More about garlic preparation. Garlin contains alliin stored in the cytoplasm which is converted by enzyme allinase, which is in the cell sap, to allicin which is the key sulfur compound responsible for its flavor and all the health benefits.
However to make the enzyme react, the crushing process needs to take place at room temperature and then allowed to mature which gives the enzyme a chance to break down allicin. Now, allicin is volatile and begins to form immediately after crushing and then peaks at about 10-15 minutes. So after crushing a few minutes are required before the enzyme gets a chance to act on alliin.
However, there is a catch. Allinase is a heat sensitive enzyme which means that no more allicin is produced after heating and implies that garlic needs to be crushed to release the enzymes and alliin and then should be left alone before cooking to form allicin.
The benefits of allicin is an antioxidant and antibacterial.