Detailed Explanation of Processing Methods and Technical Points for Allicin

Allicin is a volatile oily substance extracted from the spherical bulbs of garlic, a mixture of diallyl trisulfide, diallyl disulfide, and methyl allyl disulfide, among others. The trisulfide has a strong inhibitory and killing effect on pathogenic microorganisms, and the disulfide also has certain antibacterial and bactericidal effects.

1. Material preparation. Select mature, dry garlic heads free from insect damage and mildew, remove the stems, separate the cloves, peel off the inner skin, rinse with clean water, and remove impurities and substandard garlic cloves.

2. Crushing and drying. Use a grinder to process the garlic cloves into a paste. Place the garlic paste into a drying oven and dry over a gentle fire, with the temperature controlled at 60-65°C, drying for 6-8 hours, turning once every 2 hours to ensure the garlic paste is heated evenly.

3. Grinding. Grind the dried garlic pieces into powder with a grinder, and pass through an 80-100 mesh sieve.

4. Soaking to remove odor. Place the garlic powder into 30-40°C alcohol and soak sealed for 6 hours to remove the odor (garlic powder to alcohol) ratio is (1:3).

5. Separation. Using the suction filtration method, take out the upper layer of solution, which is the odorless allicin stock solution.

6. Process flow

Material selection → cleaning and peeling → active catalyst soaking → rinsing → pulping → dehydration → drying → crushing → sieving → quality testing → finished product packaging

7. Supercritical CO2 fluid extraction technology is a new type of extraction and separation technology, and is also one of the key high-tech technologies promoted during the "Tenth Five-Year Plan" period. Compared with conventional solvent extraction, it has the advantages of mild operating conditions, no solvent residue, and maximum retention of the active ingredients of the raw materials, and is widely used in the food field for extracting and preparing various high-value-added foods. This project uses garlic as the raw material and adopts a method combining ethanol extraction with supercritical CO2 purification to purify allicin, retaining the original strengths of both while avoiding their weaknesses, and can achieve continuous supercritical CO2 extraction and purification of allicin. The process technology is as follows.

(1) Ethanol extraction of garlic liquid. Peel and slice garlic heads, soak in ethanol, and separate out the ethanol garlic liquid as the raw material for supercritical CO2 extraction. The ethanol garlic liquid contains 1.2~2.2mg allicin/ml.

(2) Supercritical CO2 purification of allicin. Feed the ethanol garlic liquid into the extraction vessel via a liquid pump, and CO2 from a steel cylinder is sent by a high-pressure metering pump to the extraction vessel to extract allicin, then passes in sequence through a first-stage pressure reducing valve, a flash vessel, and a second-stage pressure reducing valve to recover CO2. After extraction is completed, the extraction residue and allicin are taken out from the extraction vessel and the flash vessel respectively. Using the technology combining ethanol extraction with supercritical CO2 extraction to extract allicin, the extraction rate can reach over 92%, and the allicin purity reaches 84%, comparable to fresh garlic juice. Therefore, adopting the supercritical CO2 extraction process can keep the extract retaining the original fresh flavor and medicinal components of garlic.