School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou 510640, China.
Department of Chemical Engineering, Monash University, Clayton Campus, VIC 3800, Australia.
Food Funct. 2021 Jul 5;12(13):6070-6082. doi: 10.1039/d1fo00488c.
Processing induced structural changes of whole foods for the regulation of the colonic fermentation rate and microbiota composition are least understood and often overlooked. In the present study, intact cotyledon cells from pinto beans were isolated as a whole pulse food model and subjected to a series of processing temperatures to modulate the structure, most dominantly the cell wall permeability. The cell wall permeability, observed with the diffusion of fluorescently labeled dextran (FITC-dextran), was increased as a function of the hydrothermal temperature, which is in line with the rise in the in vitro fecal fermentation rate and production of short-chain fatty acids (SCFAs) from the pinto bean cells. Further, the abundance of beneficial microbiota, such as Roseburia, Lachnospiraceae, Bacteroides, and Coprococcus, were significantly higher for cells processed at 100 °C compared to the 60 °C-treated ones. We conclude that cell wall provides an effective barrier for the microbial fermentation of intact cells. With an increase in cell wall permeability, microbes and/or microbial enzymes have easier access to intracellular starch for fermentation, leading to an increase in the production of metabolites and the abundance of beneficial microbes. Thus, desired colonic fermentation profiles can be achieved with the controlled processing of whole foods for enhanced gut health.
加工引起的全食物结构变化可调节结肠发酵率和微生物组成，但目前对此知之甚少，且常被忽视。本研究以完整的利马豆子叶细胞作为全豆食品模型，经一系列加工温度处理以调节结构，主要是细胞壁通透性。用荧光标记葡聚糖（FITC-dextran）的扩散观察到细胞壁通透性随水热处理温度升高而增加，这与体外粪便发酵率的升高以及利马豆细胞产生短链脂肪酸（SCFA）一致。此外，100°C 处理的细胞中有益微生物（如Roseburia、Lachnospiraceae、Bacteroides 和Coprococcus）的丰度明显高于 60°C 处理的细胞。我们得出结论，细胞壁为完整细胞的微生物发酵提供了有效的屏障。随着细胞壁通透性的增加，微生物和/或微生物酶更容易接触到细胞内的淀粉进行发酵，导致代谢物的产生增加和有益微生物的丰度增加。因此，通过控制全食物的加工可以实现期望的结肠发酵谱，从而促进肠道健康。
