Effect of different cross-linking agents on encapsulation of Olive Oil
Volume Title: 1
faculty of chemical engineering, Tarbiat modares university
Most edible oils in spite of all proven health benefits are chemically unstable and sensitive to oxygen, light, moisture, and temperature. Hence, microencapsulation of active ingredients and their delivery needs to be employed to stabilize the oil in order to fix the problem. On the other hand, lipophilic drugs could not be encapsulated with water-soluble polymers as shell materials. To overcome this problem, olive oil which contains essential vitamins, fatty acids, and other natural nutrients, is used as a solvent of these hydrophobic drugs.
The present study aims at synthesizing gelatin A–sodium alginate complex coacervates and encapsulation of olive oil in the polymer system. Optimization of different reaction parameters such as pH and ratio between the polymers and cross-linker concentration was carried out to attain higher product yield. The optimum ratio between gelatin and alginate and pH value in this study was set to 3.5 and 3.6, respectively. Microcapsules were crosslinked by glutaraldehyde and sodium tripolyphosphate (TPP). Optical microscopy studies proved the formation of spherical microcapsules of different sizes. It was observed that the effect of using TPP as a crosslinker was acceptable whereas increasing its amount in the case of a constant amount of polymer and oil caused the interruption of the electrostatic attraction between proteins and polysaccharides. Therefore substitution of TPP by glutaraldehyde was studied and led to a desirable result. The optical microscopy analysis showed that the number of microcapsules increased by using glutaraldehyde as the cross-linker.