Why Solid-state NMR coffee analysis is the future of your morning brew
Source PublicationSpringer Science and Business Media LLC
Primary AuthorsAisya, Wihadi, Rasool et al.
The Science of Solid-state NMR coffee analysis
Imagine your coffee bean is a locked safe. Traditionally, scientists had to crack it open and dissolve the contents to see what was inside. This early-stage research, currently presented as an abstract, suggests we can peer through the steel using high-powered magnets instead.
Note: This article is based on a preprint. The research has not yet been peer-reviewed and results should be interpreted as preliminary.
Researchers applied Solid-state Nuclear Magnetic Resonance (SS NMR) to Bengkulu Robusta beans. This method is fast and non-destructive, allowing scientists to observe chemical shifts during roasting without ruining the sample. The 2D HETCOR approach confirmed specific proton and carbon correlations, mapping the aliphatic chains present within the bean.
The study measured a significant rise in caffeine signals at 3.2 ppm after roasting. It also identified melanoidins at 4.5 ppm. These are the molecules that give your coffee its deep brown colour. The 13C MAS NMR spectra produced a surprise: the team found kahweol, a compound usually exclusive to Arabica beans.
This finding suggests the sample may have been a Robusta-Arabica blend. It indicates that magnets can spot a counterfeit roast or an undeclared mix. The data also tracked the Maillard reaction by measuring succinate and carboxylic acid peaks at 60.3 ppm and 171.7 ppm.
While these laboratory findings are currently limited to specific Bengkulu Robusta samples, they suggest that SS NMR could help roasters monitor their production with greater insight. It offers a way to verify bean authenticity and quality rapidly. This technique could become a vital tool for the global coffee trade as the research matures.