Sunday, October 11, 2009

Garlic, Allicin, and Does Garlic Gets into Human Perspiration?

The aroma of garlic develops when the garlic plant (alliaceae sativum, et alis damaged. So if a garlic plant stem is cracked or bit off by a rabbit, the adjacent crushed plant cells form allicin from alliin. Allicin is the primary ingredient in garlic extract. Alliin is stockpiled in the garlic cells for just such an occasion, and an enzyme is ready to oxidize the alliin when needed. Allicin is shown below right.

Allicin is an antimicrobial material, and presumably kills microbes which might damage the injured plant. The flavor of the allicin may or may not keep the rabbit from eating more.

Of course, garlic and the allicin within are important gastronomically, but it is also an anti-oxidiant, and an anti-microbial material.

Allicin gets into the blood stream, and it has a half life of 16 hours there.  Allicin also degrades in acid conditions, so don't mix garlic with your lemon juice.

Most people feel it gives them bad breath, and I think that is beyond doubt, but I can't find anything credible confirming that allicin gets into human sweat and makes one smell like pizza while exercising. I have looked pretty hard. There are some personal care sites that want you to simplify your whole diet and include garlic with onions and peppers.  [If anyone can find something on garlic in human sweat, please leave a comment.]

There is the mosquito argument.  One dubious article from Australia that says that allicin causes mosquitos to bite. On the other hand, StableKare produces Garlic-Eze, which is a garlic based mosquitto repellent for horses -- so they think the opposite.

Polymer chemists might note that the double bonds are conjugated with the sulfurs, and may be free-radical polymerizable. Some polymerization occurs in nature, and in fact in the sauce pan -- if you take the allicin and mix it with oil, you can encourage the formation of ajoene - which is an oligomer of allicin. Ajoene is most abundant form when crushed garlic is mixed with oil. Ajoene is an anticlotting agent and broad spectrum anti-microbial. [Ajoene is usually pronounced like a Spanish word with the "j" being an "hg."]

Interestingly ajoene inhibits lipase from metabolizing fat, so potentially more fat will pass though the body undigested. There is one patent on polymer grafted ajoene (and other cysteine blockers) to reduce fat absorption in the body.

Another patent uses ajoene and allicin in polymer coating for arterial stints. No covalent bonding to the matrix polymer though.

==========================See my 20-October-2009 post on Red Baneberry which similarly generates anti-microbials when damaged.===========================================