Tannic Acid

It is a type of tannin found in plants such as tea, oak bark and many fruits.

Tannic acid is a plant tannin used in very small amounts. FDA lists tannic acid for human food mainly as a flavoring agent and flavor enhancer, with a maximum level set for each food category (21 CFR 184.1097). It is obtained by extraction from oak galls, tara seed pods or sumac. If your cat has a medical condition, ask your veterinarian about its diet.

Source: ecfr.gov

Tannic acid is added in small amounts as an antioxidant and for flavor. As an antioxidant it helps slow fat oxidation. It also has a dry, slightly bitter taste, so it can change how a food tastes. It is rare in cat food, and only a few dry foods in our list use it.

In large amounts, tannins can bind protein and iron in the gut, which can lower how much is absorbed. The amount of tannic acid in a cat food is small, and we found no study showing that it changes iron levels in cats. A cat with anemia needs a veterinary workup to find the cause.

FDA lists tannic acid for human food mainly as a flavoring agent and flavor enhancer, and in some foods as a pH control agent or processing aid. It may also be used in rendered animal fat. The rule we checked does not list it as a preservative. Pettings groups it with natural preservatives and acidifiers. The label does not say which job it is doing in a given recipe.

Source: ecfr.gov

Pettings gives tannic acid 3 out of 5 and lists it as a natural preservative or acidifier. It appears on 2 of the 149 dry cat foods we list. A middle score means we see no strong reason to favor or avoid it. Each food's page shows how it scores overall.