What is the mechanism of action of antioxidants?

(1) reducing the oxygen content in and around foods through the reduction of antioxidants. Some antioxidants, such as ascorbic acid and D-isoascorbic acid acid, are readily oxidized and allow the oxygen in foods to react with them first, thus the oxidation of the oil is avoided. 

(2) antioxidants release hydrogen atoms that bind to the peroxide produced by the automatic oxidation of fats and oils, interrupting the chain reaction and preventing the oxidation process from continuing. 

(3) through destroying and weakening the activity of oxidase, it can not catalyze the oxidation reaction. 

(4) blocking the substance which can catalyze and cause the oxidation reaction, such as metal ions which can catalyze the oxidation reaction.