Ozônio na conservação pós-colheita de mamão

Abstract

Phytosanitary treatments should minimize the risk of post-harvest diseases and delay the physiological processes of maturation and senescence. The best alternatives are alternative treatments, especially ozone that, in addition to controlling the fungus, increases the shelf life of papaya, without depreciating the quality of the fruits. Thus, the objective of this work was to study the effect of ozone on post-harvest conservation, aiming the control of the anthracnose and the increase the shelf life of papaya fruits. The experiment was conducted at Product Technology Laboratory, Federal University of Amazonas (UFAM), Manaus-AM. The treatments were constituted by application of ozone at concentrations of 0 (control); 0.6; 1.5 and 3.3 ppm; and post-harvest application of commercial fungicide. The fruits were stored at room temperature (27 ± 2 ° C and 85 ± 5% RH). Phytosanitary action of ozone was determined by the incidence, severity, number and size of the anthracnose lesions; and the post-harvest quality of the fruits, through the shelf life evaluation; accumulated and daily mass loss (%), fruit peel color; electrolyte leakage (%); soluble solids (%); titratable acidity (g 100 g-1); SS/AT ratio; pH and vitamin C (mg 100 g-1). A completely randomized design was used with ten (incidence, severity, number and size of anthracnose lesions and fruit shelf life) and five replicates (other post-harvest quality analyzes). For the shelf life analysis, the Log-Rank test (p <0.01) was used by the Kaplan-Meier estimator. Regression analysis was performed considering the time of storage for the incidence, severity, number and size of lesions and accumulated mass loss. Outher quality data were submitted to analysis of variance and the means were compared by the Tukey test (p <0.05). The Pearson correlation coefficient was estimated for all variables at the level of significance of 1 and 5% by the t-Student test. Ozone reduced the severity of anthracnose to short (3.3 ppm) and long term (1.5 ppm), making it as effective as the commercial fungicide. Ozone increased the shelf life by seven days and maintained the post-harvest quality of papaya fruits. Thus, ozone becomes a potential technology for post-harvest use as a safe alternative to the use of pesticides in reducing anthracnose and increasing the conservation of papaya fruits.