Cocoa bean shells (CBSs) are a byproduct of the chocolate production process, representing the external layer of the cocoa bean. CBSs exhibit many interesting chemical and nutritional characteristics resulting in a very rich content of dietary fiber (DF) and antioxidant compounds such as phenolic acids and flavan-3-ols. The DF fraction of CBSs is notably rich in soluble dietary fibers (SDFs), which may be associated with fermentability and prebiotic properties. The objective of this study was the valorization of CBSs through enzymatic treatments, thereby increasing the solubility of DF and potentially augmenting fermentability. CBSs were treated both raw and defatted. Three sets of carbohydrases were used in order to impact the dietary fiber profile. Cellulase, xylanase, pectinase and their combinations were used to perform enzymatic treatments. The application of cellulase, xylanase and a combination of both enzymes proved effective in achieving a high SDF destructuring of the insoluble dietary fiber (IDF) fraction in both defatted and raw CBSs. Notably, the SDF/IDF ratio was significantly elevated in the enzymatically hydrolyzed samples (1.13–1.33) compared to the untreated CBSs (0.33). Furthermore, the various treatments did not affect the antioxidant activity or the content of the main bioactive compounds. These results provide a foundation for new opportunities in the biovalorization of CBSs through green techniques for a range of potential industrial applications in the food and nutraceutical sectors.

Cocoa bean shells (CBSs) represent the external layer of cocoa beans. The shells are removed during the winnowing after the pre-roasting, a processing step of chocolate production; in in the past they were considered a waste. CBSs possess many interesting nutritional characteristics in both macro and micronutrients. CBSs result very rich in dietary fiber and antioxidant compounds such as phenolic acids and flavan-3-ols. Soluble dietary fibers are potentially associated with fermentability and prebiotic activity on human gut microbiota instead antioxidants compounds have been linked with positive effects on human health. Based on these properties, the aim of this study was the valorization of CBSs thorough enzymatic treatments. The shells were treated both raw and defatted; three sets of carbohydrases have been used in order to destructure the fiber profile, potentially enhancing the potential prebiotic activity of CBSs. Cellulase, xylanase and pectinase were used to perform enzymatic treatments. After the enzymatic hydrolisis, both soluble and insoluble fibers fraction were quantified, in parallel with the total phenolic and the total flavonoid contents and the antioxidant activity. Moreover, the HPLC-PDA analysis was carried out for the main compounds of CBSs. The enzymatic treatmens allowed to obtain an enhancement in soluble fibers, for both defatted and raw CBSs, particularly using cellulase, xylanase and their combinations. Finally, a parallel preservation of the antioxidant capacity and the content of the main bioactive compounds after the treatments was observed. These results can be used to exploit the enzymatic treated CBSs to further industrial applications in the food and nutraceutical fields.