Author : Khin Thanda Oo

Summary : The physico-chemical and physiological bases of browning alleviation with postharvest application of 1-MCP in the presence or absence of exogenous ethylene were investigated during storage at 25C, the normal temperature during retail condition and 10C, the supermarket retail temperature. The experiments conducted included optimization of ethylene concentration and exposure time which can develop browning; optimization of 1-MCP concentration which can alleviate browning; and alleviation of browning in cauliflower curds by 1-MCP treatment with or without exposure to exogenous ethylene. Ethylene at 100 ppm (24h) exhibited the highest browning among treatments and, thus, this concentration and exposure tome was used in the optimization of 1-MCP concentration needed to alleviate browning in the presence of 100 ppm exogenous ethylene. The lowest browning was noted in 10 ppm 1-MCP (3 h) in the presence and/or absence of ethylene, thus this concentration was chosen for the third phase of the study. 1-MCP treated cauliflower curds exhibited suppressed ethylene production rate, reduced activities of phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) and maintained the antioxidant levels; ascorbic acid and total glucosinolates. The accumulation of total phenolics in the presence or absence of ethylene under both ambient and cold storage was delayed by 1-MCP treatment.