Is There Manure in Your Cookies? Chromatography Investigates

As you settle down to read this article perhaps you are eating a chocolate-chip cookie, or maybe enjoying a vanilla latte with a vanilla scented candle to help you feel relaxed and refreshed. In terms of flavour and scent, vanilla is one of the most widely used ingredients — but how would you feel if the vanilla flavour in your latte was made from manure? Let’s take a closer look at this exotic ingredient and find its origins.

What is Vanilla?

Vanilla comes from the pods or beans of an orchid that is native to Mexico. The Meso-Americans used vanilla in drinks and as a medicine — and it was introduced as a flavouring into Europe by the Conquistadores in the sixteenth century: although it would be another 300 years until vanilla was successfully cultivated outside Mexico. The majority of vanilla cultivated today comes from Madagascar and Réunion.

The cultivation, harvesting and production of natural vanilla is a very labour intensive process. The orchids have to be hand pollinated, if they are grown outside of Mexico, and the fruits of the orchids have to be picked by hand. This time consuming process, coupled with the fact that demand for natural vanilla far outstrips supply, means that the price of natural vanilla is very high and there is a market for cheaper alternative ‘vanilla’ supplies. But what is it that gives vanilla its flavour and scent?

Artificial Vanilla

Over 250 compounds have been identified in vanilla beans, with the most abundant being a compound called 4-hydroxy-3-methoxybenzaldehyde or vanillin. Vanillin was identified as the key flavour molecule in vanilla in 1874 — and has been synthesized ever since.

There are two main routes to vanillin: crude oil or lignin. Crude oil is the cheapest readily available chemical feedstock for many products — not just petrochemicals — and provides most of the vanillin used today. But producers are always searching for other methods to produce goods which are more natural or more environmentally friendly, even if it is only to market a product as ‘natural’. And one way to manufacture vanillin is from lignin — a polymer found in the cell walls of many plants.

Natural or Artificial — Does it Matter?

Natural vanilla, with its complex combination of molecules and difficulty is meeting demand, is over 200 times more expensive than vanillin. So it has to be carefully regulated so consumers are not deceived. Subsequently, analytical methods for natural vanilla are vital — and with so many compounds in vanilla it usually requires both HPLC and GC methods to fully characterize natural vanilla as discussed here. Detection of food adulteration in general is an important task for chromatographic methods as discussed in this article: LC-MS/MS Analysis of Emerging Food Contaminants - Quantitation and Identification of Dicyandiamide in Milk and Other Protein-Rich Foods.

Cow Poo Vanillin?

While it is unlikely that your biscuit contains vanillin essence from manure — it is possible to make vanillin from manure, as manure contains lignin. One intrepid researcher even won an Ig Nobel Prize in 2007 for carrying out the research. Enjoy you cookie.

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