Microencapsulation of fish oil by casein-pectin complexes and gum arabic microparticles: oxidative stabilisation

Abstract

This study was aimed to microencapsulate fish oil (FO) in two biocompatible polymeric blends: gum arabic (GA)-maltodextrin (MD) and casein-pectin (CP)-MD. GA-MD microparticles and CP-MD microparticles were produced by spray-drying and complex coacervation and spray-drying, respectively. Encapsulation efficiency, particle size, moisture content, oxidative stability, and morphological properties were analysed. Encapsulation efficiencies of 51.2-56.8% (w/v) for GA and 64.7-67.9% (w/v) for CP preparations were found. GA particle sizes varied from 2 to 100 μm and from 2 to 120 μm for CP microparticles. Spherical forms with depressions in the topography of both systems were evidenced by scanning electron microscopy. Confocal microscopy evidenced surface oil on GA microparticles, corroborating encapsulation efficiency. CP was more efficient than GA to reduce oxidation, with maximum peroxide values (PVs) of 17.40 mmol/kg oil after 28 d at 40 °C/75% relative humidity (RH). Thus, CP is a promising biopolymeric blend for encapsulation of FO that provides protection against lipid oxidation.

Keywords: Microencapsulation; casein; complex coacervation; fish oil; gum arabic; maltodextrin; omega-3; pectin; spray-drying.