Study of Complex Coacervation of Gelatin A and Sodium Alginate for Microencapsulation of Olive Oil

Abstract

Complex coacervation of gelatin A and sodium alginate was carried out to obtain the maximum coacervate yield. Turbidity and coacervate yield (%) measurements were carried out to support the ratio of the two polymers and pH that produced maximum coacervation. The optimum ratio between gelatin A-sodium alginate and pH to form the maximum coacervate complex was found to be 3.5:1 and 3.5–3.8, respectively. Olive oil microencapsulation was carried out at the optimized ratio and pH. Microcapsules were crosslinked by using glutaraldehyde. Scanning electron microscopy studies confirmed the formation of free flowing spherical microcapsules of different sizes. The size of microcapsules increased with the increase in the concentration of the polymer. The encapsulation efficiency and the release rates of olive oil were dependent on the amount of crosslinker, oil loading and polymer concentration. Thermogravimetric study revealed improvement of thermal stability with crosslinking. Fourier Transform Infrared Spectroscopy study showed that there was no significant interaction between olive oil and gelatin-alginate complex.

Keywords:

• Complex coacervation
• microcapsule
• gelatin
• sodium alginate
• crosslinking

Acknowledgments

The research has been sponsored by the University Grants Commission under the UGC Dr. D.S. Kothari Post Doctoral fellowship Scheme. The author (N.D.) is grateful to UGC for financial assistance.