Study On Suitable Harvesting Period Of Fresh Jujube

In order to determine the suitable harvest time of fresh jujube,this study took Mama jujube,Apple jujube,HN-1 and honey pot as experimental materials,evaluated and screened the fruit quality of four fresh jujube varieties at the late maturity stage,and selected three kinds of jujube fruits at different maturity stages,namely,pinkish,semi-red and full-red,to make a comparative analysis of their quality at room temperature and low temperature during storage.The main results are as follows:(1)With the fruit ripening,the fruit weight,total sugar and organic acid content of the four fresh jujube varieties showed an upward trend,while the hardness,vitamin C and flavonoid content showed a downward trend,and the protein content first decreased and then increased.There was no obvious regularity in the change of phenol content.The grey correlation degree analysis was carried out on the fruit quality of the 4 fresh jujube varieties during the mature and developmental process: the fruit quality of Mama jujube was directly proportional to the maturity,and the other 3jujube varieties were different from Mama jujube,indicating that the quality of different fresh jujube varieties was the best The period is different,so three periods of point red,half red and full red are selected for storage comparison,and then the best harvest period is selected.(2)During the storage period of the four fresh jujube varieties at room temperature,the fruit weight of jujube harvested in the full red period generally decreased faster than that in the red point and half red period.The fruit firmness of mother jujube,HN-1 and honey jars after storage at room temperature was as follows: red-red stage>full-red stage>half-red stage,and apple jujube fruit firmness showed as follows: half-red stage>full-red stage>spot-red stage.In the later stage of storage at room temperature,the contents of total sugar and flavonoids in jujube fruits of all varieties were as follows: half-red stage>full-red stage>spot-red stage(except for the total sugar content of apple jujube),and the total acid content showed: spot-red stage>half-red stage > Full red a period(except honey pot).At the end of storage,the starch and total phenolic contents of jujube fruits harvested in the red stage and half-red stage were higher than those in the full-red stage.It can be sinve seen that the quality of the jujube fruits harvested in the red period and half red period of the four fresh jujube varieties in this is study are better than those in the full red period during the shelf life at room temperature.The quality of the jujube fruit is not as good as that of the half-red period and the full-red period,so the half-red period is the best harvest period for the shelf life at room temperature.(3)During the low-temperature storage(4℃)of the 4 fresh jujube varieties,the single fruit weight of jujube fruits in different harvesting periods showed a downward trend and no significant change(except for the mother jujube in the whole red period),and the fruit weight loss rates all showed: Spot red period > half red period > full red period.The firmness of jujube pulp of the four fresh jujube varieties decreased to different degrees during different harvesting periods during low-temperature storage.Among them,the hardness of HN-1 and Mama jujubes decreased the most rapidly after harvesting in the red period,and the Mama jujube harvested in the full red period decreased the most.Fruit firmness decreased slowly in the early stage.The vitamin C content of the 4 fresh jujube fruits showed a downward trend with the time of low temperature storage.Among them,the mother jujube and the honey pot showed the following: full red period >half red period > red point period,HN-1 and apple jujube showed the following: full red period The red period > the red period > the half red period.The total sugars,organic acids and flavonoids of the four fresh jujube varieties showed the following order: half-red stage>full-red stage>spotted-red stage,and total phenols were the opposite.In general,the fruit quality of jujubes harvested in the half-red period and full-red period of the four fresh jujube cultivars during low temperature storage was better than that in the red period.Therefore,both the half-red period and the full-red period are the best harvest periods.