Effect of roasting on chemical composition of coffee.

Roasting coffee involves complex chemical reactions that shape the sensory and chemical traits of the final product. This study examined how different roasting profiles influence coffee color, using the CIELAB system, and chemical composition, analyzing volatile and non-volatile compounds through chromatography techniques. Principal component analysis revealed distinct clusters based on roasting intensity, identifying specific chemical markers. Non-volatile compounds, such as 2-furfural, 5-hydroxymethylfurfural, chlorogenic acids, caffeine, and 3,4-hydroxybenzoic acid, were more abundant in light to medium roasts but degraded significantly in dark roasts, except caffeine. Volatile compounds like acetone and 3-methyl-butanol varied notably with roasting, while diacetyl emerged as a roasting degree marker. CIELAB values correlated with roasting intensity, aiding in quality control. These findings highlight the potential of color-based monitoring, chemometric techniques, and optimized roasting to enhance coffee quality by linking chemical composition to sensory properties.