Quality attributes and related enzyme activities in peppers during storage: effect of hydrothermal and calcium chloride treatment

The effects of hydrothermal (HT)-calcium chloride (CaCl 2 ) treatment on water loss, chlorophylls, L-ascorbic acid, total phenol, antioxidant capacity, malondialdehyde (MDA), peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT), and phenylalanine ammonia lyase (PAL) of peppers were assessed for 32 days of storage at 8°C. The results showed two water populations corresponding to strongly immobilized water and weakly bound water were observed in all the peppers. Comparing with other treatments, HT-CaCl 2 treatment restricted water mobility and maintained higher immobilized water content during storage. HT-CaCl 2 treated peppers showed lower MDA content whereas presented higher chlorophylls, L-ascorbic acid, total phenol content, and stronger antioxidant capacities than those subjected to other treatments. These characteristics indicated HT-CaCl 2 treatment improved storage quality of postharvest peppers. In addition, HT-CaCl 2 treatment retained lower POD, PPO, and PAL activities and higher CAT activity in the peppers during storage than other treatments, respectively. Based on above results, the combination of HT and CaCl 2 treatment showed positive and continuous effects on the quality attributes and related enzyme activities of peppers during storage.