< h1 class = "pgc-h-arrow-right" >1, the maturation process of dates</h1>
According to the development characteristics of jujube fruit, its maturation process is divided into three stages: white ripening stage, crisp ripening stage and complete ripening period.
(1) White ripening period: the peel fades green, appears greenish white, and turns milky white. The size and weight of the fruit no longer increase, the flesh is softer, less juicy, and the sugar content is low. The peel is thin and soft, and the peel is not easy to separate from the pulp after cooking.
(2) Crisp ripening period: After white ripening, the peel gradually turns red from the stem and shoulder to the full red. The sugar content of the pulp increases quickly, the texture becomes brittle, the juice increases, the flavor is enhanced, and the flesh color is still green or milky white. The peel is thickened, slightly hard, and easily separated from the pulp after cooking.
(3) Maturity period: After the crisp ripening period, the fruit continues to accumulate nutrients, the sugar content of the pulp increases, and finally the end of the stalk connecting with the fruit begins to turn yellow and fall off. The color of the flesh changes from greenish white to milky white, which is yellowish brown near the core, and the texture gradually becomes soft from the near core, and the water content decreases. The content of soluble solids in the pulp of the above three periods has been increasing. For example, the soluble solids of winter jujube are 23.2% in the white ripening period and increase to 37.2% in the crisp ripening period, and the sugar content and quality of these two periods are very different; other varieties have their commonalities, and with their maturity growth, their sugar content, flavor and other qualities are optimized, and the difference is large. Therefore, the harvest period must be determined according to different processing requirements.
<h1 class = "pgc-h-arrow-right" >2, the harvest period of jujube fruit</h1>
Harvest maturity has a great impact on the storage life of fresh dates. The first red fruit is the most resistant to storage, followed by the semi-red fruit, and the whole red fruit has the worst storage tolerance. Premature harvesting affects the quality of dates and fruit, and late harvest shortens the shelf life.
Raw food seeds are best harvested during the crisp ripening period, when the jujube fruit is brightly colored and there is more juice,
Good flavor. The dried varieties of jujube fruit are best harvested at the end of the ripening period, when the fruit is fully ripe, the color is rich, the fruit shape is full, elastic and the quality is the best. The harvesting period of the processed varieties is determined by different processing methods. Processing dates are best harvested at the white ripening stage, when the meat is soft, easy to absorb sugar when cooking, the finished product is shiny, and there is no skin residue when eating.
<h1 class="pgc-h-arrow-right" >3, jujube harvesting method</h1>
Fresh fruit harvesting, mainly artificial picking. When picking, it should be picked in stages and batches, carefully and gently, and do not hurt the peel. There is also shock harvesting and mechanical shaking method harvesting.
<h1 class="pgc-h-arrow-right" >4, the method of post-harvest treatment of fresh dates</h1>
(1) Preservative treatment: before the jujube fruit harvest, sterilization and anti-mildew treatment should be carried out, and the good fruit rate is higher than that of the control, and the hardness of the fruit can be improved and the storage life can be extended after treatment. Thiabendazole (TBZ) fumigation agents are effective in preventing moldy dates, and thiazole (TBZ) not only prevents mold from multiplying, but also kills growing mold.
(2) Physical treatment: the use of physical methods, such as Co radiation treatment, vacuum preservation, electromagnetic radiation, rapid cooling, heat treatment, etc. are all under discussion and discussion. The use of micro-pressure reduction facilities to store winter dates and golden jujubes are significantly better than ordinary refrigeration (about -1C) in terms of hardness, taste, freshness, etc.
< h1 class = "pgc-h-arrow-right" >5, the appropriate conditions for the storage of fresh dates</h1>
(1) Temperature: Temperature is the most important environmental factor affecting the storage life of fresh dates. In the range of --fixed, the lower the temperature, the better the storage effect, because the low temperature can effectively inhibit the respiration of the fruit, and the respiratory intensity of the jujube at 0C is less than 1/2 at 20 °C. At the same time, the low temperature can slow down the transpiration rate of fruit water and inhibit microbial activity, delay the aging process of fruit, reduce decay, and thus effectively extend the storage period of fruit. However, frostbite can occur when stored below freezing.
(2) Humidity: Fresh dates are a very water-losing fruit, in the refrigeration or cold cellar, the humidity is about 95%, and the storage period of the jujube fruit can be greatly extended. --The humidity of jujube fruit storage should be 90% to 95%.
(3) Gas composition: oxygen 3% to 5%, carbon dioxide less than 2%. By controlling the appropriate storage environment, the storage period of fresh dates can be more than 60 days, and the crisp fruit rate of some varieties is still more than 70% when it is more than 90 days.
<h1 class = "pgc-h-arrow-right" >6, fresh date storage technology route</h1>
Choose a kind of food resistant to storage and storage - * pre-harvest treatment - + timely and injury-free picking - ➢ post-harvest treatment (anti-corrosion, grading) → quickly pre-cool to 0C ~ 1C→ perforated small package or modified atmosphere storage - → regular inspection - → out of the warehouse - → cold chain transportation (0 ° C ~ 5C) → market sales.