A systematic study of key odourants, non-volatile compounds, and antioxidant capacity of cascara (dried Coffea arabica pulp)

Abstract

Derived from the residues of coffee processing (pulp), cascara has been consumed traditionally as a tea-like infusion, in part due to its pleasant flavour and nutritional properties. In this study, the volatile and non-volatile compositions of five cascaras (Coffea arabica) were systematically characterised to understand their organoleptic and antioxidant properties. Using solvent assisted flavour evaporation, 151 volatile compounds were identified by gas chromatography-mass spectrometry. Furthermore, 18 key odourants were elucidated by aroma extract dilution analysis, of which some were common odourants of dried fruits and black tea. Non-volatile compounds, including 7 sugars, 6 organic acids, 3 methylxanthines, and 35 polyphenols were detected and quantified via liquid chromatography techniques. Finally, the volatile and non-volatile compositions of the five cascaras were differentiated through principal component analysis. Therefore, this study expands the current knowledge about cascara and may facilitate further research on its application.