The reaction of antioxidants with oxidation is believed to occur through two major pathways.
First is by donating electrons to break
and terminate the oxidation cycle at the propagation step and thereby
preventing additional lipid and protein radicals from forming
However, in the absence of antioxidants, the reaction becomes
auto-propagative leading to the production of non-radical products
Second is by removing free radical (ROS) initiators in order to
quench chain-initiating catalysts (radicals) or limiting the radicals
initiators by binding metals such as iron and copper as metal chelators to stabilise them in an inactive or insoluble form . Moreover, the antioxidant free radical (oxidized antioxidant) formed in reaction
may further interfere with chain propagation reactions by forming peroxy antioxidant compounds as shown in reaction The metal chelating power of plant materials has been proposed to be associated with chemical composition of the sample including the presence ofcompounds, such as phytate and oxalates.
found that the extract of Coriander sativum possesses higher iron chelating activity than Petroselium crispum,
while the addition of Menthagentilis L. showed higher chelating activity than other menthe species