Thermal and pH stability of spray-dried encapsulated astaxanthin oleoresin from Haematococcus pluvialis using several encapsulation wall materials

The astaxanthin oleoresin from Haematococcus pluvialis was dispersed in aqueous solutions with soy lecithin as dispersant agent and encapsulated by spray drying using gum arabic (GA) and whey protein (WP) alone or in combination with maltodextrin (MD) or inulin (IN) at 50:50, 25:75 ratios as wall materials. WP alone or combined with GA presented the best encapsulation yield (612-70.1%). The powders exhibited red and yellow colors with h degrees values in the order of GA-WP 50:50 (41.2 degrees) < GA-IN 25:75 (42.4 degrees) < GA-IN 50:50 (43.8 degrees) < GA-WP 25:75 (45.2 degrees) < WP (45.8 degrees) < GA (48.0 degrees) < GA-MD 25:75 (61.1 degrees) < GA-MD 50:50 (70.2 degrees). The degradation kinetics and antioxidant activity followed first-order reaction kinetics. The microcapsules with 100% WP exhibited the highest temperature stability, and their pH stability was in the order 6 > 5 > 4 > 7 > 3 with half-life values of 169.43, 137.38, 93.72, 83.02 and 61.35 h, respectively. The turbidity retention of the microcapsules in aqueous dispersions depended on the pH and the carrier. (C) 2013 Elsevier Ltd. All rights reserved.