Free radicals, products of hydroperoxide decomposition,
act as initiators of autoxidation. Thermal, metal-catalyzed
or photo-catalyzed hydroperoxide decomposition results in the formation of hydroxyl-, alkoxyl- and peroxyl
radicals, e.g. [Geoffroy et al., 2000]:
Radicals generated from food contaminants may also
participate in oxidation process acting as catalysts.
Some molecules absorb UV light energy and are converted
into an excited single state. In foods containing lipids
photosensitized oxidation may be initiated by pigments,
such as riboflavin and porphyrins (chlorophyll, hemoglobin,
myoglobin) or some synthetic dyes [Frankel, 1998d].