Microencapsulation of algae oil by complex coacervation of chitosan and modified starch: Characterization and oxidative stability

The formation of complex coacervation using chitosan and octenyl succinic anhydride modified starch (OSA starch) and microencapsulation of algae oil were investigated in this study. The zeta-potential, turbidity and coacervate yield were evaluated as a function of pH and the chitosan- OSA starch mass ratio. The highest coacervate yield was achieved at pH 6.0 with a chitosan to OSA starch ratio of 1:3 (w/w). Isothermal titration calorimetry (ITC) indicated favorable affinity (Ka = 1.51 × 105 M-1) between chitosan and OSA starch. The microcapsules yielded an encapsulation efficiency (EE) in the range of 42.8 ± 0.8%- 93.1 ± 1.2%, the loading capacity ranged between 30.4 ± 2.7% and 58.3 ± 1.3%. Fourier transform infrared spectroscopy (FT-IR) spectra and scanning electron microscopy (SEM) further confirmed the microencapsulation. In comparison with the bulk oil, the microencapsulated algae oil exhibited improved oxidative stability during storage.