n the new study, Toyohiko Ariga and colleagues point out that allicin is one of the main active ingredients in garlic. Other studies have shown that allicin has beneficial effects in preventing blood clots, cancer, and bacterial infection. Although commercially bottled garlic is often stored in oil or water, researchers did not know how various storage and preservation methods affect levels of allicin, which is fragile and disappears quickly.
Compared to bottled garlic, fresh garlic contains higher levels of an ingredient called allicin, which can help prevent blood clots and bacterial infections. (Credit: Courtesy of Bruce Fritz)
To find out, Ariga's group compared allicin levels in extracts of fresh garlic after 1-2 weeks of storage in water, alcohol, and vegetable oil. Garlic stored in water at room temperature lost about half its allicin in 6 days and garlic in vegetable oil lost half its allicin in less than an hour. The garlic lost its antibacterial action as allicin broke down. However, allicin broke down into materials that still are believed to have some anticancer and anti-blood clot effects.
Fujisawa et al. Biological and Chemical Stability of Garlic-Derived Allicin. Journal of Agricultural and Food Chemistry, 2008; 56 (11): 4229 DOI: 10.1021/jf8000907
(Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.)