Abstract
Due to the globalization of coffee trade, ensuring the safety and traceability of coffee has become a critical challenge, prompting global authorities to implement new traceability systems to enhance quality identification and protect consumers from fraud. Aroma is a crucial parameter in the evaluation and differentiation of coffees, influenced by factors such as genetics, origin, post harvesting process, roast level, and brewing method. This paper provides, for the first time, a comprehensive overview of the volatile fingerprints of specialty coffees, categorized by their respective quality levels. In particular, this study aimed to evaluate the potential of volatile compounds monitored through Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) as objective, fast, reliable and repeatable tool for tracking the quality and genetic lineage of Arabica specialty coffees. The spectra of volatile organic compounds (VOCs) were acquired from 1132 coffee samples (both specialty and non-specialty) from various varieties, origins, and processing methods. Results clearly indicate that the volatile composition of specialty coffee is predominantly influenced by its genetic lineage. Arabica coffee species belonging to Bourbon, Typica, and Ethiopian landraces showed higher total VOCs emission, while varieties related to Robusta, which are related to the Canephora one, emit less. Finally, by employing a complex network analysis approach based on headspace VOC analysis, it was possible to accurately distinguish between different categories of specialty Arabica coffee. Notably, our analysis shows that the quality of specialty coffee is not linked to the number of VOCs emitted, but rather to the level emission of some pleasant aroma compounds. These findings open new perspectives for the development of aroma profiling techniques and demonstrate the unique aroma release characteristics of specialty coffees.