Colonic fermentation of enzymatically treated cocoa bean shells (CBSs) and short chain fatty acids (SCFAs) production.

Cocoa bean shells (CBSs) are a by-product of the cocoa production chain characterized by a substantial dietary fiber (DF) content. The aim of this work was the evaluation of the prebiotic activity of DF from raw CBSs as well as defatted and dephenolized CBSs (polyphenols in their free form) treated with different enzymes mixtures to increase the fermentable fiber portion. Fermentability was tested through an in vitro model of colon fermentation using microbiota selectively adapted to more proximal and most distal compartments of the colon. Results showed a significant amount of short chain fatty acids (SCFAs) produced, particularly acetate, from fermentation of the lipid- and polyphenols-free CBS treated with the cellulase mixture. In both colonic regions, this sample boosted the production of SCFAs, suggesting the potential usefulness of this enzyme-driven processing to improve the prebiotic effect of CBS. Despite these findings, there was not a change in the DF content of the enzymatically treated samples, especially regarding the soluble dietary fiber (SDF) fraction. This outcome suggests that a structural change may have occurred in the fiber fraction increasing its fermentability. These outcomes open a new scenario in the bio-valorization of CBSs, in accordance with the concept of circular economy.