Effect of chitosan-based coating on postharvest quality of tangerines (Citrus deliciosa Tenore): Identification of physical, chemical, and kinetic parameters during storage

In this study, chitosan-based coating was used in tangerines in a 30-day storage period, at controlled temperature of 10°C. The selected fruits presented green surface (± 90%); they were sanitized in chlorinated water (100 mg/L) then immersed in chitosan solutions at chitosan concentrations of 0.5 g/100 ml (T2), 1 g/100 ml (T3), and 2 g/100 ml (T4) and a lot was placed aside as control treatment (T1). Tangerines were evaluated in terms of loss of mass, skin color, soluble solids, vitamin C, and titratable acidity in a 30-day storage period and weight loss kinetics was evaluated through mathematical models. The results showed that chitosan coating was effective in delaying weight loss of tangerines and the mathematical models used in the evaluation could properly explain the weight loss. The polynomial model showed better adaptation to experimental data. Tangerines with higher chitosan concentration showed small color alteration during storage. Chitosan-based coatings were effective in keeping soluble solids, vitamin C, and titratable acidity during storage. In all physicochemical characteristics analyzed, chitosan-based coating in tangerines were superior when compared with control fruits.   Key words: Citrus, chitosan, postharvest, shelf life, quality.