I too was incredibly
curious about the true nature of
stainless steel and its incredible ability to prevent you from having to feel
self-conscious about how you cannot stop
sniffing your
kebab- or
gyro-scented fingers.
I came upon two credible
chemical explanations for the
mystical odor-banishing powers of
stainless steel:
- Explanation One: Allicin, the chemical which causes garlic to smell as it does (very similar to the chemicals which cause onion-smell and other such smells), has "S+ --- O-" in its middle, which means that it can be broken down to produce another less odorous chemical when introduced to water. Stainless steel contains many trace metals that are not found in regular steel, many of which such as palladium, chromium, and zirconium are known to catalyze organic reactions. It is likely that they could serve as catalysts to the breakdown of allicin.
(confusing minimalist molecular diagram and description courtesy of drew, of drew.corrupt.net).
- Explanation Two: When stainless steel is being created, it is cleaned by being introduced to a highly acidic environment (chlorine/chloric acid), and some of this acidity becomes inherent in the steel. Therefore, the steel is able to neutralize many weak alkalines that come into contact with it. Most chemicals resembling garlic in odor are basic, so they are broken down by contact with stainless steel.
(explanation paraphrased from a conversation between this guy from England named Phil and a physicist he knows)
Either explanation is possible, and though the latter of the two seems to come from a slightly more credible source the former sounds more plausible to me. A combination of the two factors is also possible.