Study On The Effects And The Physiological Mechanism Of Heat Treatment On The Quality Of Fresh Keeping Of Postharvest Peach

1.Taking two peach varieties of'Cangfangzaosheng'and'qingwang', which were mainly cultivated in Tianshui county, Gansu province, China, as materials, Studied the effects and the physiology mechanism of heat treatment on the quality of fresh keeping of postharvest peach. Preliminary experiment with the heat water of different temperature showed that the best temperature range from 40℃to 50℃. Consequently, three kinds of warm water(40℃,45℃,50℃)were used to treat the postharvest peach. Soaked the peaches in warm water for was 1min, then moved to storehouse with the temperature of 25±2℃to store. At every regular interval, observed the disease rate and the disease index; measured the activity of several protective-bearing enzymes and the indexes related to the fruit qualities; isolated, purified and cultivated the main pathogenic bacteria(Alternarta alternate, CercosporelIa persicae and Monilinia fructicola), and carried out the artificial inoculation then observed the disease rate and the disease index. All these indexes above were used to evaluate the effects and the physiological mechanism of heat treatment on the disease resistance and the quality of peach in storage. The results showed that heat treat is used to keeping the peach to be fresh.2. Heat treatment inhibited the proliferation of main pathogenic bacteria in vitro, that was to say, heat treatment contributed to part of the results of disease rate reduction and disease index decline by killed directly the spores of pathogenic bacteria inhabiting in the fruits or inhibited them form germinating and growing.All the above are the disease reasones of heat treatment can keep peach freshing.3.From the experiments on CAT,SOD,POD,CHT,GLU,PPO and the respiratory intensity of the peach fruit in storage we can see that: Right heat treatment promoted efficiently the activity of chitinase andβ-1,3-glucanase, inhibited significantly the generation rate of peroxide, polyphenol and hyperoxide, as a reault, the activity of catalase, cuperoxide cistmuase, peroxidase and peroxidase within the fruit of peach were declined.And the above are the phisycal reasons why heat treatment can keep keep peach freshing.