Study On Storability And Postharvest Technology Of Xinyu Tangerine

The postharvest technology of Xinyu tangerine was a current problem to be solved. Xinyutangerine was easily rotten and lighten flavor, especially because of ambient temperature storage. Thepostharvest physiological changes of Xinyu tangerine at ambient temperature and low temperaturewere studied in this paper. Effect of compound coating on postharvest fresh-keeping effect and fruitquality of Xinyu tangerine was verified, which was consisting of carboxymethyl cellulose, plantfungicide, citric acid, sucrose ester, glycerin and calcium propionate filtered by orthogonal test. Effectof heat treatment on postharvest fresh-keeping effect and active metabolism of Xinyu tangerineduaring cold storage were also researched, which provided the theoretical and practical foundation forthe commercial storage of Xinyu tangerine. The main study content and results were as follows:1. The postharvest physiological changes of Xinyu tangerine at (20±1)℃and (5±0.5)℃werestudied. The results showed that the tendency of changes in the tow varieties were quite similar.Under storage, the value of total soluble solids, total sugar content, Vc content and the activities ofSOD, CAT and POD rose firstly and then depressed; MDA content increased steadily, but titratableacid content diminished gradually. The results of experiment showed that: Xinyu tangerine was aclimacteric fruit. Compared with room temperature, low temperature can reduce effectively the rottingrat and weight loss, inhibiting respiration rate and being good for the storage, and prolong storageperiod of Xinyu tangerine for96days.2. Through the assay to decay rate and weight loss rate of Xinyu tangerine, Confirm Xinyutangerine’s compound coating with clove and Impatiens balsamina L. extracts by orthogonal test.The best compound coating formulas were as follows:The formula of compound coating with clove extracts:1.0%CMC,700mg/L citric acid,50mg/mL clove extracts,1.0%sucrose esters,0%glycerine and1.0%calcium propionate.The formula of compound coating with Impatiens balsamina L. extracts:1.5%CMC,700mg/Lcitric acid,80mg/mL Impatiens balsamina L. extracts,0.5%sucrose esters,0.5%glycerine and1.0%calcium propionate.3. The compound coating with two plant extracts can reduce the decay rate and weight loss ofXinyu tangerine during ambient temperature storage, substantially delayed the reduce of TSS, TA, Vcand total sugar contents, and maintain better overall quality and nutrients. Both of them can inhibitrespiration rate of Xinyu tangerine, reduce the accumulation of MDA, improve SOD, CAT and PODactivity, thereby delayed senescence of fruits. Meanwhile, all treatments improved activities of PPO,CHT and PAL. Compound coating with Impatiens balsamina L. extracts showed better effects.4. The effect of a postharvest hot water dipping treatment (HWD) at53°C for3min and heat airflowing treatment (HAF) at37°C with air for36h at90–95%RH on fruit quality and reactive oxygenmetabolism was compared in Xinyu tangerine. The activities of related enzymes of disease resistancewere also determined.The results showed that compared with contrast, HWD and HAF treatments caneffectively decreased the decay and weight loss rate of fruit, substantially delayed the reduce of t TSS, Vc and total sugar contents. Meanwhile, heat treatments inhibited the respiration rate, H2O2and MDAcontent of fruits during storage.The activities of SOD, CAT, POD, POD and APX)in the peel of heattreated fruit, decrease compared with the control, the activity of PPO and CUN displays no difference,while the activities of CHT and PAL increase dramatically. The above results indicate that heattreatment performed the better effect on the storage quality and extend the shelf life of Xinyutangerine fruits, which provided feasibility for the use of HWD treatment in the storage of Xinyutangerine.