Reduction of the pericarp browning of lychee with hydrochloric acid/Reducao do escurecimento do pericarpo de lichia com acido cloridrico

This study assessed the effects of immersion in different concentrations of hydrochloric acid (HCl) on pericarp color retention and postharvest conservation of lychees. 'Bengal' lychees were harvested with completely red pericarp and immersed for two minutes in HCl at concentrations of 0 (control), 0.25, 0.5, 1 and 2 M. After the treatments, fruits were packed in expanded polystyrene trays and covered with polyvinyl chloride film (PVC). The fruits were stored in cold chamber at 10 ± 0.9°C and 90 ± 5% RH. The fruits were evaluated every 4 days over a period of 24 days. After 24 days of storage, fruits of all treatments showed weight loss of around 4.5%. By the 16th day of storage, fruits treated with 2 M HCl showed nonsignificant changes in pericarp color (ΔE, Hue angle and luminosity) in relation to the harvest day. These fruits remained without visually perceptible change in color up to 24 days of cold storage. Pericarp darkening began on the 4th day of cold storage in fruits untreated (control) and treated with 0.25 and 0.5 M of HCl.