Reinvestigation of vanillin contents and component ratios of vanilla extracts using high-performance liquid chromatography and gas chromatography

Abstract

The major components vanillin, vanillic acid, 4-hydroxybenzaldehyde and 4-hydroxybenzoic acid are analysed in 15 vanilla pod samples of different origin and year of harvest. The pods are extracted with ethanol/water and with diethyl ether, respectively. Using ethyl vanillin and veratraldehyde as internal standards new HPLC and GC methods were developed and utilised to establish authenticity profiles. Extracting efficiency for vanillin was lower when diethyl ether was used. However, the ratios of compounds are not affected by the applied extracting procedure. Comparing the measured data with commonly used reference values for the authenticity control of vanilla it becomes evident that the authenticity ranges of the reference values used up to now, are too narrow, bearing the risk of an incorrect quality assessment.