We know that allicin has a very short/limited half-life (allicin is formed by cutting into the clove, which allows the chemical interaction that produces allicin to take place)...and we know that heating garlic changes it's actions & efficacy.
So, how's about you do some Googling on this topic and post the links & information you find - to help answer your own question and for the benefit of everyone?! Methinks that's a jolly-good idea :)