Microencapsulation of oils using sodium alginate

The feasibility of encapsulating wheatgerm oil and evening primrose oil usi ng sodium alginate by the emulsification method was explored in this study. It is based on the chemical reaction between the water-soluble sodium algi nate and polyvalent cation, calcium, to form the water-insoluble alginate. The factors investigated were the physical appearance of the microspheres, the amount of oil that could bu encapsulated, the flow property, size distr ibution and mean size of the microspheres produced. Encapsulation efficienc y and oil content of wheatgerm oil increased with an increase in oil load. The mean size of the microspheres increased sharply at a high oil load of 2 50% w/w. Photographs of microspheres taken showed that the microspheres wer e larger, spherical and had more vesicles within, as oil load increased. En capsulation efficiency of evening primrose oil microspheres was similar to wheatgerm oil microspheres at the respective oil loads of 50, 250 and 350% w/w. The emulsification method developed was successfully applied to wheatg erm oil, a fixed oil, with a maximum encapsulation efficiency of similar to 88%. It was satisfactory for evening primrose oil, which also belongs to t he family of fixed oils.