Distribution and bioactivity of polyphenols in Opuntia ficus-indica (L. ) Mill

Objective: To study the distribution of the polyphenols of Opuntia ficus-indica(L. ) Mill, and study its antioxidant and the inhibition of sugar digestive enzyme activities by vitro experiments.

Methods: Using ethanol as solvent, free polyphenols, esterified polyphenols, and insoluble bonded polyphenols were extracted from the peel, pulp and seeds of Opuntia ficus-indica(L. ) Mill, and their contents were determined by the Folin-Ciocalteu method. Antioxidant activity was measured according to their ability to scavenge DPPH, OH and ABTS~(+ )radicals, and the inhibition of α-glucosidase and α-amylase activities by various types of polyphenols in various parts was observed in vitro.

Results: The peel polyphenol content of Opuntia ficus-indica(L. ) Mill was(1427.15±34.48) mg GAE/100 g, the pulp polyphenol content was(525.88±51.66) mg GAE/100 g, and the seed polyphenol content was(256.92±3.81) mg GAE/100 g. The free polyphenols, esterified polyphenols, and insoluble bonded polyphenols of different parts of Opuntia ficus-indica(L. ) Mill have the ability to scavenge DPPH, OH and ABTS~(+ )radicals, and the seeds had the strongest antioxidant capacity among all parts, the esterified polyphenols and insoluble bonded polyphenols of pulp and seeds of Opuntia ficus-indica(L. ) Mill have inhibitory effects on the activities of α-glucosidase and α-amylase, with seed polyphenols have the strongest inhibitory ability.

Conclusions: Opuntia ficus-indica(L. ) Mill has the highest content of polyphenols in the peel, and seed polyphenols have good antioxidant and the inhibition of sugar digestive enzyme activities.