Optimization and identification of bound polyphenols from rice bean (Vigna umbellata) skin dietary fiber, antioxidant activities and α-glucosidase inhibition mechanism

-glucosidase. Chemical compounds: Protocatechuic acid (PubChem CID: 72); Malic acid (PubChem CID: 525); Isoferulic acid (PubChem CID: 736186); p-Hydroxybenzoic acid (PubChem CID: 135); Citric acid (PubChem CID: 311), (+)-Catechin (PubChem CID: 9064), Fumaric acid (PubChem CID: 444972), Gallic acid (PubChem CID: 370), Azelaic acid (PubChem CID: 2266), (-)-Epicatechin (PubChem CID: 72276).