Laboratory of Food Proteins and Colloids, 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 510641, China.
Guangdong Longsee Biomedical Co.,Ltd., Guangzhou 510700, China.
J Agric Food Chem. 2022 Jul 20;70(28):8776-8787. doi: 10.1021/acs.jafc.2c02603. Epub 2022 Jul 8.
Previous studies have found that soybean protein, especially soybean 7S protein (β-conglycinin), exhibits digestion resistance, but the mechanism of digestion resistance and its implications for human health are still unclear. Here, we show that the extracted soybean 7S protein contains both oligomer globulins and amyloid aggregates, while the gastric digested soybean 7S protein only contains amyloid aggregates and thus exhibits digestion resistance. An animal experiment shows that un-digestible soybean 7S protein effectively prevents aspirin-induced acute gastric mucosa damage. The impacts of un-digestible soybean 7S protein on gastric mucus barrier properties are investigated using quartz crystal microbalance with dissipation (QCM-D), Langmuir monolayer, and multiple particle tracking (MPT). Results show that these un-digestible protein aggregates can penetrate into gastric mucus, increase the viscosity and compactness of the mucin layer, and reinforce the gastric mucus barrier properties. The findings are helpful to understand that high consumption of non-fermented soybean foods is associated with a decreased risk of gastric cancer.
先前的研究发现，大豆蛋白，尤其是大豆 7S 蛋白（β-伴球蛋白），具有抗消化性，但抗消化性的机制及其对人体健康的影响仍不清楚。在这里，我们表明提取的大豆 7S 蛋白既含有低聚物球蛋白又含有淀粉样蛋白聚集物，而胃消化的大豆 7S 蛋白仅含有淀粉样蛋白聚集物，因此表现出抗消化性。动物实验表明，不可消化的大豆 7S 蛋白可有效预防阿司匹林诱导的急性胃黏膜损伤。利用石英晶体微天平（QCM-D）、Langmuir 单层膜和多颗粒跟踪（MPT）研究了不可消化的大豆 7S 蛋白对胃粘液屏障特性的影响。结果表明，这些不可消化的蛋白聚集物可以穿透胃粘液，增加粘蛋白层的粘度和致密性，并增强胃粘液屏障特性。这些发现有助于理解，大量食用未经发酵的大豆食品与降低胃癌风险有关。
