Authentication of vanillin ex glucose – A first study on the influence of the glucose-source on the δ¹³C and δ²H value

Vanillin is the most characteristic compound in vanilla flavour. Since vanilla pods are very expensive, vanillin is mainly produced by synthetic and sometimes biosynthetic methods. Biosynthetic vanillin is called ‘biovanillin’ and can -by law-be labelled as ‘natural’. The isotopic carbon ratio (expressed as δ¹³C) is a widely established and valuable authentication parameter for vanillin. Furthermore, currently available data about δ²H values indicate, that the isotopic hydrogen ratio can make a decisive contribution to the authentication of vanillin. One of the most recent developments is the bio-production of vanillin derived from glucose. However, very little is known about its isotopic composition. Here, we present the δ¹³C and δ²H values of glucose from corn and wheat and the vanillin that was derived from these. The isotopic composition of the glucose is clearly reflected in the resulting vanillin molecule. All ‘glucose-vanillin’ samples could be distinguished from vanillin originating from other sources when combining the δ¹³C and δ²H value.