Previous studies have demonstrated that enzymatically prepared coix seed prolamin hydrolysates (CHPs) contain several bioactive peptides that efficiently inhibit the activity of target enzymes (α-glucosidase and dipeptidyl kinase-IV) in type 2 diabetes mellitus (T2DM). However, the anti-T2DM effects and potential mechanisms of CHPs as a whole in vivo have not yet been systematically explored. Therefore, we evaluated the preventive, therapeutic, and modifying effects of CHPs on T2DM by combining physiological and liver transcriptomics with a T2DM mouse model. The results showed that sustained high-fructose intake led to prediabetic symptoms in mice, with abnormal fluctuations in blood glucose and blood lipid levels. Intervention with CPHs effectively prevented weight loss; regulated abnormal changes in blood glucose; improved impaired glucose tolerance; inhibited the abnormal expression of total cholesterol, triglycerides, and low-density lipoproteins; alleviated insulin resistance; and restored pancreatic islet tissue function in mice fed a high-fructose diet. In addition, we found that CHPs also play a palliative role in the loss of liver function and protect various organ tissues (including the liver, kidneys, pancreas, and heart), and are effective in preventing damage to the liver and pancreatic islet cells. We also found that the intake of CHPs reversed the abnormally altered hepatic gene profile in model mice and identified 381 differentially expressed genes that could serve as key genes for preventing the development of T2DM, which are highly correlated with multiple glycolipid metabolic pathways. We demonstrated that CHPs play a positive role in the normal functioning of the insulin signalling pathway dominated by the IRS-1/PI3K/AKT (insulin receptor substrates-1/phosphoinositide 3-kinase/protein kinase B) pathway. In summary, CHPs can be used as effective food-borne glucose-modifying components of healthy foods.

The present study aimed to evaluate the phenolic compounds and antioxidant activity of rice–tartary buckwheat composite (RTBC) as affected by in vitro digestion to explore the structure-activity relationship of the release of total phenolic content (TPC) and total flavonoid content (TFC) with the antioxidant activity of RTBC during in vitro oral, gastric, and intestinal digestion stages. The release of TPC and TFC from RTBC increased significantly after in vitro digestion ( ), and the change of antioxidant activity was consistent with that of TPC and TFC. Compared with the initial stage of digestion, the antioxidant activity of RTBC was increased after digestion ( ), and there was a strong correlation between antioxidant activity and the release of TPC and TFC (0.954 < R < 0.997; ). The phenolic compounds released in the oral, gastric, and intestinal digestion stages varied, and eight phenolic compounds were identified by UPLC-Triple-TOF/MS, namely, quercetin-3-O-robinoside-7-O-sophoroside, quercetin-3-O-neohesperidoside-7-O-glucoside, forsythobiflavone A, forsythobiflavone B, quercetin-3-O-rutinoside-7-O-glucoside, rutin, isoquercetin, and ferulic acid. These results indicated that in vitro digestion significantly increases the release of phenolic compounds and flavonoids from RTBC and there is a higher antioxidant activity after digestion than before digestion. The phenolic compounds released after digestion of RTBC are beneficial to health protection.

Ultrasound and slightly acidic electrolyzed water (SAEW) treatments have been widely applied to enrich γ-Aminobutyric Acid (GABA) during the germination of grains and legumes; however, the effects and underlying mechanisms of their combined treatment on GABA enrichment remain unclear. After 72 h of germination, this study investigated the impacts of different treatment methods-distilled water treatment (GM), ultrasound treatment (UGM), SAEW treatment (SGM), and combined treatment (USGM)-on key enzyme activities, protein structural characteristics, and the GABA metabolic pathway in germinated mung beans. The results indicated that the combined treatment of ultrasound and SAEW promoted GABA enrichment in germinated mung beans, with the GABA content reaching 6.25 ± 0.025 mg/g. Additionally, it significantly enhanced the activities of glutamate decarboxylase (GAD), diamine oxidase (DAO), and polyamine oxidase (PAO) to 0.359 ± 0.008 U/g, 0.554 ± 0.021 U/g, and 1.265 ± 0.036 U/g, respectively (p < 0.05). Fourier-transform infrared spectroscopy and intrinsic fluorescence spectroscopy analyses revealed that the combined treatment significantly increased the content of α-helix and β-turn structures in the protein secondary structure (p < 0.05), while reducing the proportions of β-sheet and random coil structures, and enhanced protein surface hydrophobicity. Untargeted metabolomics analysis further demonstrated that the combined treatment significantly upregulated the levels of amino acid-related compounds, with a strong positive correlation observed between Glu and GABA content. Moreover, it primarily facilitated GABA synthesis by modulating pathways such as arginine-proline metabolism, arginine biosynthesis, alanine, aspartate, and glutamic acid metabolism, and butanoate metabolism. The findings of this study provide theoretical support for elucidating the molecular mechanisms by which ultrasound and SAEW promote GABA enrichment in mung beans and offer new insights for developing functional mung bean foods rich in GABA..