Tea polyphenols are not a common preservative. Although tea polyphenols have antioxidant and antibacterial effects, they are usually used as natural health ingredients in food and beverages, rather than as preservatives.
Preservatives commonly used in food include sulfate, nitrite, benzoic acid and its sodium salt. These chemicals can inhibit the growth and reproduction of microorganisms, thus extending the shelf life of food.
It should be noted that although preservatives can extend the shelf life of food, long-term intake of excessive preservatives will cause harm to human health. Therefore, when choosing food, we should try to choose products without or with low content of preservatives.