Ácido giberélico na conservação pós-colheita de frutos de umbuzeiro (Spondias tuberosa Arruda Câmara) em condição refrigerada

Abstract

The umbuzeiro is a native species of Caatinga, it has as fruit the umbu, with great social and economic importance for the Northeastern region of Brazil. The umbu has great acceptance in the market for in natura consumption and of products such as popsicles, jellies and sweets, however, the absence of post-harvest technologies to preserve this fruit causes that much of the harvest is lost. An alternative to increasing the shelf life of umbu is the use of refrigeration associated with regulators such as gibberellic acid (GA3), which acts to reduce the rate of respiration and inhibit the synthesis of ethylene in post-harvest. In this sense, the objective of this study was to evaluate different concentrations of GA3 in the post-harvest conservation of umbu in refrigerated conditions, based on the attributes of fruit quality. The fruits were harvested manually at maturation stage " for once", immediately washed and sanitized in 2% (w/v) sodium hypochlorite solution, dried in ambient condition and selected for size, appearance and physical damage. Then, the following treatments were performed: T1: 0 mgL-1 (Witness), T2: 10 mgL-1 of GA3, T3: 20 mgL-1 of GA3 and T4: 30 mgL-1 of GA3. The fruits were immersed for 60 seconds, dried in ambient condition and conditioned in refrigerated condition. The experimental design was completely randomized, with plots subdivided in time, the plots consisted of the four concentrations of GA3 and the subplots for storage time (0, 5, 10 and 15 days), except for mass loss, with evaluation three days. Five replicates with 5 fruits were used for each subplot, totaling 100 fruits per plot. The data were submitted to analysis of variance and when significant, the Tukey test was applied at 5% for the concentrations of GA3 and the regression analysis to the subplots. The attributes of quality evaluated were: length, diameter and shape of the fruit; weight loss; weight and yield of pulp; fruit mass, bark and seed; yield of pulp and seed; soluble solids, titratable acidity; pH; ratio and technological index. The concentrations of gibberellic acid did not present significant interference with the physical attributes of umbuzeiro fruits in refrigerated conditions, except for pulp mass and pulp yield, which presented the best results for GA3 20 and 30 mgL-1 concentrations. The weight loss of the fruits did not differ from the control among the applied treatments, being the highest loss obtained in the concentration of 30 mgL-1 of GA3. The storage time was the factor of greater interference on the physical-chemical attributes, however, for the ratio, there is interference of GA3 concentrations up to the 10th day of storage. There is a need for further investigation regarding the use of GA3 in the post-harvest conservation of umbu, with test of other concentrations and immersion time in order to prove the efficiency of this regulator in the maintenance of post-harvest life of umbu in refrigerated condition.