Role of Chitosan in the Coloring of Berries and Phytochemical Changes in Physalis angulata L. During Harvest Maturity

Physalis angulata L. berries are green in the initial stage of maturity and turn yellow when fully mature due to an increase in carotenoids. However, the coloration of the epidermis of the berry should not be the reference for harvesting maturity, since the calyx is fully closed. The use of an edible chitosan coating delays the color changes in the berry by reducing the respiration rate. This work studies the effect of harvest maturity and chitosan on the shelf life and berry coloring in Physalis angulata L. Three factors were considered, being harvest maturity stage (green mature (GM), yellowish-green (YG) and yellow (Y)), chitosan coating (0, 0.5, and 1%), and storage time (10, 20, 30 days). The fruits were stored at 20 °C and 85% Rh. The results showed that on the harvesting stage, chitosan coating had a significant effect on the quality and shelf life of berries during storage time. The value of carotenoid and phenol contents, flavor index, chroma, and hue significantly increased with berry maturity. Chitosan delayed the decrease in chlorophyll, phenol contents, antioxidant capacity, berry maturity, and color change. The results show that in the berries coated with 1% chitosan during storage, changes in color were less in comparison with the control condition (no chitosan). The highest decrease of hue angle and color index (17.92°) was observed in the control. The highest total antioxidant (78.42%) was observed after 30 days of storage in MG berries treated with a 0.5% chitosan coating.