An Approach to Value Cocoa Bean By-Product Based on Subcritical Water Extraction and Spray Drying Using Different Carriers

The aim of this study was to establish an efficient, sustainable technological procedure for valorization of food by-product, that is, cocoa bean shells (CBSs). The properties and stability of CBS extracts obtained by spray drying process with maltodextrin (MD) and whey protein (WP) as carrier agents were evaluated. For this purpose, phytochemicals of CBSs were extracted by subcritical water extraction. Physico-chemical properties, total phenolic (TP) and total flavonoid (TF) contents of the encapsulated extracts were determined in order to verify the efficiency of spray drying. Additional analyses for phytochemical characterization of the obtained powders were also performed. The efficiency of microencapsulation process was characterized by product recoveries higher than 58%. Both coating materials significantly influenced the encapsulation of phytochemicals in terms of rehydration, water solubility index and water absorption index, with WP being at an advantage. The best results for TP and TF contents were achieved when CBSs were encapsulated using WP (37.68 mg GAE/g and 7.66 mg CE/g, respectively). Microencapsulation using WP yielded higher content of gallic acid, caffeine, and theobromine than those with MD. According to the results, the formulation using 50% WP provided a better preservation of polyphenols compared to 50% MD. Therefore, spray drying with WP can be used as a method of choice for obtaining high quality CBS powders.