Circular bioeconomy for cocoa by-product industry: Development of whey protein-cocoa bean shell concentrate particles obtained by spray-drying and freeze-drying for commercial applications

Abstract

The revalorization of cocoa (Theobroma cacao L.) processing wastes, mainly cocoa bean shells, involve some strategies to obtaining maximum benefits of the bioactive compounds and reducing the amounts of waste through its use in new products in the context of the circular bioeconomy. Cocoa bean shells were used to obtain a phenol concentrated and formulate a matrix with isolated whey protein particles. Spray-drying and freeze-drying were used to pulverize the samples. The results indicated that both methods improve the stability of the compounds and the antioxidant capacity of the phenol-protein matrix powder, with significative differences (p<0.05), being the spray-dried matrix the sample with the higher amounts of the total polyphenols. Different amounts of the phenol-protein matrix powder obtained by spray-drying and freeze-drying were used for the formulation of the cookies, and significant differences (p<0.05) were observed in the physicochemical characteristics, proximal analysis, bioactive compounds and antioxidant capacity, among the formulations. The cookies with the highest protein content were those to which a 12.5 and 20% of the matrix obtained by freeze-drying was added. While the cookies with the highest content of total phenolic compounds (4118.72±27.43) and highest values of antioxidant capacity (521.33±33.68 mmol Trolox/g and 4249.10±51.24 FeSO4/g, by DPPH and FRAP assay, respectively) were those that were added with 20% matrix obtained by spray drying. Likewise, the discriminating variables identified between the cookie formulations were the results of polyphenols, DPPH, FRAP and proteins. This indicate that the addition of a phenol-protein matrix powder as an ingredient in cookies, as comercial application, exhibited an increasing of proteins and polyphenols content, including higher values of antioxidant capacity, in the final product.