(1) Antioxidants can be divided into synthetic antioxidants (such as BHA, BHT, PG, etc.) and natural antioxidants (such as tea polyphenols, phytic acid, etc.) according to their sources.
(2) Antioxidants can be divided into oil-soluble, water-soluble and compatible three categories according to their solubility. Oil-soluble antioxidants include BHA, BHT, etc.; water-soluble antioxidants include ascorbic acid, tea polyphenols, etc.; compatible antioxidants include ascorbyl palmitate, etc.
(3) Antioxidants can be divided into free radical absorbers, metal ion chelating agents, oxygen scavengers, peroxide decomposers, enzyme antioxidants, ultraviolet absorbers or singlet oxygen quenchers according to their mode of action.
Commonly used antioxidants include tea polyphenols (TP), tocopherols, flavonoids, butylated hydroxyanisole (BHA), dibutylhydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), etc.
Precautions:
Fully understand the performance of antioxidants; correctly grasp the timing of antioxidant addition; mix and use antioxidants, synergists, and stabilizers; select the appropriate amount of addition; control the factors that affect the effect of antioxidants.
Mechanism of action:
(1) Through the reduction reaction of antioxidants, the oxygen content in and around the food is reduced. Some antioxidants, such as ascorbic acid and erythorbic acid, are easily oxidized and can cause the oxygen in the food to react with it first, thereby avoiding the oxidation of oil .
(2) Antioxidants release hydrogen atoms and combine with peroxides produced by the auto-oxidation reaction of oils, interrupting the chain reaction, thereby preventing the oxidation process from continuing.
(3) By destroying and weakening the activity of oxidase, it can not catalyze the oxidation reaction.
(4) Enclose substances that can catalyze and cause oxidation reactions, such as complex metal ions that can catalyze oxidation reactions, etc.