RE: Eat Your Greens!!

Information is taken from this website: http://whfoods.org/

Preparation for Cooking

The latest scientific research tells us that slicing, chopping or mincing Onions before cooking will enhance their health-promoting properties. A sulfur-based compound called S-alk(en)yl-L-cysteine sulfoxide and an enzyme called sulfoxide lyase (also known as alliinase) are separated in the Onion's cell structure when it is whole. Cutting Onion ruptures the cells and releases these elements, allowing them to come in contact with each other to form a powerful new compound called thiopropanal sulfoxide. This new compound not only increases Onion's health-promoting properties but is also the culprit behind their pungent aroma and the cause of the eye irritation that results from cutting Onions.

The finer the Onion is cut, the more extensive is the transformation of the sulfur compounds. The stronger the smell and the more they affect your eyes, the more health-promoting nutrients they contain. So the next time you cut your Onions, you will have a greater appreciation of its "irritating" effects, knowing that the pungent smell that makes you cry will also make you healthy!

So, to get the most health benefits from Onions, let them sit for a minimum of 5 minutes, and optimally for 10 minutes, after cutting, before eating or cooking. This is to ensure the maximum synthesis of the sulfur compounds.

Heat will inactivate the effect of thiopropanal sulfoxide, which is why it is important to allow the Onions to sit for 5-10 minutes before cooking to give the enzyme ample opportunity to enhance the concentration of active phytonutrients in your Onions. Cooking at low or medium heat for short periods of time (up to 15 minutes)such as with methods like healthy sauté should not destroy the active phytonutrients since once they are formed, they are fairly stable.