An investigation into green coffee press cake as a renewable source of bioactive compounds

Abstract

The residual biomass of coffee, obtained after the oil extraction from coffee beans, called coffee beans residual press cake, has been attracted interest as a source of compounds with antioxidant capacity. This study investigated the effects of ethanolic and methanol‐acetone extracts of green coffee beans (GCB) and its residual press cake (GCC) on the phenolic composition and antioxidant capacity. Antioxidant capacity was assayed through five different methods (total phenolic compounds, •DPPH, ABTS, FRAP and β‐carotene bleaching assay), and the phenolic profile of the samples through High Performance Liquid Cromatography. GCB and GCC enclosed chlorogenic (55.16 and 64.96 mg g−1, respectively) and caffeic (25.07 and 44.37 mg g−1, respectively) acids as the major components, and the cake presented higher antioxidant capacity than the actual green bean. Antioxidant capacity was higher for GCC extracted with methanol and acetone. This study on the evaluation of the effects of the type of solvent on the bioactive compounds from GCB and GCC showed that this by‐product can be a source of new value‐added products, such as phenolic antioxidant adjuncts for food or pharmaceutic processing.