Profiling volatile compounds from Mucuna beans by solid phase microextraction and gas chromatography-high resolution time of flight mass spectrometry

Four solid phase microextraction (SPME) fibres, polydimethylsiloxane (PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB), polyacrylate (PA), and carboxen/polydimethylsiloxane (CAR/PDMS), were evaluated for profiling of volatile compounds during cooking of Mucuna pruriens beans. A gas chromatograph coupled to a high resolution time of flight mass spectrometer system was employed for separation, detection and identification of the volatile compounds. For the first time we report a total of 26 compounds, mostly alkyl benzenes and polycyclic compounds, identified in black, white, black–white, and yellow green Mucuna beans during head space sampling employing a CAR/PDMS fibre with subsequent detection with high resolution mass spectrometry. The number of volatile compounds sampled, most notably alkylbenzenes, decreased with each hour of boiling and discarding of water extracts. As the beans approached being fully cooked, benzoic acid 2-hydroxy methyl ester was the most dominant compound in all the four types of beans. These results are a first step towards addressing some of the occupational exposure associated with cooking Mucuna beans by rural communities.