Improved encapsulation efficiency and storage stability of spray dried microencapsulated lutein with carbohydrates combinations as encapsulating material

Lutein is utilized in food industry as a natural colorant or functional ingredient. Nevertheless, its application is limited by its chemical instability. The aim of this research was to develop and optimize lutein microencapsulated powders (LMPs) by spray drying to enhance storage stability of lutein. In formulation screening, LMPs, with inulin and modified starch as combined encapsulating materials (EMs), exhibited maximum encapsulation efficiency (EE) of 80.0 +/- 0.6% and retention value (RV) of 87.9 +/- 0.4%. The preparation process was further optimized by Box-Behnken design with EMs concentration, proportion of inulin and modified starch as EMs and inlet-drying temperature as crucial factors. EE, RV and product yield (PY) as critical quality attributes were considered. The micro-structural characterizations of six experimental LMPs were observed by scanning electron microscopy and used to describe the effects of the three crucial factors on morphological characterization of LMPs. Subsequently, the optimal condition for preparing LMPs was identified by response surface analysis. The actual EE, RV and PY values of the optimal LMPs were measured to be 85.0 +/- 0.5, 90.1 +/- 0.4 and 91.2 +/- 0.7%, respectively. In the stability assessment, temperature degradation kinetics of microencapsulated lutein was analyzed. The chemical stability of the optimal LMPs significantly increased after exposure to four different temperatures.