Supporting technology for fresh-keeping packaging

Supporting technologies for fresh-keeping packaging of winter jujube

1. Pre harvest factors

1. The same winter jujube variety can be divided into early maturing and late maturing lines. Early maturing lines began to have more red fruits before September 25, and late maturing lines began to have red fruits after October 5. The late maturing strain is the best choice for long-term storage

2. The best cultivation method is to choose Dwarf Winter Jujube Garden, so as to facilitate manual picking, reduce mechanical damage, and increase the number of winter jujubes with fruit stalks

3. For disease and pest control, jujube fruits should be collected in Jujube Gardens with good disease and pest control, no weeds or less weeds. Because the winter jujube with diseases and pests is easy to accelerate its softening and mildew at the later stage of storage

4. Irrigation and rainfall. Jujube trees will be affected by excessive drought. 1. The impact of soaring vanadium prices on the cost of vanadium batteries will result in excessive softness of jujube fruits at harvest, which will reduce the percentage of intact crisp fruits in storage. Therefore, proper irrigation is necessary to improve the intact and crisp fruit rate of jujube fruit, but rainfall during harvest will increase fruit cracking and over wetting damage during storage. Therefore, the jujube fruit should be harvested after the rain stops, and the cracked fruit should be removed for storage

5. Pre harvest spraying calcium treatment spraying 0.5% calcium chloride on jujube trees 30 days and 15 days before harvest, respectively, can significantly maintain the hardness of jujube fruits in storage, and can improve the rate of good fruits. Therefore, spraying calcium before harvest can be used as an auxiliary measure to improve the storage and fresh-keeping effect of winter jujube

II. Harvest classification

1. Winter jujube is extremely intolerant to storage in the early stage of harvest, while winter jujube is relatively tolerant to storage in the middle and late stages. Therefore, in order to prolong the storage period and increase the intact crisp fruit rate of winter jujube, winter jujube harvested in the middle and late stage should be used for storage

2. Maturity white ripe, slightly red, less half red, half red, more than half red, full red and other winter jujubes with different maturity. After 90 days of storage, the percentage of intact crispy fruits at each maturity differs by 10% - 25%. Therefore, in order to improve the rate of intact crispy fruits, prolong the storage period and obtain good economic benefits, it is very important to store them after strictly sorting according to maturity. Generally speaking, the reason for choosing winter jujube for long-term storage is also the distinction between its hardware and software. White ripe, slightly red, less half red and half red fruits should be selected for storage, and should be carried out under the trees in the field

3. Harvesting method: harvest by hand, not by beating or shaking with a stick, nor by shedding with the aid of ethephon, so as not to cause mechanical damage or hormone ripening and affect the storage effect

4. The selection can be carried out at the same time as the maturity selection. It is required to remove the branches and miscellaneous leaves, and pick out the winter jujube with diseases and pests, deformities, too small size, and maturity lower than white maturity

5. Grading includes maturity grading and size grading. Short term storage (less than 2 months) can be divided into three maturities. If it does not meet the following table, it can timely report the alarm degree: full red, half red, half red and below; For medium and long-term storage (more than 2 months), winter jujubes with half red, less half red, slightly red and white maturity should be selected

Chinese Jujube