Study On Fresh-keeping Technology And Change Of Postharvest Physiology Of Ling Wu Change Date

Lingwu Chang Date is local colored favorable fresh-eat Date in Ningxia province, which is colorful and has great taste. The fruits have special flavor, great quality and taste sweet and acetous, and also be provided with various nutrition such as multiplicate minerals and vitamins.The fruit of Chang Date tended to alcoholic softening, going moldy and decaying during storage period, so it is precondition to study fresh-keeping technology of the fruit if we want to solve all of the problems of the above phenomena. In this article, Stored at 10 20℃, the change of four different sugar and physiology and biochemistry of the fruit at diverse period of storage time were studied. Then something about effects of sterilization agent on microbe were done to choose the appropriate material to store the Chang Date, and the effects of the physio-regulator on the Chang Date were studied, which is the hotspot at the present time. The preliminary methods of fresh-keeping technology were chose. By this experiment conclusions were draw just as the following.1. Stored at 10～20℃, starch content of Chang Date decreased, total sugar and reducing sugar content increased and then decreased during the storage time. Though the content of sucrose decreased, the change is not obvious.2. At the end of storage at 10～20℃, the results of different maturity of Chang Date were different. Proper maturity can give a better result. Ripe Chang Date could easily go alcoholic softening because the alcohol content quickly increased during the storage time, and the weight lost heavily. And the storable property of verdancy is also bad because of purified tissue and the flavor. The results suggested that eight degree of maturity is the proper maturity as for storage.3. There were many microbes in the Chang Date stored at 10～20℃. Main variety of microorganism separated were, Penicillium Notatum, Rhizopus sp., Gray Mould, Aspergilli, Genus Alternaria. The ratio of Penicillium Notatum was more than others. The ratio of Rhizopus sp. and Gray Mould was in the second place. Aspergilli and Genus Alternaria had the least ratio. The experiments of inhibitor and living body showed that the effect of KDZ was the best inhibitor used for inhibiting the growth or action of microorganisms though the other inhibitors also had effects on them.4. Stored at 10～20℃, dipping fruits in 2% CaCl₂ could decrease the activity of respiration of Chang Date. The consumption of organic acid and Vc was lower. And the accumulation of alcohol was lower too. The ability of antioxidant enhanced, and endosmosis declined.5. The rate of the edible fruit is more than 70% after 30 days' storage at 10～20℃, which is treated by compound preservative. Compound preservative could prevent water loss, Vc loss, and also could delay accumulation of alcohol, depress respirations, restrain the activity of microbe.