Studies On The Effect Of Controlled Atmosphere And1-MCP On The Wound Healing In Peaches And Pears

To study the effect of controlled atmosphere on the wound healing in peach fruit and its possible mechanism, postharvest peaches were wounded by probe which diameter was14mm, at the speed of30mm/s and6mm compressed displacement. Wounded peaches were then stored at5%、10%and15%O2respectively with the controlled temperature20℃and relative humidity90%. Firmness, decay percent, lignin content, malondialdehyde (MDA), phenylalanine ammonialyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) activities were measured. We can define the degree of wound healing ability by observing the differentials between the experiment group and the control group.Results revealed that compared with10%and15%O2concentration,5%O2concentration can maintain the fruit firmness, reduce decay rate and PPO activity, stimulate PAL and POD activity, and cause lignin accumulation.To study the effects of1-methylcyclopropene on the wound healing in peaches and its possible mechanism, a testing machine was used to simulate an impact injury on peaches. Peaches were treated with1000nl/L1-MCP for24h at20℃before or after the impact injury. Increase in the ethylene production was delayed after3days’ storage for1-MCP treated injured fruit in comparison with untreated injured ones.1-MCP treatment also delay the decline of fruit firmness, reduce fruit rotting rate and stimulate PAL and POD activity that are related to fruit defense mechanisms.To study the effects of1-methylcyclopropene on the wound healing in pears of different mechanical damage and its possible mechanism, a testing machine was used to simulate an impact injury on pears. pears were then divided into two groups. One group was treated with1000nL/L1-MCP for24h at20℃after the impact injury, the other group remained untreated and stored in the same conditions as the former group. Increase in the respiration rate as well as the decline of fruit firmness was delayed for1-MCP-treated injured fruit in comparison with untreated injured ones and not injured ones.1-MCP treatment also stimulate PAL and POD activity that are related to fruit defense mechanisms as well as the lighten content. Results revealed that1-MCP stimulate the wound healing mechanism in injured peaches and this ability changes with the degree of fruit damage.