engleski

Recovery of macrostructural and bioactive constituents from cocoa bean husk and their application in encapsulation purposes

BRIEF INTRODUCTION: In recent years new technological trends in food production have been directed to the biorefinery approach of agro-industrial waste materials, resulting in the production of multitude of valuable products, especially functional ingredients such as biopolymers and bioactive compounds. Compositional analysis of cocoa bean husk (Theobroma cacao L.) conducted in this study revealed this agro-industrial waste material as the predominant source of carbohydrates (64% on a dry matter basis), but also proteins (16% dmb) as the macrostructural components. Additionally, distinguished by a very high content of bioactive compounds, especially polyphenolic antioxidants and methylxanthine theobromine, the potential of utilising these components in the formulation of new added value products focused this study on the recovery of cocoa bean husk functional compounds and their application in the formulation of alginate-based hydrogel particulate delivery systems. MATERIALS AND METHODS: A sequential recovery procedure was developed for obtaining a bioactive extract and carbohydrate and protein isolates from the raw material. Alkaline extraction-isoelectric precipitation at two temperatures (20°C and 70°C) was employed for recovery of the macrostructural fraction, whoose functional properties (solubility, foaming properties, electrical conductivity, fat absorption (FAC) and water holding capacity (WHC), emulsification activity) were characterized. RESULTS: In general, isolates obtained at higher extraction temperature (70°C) were characterized by higher recovery yields (7.9%), lower WHC, higher FAC, higher foaming capacities and stabilities. The recovered macrostructural isolates were used in combination with alginate to formulate particulate delivery systems encapsulating previously obtained bioactive extract. The isolate-reinforced encapsulates were not improved markedly in their physico-chemical properties but augmented the polyphenols retention in the particulate delivery matrix. CONCLUSIONS: The peformed characterization measurements point to expressed binding properties of polyphenols and interactions that those bioactive compounds display with proteins and polysaccharides, which indicates on the potential of utilizing the recovered cocoa bean husk constituents for development of novel, functional delivery systems.

Cocoa bean husk, Encapsulation, Protein isolates, Polysaccharides, Polyphenols

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