Effect of cassava-starch coatings with ascorbic acidic and N-acetylcysteine on the quality of harton plantain (Musa paradisiaca)

Abstract

The effect of coatings was evaluated on the quality ofharton plantain fruits (Musa paradisiaca) in the postharvest stage.Solutions for three treatments were prepared from 50 g L-1 cassavastarch (Manihot esculenta) with 30 g L-1 glycerol as the plasticizerand 6 g L-1 polyethylene glycol-600®; for anti-browning agents, 6g L-1 ascorbic acid (AA) and 8 g L-1 N-Acetyl-Cysteine (NAC) wereadded. The fruits were coated by immersion, stored at 18 ± 4°Cand 85% RH. Physicochemical properties were determined at 32days postharvest. The applied coatings decreased the physiologicalweight loss (%WL) and resulted in a higher pulp firmness (PF); nosignificant difference was seen with a confidence level of 95% inthe concentration of total soluble solids (TSS), acidity or maturityindex. The skin color was measured by the CIE L*a*b* method, withan average L value of 70 for the fruits coated with the 6 g L-1 AAand 8 g L-1 NAC mixture, while the control fruits had a value of 57.Also, lower a* coordinate values and browning indices were foundfor the epidermis of the coated fruits. The enzymatic activity of thepolyphenol oxidase decreased with the number of postharvest daysfor all of the treatments, being lower for the fruits with the mixtureof anti-browning agents by 27%, as compared to the control. It wasconcluded that the coating mixture containing the anti-browningagents ascorbic acid, 6 g L-1, and N-acetyl-cysteine, 8 g L-1, showeda better effect as an alternative for storing fruits and prolongingthe shelf-life of harton plantain.