Citric Acid

It is used as a preservative and to strengthen the effect of other antioxidants, which keeps the food fresh and slows the growth of microbes.

Citric acid is a natural fruit acid used in small amounts in cat food to keep it fresh. FDA lists citric acid as GRAS for animal feed under good manufacturing or feeding practice (21 CFR 582.1033). At the amounts used in pet food, Pettings has found no known risk for cats. If your cat has a urinary condition or another medical issue, ask your veterinarian about its diet as a whole.

Source: ecfr.gov

Citric acid is the same acid that gives lemons and limes their sour taste. In cat food it works as a preservative and acidifier. It binds trace metals that would otherwise speed up fat oxidation, which helps antioxidants such as mixed tocopherols last longer. It also lowers pH a little, and that slows some microbes.

Citric acid occurs naturally in citrus fruit, so pet food makers describe it as a natural preservative. Tufts veterinary nutritionists note that natural preservatives are not as potent as synthetic ones, so their protection does not last as long, and that manufacturers should account for this in the best by date. Check that date and store the bag properly, sealed and in a cool, dry place.

Source: sites.tufts.edu

Citric acid is a helper for mixed tocopherols. Tocopherols, a natural form of vitamin E, slow the oxidation of fats. Citric acid binds traces of metals such as iron and copper that speed up that oxidation, so the pair keeps fat fresh longer than tocopherols alone. That is why labels so often read preserved with mixed tocopherols and citric acid.

Pettings gives citric acid 3 out of 5 and lists it as a natural preservative or acidifier. It appears on 26 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.