Desenvolvimento e aplicação de cobertura de quitosana e levana na conservação pós-colheita de manga minimamente processada

Abstract

Brazil is a great fruit producer due to the climatic conditions that favor the cultivation of tropical fruits. Among the cultures that stand out for their high production and export is mango. Mango (Mangifera indica L.) is one of the tropical fruits most consumed by Brazilians, having high nutritional value, such as vitamin C, β-carotene, and minerals. Because they are perishable products, such as fruit, they reduce losses from their production until they reach the consumer, and this annual waste of tons of food causes an economic loss, in addition to environmental impacts. Chitosan is a polysaccharide that has antifungal activity and semi-permeable properties, decreasing the respiration rate and water loss of fruits. Levana is also a polysaccharide used in the food industry as a core and flavor fixative, thickener, and stabilizer in dessert gels. This study aimed to develop a coating for application in minimally processed mangoes from a combination of levan and chitosan, determining the best proportion between them that presents satisfactory characteristics and properties to store at different prices over a while. The topping was prepared at a concentration of 90% w/v chitosan and 10% w/v levan with a concentration of 0.5% v/v glacial acetic acid and 1% w/v glycerol, and then applied to the mango pieces that were stored at temperatures of 25 ± 2ºC and 2 ± 1ºC. The samples were analyzed every 3 days for color, soluble solids, water activity, moisture, titratable acidity, and pH. Mango slices stored at a temperature of c were not analyzed for showing fungus on the fourth day of storage. Mango slices at 2 ± 1°C temperature not alternated probably from water activity, pH and humidity during the entire storage time. There was a significant increase during the storage period in the soluble solids content, titratable acidity and as variables color L*, a*, and b*. There was also a delay in darkening and an increase in yellow pigmentation. The coating with chitosan (90% w/v) and levan (10% w/v) present satisfactory characteristics for application in minimally processed mangoes. Physical analyzes increased that coating could be effective in increasing shelf life, as it delayed browning, likely undistorted pH, and water activity.