Autoxidation of lipids

Products that contain fats and oils turn rancid and deteriorate in other ways when they are exposed to air. The action known as autoxidation. Oxidation in lipids (autoxidation) and in fat and oil containing foods, on the other hand, occurs as a result of the susceptibility of fatty acids to oxidations and subsequent formation of reactive compounds referred to as “free radicals”.

One of the most important problems of lipid oxidation is the generation of harmful compounds that implicate several human pathologies, including atherosclerosis, cancer, inflammation and aging processes, among others.

Autoxidation reaction leads to lipids breakdown and formation of wide range of oxidation products. The reaction happens between oxygen and the unsaturated lipids to form a lipid hydro-peroxide, which then undergoes further reaction with or without the participation of other compounds. This reaction is enhanced by light and metal ions.

Oxidation affects many interactions among food constituents, leading to both desirable and undesirable products.

Oxidation reactions not only reduce the nutritional value of products due to the loss of essential fatty acids and vitamins. Generally, the first change observed results in a gradual reduction of sensory quality. The oil, meat, fishery, dairy, and bakery industries suffer serious losses from autoxidation of their products.

The most common antioxidant is vitamin E, or tocopherol. Fats and oils generally contain phosphatidcs, complex substances that sometimes act as an antioxidant and sometimes also enhance the activity of other antioxidants present.
Autoxidation of lipids