Yeast Cell Microcapsules as a Novel Carrier for Cholecalciferol Encapsulation: Development, Characterization and Release Properties

In this study Saccharomyces cerevisiae yeast cells was used as a novel vehicle for encapsulation of vitamin D-3. The effects of initial cholecalciferol concentration (100,000 and 500,000IU/g yeast), yeast cell pretreatment (plasmolysis with NaCl) and drying method (spray or freeze drying) on microcapsules properties were investigated. It was found that the vitamin concentration and drying method had significant influence on encapsulation efficiency (EE) and size of yeast microcapsules. Furthermore, EE values were more increased by the plasmolysis treatment. The highest EE was obtained for plasmolysed and spray dried yeast cells prepared using initial cholecalciferol concentration of 2.5mg per gram of yeast cells (76.10 +/- 6.92%). The values of mean particle size were 3.43-7.91m. The presence of cholecalciferol in yeast microcapsules was confirmed by X-ray diffraction (XRD) and Fourier transform-infrared (FT-IR) analyses. The in vitro cholecalciferol release from yeast microcapsules in phosphate buffer saline solution (PBS) followed a controlled release manner consistent with a Fickian diffusion mechanism. In addition, the release studies in simulated gastrointestinal tract showed sustained release of cholecalciferol in the stomach condition and significant release in intestinal medium.