Photodamage determination of human hair

Sunlight on human hair causes photo-degradation. This results in bleaching due to melanin oxidation through free radicals, and induces keratin impairment. Protein degradation, tryptophan degradation, lipidic peroxidation and electron paramagnetic resonance can be used to evaluate proteic and lipidic photodecomposition and free radical formation in hair fibres subjected to antioxidant action and different UV intensities. All these methodologies have been optimised to determine protein, lipid and melanin degradation in hair subjected to different UV intensities.