Quantitation of propionic acid in emmental cheese products by direct solvent extraction

Propionic acid (PA) is commonly present in Emmental cheese (EM) with relatively high concentration. Even though PA is allowed as GRAS in the USA, it may cause neurological disorders if it is consumed excessively. The maximum level of the preservative PA in cheese is set at 3.0 g/kg by the Korean Food Code. Also, the minimum level of PA in EM (150 mg / 100 g) was set by Codex in 1967. Therefore, PA monitoring in EM, with relatively high level of intrinsic PA, is necessary to recommend the sound use of the PA in the EM ripened. The current official PA analysis method consisting of steam distillation and solvent extraction / evaporation, is too cumbersome to be handled in sample preparation process. In this study, acidic acetone-based direct extraction method was successfully applied to 12 EM samples for the determination of PA level.