Comparison of phenolic compounds, antioxidant and antidiabetic activities between selected edible beans and their different growth periods leaves

The aim of this study was to determine and compare a polyphenolic profile, antioxidant and antidiabetic activities between seeds and different growth periods leaves (from week 3 to 14) of three selected edible beans: yellow and black soyabean (Glycine max), as well as adzuki bean (Vigna angularis). Polyphenolic profile was determined by HPLC-ESI-TOF-MS and HPLC-DAD, antioxidant activity were analysed by ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)), FRAP (ferric reducing antioxidant power), and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. We also evaluated for their antidiabetic activity against a-glycosidase. The results showed that the leaves of three edible beans were a valuable source of polyphenolic substances. Furthermore, adzuki bean leaves contained significantly higher polyphenol content than their seeds. Thus, they exhibited stronger antioxidant and a-glucosidase inhibitory activities than seeds. However, soyabean contained more polyphenols than their leaves. Therefore, soyabean displayed a more positive effect on antioxidant and a-glucosidase inhibitory activities than their leaves. (C) 2017 Elsevier Ltd. All rights reserved.