The antioxidant property and α-amylase inhibition activity of young apple polyphenols are related with apple varieties

Abstract In this study, compositional profile, antioxidant activities and α-amylase inhibition of young apple polyphenols (YAP) from five cultivars (Short-branch Fuji, Pink Lady, Jinshiji, Ruiyang and Qinyang) were investigated. The possible inhibition mechanism of YAP on porcine pancreatic α-amylase (PPA) was studied through kinetic analysis, fluorescence quenching (FQ) and differential scanning calorimetry (DSC). The results showed that YAP exhibited strong antioxidant activities, and showed a significant inhibitory effect on PPA through a competitive inhibition mode. Jinshiji YAP exhibited the highest inhibitory capacity with the IC 50 value of 0.023 mg/mL. Besides, combination of DSC and FQ results demonstrated that the potential unfolding of PPA structure was induced by binding with YAP.