| Xinjiang Ruoqiang Dongzao jujube is popular among consumers because of its crisp and juicy flesh,rich in Vc and other nutrients.Dongzao jujube is easy to lose water,soften and can't bear storage,Therefore,how to effectively ensure the quality of Dongzao jujube storage has important practical significance.Ice temperature storage can not only protect jujube tissues from damage,but also maintain a higher level of nutritional value and prolong the storage period of jujube.In this experiment,Xinjiang Ruoqiang Dongzao jujube was used as material,to study the physiological and biochemical changes during ice temperature storage.At the same time,compared with different pretreatment before ice temperature storage,To study the way to better maintain the storage quality of Xinjiang Ruoqiang Dongzao jujube.The findings are as follows:1.By placing Dongzao jujube under ice temperature storage conditions,the effects of ice temperature storage on physiological and biochemical aspects of jujube fruits were studied.Before the formal experiment,the freezing point temperature of Dongzao jujube was confirmed to be-2.5?,and-1.0?1.5?was used as the ice temperature storage temperature this time.The quality of jujube fruits stored under ice temperature is compared with the quality of jujube fruits under ordinary refrigeration 0?1 ?:The way of ice temperature storage reduced the weight loss rate of fruit 83.33%;the hardness decreased by 16.33%;maintaining the soluble solid content of jujube fruit,inhibited the increase of PG,PME and ?-gal activity,it reduces the accumulation of ethanol content 43.90%.2.Compared with the active oxygen metabolism of Dongzao jujube under normal temperature storage through ice temperature storage:The storage method at ice temperature can effectively reduce the permeability of cell membranes.The Vc content decreased by 16.48%,and maintain the level of total phenol;Compared with the ordinary cold storage,ice temperature storage can effectively delay the decline of SOD,POD and APX activity;At the same time,the formation rate of superoxide anion is reduced 10.56%,and improve the ability of scavenging hydroxyl radicals.3.Compared with the disease resistance-related enzyme activities of Dongzao jujube under ordinary cold storage through ice temperature storage,it was found that:Compared with ordinary cold storage,the decay rate of Dongzao jujube under ice temperature storage was 2.90%,which was reduced by half compared to cold storage;In addition,compared with refrigeration,the activities of PAL,Chitinase and ?-1,3-glucanase of jujube fruits were significantly increased,and the MDA content was reduced by 56.26%.4.According to the preliminary test,it is concluded that the storage method of ice temperature can improve the storage quality of jujube fruits.It is now studied whether the pretreatment method before ice temperature storage guarantees the quality of jujube fruits and prolongs the storage period.Orthogonal test L9(34)was used to screen the optimal combination of different concentrations of sodium chloride solution,heat treatment at different temperatures,and different soaking times.Taking the average decay rate,average hardness,and average soluble solids content of jujube fruit during 42 days as the screening conditions,it was found that the storage effect was best when the sodium chloride concentration was 3%,the hot water temperature was 55?,and the immersion time was 6 minutes.Compared with the control group,the Vc content of jujube fruit decreased by 15.64%under the combined treatment,less MDA accumulation 47.06%,increase PAL activity,delay the decline of POD and SOD activity during storage. |
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