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

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.

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.

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.

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.