[DeRosa_ITA]

Als Einleitung zum Thema n-3 Fettsäuren (bzw. mehrfach ungesättigte FS) und Erhitzung:

http://www.whfoods.com/genpage.php?t...trient&dbid=84

How do cooking, storage, or processing affect omega 3 fatty acids?

Polyunsaturated oils, including the omega 3 fats, are extremely susceptible to damage from heat, light, and oxygen. When exposed to these elements for too long, the fatty acids in the oil become oxidized, a scientific term that simply means that the oil becomes rancid.

Rancidity not only alters the flavor and smell of the oil, but it also diminishes the nutritional value. More importantly, the oxidation of fatty acids produces free radicals, which are believed to play a role in the development of cancer and other degenerative diseases.

Under most circumstances, the problem of rancidity only arises when the oils are removed from their natural food package. For example, the hard shell of the flaxseed protects the oil inside the seed from heat, light, and oxygen. Flaxseeds also contain antioxidant compounds, such as vitamin E, that provide additional protection against oxidation. But, when the seed is pressed to isolate the oil, the oil becomes vulnerable to the elements.

As a result, oils rich in polyunsaturated fatty acids should be stored in dark glass, tightly closed containers in the refrigerator or freezer. In addition, these oils should never be heated on the stove. So, instead of sautéing your vegetables in flaxseed or walnut oil, make a salad dressing using these oils.