Food additives, especially antioxidant preservatives, are key elements in the food industry and production. Food antioxidants can be natural products such as extracts and purified natural metabolites, or synthetic compounds. They act as radical scavengers, chelators, quenchers, or antioxidant regenerators. Generally, food antioxidants target the preservation of food without altering its taste and colour. Synthetic antioxidants are cheap, easy to use and efficient as preservative agents; however, consumers tend to seek natural antioxidants. This chapter focuses on the different functional antioxidants such as polyphenols, tocopherols that can be used as food additives. These compounds are characterized by different chemical structures and different mechanisms of actions.