Screening Your Coffee for Furan with GC-VUV

Coffee is a beverage that people all over the world consume.  Whether you like dark, medium, or light blends, it all comes down to the roast.  Roasting coffee transforms green coffee beans into the traditional black beans we see at coffee shops and stores.  From there, the coffee beans are ground and hot water is added to extract the vibrant compounds, creating that lovely cup of coffee we all enjoy.

It’s not surprising coffee is an active area of research in food chemistry.  The aroma of freshly roasted coffee easily consists of more than 1,000 chemical compounds. So, what compounds are important and why?  Obviously, studies on health effects of coffee compounds are of high priority, especially for furan.  Furan is an aromatic compound that is toxic, a pollutant, and potentially carcinogenic for humans.  It’s generated during coffee bean roasting and can linger in the beans and ground coffee.  Interestingly, coffees made from expresso and coffee-capsule machines contain more furan than traditional drip coffee makers.   However, the levels are still considered safe for consumption.

Out of curiosity, I decided to screen ground coffee with static headspace – gas chromatography – vacuum ultraviolet spectroscopy (HS-GC-VUV) for furan.  Figure 1 shows a HS-GC-VUV chromatogram, rich with volatile organic compounds. Furan is present along with additional furan compounds such as 2-methylfuran and 2,5-dimethylfuran. Figure 2 shows the VUV absorbance spectra of the furan compounds, which are distinct from one another, and from other compounds in coffee, mainly due to strong absorbance features in the 180-240 nm wavelength range.

Figure 1. HS-GC-VUV chromatogram of coffee grounds, showing a subset of volatile organic peaks identified by their absorbance spectra.

Figure 2. Vacuum ultraviolet absorbance spectra of Furan, 2-Methylfuran, and 2,5-Dimethylfuran, compounds that occur in ground coffee. Their spectra are are easily discernible from one another, while also having similar features that help class them as furans.

The moral of this blog post is that GC-VUV can identify furan and a variety of other compounds present in ground coffee. So, even if you aren’t interested in furan, perhaps there are other compounds of interest that GC-VUV could detect! I hope you enjoyed this quick post and learned a thing or two. I know I did!