Keywords: Stenocereus pruinosus, antioxidant activity, betalains, phenols, postharvest life.
Pitaya (Stenocereus pruinosus) is a columnar cactus that can be found in semi-arid regions. Fruit have deciduous thorns and shelf life is less than six days at ambient temperature, which limits commercialization. The objective of this study was to evaluate the postharvest behavior of pitaya fruit under refrigeration conditions and also to evaluate the effect of thorn removal on fruit quality attributes. Storage for 21 d at 12 °C was conducted with pitaya fruit of red and orange flesh, handled with or without thorns. Fruit weighed between 168.1 and 197.6 g, with respiration rate between 11.9 and 12.6 mL⋅kg-1 ⋅h-1 , and with soft consistency, expressed through firmness in flesh less than 2 N. Color attributes, total soluble solids (TSS), betalains and total soluble phenols (TSP) contents, and antioxidant activity were different between variants. Hue angle, chroma, and lightness in flesh were 22.0-25.0°, 29.0-31.0, and 22.8-23.8, respectively, in red fruit, and 35.5-37.7°, 38.9-41.5, and 29.7-32.6, in orange fruit. The TSS/acidity ratio was higher in orange (152.8-157.0) than in red (115.5-132.0) fruit. Betalains and TSP had average values of 4.7-423.0 and 2.5-221.6 mg⋅kg-1 in red and orange material, respectively, which caused higher antioxidant activity in the former. Betalains content remained constant over time, but TSP diminished and this caused a reduction in antioxidant activity. Thorn removal only affected weight loss and it was considered an advisable practice. Based on firmness modification and loss of antioxidant activity, shelf life was estimated to be 12-14 d.