Fisiologia, qualidade e conservação pós-colheita de frutos do umbuzeiro armazenados sob recobrimentos a base de amido de semente de manga

Abstract

Umbuzeiro is an important fruit tree of the Semi-Arid whose fruit, umbu, has a highly appreciated flavor and aroma, being a safe source of employment and income for populations in the areas of occurrence during fruit season. However, umbu is highly perishable, requiring strategies to maintain post-harvest quality. The use of starch-based coatings can ensure the maintenance of quality as an alternative to plastics derived from petroleum in the generation of modified atmosphere (MA). The use of agroindustry residues can generate viable by-products for obtaining starchy sources for coatings, such as mango seed. Thus, mango seed almond starch can represent a sustainable innovation in the development of biodegradable coatings to promote MA, aiming at postharvest conservation of umbu. Given the above, the objective of the present study was to determine changes in the physiology, quality and postharvest conservation of the umbuzeiro fruits during storage with edible coatings of starch obtained from mango seed almond added with glycerol under refrigeration (12 ± 1 ° C and 75 ± 2% RH) and at room temperature (25 ± 2 °C) to determine the ethylene and CO2 production. The design was completely randomized in a 5x4 factorial scheme (5 coatings, 4 evaluation periods) with 4 repetitions. The formulations were: starch (A) (3%) with glycerol (G) (0.6%) (A3G), starch (2.5%) with G (A2.5G), starch (2.5%) without G (A2.5), starch (2%) with G (A2G) and Control (C), umbus without covering. For the Ethylene and CO2 evaluations, the design was completely randomized in a 3x5 factorial scheme (3 coatings, 5 evaluation periods). The coating of umbus with A2.5G provided a delay in the peak of ethylene and CO2 production at the ambient room condition, clearly delaying the ripening of these fruits. During storage at 12 oC, umbus with A2G and A2.5 showed higher values of L *, indicating greater brightness. The values of a* were lower in umbus coated with A2.5, A2.5G and A3G, indicating the maintenance of green color. Under these coatings the levels of vitamin C, soluble solids and titratable acidity were also maintained, indicating delay in ripening. Under refrigeration, umbus coated with A2G and A2.5 reduced dehydration, maintained brightness and the purchase intention for 12 days, extending fruit conservation by five days related to the control. Together, the application of mango seed almond starch-based coatings provides a clear delay in ripening and increased postharvest conservation of umbu, which characterizes this as a viable, clean and sustainable technology for postharvest conservation and opening new markets for these important semi-arid fruit.