Optimization of chitosan and gum arabic coating formulations to physicochemical properties of fresh-cut mango

Fresh-cut mango has a short shelf life storage, which both markets and consumers would like to be longer. Response surface methodology (RSM) was applied to determine the effect of chitosan (0.25-0.5% w/v) and gum arabic (1.0-5.0% w/v) to the physicochemical properties of fresh-cut mangoes to optimize the suitability of edible coating. 80% mature mangoes were dipped in 200 mg L^-1 ethephon for ripening stage and kept at room temperature for 3 days. In the processing, ripe mangoes were washed with 100 mg L^-1 peroxyacetic acids and dipped in warm water at 50°C for 5 min. Then the whole fruits were manually peeled with a ceramic sharp knife and cut into 2×2×2 cm³ cubes. Fresh-cut mangoes were coated with the chitosan and gum arabic edible coating in various formulations, placed in polypropylene plastic boxes and covered with nylon/LDPE bags before being stored at 5°C for 5 days. Weight loss, firmness, the total color difference (DE), ascorbic acid content, polyphenol oxidase and phenylalanine ammonia lyase activity were measured as response variables in the experiment. The results showed that the response variable was highly fitted to the regression coefficients (R²) from 0.816 to 0.968 for weight loss, firmness, total color difference, ascorbic acid content, and polyphenol oxidase activity. The optimum concentration of chitosan and gum arabic were predicted to be 0.50 and 4.51%, respectively. Under this optimum condition, there was no significant difference between the predicted and the experimental values. Thus, RSM was an effective tool for identifying optimized coating formulations.