Efficacy of pullulan in emulsification of turmeric oleoresin and its subsequent microencapsulation

Numerous advantages of turmeric oleoresins over ground turmeric are offset by their sensitivity to light, heat, oxygen and alkaline conditions. This can be overcome by microencapsulation. The present work evaluates the efficacy of pullulan to achieve a stable emulsion of turmeric oleoresin and its subsequent microencapsulation. Different ratios of gum arabic and maltodextrin (100:0–0:100) were used to evaluate the appropriate wall material for encapsulation of turmeric oleoresin by spray drying. The emulsions were prepared at 10% loading of turmeric oleoresin, and evaluated for emulsion stability index, particle size and viscosity. The microcapsules prepared by spray drying of these emulsions were evaluated for encapsulation efficiency, encapsulation yield, and stability of volatiles, non-volatiles and total curcumin for six weeks. The efficacy of pullulan was seen from emulsion characteristics, encapsulation efficiency and yield, and t_1/2, the time required for a constituent to reduce to 50% of its initial value.