According to the International Program on Chemical Safety, sodium benzoate is heavily used by the soft drink industry due to the demand of high-fructose corn syrup in carbonated drinks. Sodium benzoate increases the acidity of soft drinks, which also increases the intensity of flavor you get from the high-fructose corn syrup. On the back of a soda can, you can find sodium benzoate in the ingredients list as E211, which is the number assigned to it as a food additive.