Co-encapsulation of saffron petal and Stachys schtschegleevii extracts via complex coacervation and graphene oxide-assisted spray drying for co-delivery and stability enhancement

This study focused on the co-encapsulation of selected bioactive compounds including saffron petal (SPE) and Stachys schtschegleevii (SSE) extracts using complex coacervation and spray drying. SPE or SSE was first encapsulated via complex coacervation between chitosan and gum Arabic. The resulting mixture, along with SSE or SPE, maltodextrin, basil seed gum, and graphene oxide (GO, 0.1–0.2 %), was then spray dried. The mean particle size and polydispersity index of the SPE (SPE CO ) and SSE (SSE CO ) coacervates were 385.32 nm and 0.3, and 579.06 nm and 0.32, respectively. The co-encapsulated powders had spherical shapes with wrinkled surfaces, and nanoparticles ranging from 141 to 291 nm were observed on their surfaces. Increasing the GO concentration reduced surface wrinkling but increased the mean particle diameter. FTIR analysis confirmed the successful co-encapsulation of bioactive compounds through physical interactions. The encapsulation sequence, GO concentration, and type of core material significantly influenced the release rates of anthocyanins (from SPE) and D-germacrene (from SSE). The co-encapsulation system improved bioavailability through the co-delivery of core materials, achieving an average release of 88 % in the intestine. • Saffron petal and Stachys schtschegleevii extracts were successfully co-encapsulated. • Graphene oxide enhanced capsule compactness and encapsulation efficiency. • Achieved co-delivery of bioactives, with 88 % delivery in the intestine. • Co-encapsulation enhanced the stability and bioavailability of bioactive compounds. • Graphene oxide significantly improved encapsulation efficiency and powder stability.