Effects of coating layers chitosan/pectin on lipid stability and in vitro digestion of astaxanthin-loaded multilayer emulsions.

Astaxanthin (Ax), a hydrophobic carotenoid from marine animals and microalgae, is claimed to exhibit various beneficial biological activities. In this study, quillaja saponin, chitosan and pectin were employed to formulate Ax-loaded primary, secondary, and tertiary multilayer emulsions using a layer-by-layer electrostatic deposition technique. The effects of the coating layers on the antioxidation of lipid, in vitro digestion properties, and Ax bioaccessibility were investigated. The results showed that the coating layers improved the lipid stability during the storage process and gastrointestinal digestion of lipid droplets effectively. In particular, the release of free fatty acids was reduced by nearly 20% in tertiary multilayer emulsions coated by chitosan and pectin. Meanwhile, the coating layers postponed the release of Ax effectively. The multilayer emulsions developed in this study could be used to load, protect, and deliver astaxanthin, which may contribute to the development of more effective functional foods, supplements, and pharmaceutical products. • Chitosan and pectin as the outer layer of astaxanthin-loaded lipid droplets were formed by electrostatic deposition. • The oxidative stability of lipid was improved effectively in multilayer emulsions. • Chitosan/pectin coatings reduced the lipid digestibility in emulsions. • Chitosan/pectin coatings prolonged the release of astaxanthin effectively. [ABSTRACT FROM AUTHOR]