Efeito do tempo de armazenamento refrigerado de maçã cv. ‘Gala’, in natura: na qualidade sensorial, físico-química e bioquímica de produto minimamente processado em fatia, com epiderme, tratado com eritorbato de sódio e três diferentes coberturas comestíveis

Abstract

The apple, following mechanical damage, such as cutting for the production of the minimally processed fruit, undergoes rapid degradation of the physicochemical and sensorial characteristics, and may become inappropriate for consumption. In this work, the effect of refrigerated storage time of fresh apple; combined with the effect of applying antioxidant and edible toppings, immediately after cutting the fruit into eight slices with wedge shape, was studied. Apple cv. 'Gala', from Vacaria, RS, harvested in the year of 2015, selected, sanitized, treated with MCP, and refrigerated (temperature of 1 °C ± 1 °C and relative humidity of 90 % ± 5 %), according to standard procedures used by RASIP Company, was transported to the Postharvest Physiology Laboratory of Embrapa Clima Temperado, in Pelotas, RS, and stored in natura, under refrigeration, for 60 d, 120 d and 180 d. At the end of each period of storage, the apple was re-sanitized, cut longitudinally into eight slices of same size and with wedge shape, immersed for 1 min in calcium chloride solution (1.0% w/v), with or without the antioxidant sodium erythorbate (5.0% w/v), drained, and immediately immersed for 1 min in cassava starch solution (3.0%, w/v), sodium alginate (2.0%, w/v) or chitosan (1.5% w/v), to form the edible cover, and finally dried with forced air (4.3 m / s at 16 ° C ± 1 ° C and 65% ± 5% RH, for 20 min). The experimental unit consisted of eight slices of apple placed in a polyethylene tray, sealed with a single layer of PVC film, 9 μm thick, and stored for 0 d, 3 d, 6 d at 4 °C ± 1 C and 90% ± 5% RH. After each storage period, physicochemical and sensory variables were evaluated, as well as enzymatic activity. The F test (p ≤ 0.05) was used in the analysis of variance, the DMS test (p ≤ 0.05) in the comparison of means of treatment and factorial correlation analysis between variables. In the in natura fruit it was observed an increase in the variable ratio (soluble solids / acidity) throughout the storage. The effect of the storage time of the apple in natura was significant in some physical-chemical variables, but without repercussion in the sensorial analysis. The application of sodium erythorbate, combined with the application of cassava topping, provided the best results, both in 10 the sensorial evaluation and in the physicochemical characteristics, including the delay of darkening of pulp.