Enzymatic and non-enzymatic antioxidant systems of minimally processed cactus stems (Opuntia ficus-indica Mill.) packaged under modified atmospheres

Summary: The aim of this work was to determine the enzymatic activities of catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) together with the total phenolic and carotenoid contents and antioxidant capacity of two cultivars of cactus stems under modified atmosphere packaging containing a passive atmosphere, an active (with N₂) atmosphere and control (unsealed polyurethane trays) all stored at 4 ± 1 °C. Results indicated that Atlixco cultivar cactus stems had a shelf life that was twice as long (20 days) than that of Milpa Alta cultivar under N₂ MAP. The total enzyme activities of SOD, APX and CAT as well as the carotenoid content were higher in Atlixco than in Milpa Alta. The antioxidant enzymatic and non-enzymatic systems as well as the antioxidant capacity and the phenolic content retention determined in Atlixco cactus stems under N₂ MAP appear to explain the longer postharvest life of this cultivar.