Evaluation of a novel self-emulsifiable dodecenyl succinylated agarose in microencapsulation of docosahexaenoic acid (DHA) through spray-chilling process

Agarose is a potential wall material for encapsulation owing to its high oxygen barrier, but its high hydrophilia and low emulsifying activity restrict its application as a wall material for hydrophobic actives. The aim of this study was to evaluate the potential of a novel self-emulsifiable dodecenyl succinic anhydride-esterified agarose (DSAG) as a single emulsifier and a wall material to encapsulate DHA. Results showed that DSAG was suitable for DHA encapsulation via spray-chilling process, and DHA microcapsules with different sizes (100-400 μm) could be easily prepared by controlling the spray pressure. The encapsulation efficiency of DSAG reached as high as 65-85%. The wet microcapsules were nearly spherical but they showed cavities or wrinkles on the surface after freeze drying. The DHA microcapsules, whether dry or wet or of different sizes, showed excellent oxidative stability, and exhibited good release characteristics under the simulated gastric and intestinal fluid conditions.

Keywords: Agarose sodium dodecenyl succinate; Docosahexaenoic acid microencapsulation; Spray-chilling process.