Purple cocoa beans release oil alongside a phenolic-rich fraction
A laboratory study recovered cocoa butter and a phenolic-rich liquid from under-fermented purple beans in one processing step. A selected solvent mixture recovered more oil than ethanol extraction, while mechanical pressing recovered more still. The peer-reviewed work examined combined recovery from a Thai cocoa batch and found that different mixtures favoured different products.
Science··Evening
One treatment yielded oil and a separate liquid fraction
The experiment targeted purple cocoa beans whose incomplete fermentation leaves them unsuitable for standard chocolate production. Beans came from farmers in Thailand’s Nan province; suppliers classified about half the batch as under-fermented. Researchers investigated mixtures called natural deep eutectic solvents, seeking both a released oil phase and an aqueous fraction containing phenolic compounds. The work was a peer-reviewed laboratory study.[1]
Oil recovery reached a measured share of the extractable total
The selected mixture of choline chloride and lactic acid recovered 63.02 per cent of the oil defined as extractable by the study’s reference method. That was above ethanol extraction and below screw pressing. Pressing involved whole beans retaining moisture, while the solvent methods used dried, ground beans.[1]
Mixtures that performed well for oil did not necessarily lead the phenolic measurements. The combined process left a phenolic-rich aqueous fraction alongside the recovered fat. Chemical tests measured antioxidant activity in that fraction; these were measurements of the extracts in the laboratory.[1]
Cell-wall changes accompanied oil release
Microscopy and composition measurements indicated altered plant cell walls after treatment. The authors describe this alteration as a possible contributor to oil release. They did not directly quantify solvent remaining in the recovered oil. The study’s findings therefore concern combined extraction from this cocoa batch, with the contribution of cell-wall disruption still expressed as a proposed mechanism.[1]
