Citrus peel extract has been observed with many benefcial-promoting effects. Pomelo (Citrus grandis (L) Osbeck) peel extracts (PPE) from the flavedo and albedo of two varieties namely Long Co Co and Tanh Kieu were investigated. In this study, the qualitative analysis indicated the presence of phytochemical groups including alkaloids, flavonoids, saponins, and tannin in the PPE from the flavedo and albedo. Te PPE from the Tanh Kieu flavedo was found to possess the highest antioxidant activity at the EC50 values of 60.89 ± 0.31 µg/mL, 60.69 ± 0.21 µg/mL, and 24.16±0.06 µg/mL for DPPH, ABTS, and FRAP assay. However, the Long Co Co albedo- PPE induced better inhibitory effect against α-amylase (EC 232-560-9) and α-glucosidase (EC 232-604-7) with respect to EC50 values of 3.59 ± 0.02 mg/mL and 80.77 ± 0.34 µg/mL. Tis result suggested potential in the anti-hyperglycemic effect of pomelo peel extract from the flavedo and albedo that can serve as a nutraceutical in food and pharmaceutical industries.

Keywords: antioxidant activity; albedo; flavedo; pomelo peel extract; α-amylase inhibition; α-glucosidase inhibition.
Practical application: Potential in anti-hyperglycemic treatment by inactivating carbohydrate digestive enzymes of PPE.