Encapsulation of α-Tocopherol by Emulsion Hydrogel Particles, Made of Whey Protein Isolate & Iota-carrageenan Applying Emulsion Templating Method

Abstract

In the present study, hydrogel emulsion particles made by emulsion templating method were used in order to encapsulate a-tocopherol. An oil-in-water-in-oil emulsion was used as mold to make microgel particles. The aim of this study was to investigate the effect of partial replacement of whey protein with iota-carrageenan (0, 0.2 and 0.4 wt%) on emulsion properties, hydrogel particles and release of a-tocopherol. The results showed that the introduction of iota-carrageenan in the formulation increased the apparent viscosity of the simple emulsions, droplet size increased from 2.69 μm in emulsions containing whey protein alone to 2.95 and 2.71 μm in emulsions containing 0.2 and 0.4 of iota-carrageenan. Replacing 0.2 and 0.4% of iota-carrageenan reduced the zeta potential from -43.93 mV to -46.56 and -46.68 mV, respectively. The introduction of iota-carrageenan in the formulation also reduced the particle size and reduced the encapsulation efficiency of a-tocopherol in hydrogel emulsion particles. Addition of iota-carrageenan to the formulation of hydrogel particles reduces the release rate of a-tocopherol in simulated gastric fluid from 30.36% in particles containing whey protein alone to 28.90 and 28.22% in particles containing 0.2 and 0.4% of iota-carrageenan, respectively. The results of this study showed that replacing part of the whey protein with iota-carrageenan improved the release and delivery of the lipophilic bioactive compound to the intestine in hydrogel emulsion particles.

Keywords

• micro-encapsulation
• microgel
• protein-polysaccharide mixture
• vitamin e