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 three categories according to their solubility: oil-soluble, water-soluble and compatibility. 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 chelators, oxygen scavengers, peroxide decomposers, enzyme antioxidants, ultraviolet absorbers or singlet oxygen quenchers according to their mode of action. Agents, etc.

4. Commonly used antioxidants include tea polyphenols (TP), tocopherols, flavonoids, butylated hydroxyanisole (BHA), dibutylated hydroxytoluene (BHT), tert-butyl p-phenylene diphenol (TBHQ), etc.