Ozônio na conservação pós-colheita de bananas

Abstract

Banana is one of the most consumed fruits in the world, however, there is a loss of a good part in the post-harvest, caused by lack of technical knowledge, with this, ozone is a great ally in the importance of the food sanitization process, as well as one of the alternative ways to extend your life of perishable products. The objective of this work was to test the effects of ozone gas for post-harvest conservation of 'Pacovan', 'Prata' and 'Thap Maeo' banana cultivars. The experiment was carried out at the Product Technology Laboratory, at Post Bio-Agro, Faculty of Agricultural Sciences (FCA) Federal University of Amazonas – UFAM, in Manaus-AM. The work was developed in 3 stages, taking into account that all of them received ozone gas treatments in doses: 0 (control), 0.6, 1.5 and 3.3 g L-1. In the first stage, the effect of treatment with ozone gas (O3) on the microbiological quality of bananas was verified, the experimental design was completely randomized, consisting of five treatments: O3 and Sodium Hypochlorite (1%), with three replications each. , and each repetition were made three dilutions (10-1, 10-2, 10-3) to evaluate the Colony Forming Units (CFU): such as the presence of Salmonella sp., counting colonies of thermotolerant coliforms, mesophilic aerobic bacteria and Coagulase positive Staphylococcus aureus. The evaluation was in Petri dishes containing specific medium for each bacteria. The data obtained were converted into a log of 10 and submitted to analysis of variance and means compared by Tukey test at 5% probability. In the second experiment, the effect of exposure to O3 gas on the control of anthracnose in fruits was evaluated. The design was in DIC, consisting of five treatments: O3 and Nativo® fungicide (1.2mL L-1), with ten replications, with two fruits each. Variables analyzed were severity, incidence and area under the disease progress curve (AUDPC). Assessing the severity of the disease was performed by regression analysis and compared at significance levels by the t test at 5% probability; incidence and AUDPC were subjected to analysis of variance and means compared by Tukey test at 5% probability. In the third and last stage, the effect of O3 on the shelf life of bananas was evaluated. The experimental design used was in DIC, consisting of six treatments: O3, Sodium Hypochlorite (1%) and Nativo® (1.2mL L-1). Variables analyzed were survival analysis with ten repetitions; to study the postharvest quality of the fruits, four replicates were used in the initial and final evaluations of shelf life. the fruits were preserved at room temperature (27±2 ºC and relative humidity of 65±2%). The data collected in the external appearance were submitted to survival analysis, with the application of the LogRank test, by the Sigmaplot 10 statistical program, and the data from the post-harvest analyzes were submitted to the variance analysis and the means were compared by the Tukey test at 5 % probability. All analysis of variances and Tukey test was used free software for statistics, Sisvar. First experiment, hear only the presence of CFU from mesophilic aerobic bacteria and ozone had no significant effect. According to the experiment, ozone at the concentration 1.5 mg L-1 had the lowest incidence on the 5th day of evaluation when the fruit was in the 5th stage (yellow with green tips) for 'Pacovan', at the concentrations 1.5 and 3.3 mg L-1 does not hear incidence and at the concentration 0.6 mg L-1 in 'Thap maeo'. Third experiment, ozone at 3.3 mg L-1 concentration obtained the best result in 'Pacovan' and 'Thap maeo', as it increased the shelf life longer, and in 'Prata it was 1.5 mg L-1 concentration. Thus, the work showed that ozone has great potential as an alternative method to the use of pesticides on post-harvest bananas.