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Agilent 5975 Gas Chromatograph Analyzes Vegemite Yeast Extract

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I know this is a cliche, but either you love it or you hate it. We’re talking about Vegemite. Actually, I’ve never tasted Vegemite, but I love to eat Marmite, a British and South African almost-clone of the Australian Vegemite. The rest of my family hates it. How can you kill a piece of toast with that extremely salty, hard-to-smear, strong smelling stuff, they ask?! In answer, I tell them that the trick is to spread a generous helping of butter on your toast, followed by a thin layer of Marmite. (If you’re avoiding either fat or salt, forget about it.)

But there is no need to convert the converted and I doubt I’ll be able to sway those diehard Marmite/Vegemite objectors.

I have to “import” Marmite from South Africa, where it is kosher. I hope my cousin does not have to pay for the extra weight of her luggage when she brings me my little jars of Marmite, but the good news is that it lasts FOREVER, so she does not have to satisfy my yeast extract fix too often.

Here are two of my current jars of Marmite.


Marmite in my kitchen.









So where does Agilent come into this culinary discussion? Well, I don’t know if the recipe for Vegemite has been as closely guarded a secret as the recipe for Coca Cola, but Renée Webster, an Australian pursuing her doctorate, has analyzed the contents of Vegemite to find the distinct chemical compounds that produce the unique odor of the much-loved (or much-rejected) yeast extract. The Agilent 5975 gas chromatograph played a major role in the Vegemite analysis by breaking up this smelly (but delicious) mass that smells distinctly of – well – Vegemite – into more than 35 compounds that smell of everyday items such as flowers, wine, and leather, and which seem to have no connection to the smell of the yeast extract itself. I’m not sure if I really needed to know what Vegemite (and possibly Marmite) is composed of. You would not normally catch me spreading anything that smells of wax – or rancid fat (yes, rancid fat really is one of the detected odors) – or sweat – on my toast!

Renée Webster conducted her analysis in three stages:

  1. Sampling: Using a kitchen knife, a Solid Phase Microextraction (SPME) sampler, and a lab oven. I wonder if she regrets sacrificing to science the sample of Vegemite she needed for her experiment – never to be spread on a piece of toast!
  2. Separation: Using an Agilent 5975 GC/MSD (gas chromatograph with mass spectrometer) to separate the Vegemite compound into its multiple chemical components for individual analysis. The 5975 is built with 7890 GC technology. The gas chromatograph is responsible for the separation part of the process.
  3. Analysis: Using the mass spectrometer that, together with the included software, analyzes the detected chemicals. Hmm, couldn’t she simply use her olfactory system, that is, her nose, instead of the mass spec? Well, that might not be ideal if you want exact measurements, percentages, and specific odor descriptions.

According to the article, Agilent Helps Uncover Vegemite Mystique, on the Agilent News Hub, the GC performs the separation, and the mass spec does all the detection work. I’m guessing that with over 35 compounds and odors to detect, the 5975 GC/MSD is ideal because it allows for quick column changing; thus speeding up the detection and analysis process.

Here are a few of the top chemicals that were found in Vegemite, including their accompanying odors.

Vegemite Compound Analysis (Top three by percentage)

Percentage of TotalChemical CompoundAssociated Odor
43.8ethyl decanoatefruit, oil, sweet, wax
16.6ethyl trans-4-decenoatewax, leather, pear
12.5octanoic acid, ethyl esterfruity, fatty, floral, green, menthol, anise

To see the complete results of the separations and each component’s odor, you can read the Guardian’s Australia FoodBlog on the Vegemite analysis. As well, for details on the process Renée used to conduct her analysis, view her own blog.

If you are now inspired by the 5975’s work on Vegemite, take a look at the list of 5975’s currently available on Used-Line.

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