The antioxidant assay using the discoloration of β-carotene iswidely
used to measure the antioxidant activity of bioactive compounds, because
β-carotene is extremely susceptible to free radical-mediated oxidation
of linoleic acid. In this test, β-carotene undergoes rapid
discoloration in the absence of antioxidant, which results in a reduction
in absorbance of the test solution with increasing reaction time. The
presence of antioxidant hinders the extent of bleaching by neutralizing
the linoleic hydroperoxyl radicals formed