Author(s): ROSA, J. S. da; FREITAS-SILVA, O.; ROUWS, J. R. C.; MOREIRA, I. G. da S.; NOVAES, F. J. M.; AZEVEDO, D. de A.; SCHWAB, N.; GODOY, R. L. de O.; EBERLIN, M. N.; REZENDE, C. M. de

Summary: Coffee roasting needs precise control and innovative techniques that are economically viable to monitor and improve its consistency. In this study, mass spectrometry was used as a tool to screen chemical markers that appear on the surface of coffee beans (whole bean) along the roasting process. A non-target and non-volatile approach was used with an ambient technique (EASI) coupled to a single quadrupole mass analyzer to monitor roasting chemical changes in the coffee bean. Green (raw), soft, medium, dark and very dark roasted coffee beans showed a decrease in ions in the range of m/z 500–600, whereas an increase in abundance in the m/z 800–900 range was clearly observed in the most roasted coffees. A multivariate approach through PCA separated the different roasts in 70% of the variance using PC1 and PC2. The major ions in the range of m/z 500–600 were characterized by ESI-MS and also HPLC-fluorescence as the N-alkanoyltryptamides, surface constituents of coffee wax layer which are almost fully degraded in darker roasts. The ions in the range of m/z 800–900 were characterized as di-and triacylglicerols and its increase during the roasting process was systematically observed. For these classes of chemical markers of the roasting process, ESI-MS showed also the sodium and potassium adducts with good relative abundances.

Publication year: 2016

Types of publication: Journal article

Unit: Embrapa Food Technology

Keywords: Café, Café arábica, Diacylglycerols, Espectrometria, Espectrometria de massa, Fluorescence, Food technology, High resolution, Mass spectrometry, Roast consistency, Roasting, Tecnologia de Alimento, Torrefação, Triacylglycerols, Tryptamides