On April 6, Beijing Technology and Business University and new vegetarian researchers Li Wenhui, Fu Xiaohang, Zhang Tianyu, Li He, Chen Tianpeng, and Liu Xinqi published a research paper on soybean protein lowering blood sugar in the JCR Q1 journal “Food&Function”.
Although extruded soy protein (ESPro) is currently used to produce plant-based meat, there are few studies involving its in vitro and in vivo hypoglycemic activity. In this study, the α-glucosidase inhibitory activity of ESPro with different extrusion parameters was compared, and it was found that ESPro1 (160°C, 30r/min) had the highest inhibitory activity. Then, ESPro1 was mock digested and ultrafiltered in vitro, yielding the ESPro1 digest (<1 kDa) with the highest inhibitory activity. Further separation by gel filtration chromatography yielded the ESPro1 F3 fraction with the highest inhibitory activity.
Finally, six peptides with α-glucosidase inhibitory activity were screened from ESPro1 F3 fraction and synthesized by solid-phase synthesis, among which LLLPPK showed the highest inhibitory activity (46.98±0.63%). During a four-week dietary intervention in mice with type 2 diabetes mellitus (T2DM), ESPro attenuated the tendency towards weight loss, lowered blood sugar, alleviated insulin resistance, and improved glucose tolerance, while ESPro1 reduced blood sugar levels by 22.33% at 28 days.