Effect of ultrasound homogenisation on the stability of curcumin microencapsulated by spray-drying

Microencapsulated curcumin (MEC) that has been by spray-dried has the potential to improve curcumin stability during storage. In the present work, curcumin was encapsulated using soy lecithin and gum Arabic, and different ultrasound energy inputs (UE) for emulsion homogenisation were applied before spray-drying. The microencapsulation yield (MY), microencapsulation efficiency (ME), solubility, powder morphology, and curcumin degradation in the accelerated test were determined. The UE at 70 kJ/kg caused a 2.2-fold increase in the ME of the powder as compared to the control sample. Furthermore, increasing UE from 70 to 175 kJ/kg led to a decrease in particle size, MY, and ME by 32, 15, and 8.9%, respectively. The stability of MEC under different pH conditions was in the order of pH 2 > 7 > 9. Furthermore, MEC showed an improvement in curcumin stability after 30 days of light exposure at 70°C. In general, a lower UE energy showed better performance in terms of curcumin protection and stable morphology of the MEC powder. However, higher UE energy could create smaller particles, and increase product solubility.