COMPUESTOS BIOACTIVOS Y CAPACIDAD ANTIOXIDANTE EN FRUTOS DE XOCOTUNA, TUNA Y XOCONOSTLE (Opuntia spp.)

The objective of this research was to determine the content of some bioactive compounds and the antioxidant potential of xocotuna (Opuntia chiangiana) compared to that of cactus pear (Opuntia ficus-indica) and xoconostle (Opuntia spp.). Fruits at physiological maturity were harvested in the months of June, August and October of 2013 in El Orito, Zacatecas, Mexico. The variables evaluated were: antioxidant capacity, total phenolic content, vitamin C, betalain content, and total chlorophyll and carotene contents. Statistical differences were observed in ‘Coral’ xocotuna after 3, 6, 9 and 12 days of storage, reaching the highest levels of antioxidant capacity (between 0.92 and 1.04 mg VCEAC g-1). ‘Cuaresmeno’ recorded the highest total phenolic content with initial values of 44.61 mg GAE 100 g-1, while ‘Amarilla Platano’ recorded the lowest value of 6.27 mg GAE 100 g-1. Significant differences were also found in the content of vitamin C; xoconostle cultivars showed the highest levels during the evaluated period, with values ranging between 41.80 and 125.98 mg 100 g-1. Regarding the content of betalain, and total chlorophyll and carotene contents, a high variability was found because of the characteristic color of each cultivar. The cultivars analyzed, mainly those of xoconostle and xocotuna, could be considered as an excellent source of vitamin C and antioxidants to be included in the diet or as natural ingredients to prepare other products.