Authenticity control of flavour compounds. Determination of H-2/H-1 ratio of benzaldehyde in foods by gas chromatography isotope ratio mass spectrometry

A number of commercial samples containing benzaldehyde either as genuine fo od constituent or as a 'key component' of the added aroma was used for the determination of the H-2/H-1 ratio by on-line gas chromatography pyrolysis isotope ratio mass spectrometry (HRGC-P-IRMS). Concentrates obtained by sim ultaneous distillation extraction (SDE) from (i) processed cherries; (ii) p rocessed milk products 'with natural aroma' cherry; (iii) various alcohol-f ree beverages; and (iv) aromatized teas (,with aroma') were employed. With delta(2)H(SMOW) values from +170 to +390 parts per thousand 27 % of the mil k products were found to contain synthetic benzaldehyde, and in additional 27 % of the samples exhibiting delta(2)H(SMOW) values from -19 to +90 parts per thousand the required range for natural aromatization (delta(2)H(SMOW) = -110 to -190 parts per thousand) was also not found. The applied techniq ue allows clear-cut differentiation between the (ex-toluene) synthesized na ture-identical and the natural compound, but does not allow to separate ben zaldehyde ex plant tissues from the product originating from natural cinnam aldehyde ('ex cassia').