Chitosan-Based Colloidal Delivery Systems as Natural Carriers for Propolis: Physicochemical Characterization and Application in Walnut Sausage

In this study, a chitosan-based colloidal delivery system (CD) was developed as a natural delivery system for phenolic compounds from propolis extracts obtained via accelerated solvent extraction (ASE) and evaluated for improving the functional properties of walnut sausages. Propolis extract was incorporated into a chitosan (C)-based colloidal delivery system formulated with varying concentrations of diacetyl tartaric acid ester of mono- and diglycerides (DATEM) and lecithin (L). The formulation containing 2.5% chitosan, 12% DATEM and propolis, with a particle size of 265.9 nm and a ζ-potential of +40.8 mV, was selected for further characterization and food applications. The phenolic encapsulation of CD depended on the structural characteristics of individual phenolic compounds, with chrysin (70.51%), vanillin (65.12%), and benzoic acid (51.26%) exhibiting the highest encapsulation; CD-treated walnut sausage decreased the lipid oxidation and improved the storage stability of the walnut sausage during storage. These findings indicate that the chitosan-based colloidal delivery system is a promising carrier for improving the encapsulation of propolis phenolics in walnut sausage.