkPP had good thermal stability. Compared to inulin, AkPP more effectively promoted the proliferation of Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, Lacticaseibacillus casei, and Lacticaseibacillus paracasei and the production of lactic, acetic, and propionic acids. This study presents the unique structural features of AkPP and provides a scientific basis for further investigation of the potential of AkPP as a promising prebiotic.