Molecular Screening of the Volatilome of Cocoa Intermediates in Industrial Chocolate Production via Gas Chromatography-Mass Spectrometry (GC-MS) and Fast Enantioselective (Fast ES)-GC-MS

The quality of cocoa, the key ingredient in chocolate production, is shaped by a complex interaction of genetic, environmental, and post-harvest factors, including fermentation, drying, and roasting. These processes influence the formation of both volatile and non-volatile compounds that define the sensory characteristics of cocoa. However, the presence of off-flavors—often originating from suboptimal processing or environmental contamination—represents a critical challenge for the chocolate industry, impacting product consistency and consumer acceptance. Traditionally, cocoa quality assessment has relied on sensory analysis performed by trained panels, a method that, while effective, is both time-consuming and resource-intensive. The increasing demand for faster, standardized quality control methods has driven research toward the identification of chemical markers that can serve as objective indicators of cocoa quality. This thesis explores the volatilome of high-grade cocoa intermediates using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and fast enantioselective GC-MS (Fast ES-GC-MS) coupled with chemometrics and statistical tools. The study aims to identify volatile organic compounds (VOCs), including chiral molecules, associated with off-flavors commonly encountered in industrial cocoa production. Although the approach enabled a detailed characterization of the volatile fraction, including the exploration of its chiral composition, and provided insights into the aroma profiles of cocoa liquors, the identification of reliable markers able to significantly distinguish defected samples has proven to be more complex than expected. However, this work helped to identify fermentation as a critical step potentially linked to the off-flavors development. This finding was promptly communicated to the industrial partner, who has since implemented corrective actions in the fermentation process. Preliminary results suggest that these interventions are already leading to improvements, although further monitoring will be necessary to confirm this positive trend. In conclusion, while definitive chemical markers have not yet been established, due to some limitations related to the number of samples representing the variability of the off flavors perceived, this research has provided valuable insights, including the role of chiral analysis, and laid a solid foundation for future advancements, supporting the cocoa industry in its commitment to guaranteeing high product quality.