Jujube is one of the fruit trees native to China, the fruit is rich in nutrients, containing twice as much sugar as the general fruit and more protein, fat, iron, phosphorus, calcium and other substances. However, fresh dates are extremely intolerant.
The following are a few technical points for the storage and preservation of fresh dates:
First, the selection of tibet-resistant varieties Is generally considered to be more resistant to storage than early-maturing varieties; crack-resistant varieties are resistant to storage; small fruit varieties or large fruit varieties in the loose flesh of the varieties resistant to storage. Among the main cultivars, aconitum jujube, Xiangfen jujube, clam jujube, winter jujube and so on are the most resistant to storage, and the longest storage period can reach 120 days.
Second, the application of correct harvesting Production according to the degree of redness of the jujube fruit surface is divided into three maturity levels: full red (100% coloring), semi-red (about 50% coloring) and primary red (coloring less than 25%). Jujube fruits for storage should be harvested at the semi-red period, taking into account both storage resistance and quality. The jujube fruit for storage should be picked manually, and it is strictly forbidden to pick methods such as rod beating and shaking, and the stalk of the fruit should be retained when picking. Because the flowering period of jujube is very long, the result is early and late, so the ripening period is also early and late, and it should be picked in batches according to the requirements to ensure the same maturity of the jujube fruit harvested each time.
Third, the requirements of fresh jujube storage on environmental conditions The suitable storage temperature of fresh dates is 10. 5℃——0℃。 Due to the less waxy layer on the surface of the fresh jujube fruit and the poor water retention performance, the water loss rate of the fresh jujube at room temperature is 5-7 times that of the apple, and the lower the ripeness, the faster the fruit loses water, so it is particularly important to maintain the relative humidity of more than 90% of the storage environment for the storage of fresh dates.
Fourth, storage method 1. Refrigeration Can be used in perforated bags or with cardboard boxes, wooden boxes, plastic tote boxes and other lined preservation bags. The specific method is: the harvested fresh dates are selected and put into the cold storage for 1-2 hours, and then loaded into 0.01-0. 02 mm thick non-toxic PVC or polyethylene film bags, each bag does not exceed 2. 5 kg, 2 small holes of about 1 cm in diameter on each side of the middle of the bag (it is accurate and easy to iron with a cigarette butt), and then the mouth is erected on a multi-layer storage rack. When using the method of lining the box with a plastic bag, it is best to use a 0.03 mm thick non-toxic POLYVIN film, each box does not exceed 10 kg, and the bag mouth cannot be sealed after loading, and the folding mask can be. Before masking, the opening should be fully pre-cooled, and when the fruit temperature drops close to the storage temperature, the sealing box should be stacked and stored. Fruit boxes should be stacked in the shape of "pins", and ventilation channels should be left between the boxes. The fruit is best pretreated before storage, and the fruit is soaked with 2% calcium chloride 130 mg/kg gibberellin for 30 minutes, which can improve the storage effect of the fruit, and the fruit after soaking treatment should be dried in time and then bagged for storage. 2． Modified atmosphere storage The temperature of fresh dates should be controlled at a temperature of 1-0 °C, the relative humidity is more than 95%, the oxygen is 3%-5%, and the carbon dioxide is less than 2%. Jujube fruits stored in air conditioning should be treated with jujube preservative before being stored (developed by the Institute of Agricultural Product Storage and Preservation of Shanxi Academy of Agricultural Sciences). Using modified atmosphere storage, the storage varieties of aconitum jujube, Xiangfen round jujube, Linfen tuan jujube, clam jujube, winter jujube, and large snow jujube can be stored 3. 5-4 months, golden silk jujube, Zanhuang jujube, pear jujube and other storage for 2-3 months, crisp fruit rate of more than 70%.