A preliminary evaluation of the effect of processing temperature on coffee roasting degree assessment

The objective of this study was to analyze the volatile profiles of both green and roasted coffee beans, for assessment of roasting degrees under two different processing temperatures. Volatiles extraction and concentration were performed by solid phase micro-extraction (SPME) of the ground coffee headspace and analysis of the volatiles profile was performed by GC–MS. Four SPME fibers were evaluated, with the one that extracted the highest amount of substances (DVB/CAR/PDMS) being selected. Statistical analysis of the data by principal components (PCA/clusters) showed that the volatile components profile provided separation of green and roasted coffees and also separation according to roasting degree and roasting temperature. Results also indicate that color and weight loss measurements alone are not reliable for roasting degree assessment.