CHITOSAN ON DELAYING OF THE DARKENING OF THE PERICARP IN LYCHEE

Abstract

After harvest of lychee (Litchi chinensis Sonn.) pericarp browning occurs rapidly, this causes the fruit to submit short postharvest life. This study evaluated the effect of different concentrations of chitosan in delaying the browning of the pericarp and in maintaining the postharvest quality of lychees. Fruits of litchi ‘Bengal’ uniformly red pericarp were immersed for one minute in solution with different concentrations of chitosan (0 g.L-1, 5 g.L-1, 10 g.L-1, 15 g.L-1 and 20 g.L-1). After drying the environment, the fruits were packed in polystyrene trays, covered with plastic wrap for 12 mm thick and stored at 19.0 ± 2.4°C and 75 ± 5% RH. Every two days, during eight days, the fruits were evaluated for weight loss, color of the pericarp, soluble solids and titratable acidity and vitamin C from the pulp of the pericarp and pulp. The weight loss increased linearly during the period of storage, independent of the concentration predominantly of chitosan. The concentrations of 5 and 10 g.L-1 were the most effective in keeping the color of the pericarp for up to four days, without compromising other characteristics.