Studies On The Functional Properties Of Legume Proteins And Preparation And Activities Of Black Soybean Peptides And Anthocyanins

Legume resources are abundant in our country,which have been widely used due to its nutritional and pharmaceutical properties.The active peptides released from legume protein and some small molecules of legume possess various beneficial bioactivities,includinganti-oxidative,anticancer,immunoregulatory,antihypertensive,hypoglycemic and other biological effects.In recent years,the active substances of legume have become an important resource for functional food and drug research and development.In order to facilitate the utilization of legumes and provide a theoretical basis for the new functional food and drug development,in this paper,the physicochemical properties,functional properties,antioxidant and anticancer activities of the proteins from soybean,black soybean,adzuki bean and mung bean were studied.At the same time,the preparation,purification and identification of anticancer peptide released from black soybean protein were investigated and the hypoglycaemic and hypolipidemic activities of anthocyanin extract of black soybean seed coat in vitro and in vivo were also evaluated.Firstly,proteins of soybean?SP?,black soybean?BSP?,adzuki bean?ABP?and mung bean?MBP?were extracted by isoelectric precipitation method.Then,the amino acid composition and molecular weight distribution of proteins were analysed by HPLC and SDS-PAGE.The functional properties,antioxidant and anticancer activities in vitro of these four kinds of proteins were also comparatively investigated.The results showed that MBP contained abundant essential amino acids and exhibited higher thermal stability than the other three proteins?p<0.05?;The solubility,foaming capacity and antioxidant activity of ABP were higher than those of SP,BSP and MBP?p<0.05?;BSP showed higher water holding capacity and significant growth inhibitory activity?p<0.05?against ovarian cancer?SKOV3?and hepatocellular carcinoma cell lines?SMMC-7721?(The IC₅₀ values of SKOV3 and SMMC-7721 were 327.9 and 88.9?g/m L,respectively).In addition,BSP was hydrolyzed by using alcalase and the black soybean seed protein hydrolysate?BSPH?was obtained.Then,BSPH was purified sequentially by ultrafiltration,gel filtration chromatography?Sephadex G-25?and reversed-phase high performance liquid chromatography?RP-HPLC?.Finally,the peptide fraction?F2-c?with the strongest anticancer activity was selected by the anticancer activity screening test and the structure of F2-c was identified as Leu/Ile-Val-Pro-Lys?L/I-V-P-K?by LC-MS.As for the study of black soybean seed coat extract?BSSCE?,the hypoglycemic and hypolipidemic activities of BSSCE in vitro and in vivo were studied.The results elucidated that BSSCE exhibited strong inhibitory activity on?-amylase and potential inhibition activity against the lipid accumulation of denatured adipocytes in HepG2.Animal experimental results of the type 2 diabetes mellitus?T2DM?model mice showed that the fasting blood glucose level and insulin level of BSSCE 400mg/kg group mice were significantly decreased by 47.97%and 46.49%,respectively,when compared with the diabetic control.After BSSCE treatment,the oral glucose tolerance and the activities of antioxidant enzymes such as superoxide dismutase,glutathione peroxidase and catalase were notably improved?p<0.05?.At the same time,BSSCE could remarkably ameliorate the atherogenic dyslipidaemia of diabetic mice.In summary,this research could help provide a theoretical basis for legume proteins,bioactive peptides and anthocyanins used in functional food application and related drug development.