Studies On The Post-harvest Physiology And Storage Technology Of "DaWuXing" Loquat Fruits

Loquats {Eriobotrya japonica Lindl. ) are subtropical rare fruits, which have nutritional and commercial importance in terms of their special functional composition and consumption demand. The loquat fruit industry develops quickly in recent years, and the cultivating area and the output turn up the progressive tendency year by year. However, they are easy to belt under improper storage conditions like some other tropical or subtropical fruits. The common problem of loquat fruits after post-harvest is shriveling, flesh woodiness, decay and pathogenic disorder. In a long period, the systematic fundamental research in the physiological, senescence physiological and chilling injury after post-harvest was deficiency. That is one of the important reasons to restrict the development of storage technology for loquat fruits.The experiment was performed "Dawuxing" loquat fruits as sample, which study on their post-harvest physiological and biochemical changes and the optimum conditions during storage. The main idea is to offer theoretical basis for the long-distance transport and storage of the loquat fruits in the future.The result indicated that there was not respiration peak during the storage of loquat fruits. Under the storage conditions of no chilling injure, the firmness, the content of MAD, membrane permeability increased significantly with the increase of storage period. The tendency of PAL activity and CAT activity dropped slowly, POD activity still rose. There is a significant relationship between firmness and PAL activity. So did the content of MAD and membrane permeability. Furthermore, the content of TSS, TA and Vc descended gradually. The firmness, the content of MAD, the membrane permeability and PAL activity at 4°C were much higher than those of other temperature condition. Meantime, the activity of activated oxygen eliminating enzymes was lower. Corresponding to these physiological and biochemical changes above, the appearance symptom of loquat fruit at 4°C showed that it was difficult to shell, color tend to decrease and pulp became rough. At the same time, the surface of loquat fruit appeared little hollow spot. The chilling injure fruits occurred caused these expressions above.Seven preservatives could restrain the growth of Colletotrichum gloeosporioides Penz. to the degree. The result suggested that Shigao had the best affection. EC₅₀ and EC₉₀ were 1.52mg/L and 36.47 mg/L respectively.Moreover, fresh-keeping technology of loquat fruits was researched tentatively. The result showed that the optimum storage technology for "Dawuxing" loquat fruits is the treatment with 50mg/L Shigao or 5ml/L Chitosan and packed with LDPE (thickness 0.02mm) at 8℃ was. After the 32nd day of storage under thiscondition, decay indexes was 8.61% and 9.98% respectively, fresh rate was 81.67% and 78.33% respectively, weight loss rate was only 4.37% and 4.24% respectively. The storage effect of this treatment showed significant difference compared to comparison. Furthermore, loquat fruits applied could be products with better quality retention and the speed of reduction for TSS> TA> Vc and carotenoid were slowed down under this optimum condition .