Prepare materials. Choose tangerines that are moderately mature, dense in texture, bright in color, sweet and sour as raw materials. Remove green, diseased, and rotten fruits, classify and clean them according to size, boil them in water at 95 to 100°C for 1 minute (based on the ease of peeling and removing orange peels), and peel off the orange peel and orange peel while it is hot. . Soak the petals separately in clean water according to their size and set aside.

Acid treatment. Put the orange slices into a hydrochloric acid solution with a concentration of 0.15% to 0.2% (the ratio of orange slices to acid solution is 1:3), treat it at a temperature of 25 to 30°C for 30 to 50 minutes, and add a little Stir.

Alkali treatment. Rinse the acid-treated citrus slices with clean water, and then immerse them in 0.05% sodium hydroxide solution at 28-30°C for 3-6 minutes (subject to appropriate removal of the coating). Release the alkali immediately. Rinse with running water for 1 to 2 hours, then neutralize with 1% citric acid solution to improve the flavor.

Plastic surgery. Use curved scissors to cut off the heart, and use tweezers to remove the remaining capsule coating, orange veins, core, etc. At the same time, pick out the broken, stiff, and shrunken orange slices. Classify the pieces according to their size and wash them once with running water.

Graded canning. Classify according to size, color, and shape to achieve no seeds, no orange peel, neat cuts, and roughly uniform size and color in the same can, and then can them separately. 500-type open glass bottles contain 285 grams of fruit pulp and 215 grams of sugar water (sugar water preparation method: add 68 kg of water to 32 kg of sugar, heat and filter with gauze).

Exhaust and seal. Place the canned orange slices and sugar liquid in a hot pot or heat and exhaust through an exhaust box. The center temperature in the can is required to reach 75°C for 5 to 10 minutes. When vacuuming, the vacuum degree is maintained at 47 to 53 kPa, the cans are sealed immediately, and the cans are sterilized immediately after sealing.

Sterilization and cooling. After sealing the can, put it into boiling water to sterilize for 20 to 25 minutes, and then cool it in stages to get the finished product.