Abstract
Red hot chili (Capsicum annuum L.) cv. Superhot is an important commercial vegetable crop with high export potential of Thailand. The main quality changes during storage were the rapid in weight loss and spoilage. The objective of this research was to investigate the effect of pre-treatment on the qualities of red hot chili by using ultra-violet-C (UV-C) irradiation incorporated with hydro-cooling before storage. The chili fruits were irradiated with 0, 4.4 and 6.6 KJ.m-2, respectively before hydro-cooling at 0 ˚C for 15 minutes and then stored at 5˚C for 21 days in plastic tray wrapped with PVC film. Non-hydro-cooled and non-illuminated chili served as control. The results showed that all the UV-C dosages incorporated with hydro-cooling were highly effective in maintaining fresh weight and firmness. Green appearance of calyx or pedicel and redness in chili as expressed by acceptable quality score were also maintained. Chili fruit treated by UV-C irradiation at dose of 4.4 KJ.m-2 incorporated with hydro-cooling resulted in significantly (P≤0.05) reduction of 7.02 % weight loss at 21 days of storage and fruit rot as well as enhancing antioxidant capacity (DPPH) and total carotenoid content of chili. This combined treatment could prolong the storage life of chili to 21 days whereas the control could keep for only 12 days. The data suggested that the UV-C incorporated with hydro-cooling could maintain quality and extend the shelf life of red hot chili.
