In this study, multilayer sandwich nanofibers from Alyssum homolocarpum seed gum (AHSG), polyvinyl alcohol (PVA) and gelatin were created by electrospinning technique and used to encapsulate caffeine. The middle layer was prepared by electrospinning of AHSG and PVA with different mixing ratios. The average diameter of electrospun nanofibers decreased with increasing AHSG to PVA ratios. Due to their ideal morphology (smooth, uniform, and bead-free) and thinner fiber diameter, nanofibers with the volume ratio of 30:70 AHSG to PVA were chosen as the best sample for caffeine encapsulation. The second step involved spinning gelatin onto the AHSG/PVA nanofibers containing caffeine, as the outer layers. These nanofibers effectively trapped caffeine and had high thermal stability and amorphous structures. The multilayer nanofiber containing 1% caffeine had the highest encapsulation efficiency (88.2%). More than 50% of the caffeine in single-layer nanofiber was released into the saliva simulator environment in less than 60 s, but after that point the caffeine release slowed down gradually. Sandwich structured nanofibers were more resistant to caffeine release and had slower release rate. The Korsmeyer-Peppas model was chosen as the model that best describes the mechanism of caffeine release from single-layer and multi-layer nanofiber, and the release followed non-Fickian diffusion.

Keywords