Supramolecular solvent extraction of bioactives from coffee cherry pulp

Abstract

The potential of supramolecular solvents (SUPRAS) is investigated for the extraction of bioactive compounds from coffee cherry pulp, one of the major by-products generated in the coffee industry. SUPRAS made up of hexagonal inverted aggregates of octanoic acid in ethanol:water mixtures provided good extraction yields for bioactives (3.6 ± 0.3 mg caffeine g−1 and 0.9 ± 0.1 mg protocatechuic acid g−1) at a low solvent:sample ratio of 4:1 v/w and under mild operations conditions (5 min extraction at room temperature). SUPRAS-based extraction was optimized and extracts were analyzed to identify the main phenolic and alkaloid compounds. A variety of bioactives were present and extracts showed high antioxidant capacity by different assays (45% for DPPH and 91% for ABTS). Extraction efficiencies with SUPRAS were clearly superior than those obtained with organic solvents commonly used for valorization of coffee residues.