Armazenamento e qualidade de pitaia [Hylocereus undatus (Haw.) Britton & Rose] submetida à adubação orgânica

Abstract

Pitaya is a cactus native of the tropical forests in Central and South America. Considered a highly attractive fruit due to its colors and sweet flavor, it has presented a high potential for commercialization in Brazil. However, little is known about its chemical properties and post-harvest behavior. In this sense, the present work aimed at evaluating the post-harvest quality of the pitaya cultivated in different organic fertilization treatments and stored for 21 days as 13 oC. The fruits acquired from the orchard in the Universidade Federal de Lavras, in Lavras, Minas Gerais, Brazil, were separated regarding the fertilization treatments (T1- Witness, T2- Bovine manure, T3- Chicken manure and T4- Bovine manure + chicken manure). Each treatment was divided into four lots in order to compose four days of analyses (0, 7, 14 and 21 days of storage). The centesimal and mineral composition analyses were only performed in day 0, while the analyses for firmness, color, mass loss, soluble solids, titrable acidity, pH, sugars, vitamin C and antioxidant activity were performed at 0, 7, 14 and 21 days of storage. The pitaya presented, in the pulp, the highest contents of protein (1.33 mg 100 g-1), ethereal extract (0.73 mg 100 g-1), ash (0.13 mg 100 g¬-1) and glicidic fraction (11.14 mg 100 g-1). The peel presented contents of moisture (91.59 mg 100 g-1) and soluble (0.83 mg 100 g-1) and insoluble (5.21 mg 100g-1) fibers. The minerals found in the pitaya were calcium, manganese, magnesium, zinc, copper and iron. Organic fertilization positively influenced the evaluated quality parameters. The fruits from the T4 treatment presented the smallest quality loss. After 14 days, we verified fruit senescence. There was loss in the content of vitamin C and phenolic compounds during storage, consequently reducing the antioxidant activity in all treatments. The amount of carotenoids and anthocyanins were low. The peel presented content of vitamin C (11.06 mg 100 g-1), phenolic compounds (61.33 mg 100 g-1) and antioxidant activity (3.36 mg 100 g-1) superior to those of the pulp. The fruits from the T4 treatment presented higher vitamin C concentrations in the pulp and phenolic compounds in the peel. The fruits from the T2 treatment were superior in the phenolic compound content in the pulp. However, the highest antioxidant activity was observed in the fruits from the T3 treatment.