Antioxidant capacity is an overall ability of organisms or food to catch free radicals and prevent their harmful effect. There are three different ways to determine the antioxidant capacity:
Colorimetric methods, which measure the ability of an antioxidant to reduce an oxidant, with a change of color.
Fluorimetric methods, which measure the ability of an antioxidant to eliminate free radicals through the donation of a hydrogen atom.
Electrochemistry methods, which the sample is oxidized by applying a variable potential. A variable voltage is applied to the strip to “activate” the antioxidants, so they cede the electrons. Electrons are released and detected as a current at the electrode.