To oxidize means for a substance to undergo a chemical reaction involving the loss of electrons, often through reaction with oxygen or other oxidizing agents. In foods, oxidation commonly affects
lipids, pigments, vitamin form:s], and other compounds, changing their chemical structure and properties.
For example, unsaturated fatty acids can be oxidized by oxygen, particularly in the presence of heat, light, or metal ions. This can produce compounds such as hydroperoxides, which can subsequently break down into aldehydes, ketones, and other compounds responsible for rancid odors and flavors.
In simple terms:
Oxidize = undergo a chemical reaction in which a substance loses electrons, often as a result of reacting with oxygen.
In food chemistry
Oxygen + unsaturated fat → oxidation → hydroperoxides → breakdown products → rancidity
Note: Oxidation does not always require oxygen. In the strict chemical sense, oxidation is defined by electron loss; oxygen involvement is common in food oxidation but is not required.