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 anti-oxidant capacity of two cultivars of cactus stems under modified atmosphere packaging containing a pas-sive atmosphere, an active (with N 2) atmosphere and control (unsealed polyurethane trays) all stored at 4 AE 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 N 2 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 enzy-matic and non-enzymatic systems as well as the antioxidant capacity and the phenolic content retention determined in Atlixco cactus stems under N 2 MAP appear to explain the longer postharvest life of this cultivar.