Modified-humidity Packaging Reduces Decay of Harvested Red Bell Pepper Fruit

Lowering the in-package relative humidity (RH) by adding hygroscopic material (e.g., NaCl) reduced decay of bell pepper ( Capsicum annuum L.) fruit sealed in low-density polyethylene and stored 2 or 3 weeks at 8C. Without hygroscopic material, the in-package RH was close to saturation, and water droplets condensed on the fruit and inner film surfaces. Depending on the amount of NaCl, condensation was prevented or significantly reduced. Humidity level varied from ≈88% with 15 g NaCl to ≈97% with 5 g NaCl for a package containing 0.5 to 0.6 kg of fruit. Adding hygroscopic material increased the water vapor pressure deficit (VPD) in the packages and, accordingly, the weight loss of the fruit. However, peppers packaged with NaCl still had lower weight loss and better quality than the nonsealed fruit. The water regime formed in four-fruit packages in the presence of 10 g NaCl (92% to 95% RH, VPD 65 to 77Pa) enabled optimal balance between reduced fruit desiccation and inhibited pathogen development, thus extending the postharvest life of bell pepper.