Seasonal variability of phenolic compounds and antioxidant activity in prickly pear cladodes of Opuntia and Nopalea genres

The prickly pear is a cactaceae that have chemical compounds that act as natural antioxidants. In addition, the prickly pear is a plant widely used in semiarid region as it's considered very important forage for animal feed, especially in the dry season. The objectives of this research were to characterize the main classes of phytochemicals, determine the phenols content, flavonoids and anthocyanins and evaluate the antioxidant activity of the prickly pear cultivars Opuntia and Nopalea grown in the semiarid region of Pernambuco in two collection periods (dry and rainy). In the work crude ethanol extracts from cladodes of cultivars (IPA-20, Elephant Ear Mexican, F-08, V-19, Small palm, F-21 and IPA-Sertania) were used. As for the class of phytochemical compounds from ethanol extract only the flavonoids and steroids were detected in all prickly pear cultivars, in both periods analyzed. The content of phenolic compounds ranges from 1.24 to 5.41 mg GAE g(-1) DM, flavonoids 0.90 to 3.43 mg QE g(-1) DM, anthocyanins from 0.05 to 0.34 mu g QE 100 g(-1) DM and antioxidant activity 39.59 to 217.17 mu M TEAC g(-1) DM. The occurrence of chemical variability and antioxidant activity were observed, both among the botanical cultivars studied and among the collection periods.