Sustainable Intensification of Functional Compounds Recovery from Cocoa Bean Shells Using Flash Extraction

Cocoa bean shells (CBS) represent a significant by-product of the transformation of cocoa beans, constituting approximately 15% of the total cocoa bean weight. Recently, interest in exploring the potential of these shells as a sustainable source of functional ingredients for use in cosmetics and nutraceuticals has grown. The present study investigates microwave-assisted subcritical water extraction (MASWE) as a green and fast technique to recover bioactive compounds from CBS. A flash extraction (five minutes) at 170 °C yielded a maximum of 45.78 mg of gallic acid equivalents (GAE) per gram of CBS, which was higher than that obtained using conventional conditions (25.73 mg GAE/g CBS with 50% acetone solution). Additionally, the HPLC profile of the extract from MASWE revealed a significant increase in hydroxybenzoic acids and catechin, compared to the conventional extract. Following the optimization of the extraction process, seven distinct resins were examined to isolate a bioactive-enriched fraction: Sepabeads SP700 was found to be the most effective resin for concentrating such compounds, increasing both methylxanthines and TPC selectivity up to 4.2-fold. This valorization approach, integrating MASWE and downstream optimization, offers an innovative strategy to recover added-value products from CBS in line with green extraction and nutraceutical innovation.