Can edible coatings maintain sweet pepper quality after prolonged storage at sub-optimal temperatures?

Abstract

This work evaluated the efficacies of different coatings: chitosan, gelatin and chitosangelatin applied layer-by-layer (LbL); for maintaining the quality of sweet peppers that were stored for 3 weeks at a sub-optimal temperature (1.5◦C) and at an optimal storage temperature (7◦C). After the cold-storage period, fruits were kept under marketing conditions (21◦C) for 3 more days. An edible chitosan coating (2%) effectively alleviated chilling injury and the incidence of decay, and also preserved the nutritional quality of sweet peppers that were kept for 3 weeks at 1.5◦C plus 3 more days at 21◦C. The chitosan coating was more effective than the two other coatings. All three coating treatments significantly reduced external CO2 production, as compared to uncoated control fruit. Storage temperatures did not significantly affect external CO2 production, although CO2 production was slightly higher at 1.5◦C. The chitosan coating exhibited good CO2 gas permeability properties and the peppers coated with that material had lower respiration rates than those in the other two experimental treatments or the control. From a practical point of view, chitosan coating could replace the plastic bags previously found to alleviate chilling injury in peppers that are stored at 1.5◦C as a quarantine treatment.