Whether vanilla has been grown in nature or has been synthetically produced can be revealed with the help of an analytical method developed at the National Food Institute, Technical University of Denmark. The method maps the product’s chemical profile. The method can be used to ensure consumers get what they pay for as well as to safeguard producers against cheap imitations claiming to be the real thing.
Vanilla is one of the world’s most expensive spices. In 2016 i.e. production difficulties in Madagascar – where most of the world’s vanilla is grown – have increased the prices to an even higher level.
Researchers at the National Food Institute have developed an analytical method, which can distinguish between natural and synthetically produced vanilla. Therefore, the method can be used to ensure that consumers get what they pay for and to deter producers from selling cheap imitations as the real thing.
By analyzing the chemical profile of different samples using a so-called mass spectrometer the method can distinguish between natural vanilla and synthetically produced products. The method can also detect in which part of the world the natural vanilla has been grown – a parameter which is of great importance for the price of the product.
Chemical profile contains important information
First the mass spectrometer measures the ratio of heavy to light carbon isotopes in the selected samples. The two most common vanilla varieties – vanilla planifolia and vanilla tahitensis – both contain significantly more heavy isotopes than synthetically produced products, making it possible to distinguish between natural and synthetically produced vanilla.
This information is then combined with analysis of the ratio of heavy to light hydrogen isotopes in the samples. This is possible as the ratio of heavy to light isotopes varies in rainfall from different parts of the world. These differences are deposited in the chemical profile of the vanilla plant and can thus in combination with the carbon isotope ratio be used to distinguish where in the world the vanilla is grown.
There can be considerable price differences between vanilla tahitensis from French Polynesia and vanilla planifolia from Madagascar, so being able to document the product’s origins may be of significant value.
Developing the method further
When vanilla is used as a spice in composite foods, which contain e.g. fats, sugar and water, it is very challenging to separate the components in order to make it possible to carry out the analysis. Therefore the current method cannot be used directly on composite foods.
Therefore, a part of a National Food Institute PhD student’s research is to develop the method, enabling it to study the authenticity of vanilla added to foods. Authenticity studies can document that foods are what they claim to be.
Mass spectrometry analysis is already used in authenticity studies e.g. to check whether the wine was produced in the year and the area stated on the label, as well as to determine that honey does not contain added sugar.
Read more
Read more about the method of analysis on a poster from the National Food Institute: Authenticity and Traceability of Vanilla Flavour by analysis of Stable Isotopes (pdf). The method has been developed as part of Anne-Mette Sølvbjerg Hansen’s PhD study and has been described in further detail in the thesis: Authenticity of aroma components - Enantiomeric separation and compound specific stable isotope analysis (pdf).