The antioxidant properties of gallic acid and allied compounds

Summary The differences between animal fats and common vegetable oils as regards their protection by antioxidants are briefly reviewed; in general, the former can be stabilized by di- and poly-phenolic inhibitors and by inhibitols, the latter by acid-type inhibitors such as tartaric, phosphoric and other acids; these acids reinforce the action of the inhibitols which occur naturally in vegetable oils or which may be added to animal fats. A study has been made of the antioxygenic action of the polyphenols on both kinds of fats. The trihydric phenols, gallic acid and ethyl gallate are effective stabilizers in animal and vegetable fats and enhance the antioxygenic activity of inhibitols; they thus demonstrate the properties of both phenolic and acid inhibitors. The possible mechanism of this synergistic action is briefly discussed.