Effect of Wall Material and Inlet Drying Temperature on Microencapsulation and Oxidative Stability of Pomegranate Seed Oil Using Spray Drying.

Abstract

Pomegranate seed oil is a highly unsaturated fatty acid and liable to be oxidized; hence, oil was encapsulated to protect its bioactive materials and increase shelf life with the most common spray drying technique. Whey protein (WP) alone and in combination with Maltodextrin (MD) in the ratio 1:4 weight was utilized. Feed emulsion, droplet size, encapsulation efficiency (EE), moisture, bulk density, powder morphology, particle size, hygroscopicity, and solubility were also analyzed. The spray drying conditions were applied: inlet temperature 125 to 150°C and outlet 60 to 67°C, airflow rate 40-42 m3/mint, feed rate 5.2 g/m, and pump rate 40%. The shape of particles was spherical and round with dents on their surface. After encapsulation, the oxidative stability was monitored at 60°C for 15 days (8 h daily). The smaller droplet size of the emulsion was obtained at 35% total solid contents. WP alone showed better EE (90%) and oxidative stability than the combination of WP and MD as wall materials.