The key to storage of apricots is to determine the appropriate harvest maturity. The maturity can be determined by the number of days of fruit development, the change of fruit color, the texture of peel and pulp, the aroma and flavor of fruit and the firmness of fruit growth. The apricots used for storage should be harvested when the fruit reaches the inherent size of the variety, the fruit surface turns from green to yellow, and the fruit surface presents the inherent color of the variety to the sun. The pulp is still hard, the nutrients have been fully accumulated, the apricots have a slight flavor of the variety, and they are about eight ripe. Export fruits are harvested at this time to allow sufficient time for packaging and transportation.
Dry processing technology of apricot:
Selection of Raw Materials Finishing Sulfur Fumigation Drying Packaging
Selection and treatment of raw materials: Select varieties with thick flesh, seed-free, sweet taste, less fiber, strong aroma and orange pulp, full-ripe but not over-ripe fruit as raw materials. Remove the fruits that are not suitable for ripeness and fragmentation. Grade and wash them according to size. Cut them in half along the suture line with a sharp knife. The cut surface should be smooth and tidy. Remove the pits (some of them are apricot dried with pits without cutting). After slicing (half-seeded dried apricots), slices of apricots are arranged on a sieve tray facing upwards, and can not overlap.
Sulfur fumigation: The sieve tray filled with apricot slices is sent to the sulfur fumigation chamber for 3-4 hours. Sulfur consumption is about 0.4% of fresh fruit weight. Spraying 3% salt water on fruit surface before fumigation can prevent discoloration and save sulphur. The core of apricot slices with good sulfur fumigation should be filled with liquid, and the dried products can keep bright golden or orange-red.
Natural drying: Fruits are placed in the sun after sulfur fumigation and exposed to sunlight. When they are 5-70% dry, they are dried in shade to the required dryness. The dried apricot should be soft and not easy to break. After gripping with hands, it is not easy to stick to each other. Twist individual fruit slices between two fingers without juice leakage.
Heat pump drying: loading capacity 7-9 kg/m~2; initial temperature 50-55 C, final temperature 70-75 C; according to 6P drying and dehumidification integrated main engine configuration 5.8 m long and 3 m wide and 2.2 high drying room calculation, put into eight material trucks, 12 layers of each material truck, 1.2 square meters, can be put into fresh apricot slices 2000 kg at a time, drying time 18-20 hours, production apricot dried products 400 kg, system power consumption 7 degrees per hour, each batch. The total power consumption is 140 degrees. According to the calculation of 1 yuan per kilogram of electricity, the cost of electricity consumption per kilogram of dried apricots is 0.35 yuan, and the cost of electricity consumption per kilogram of fresh apricots is 0.07 yuan. If the whole drying time of fresh apricots is long, it will take 70 hours.
Packaging: The suitable amount of water for dried apricots is 16%-18%, and the drying rate is 5:1. After drying, the finished products are softened in wooden boxes for 3-4 days, and the poor color, insufficient drying and broken ones are picked out (reprocessed or graded) to be packed.