Antioxidant, α-amylase and α-glucosidase inhibition properties of polysaccharide from pomegranate peel via enzymatic and acidic approach

Pomegranate peel is the main by-product during pomegranate processing that valuable source of bioactive compounds with health-beneficial effects. This study has comparatively assessed the effects of two extraction methods (enzymatic and acidic) on pomegranate peel by measuring their bioactivity in terms of total phenolic content (TPC), antioxidant activity, and antidiabetic properties using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation decolourization assays, and the α-amylase and α-glucosidase inhibition assays. The TPC mg gallic acid equivalents per g dry weight (GAE mg/g dw) of extracted pectin was ~ 243 and ~ 116 for enzymatic and acidic methods, respectively. The DPPH IC50 of enzymatic pectin was significantly lower than that of acidic pectin (p < 0.05). The ABTS IC50 of enzymatic pectin and acidic pectin was ~ 361 and ~ 945, respectively. The enzymatic pectin showed a significantly stronger α-amylase and α-glucosidase inhibition effect as compared to the acidic pectin. The α-amylase inhibition was stronger than α-glucosidase inhibition for all samples.The results indicated that enzymatic extracted pectin showed antioxidant and antidiabetic potential, which could be considered as a promising candidate for functional foods in food formulation.