西番莲果皮硒化多糖的结构表征及益生元作用

陈郭毅; 赖心语; 张心圆; 汤兵; 李昌宝; 韦忠明; 孙永进; 李霞

doi:10.13386/j.issn1002-0306.2025080226

西番莲果皮硒化多糖的结构表征及益生元作用

Structural Characterization and Prebiotic Activity of Selenized Polysaccharide from Passiflora edulis Peel

摘要

摘要: 为探究西番莲果皮硒化多糖作为益生元的潜力，将西番莲果皮多糖（Acid-extracted Polysaccharide from Passiflora edulis Peel，APEP）与亚硒酸钠进行络合，成功制备了西番莲果皮硒化多糖（Selenized Acid-extracted Polysaccharide from Passiflora edulis Peel，APEP-Se）。对APEP和APEP-Se的理化性质进行检测，并通过紫外扫描、傅里叶红外光谱扫描、刚果红实验、热重实验和扫描电镜对样品进行结构表征，通过APEP和APEP-Se对植物乳杆菌（Lactobacillus plantarum）、德氏乳杆菌保加利亚亚种（Lactobacillus delbrueckii（subsp.）bulgaricus）、短乳杆菌（Lactobacillus brevis）和嗜热链球菌（Streptococcus thermophilus）的促进增殖效果研究其益生元作用。理化性质结果表明，APEP-Se与APEP相比除糖醛酸含量上升外，总糖含量、蛋白质含量和溶解度均有所降低，APEP-Se的硒含量为932.69±29.59 µg/g，表明硒化多糖制备成功。结构表征表明，APEP和APEP-Se均由Man、Rha、GlcA、GalA、Glc、Gal和Ara 7种单糖组成，其中Glc为主要成分；硒化修饰后，APEP-Se分子量由281.05 kDa降至210.02 kDa，红外光谱呈现多糖和硒化修饰特征吸收峰，且由无三螺旋结构转变为具有三螺旋结构，热稳定性有所提高，外观形貌亦有所改变。益生元实验表明，APEP和APEP-Se能较好地促进Lactobacillus plantarum、Lactobacillus delbrueckii（subsp.）bulgaricus、Lactobacillus brevis和Streptococcus thermophilus 4种益生菌的增殖和代谢活动，表现出一定的益生元作用。本研究可为西番莲果皮硒化多糖在益生元方向的应用提供理论依据，为其开发成新功能食品提供思路借鉴，并间接促进西番莲果皮的资源再利用。

Abstract: To investigate the potential of acid-extracted polysaccharides from the peel of Passiflora edulis Sims (APEP) as prebiotics, the APEP were complexed with sodium selenite. The selenized acid-extracted polysaccharide from Passiflora edulis Sims peel (APEP-Se) was successfully prepared. The physicochemical properties of APEP and APEP-Se were characterized. The structural characteristics of the samples were examined using a variety of analytical methods, including ultraviolet scanning, Fourier transform infrared spectroscopy, Congo red staining, thermogravimetric analysis, and scanning electron microscopy. The present study was conducted to ascertain the effects of APEP and APEP-Se on the growth of Lactobacillus plantarum, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus brevis, and Streptococcus thermophilus. The physicochemical analysis revealed that, in comparison with APEP, APEP-Se exhibited increased uronic acid content but reduced total sugar content, protein content, and solubility. The selenium content of APEP-Se was 932.69±29.59 µg/g, thereby confirming the successful preparation of the selenated polysaccharide. Structural characterization indicated that both APEP and APEP-Se are composed of seven monosaccharides: Man, Rha, GlcA, GalA, Glc, Gal, and Ara, with Glc being the main component. After selenylation modification, the molecular weight of APEP-Se decreased from 281.05 kDa to 210.02 kDa. The infrared spectrum exhibited characteristic absorption peaks indicative of polysaccharides and selenylation modification. Additionally, the structure transitioned from lacking a triple-helical conformation to possessing a triple-helical structure, while thermal stability improved and the external morphology changed. Prebiotic experiments demonstrated that both APEP and APEP-Se effectively promoted the proliferation and metabolic activities of four probiotic strains—Lactobacillus plantarum, Lactobacillus delbrueckii (subsp.) bulgaricus, Lactobacillus brevis, and Streptococcus thermophilus—thereby exhibiting certain prebiotic effects.. This study provides a theoretical foundation for the prebiotic application of selenium-enriched polysaccharides from Passiflora edulis peel, offers insights for developing them into novel functional foods, and indirectly promotes the resource reuse of the fruit peel.