Canned Apricot Kernel Processing Methods and Technical Key Points
(1) Process flow
Raw materials → cleaning → shell cracking → material selection → rinsing and soaking → peeling → debittering → color protection → blanching and rinsing → canning → adding broth → exhausting and sealing → sterilization and cooling → heat preservation inspection → finished product
(2) Technical requirements
1. Raw materials and cleaning: Select apricot kernels that are large, glossy, fresh, free from mold and damage, and wash them thoroughly with running clean water, then drain.
2. Shell cracking and material washing: Use manual or mechanical shelling to crack the shells and obtain the kernels, selecting high-quality apricot kernels that are plump, free from rot, deterioration and insect damage.
3. Soaking and peeling: Rinse the selected apricot kernels clean, soak them in twice their volume of water for 12 hours until the skins soften and preliminary debittering occurs. Then pour them into a boiling 1% NaOH solution three times the volume of the apricot kernels and boil for 0.5 to 2 minutes, quickly remove them and rinse off residual alkali with tap water, peel by hand and rinse clean.
4. Debittering: Apricot kernels contain about 3% amygdalin, which is itself non-toxic, but under conditions such as acid or heat, it hydrolyzes to produce the highly toxic substance hydrocyanic acid; eating too much can cause poisoning or even death. The debittering method is the same as above; rinse thoroughly to remove toxic substances.
5. Color protection: To maintain the milky white flesh of the apricot kernels, place the peeled and washed apricot kernels in a mixed solution of 0.5% NaCl and 0.02% NaHSO3 for color protection for 4 hours; the mixed solution must completely submerge the apricot kernels.
6. Blanching and rinsing: Blanch at 90°C for 2 minutes to destroy enzyme activity on the surface of the apricot kernels, kill microorganisms attached to their surface, and at the same time remove part of the air inside the apricot kernels to prevent oxidation during storage. After blanching, quickly rinse with running clean water to cool the apricot kernels rapidly so as to maintain their crispness.
7. Broth preparation
Broth formula (grams per kilogram): white granulated sugar 25, refined salt 20, cinnamon 3, ginger 3, Sichuan pepper 2, monosodium glutamate 2, angelica dahurica and potassium sorbate in appropriate amounts.
According to the above formula, put cinnamon, ginger, Sichuan pepper, angelica dahurica, etc. into a gauze bag and tie it tightly, boil in a measured amount of water for more than 1 hour, then add the pre-dissolved sugar, salt and potassium sorbate, and finally add monosodium glutamate, then filter and set aside.
8. Canning: For 500 g glass jars, fill each jar with 250 g of apricot kernels, quickly pour in the above-prepared hot broth up to the headspace required for fruit cans (6 to 8 mm), minimizing the time exposed to air.
9. Exhausting and sealing: After pre-sealing the cleaned can lids, send them into the exhausting box and maintain for 12 to 15 minutes so that the center temperature of the can reaches above 75°C, then quickly seal the lids. If vacuum sealing is used, the vacuum degree is required to be above 400 mmHg.
10. Sterilization: Sterilize immediately after sealing; the sterilization formula is 10 to 30 to 10 minutes at 100°C. After sterilization, use a three-stage cooling method to quickly bring the can temperature down to about 37°C, then store in a heat preservation warehouse for 7 days, and after passing inspection, label and package.
(3) Quality standards
1. Sensory indicators
Color: The apricot kernels are milky white and the broth is clear.
Taste and odor: It has the mellow aroma and odor that canned apricot kernels should have, with no off-flavors.
Texture and mouthfeel: Complete in shape, not soft or mushy, crisp in mouthfeel.
2. Physicochemical indicators
Solid content: Not less than 56% of the net weight.
Heavy metal indicators: Same as canned food.
Microbiological indicators: Meets the commercial sterility requirements for canned food.