Chromatographic Profiling of Artisanal Chocolates: Volatile Composition and Methylxanthines as Markers of Cocoa...

The increasing demand for artisanal chocolates highlights the importance of reliable analytical strategies for quality assurance and product authentication. In this study, 45 Brazilian artisanal chocolates (36%-100% cocoa) were characterized by integrated chromatographic and chemometric analyses. Seventeen representative samples were evaluated for volatile compounds using HS-SPME/GC-MS, and methylxanthines were quantified by HPLC-DAD after optimization of an ultrasound-assisted liquid-liquid extraction method. The procedure achieved recoveries of 92% ± 10% for theobromine and 95% ± 3% for caffeine, meeting international validation criteria. In total, 72 volatile compounds were identified, mainly acids, esters, pyrazines, and aldehydes, associated with descriptors such as roasted, nutty, floral, and fruity. Theobromine (1.158-21.033 g kg^-1) and caffeine (0.058-1.997 g kg^-1) concentrations showed strong positive correlations with declared cocoa content. Principal component analysis revealed clear separation between low- and high-cocoa chocolates, with theobromine as the main discriminating variable. The results demonstrate that methylxanthines are robust chemical markers for chocolate authentication and classification, and that the combined use of GC-MS, HPLC, and multivariate analysis provides a reliable workflow for quality control, traceability, and prevention of commercial fraud in the chocolate industry. PRACTICAL APPLICATIONS: The combined use of chromatographic and chemometric approaches demonstrated in this study can be applied in food laboratories to improve the authentication, classification, and quality monitoring of chocolates. The optimized analytical methods for volatile and methylxanthine profiling are suitable for both artisanal and industrial products, supporting standardization, traceability, and prevention of commercial fraud in the chocolate industry.