Effect Of Exogenous Ethylene On Physiology Reaction And Flavor At DifferentMA Storage Period In Peach Fruit

Because of high temperature, postharvest peach fruit will be rotted easily.It will be soon rotted under the condition of room temperature after harvest for 5～7 days,that will take large scale difficulties to commercial storage and transportation. Although the softening speed can be controlled by common cold storage, but the water loses quikly and it prone to chilling injure and that lead to senescence of fruit quality.Controlled atmosphere(CA)could delayed decrepitude and prevent the physiological disordes, but it needs to buy more CA equipment and gas required by CA, those increase the cost of controlled atmosphere.So the application of CA is not widespread.Modifier atmosphere(MA)storage ameliorate the gas component of the surrounding environment by the respiration of fruit, thereby delaying the process of fruit ripening and senescence.But MA storage couldn’t solve the symptom of chilling injure,such as the block of ethelene metabolic,so that the quality of peach fruit would still decline,the browning degree would be increased and the flavor would be lost. A viable approach to overcome these problems could be by application of exogenous ethylene which proposed by our laboratory. Ethylene as a hormone to start the ripening of peach fruit, its role should be phased, that is, which is the best time to treat the peach fruit during storage.The experiment studied the effect of exogenous ethylene on physiology reaction and flavor at different MA storage period in’Okubao’(Prunus persica L.) peach fruit and then 3 days shelf-life at 20℃.The results were as following.1. The treatment MA2 showed that the decrease of contents of total soluble solids, Vc and total sugar. The treatment MA2 could make peach fruit softening normally after shelf-life and that reduce inferior quality caused by chilling injury.To suppress peach fruit the treatment MA3 has good results and the content of titratable acid is higher than other treatment after shelf-life.But the treatment MA3 peach fruit lost the ability of softening.2. The results show that exogenous ethylene accelerated the rate of fruit ethylene production, increased respiration rate, but the treatment MA1, MA2 speed up release rate of ethylene and CO2, which accelerate the ripening of peach fruit.MA3 treatment peak of ethylene release rate appear normally and postponed the climacteric, which is conducive to fruit ripening and storage.On the view of pigment content of peach pericarp, treatment MA3 pigment transformation has been hampered to some extent. There is also a similar performance for MA4 process (dealed with exogenous ethylene at storaged 28d) on the 2008 experiment of peach fruit peel’a’value determination.3.2008-year experiment results showed that exogenous ethylene treatment regulated the biosynthetic process of peach fruit volatile flavor during MA storage.The derivational effect of biosynthesis is significant to peach fruit volatile flavor by MA3 (dealed with exogenous ethylene at storaged 14d), MA4 (dealed with exogenous ethylene at storaged 28d) treatment, and the same effect we acquired after shelf-life.The flavor contents of peach fruit treated by MA3 are higher than other treatment contents.So the MA3 treatment results is better than other treatment results.In a word,to think over the effect of exogenous ethylene on quality, respiration intensity, ethylene production, pigment content, protective enzymes activity and flavor content at differentMA storage period in peach fruit,we concluded that the best time to add exogenous ethylene is 14～15 day after MA storage.