Detailed Guide to Apricot Storage and Fresh-Keeping Methods and Techniques

Storage and Fresh-Keeping of Apricots

1. Determining the Suitable Harvest Maturity of Apricots

Determining the suitable harvest maturity is key to storing apricots. The judgment of maturity can be determined based on factors such as the number of days of fruit development, changes in fruit color, the texture of the peel and flesh, the aromatic flavor of the fruit, and the firmness of the fruit's attachment.

Apricots intended for storage should be harvested when the fruit has reached the inherent size of the variety, the fruit surface has turned from green to yellow, the sun-facing side shows the variety's inherent color, the flesh is still firm, nutrients have been fully accumulated, and the fruit has a slight varietal flavor, roughly at eight-tenths maturity. Fruit harvested at this time for export and long-distance sales can have enough time for packaging and transportation.

Because the ripening period of apricots coincides with the wheat harvest, to save labor, chemical agents can be used to assist harvesting. According to experiments by Northwest Agricultural College, spraying 0.1% B9 + 0.1% laundry detergent spreader during the hard-core stage can advance the ripening period by 3 days, make the ripening period more uniform, and have a good effect on apricot quality.

2. Ice Cellar Storage of Apricots

Ice cellar storage is a traditional method in northern China that uses ice blocks collected in winter or naturally frozen by artificial watering to absorb heat inside the cellar, lower fruit temperature, and allow apricots to be stored for a long time. The ice cellar is built of brick and wood, made underground, 3.5-4.5 m deep, 6-8 m wide, and the length depends on storage volume and terrain, generally 20-25 m. The surrounding cellar walls should achieve good insulation performance, a small window is set at the top for ventilation, and a drainage well is set at the bottom.

Pack the apricots in boxes or baskets and place them in the ice cellar. Ice grooves are opened at the bottom and around the cellar, with a 0.3-0.6 m ice layer left at the bottom as a base. The boxes or baskets are stacked in sequence with a spacing of 6-10 cm, and the gaps are filled with crushed ice. After stacking 6-7 layers, cover with 0.6-1.0 m of ice blocks, cover the surface with straw, and tightly seal the cellar door. During storage, conduct spot checks and promptly deal with deteriorated fruit.

3. Low-Temperature Controlled-Atmosphere Storage of Apricots

Because apricots for controlled-atmosphere storage need to be harvested appropriately early, after harvest soak them in 0.1% potassium permanganate solution for 10 minutes, remove and air-dry. This not only has a disinfecting and cooling effect, but can also delay post-ripening deterioration. Quickly put the air-dried apricots into baskets, pre-cool for 12-24 hours, and after the fruit temperature drops below 20°C, transfer them into the storage warehouse for stacking, leaving gaps of about 5 cm between baskets, stacking 7-8 layers high, with the warehouse temperature controlled at about 0°C and relative humidity at 85%-90%, combined with a gas composition of 5% carbon dioxide + 3% oxygen. Under such storage conditions, the effect is best. However, varieties that are more sensitive to low temperature are not suitable for this. After such storage, before the apricots are sold, they should be gradually warmed, and post-ripened at 18-24°C, which helps them exhibit good flavor.

4. Prevention of Apricot Brown Rot and Soft Rot

The characteristic of apricot brown rot is that the affected fruit produces water-soaked lesions, which turn dark brown within 24 hours and extend deep to the pit. At higher temperatures, this disease causes the entire fruit to rot in 3-4 days. It also spreads from one fruit to another during storage. Apricot soft rot enters the fruit through wounds. A small round light brown spot forms at the affected area, then white mold grows and spreads to the whole fruit, finally turning black and gray. The rotten area is soft and wet, and in the weakest cases leads to complete fruit rot.

To prevent the above two diseases, the first step is to strengthen pre-harvest management, improve fruit quality and storability, and avoid mechanical injury. The second is to soak the fruit after harvest in a warm water solution with dichloronitroaniline.