Garlic comes in many different forms including fresh herb or clove, liquid, oil, powder and capsules. The pungent flavor of garlic is caused by a chemical reaction that occurs when the garlic cells are broken. The flavor is most intense shortly after cutting or chopping. This chemical reaction cannot occur after garlic is cooked, which is why roasted garlic is sweet rather than pungent.
 
 

Page by:  Amy Bloodworth

References:

http://allsands.com/Health/Alternative/garlicmedicinal_yb_gn.htm

http://www.garlicshoppe.com/shared/recipes/facts.html