Allicin-Rich Extract Obtained from Garlic by Pressurized Liquid Extraction: Quantitative Determination of Allicin in Garlic Samples

Since ancient times, garlic has been used to prevent and treat various diseases. The health benefits of garlic are attributed to its content of thiosulfinates, of which allicin is the main bioactive compound. Allicin is not found in fresh garlic; it is derived from alliin through the enzymatic action of alliinase when the membranes of the garlic cloves are destroyed. Allicin is a very unstable compound, degrading within a few minutes of being produced, at high temperatures and in the presence of certain solvents. Pressurized liquid extraction (PLE) is a relatively new technique that has demonstrated high efficiency on the extraction of bioactive compounds. Thus, PLE of garlic at 313 K and 6 MPa, using ethanol as solvent, was performed. The concentration of allicin in the garlic PLE extract, garlic powder, garlic oil and fresh garlic was quantified using the Internal Standard method. The global yield of garlic PLE was 1.3 ± 0.3% on a wet basis. The garlic PLE extract had the highest allicin concentration (332 ± 5 µg of allicin.g-1 of sample), followed by fresh garlic and garlic powder. Allicin was not detected in garlic oil.