【摘要】 为研究包埋前后的海藻糖基麦芽五糖（N-G7）在模拟消化液及体外酵解过程中的变化，采用口腔、胃部及小肠的体外消化模型分析消化前后溶液中N-G7的质量和N-G7微球（ALGCa）中的糖组成变化，应用体外发酵技术评价N-G7微球的发酵行为，检测不同时间点的pH值、菌体浓度(OD₆₀₀)、产气量、短链脂肪酸（SCFA）浓度等指标的变化，并探究其对人体肠道微生物构成的影响。结果表明：N-G7在口腔消化2 min后在强酸性的胃部环境中几乎不被水解，在小肠中N-G7的水解率达到了82.70%。采用不同质量分数（1%、2%、3%）的海藻酸钙对其进行包埋，形成的微球保留80%以上的N-G7到达结肠。在体外酵解中，各实验组的pH随时间延长逐渐降低，OD600随时间延长逐渐增加。质量分数2%的ALG-Ca组产气量和碳源消耗率在0～6 h内达到最低，而后逐渐增加，证明包埋后的N-G7发酵体系属于缓慢发酵。与对照相比，质量分数2%的ALG-Ca组产生大量SCFA，肠道菌群组成发生变化，更有利于益生菌的生长。更多还原

【Abstract】 This study was conducted to investigate the changes of trehalose-based maltoheptaose（N-G7） before and after encapsulation in simulated digestive fluid and in vitro fermentation. The mass ratio of N-G7 and the sugar composition of N-G7 microspheres（ALG-Ca） in the solution before and after digestion were analyzed by in vitro digestion models of oral, stomach, and small intestine. The fermentation characteristics of microspheres were evaluated by in vitro fermentation technology. The changes in pH values, OD₆₀₀, gas production, and short-chain fatty acid（SCFA）content at different time points were detected, and their effects on the composition of human intestinal microbiota were studied. The results showed that N-G7 was almost not hydrolyzed in the oral digestion for 2 minutes and in the highly acidic gastric environment. However, the hydrolysis rate of N-G7 reached 82.70% after intestinal digestion. Encapsulation with different concentrations of calcium alginate（1%, 2%, 3%） formed microspheres that retained approximately 80% of N-G7reaching the colon. During in vitro fermentation, the pH value and OD600of each experimental group decreased and increased continuously with time. The gas production and carbon source consumption rate in the 2% ALG-Ca group were the lowest among all groups from 0 to 6 hours, followed by a gradual increase, indicating that the fermentation system of N-G7 after encapsulation belonged to slow fermentation. Compared with the control group, the 2% ALG-Ca group produced a large amount of SCFA and changed the composition of intestinal microbiota, which was more conducive to the growth of probiotics.更多还原