Baltic herring (Clupea harengus membras) oil encapsulation by spray drying using a rice and whey protein blend as a coating material

Abstract

As popular coating material for encapsulation like milk proteins and maltodextrin do not fully mask unpleasant fish flavors, rice and whey protein blend was tested to aid the use of Baltic herring (BH) oil in functional foods. Particle size and morphology of emulsions (7.5% whey protein, 7.5% rice protein, 15% BH oil and water) produced at pH 3, 6 or 8 with one or two step homogenization and resulting powders were characterized together with fatty acid composition, volatile compounds and oxidative stability. The use of rice and whey proteins lead to stable emulsions with bimodal size distribution and large dispersion (0.05-100 mu m). Emulsion's pH affected powder particle sizes, with pH 3 resulting in powders with biggest particle sizes. Morphology of powders showed spherical shape with porous structure. Emulsions with pH 6.5 produced powders with the highest induction periods (1.59-1.73 h) and low content of volatile compounds.