Chitosan-based edible coatings extend shelf life and preserve antioxidant properties of 'Gran Enano' banana under tropical conditions

Abstract

The shelf life of bananas is significantly reduced under tropical conditions due to rapid ripening, weight loss, and degradation of functional compounds. This study evaluated the effect of two chitosan concentrations (1.5% and 2%) as edible coatings on the physicochemical and antioxidant properties of 'Gran Enano' bananas stored at tropical ambient temperatures (30 ± 2 °C; 70 ± 10% RH) for 12 days. Weight loss, peel color, respiration rate, total soluble solids (TSS) and total phenolic compounds, and antioxidant activity (DPPH and ABTS methods) were monitored every two days. The results showed that the chitosan coatings modified some parameters indicative of the ripening process, with lower TSS and CO2 production values, as well as higher values of the L* and b* indices, indicative of color, being found at the end of storage. Antioxidant activity and phenolic content peaked around day 7, decreasing thereafter, although both chitosan treatments maintained significantly higher levels than the control. The 2% chitosan treatment increased antioxidant activity on day 1 (DPPH and ABTS), but at the end of storage, the values were like the control. These results demonstrate that the chitosan concentrations evaluated in edible films do not negatively alter the characteristics of the ripening process and, on the contrary, allow for extended shelf life.