MODIFIED-HUMIDITY PACKAGING REDUCES DECAY OF HARVESTED RED BELL PEPPER FRUIT

Lowering the in-package relative humidity (RH) by adding hygroscopic m aterial (e.g,, NaCl) reduced decay of bell pepper (Capsicum annuum L.) fruit sealed in low-density polyethylene and stored 2 or 3 weeks at 8 C. Without hygroscopic material, the in-package RH was close to satura tion, and water droplets condensed on the fruit and inner film surface s. Depending on the amount of NaCl, condensation was prevented or sign ificantly reduced. Humidity level varied from approximate to 88% with 15 g NaCl to approximate to 97% with 5 g NaCl for a package containing 0.5 to 0.6 kg of fruit, Adding hygroscopic material increased the wat er vapor pressure deficit (VPD) in the packages and, accordingly, the weight loss of the fruit, However, peppers packaged with NaCl still ha d lower weight loss and better quality than the nonsealed fruit. The w ater 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 reduc ed fruit desiccation and inhibited pathogen development, thus extendin g the postharvest life of bell pepper.