Survey of benzoic acid in cheeses: contribution to the estimation of an admissible maximum limit.

Benzoic acid and its salts are commonly used additives in the food industry. Their use is not allowed in dairy products even though they can be found naturally. In this work, 100 cheese samples were tested to establish the maximum concentration that can be considered as "natural" and, therefore, permitted in cheeses. Analyses were carried out by a validated ion chromatography method and "positive" samples were confirmed by two other HPLC methods. Benzoic acid concentrations higher than the method LOQ (8.8 mg kg(-1)) were found in 18 samples, ranging from 11.3 to 28.7 mg kg(-1), with a mean value of 20.5 mg kg(-1). Taking into account the distribution of benzoic acid concentrations observed in "positive" samples, it is plausible to estimate a maximum admissible limit of 40.0 mg kg(-1) for benzoic acid in cheese. Below this value, samples can be considered "compliant".