Optimization of Hot Water Temperature Dipping and Calcium Chloride Treatment to the

Abstract

popular fruits in the world and widely cultivated crops in the tropical and subtropical zones. Keitt mangoes and Cavendish bananas are the largest cultivar of these fruits found in the Mozambique market. They are only available for a short period each year mostly during the late summer and early falls. Due to mango and banana fruits high water activity and respiration rate, are perishable foods and require conservation methods for preservation and availability. The aim of this study was to optimize the hot water-calcium chloride concentration treatment regime for improved postharvest handling of mangoes and bananas. The fruits collected were of uniform size, and at greenyellowish maturity stage based on length, diameter, colour and firmness. The process was optimized by experimental central composite design using hot water temperature (50˚C - 60˚C) and calcium chloride concentration (2% - 4%) with the aid of desirability function. The samples were analyzed for the centesimal composition, firmness, colour, ˚Brix, Aw, pH, titratable acidity and vitamin C. The results showed that hot water temperature and calcium chloride concentration were influent on the Keitt mangoes b* colour attribute, pH and titratable acidity as well as the Cavendish bananas firmness, ash and vitamin C content. The optimal conditions of the process were stabilized with the desirable function and, coincidentally for both crops, obtained at 55˚C of hot water temperature dipping and 3% of calcium chloride concentration. The simulated data were similar to the experimental ones. This is the first time that calcium chloride-hot water treatment is being reported as a means of extending the shelf-life of mangoes and bananas.