Microbeads of Sodium Caseinate and κ-Carrageenan as a β-Carotene Carrier in Aqueous Systems

Abstract

β-Carotene was encapsulated in microbeads formed by ionotropic gelation of multilayered emulsions containing sodium caseinate (Na-CAS) and κ-carrageenan at pH 7 and 3.5. The influence of κ-carrageenan concentration on the morphology of microbeads was studied, as well as the effect of pH on the encapsulation efficiency and rheological properties of microbead suspensions. Most of the microbeads showed monomodal size distribution with a mean particle diameter between 25.3 and 176.1 μm. Microbead morphology was influenced by the κ-carrageenan concentration, as microbeads tended to be larger and more spherical at higher κ-carrageenan concentrations. On the other hand, microbeads were slightly affected by pH, showing similar results for encapsulation efficiency and rheological properties of microbead suspensions in salt solution. The encapsulation efficiency was higher than 60% at both pH values. In addition, rheological measurements indicated that the incorporation of microbeads exerted a slight influence on the viscosity of aqueous solutions, mainly up to the 40% volume fraction. Therefore, these microbeads are promising systems for β-carotene vehiculation in food products without compromising their texture.