Cocoa bean shell hydrolysates to be used as a basis for formulating a new functional beverage

In this work, for the first time, cocoa bean shell (CBS) has been employed to formulate a fermented functional beverage. To achieve this, hydrothermal hydrolysis of CBS, non-supplemented and supplemented with whey powder, was conducted at pH 4 and 135 °C for 10 min to obtain two different hydrolysates. Both broths were fermented using Lactiplanctibacillus plantarum. Consequently, four beverages were evaluated, i.e., unfermented and non-supplemented, unfermented and supplemented, fermented and non-supplemented and fermented and supplemented. Regarding bioactive compounds, maximum values for antioxidant activity (83.5 μmol TE/L), TPC (1.4 g/L) and methylxanthines (0.4 g/L for theobromine and 0.05 g/L for caffeine) were found after 48 h of fermentation. Notably, sufficient viability of L. plantarum was achieved to consider the beverages probiotic products (>10⁶ CFU/ml). Finally, a sensory analysis of the four beverages was carried out, with the unfermented samples being the best valued beverages, achieving a maximum overall liking score of 2.8 on a 5-point hedonic scale. The results of the present work highlight the great potential of CBS as a substrate to obtain novel functional products.