Yue Fangfang, Jiang Miao, Xu Jiaxin, Ma Jingyi, Sun Xin, Huang Jihong, Muratkhan Marat, Wang Xin, Lü Xin
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
Xijing Hospital, the Fourth Military Medical University, No. 127, Changle West Road, Xi'an, Shaanxi, 710032, China.
Food Funct. 2025 May 6;16(9):3721-3735. doi: 10.1039/d5fo00354g.
Apple pomace is a waste in fruit juice processing and is an important raw material for pectin extraction. The addition of pectinase will not only change the juice characteristics but also affect the apple pomace. However, the differences in the structure and function of pectin obtained from the pectinase-treated (TAPP) and untreated apple pomace (NTAPP) are unclear. In this paper, TAPP and NTAPP (APPs) were prepared using the subcritical-water method. Structural analysis showed that the APPs were acidic-pectin polysaccharides with low molecular weight () and a high esterification degree (DE), but TAPP had a lower , DE, and galacturonic acid content and smoother surface. Immune activity detection demonstrated that NTAPP can stimulate macrophage proliferation, phagocytosis, and cytokine release by activating the TLR4/p-ERK/p-NFκB pathway, while TAPP activates the TLR4/p-NFκB to stimulate macrophage phagocytosis and the cytokine release. fermentation characteristics indicate that anaerobic fermentation using APPs as the sole carbon source can significantly promote the production of lactic acid and the short-chain fatty acids (SCFAs). Microbial diversity analysis revealed that the APPs exhibit prebiotic properties, but their effects on the gut microbiota composition differ: TAPP mainly promotes the enrichment of , while NTAPP primarily enhances the abundance of and . Finally, structure-function correlation analysis suggests that monosaccharide composition (particularly mannose) and molecular weight () are key factors influencing the gut microbiota composition, providing a research direction for future studies on their structure-activity relationships.
苹果渣是果汁加工过程中的废弃物，也是提取果胶的重要原料。添加果胶酶不仅会改变果汁特性，还会对苹果渣产生影响。然而，经果胶酶处理的苹果渣（TAPP）和未经处理的苹果渣（NTAPP）所获得的果胶在结构和功能上的差异尚不清楚。本文采用亚临界水法制备了TAPP和NTAPP（苹果渣果胶）。结构分析表明，苹果渣果胶是低分子量（）和高酯化度（DE）的酸性果胶多糖，但TAPP的分子量、DE和半乳糖醛酸含量较低，表面更光滑。免疫活性检测表明，NTAPP可通过激活TLR4/p-ERK/p-NFκB途径刺激巨噬细胞增殖、吞噬作用和细胞因子释放，而TAPP激活TLR4/p-NFκB以刺激巨噬细胞吞噬作用和细胞因子释放。发酵特性表明，以苹果渣果胶为唯一碳源进行厌氧发酵可显著促进乳酸和短链脂肪酸（SCFAs）的产生。微生物多样性分析表明，苹果渣果胶具有益生元特性，但其对肠道微生物群组成的影响不同：TAPP主要促进的富集，而NTAPP主要提高和的丰度。最后，结构-功能相关性分析表明，单糖组成（特别是甘露糖）和分子量（）是影响肠道微生物群组成的关键因素，为今后研究它们的构效关系提供了研究方向。
