ANTIOXIDANT COMPOUNDS IN PRICKLY PEAR (Opuntia sp.) PIGMENTED VARIETIES

Abstract

This study evaluated variation in content of betacyanins, betaxanthins, phenolic compounds, flavonoids, and vitamin C in the fruit of eleven prickly pear (Opuntia sp.) pigmented varieties. Samples were harvested at 10 d before horticultural maturity (horticultural immaturity; HI), at horticultural maturity (HM), and at 10 d after harvesting at horticultural maturity (postharvest behavior; PHM). The observed levels of betacyanins (0.21 to 59.18 mg 100 g^-1 fw) were far superior than those of betaxanthins (0.12 to 24.07 mg 100 g^-1 fw) in varieties of purple and red fruits in the three maturity indexes (HI, HM, and PHM). Preharvest and postharvest variations in these pigments contents were found and depend on genotype. Betacyanins (0.46 to 49.15 mg 100 g^-1 fw), betaxanthins (0.57 to 19.91 mg 100 g^-1 fw), phenolic compounds (106.60 to 165.56 mg GAE 100 g^-1 fw), and flavonoids (1.34 to 11.21 mg QE 100 g^-1 fw) increased during storage (PHM) in most of the pigmented varieties, particularly in those with red and purple pulp. Higher levels of vitamin C were found in most of the varieties at HI, which gradually diminished until HM and PHM. In some varieties the storage of the fruits contributes to loss of vitamin C.