Antioxidants are substances that prevent the adverse effects of oxygen. It is a class of substances that help capture and neutralize free radicals, thereby eliminating free radical damage to humans.
Antioxidants are food additives that prevent or delay the oxidation of foods, improve the stability of foods, and extend the shelf life. The correct use of antioxidants not only prolongs the shelf life and shelf life of foods, but also brings good economic benefits to producers and consumers, and brings better food safety to consumers.
(1) Antioxidants can be classified into synthetic antioxidants (such as BHA, BHT, PG, etc.) and natural antioxidants (such as tea polyphenols, phytic acid, etc.) by source.
(2) Antioxidants can be classified into three categories: oil solubility, water solubility and compatibility. Oil-soluble antioxidants include BHA, BHT, etc.; water-soluble antioxidants include ascorbic acid, tea polyphenols, etc.; compatible antioxidants include ascorbyl palmitate.
(3) Antioxidants can be classified into free radical absorbers, metal ion chelating agents, oxygen scavengers, peroxide decomposers, enzyme antioxidants, ultraviolet absorbers or singlet oxygen quenchers according to the mode of action.
Commonly used antioxidants are tea polyphenols (TP), tocopherols, flavonoids, butylated hydroxyanisole (BHA), dibutylhydroxytoluene (BHT), t-butyl hydroquinone (TBHQ), etc.  .
Mechanism of action
(1) Reducing the oxygen content in and around the food by reducing the antioxidant. Some antioxidants such as ascorbic acid and isoascorbic acid are easily oxidized, which can cause the oxygen in the food to react with it first, thus avoiding the oxidation of the oil. .
(2) The release of hydrogen atoms by the antioxidant combines with the peroxide generated by the automatic oxidation reaction of the grease, interrupting the chain reaction, thereby preventing the oxidation process from proceeding.
(3) By destroying and attenuating the activity of the oxidase, it is impossible to catalyze the progress of the oxidation reaction.
(4) Blocking substances that can catalyze and cause oxidation reactions, such as metal ions that can catalyze oxidation reaction by complexation