Electrosprayed gelatin submicroparticles as edible carriers for the encapsulation of polyphenols of interest in functional foods

Abstract

In this work, the potential of the electrospraying technique to obtain food-grade gelatin capsules in the submicron range for sensitive bioactive protection was explored, studying the influence of the protein concentration on the size and morphology of the obtained particles. Gelatin was selected as encapsulating material because, being commonly used as a food ingredient, it possesses unique gelation properties and is commercially available at a low cost. The electrosprayed matrices were used to encapsulate a model antioxidant molecule, (−)-epigallocatechin gallate (EGCG). Very high encapsulation efficiencies, close to 100%, were achieved, and the antioxidant activity of the bioactive was fully retained upon encapsulation. The EGCG release profiles showed a delayed release of the encapsulated antioxidant in aqueous solutions. Furthermore, while free EGCG in PBS lost a 30% of their antioxidant activity being completely degraded in 100 h, encapsulated EGCG retained its whole antioxidant activity within this time period.