Benzoic acid is a natural compound that acts as a preservative, especially against fungi. It is normally present in high concentrations in cranberries. It is not present in most other edible berries and products. In view of its anti-microbial action, it is widely used as a food preservative. In this case it will be marked on the label as benzoic acid, benzoate (salt of benzoic acid), or E210-E213.