Quercetin derivatives in roasted Coffea arabica and its popular beverages

This study is focused on quantification of six quercetin derivatives in roasted Coffea arabica L. from different geographical origins and post-harvest processing methods for the first time. Popular beverages (espresso and moka) were also studied. By developing and validating new extraction techniques from roasted coffee and coffee beverages, it was found that Ethiopian roasted coffee exhibited the highest total contents of quercetin derivatives (108.85 ± 10.03 ng/g), with quercetin-3-glucuronide being the most abundant (60.28 ± 5.95 ng/g). Guatemalan and Colombian coffees had high levels of quercetin-3-glucuronide (56.06 ± 5.95 ng/g and 51.14 ± 0.19 ng/g) as well. The study also showed that natural and honey post-harvest processing preserved more quercetin derivatives compared to washed method. Furthermore, espresso extraction yielded higher flavonoids content than moka. This research suggests that the selection of specific combination of coffee origins and post-harvest methods could enhance the intake of flavonoids and potentially promote the health status.