Lipid oxidation is a reaction of lipid breakdown.
In the body, it is related to several reactions, some of them with positive impacts on health (e.g. fatty acids are used to produce energy through beta-oxidation reaction) and some with negative impacts on health (e.g. the oxidative degradation of lipids by free radicals form cytotoxic substances in the body).
In the nutritional sense, however, it refers to the degradation of foods. This degradation is always associated with negative health effects.
In foods, oxidation occurs in unsaturated fatty acids, more specifically at the carbon double bonds, since these are the most unstable links within the carbon chains. The more double bonds in the chains the more oxidation occurs.
Fat oxidation leads to food degradation, affecting its’ nutritional value, flavor, stability and safety. High temperatures accelerate the rate of oxidation process which is common in stir-frying. (read more..)
Auto-oxidation is the most common type of food oxidation (it is any oxidation in the presence of oxygen). This generates the so-called lipid peroxide radicals, which react with other lipids.
One of the reactions results by adding a hydrogen atom to the other side of the carbon chain, creating a more stable trans fatty acid. However, the result of this process has links to serious health problems, such as cardiovascular diseases or cancers. (1)German JB. Food processing and lipid oxidation. Adv Exp Med Biol. 1999;459:23-50. Available here. (2)Choe E, Min DB. Mechanisms and Factors for Edible Oil Oxidation. Volume 5, Issue 4. September 2006. Pages 169–186. Available here.
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