Ternary Complex Microparticles Assembled from Vanillin, γ-Cyclodextrin, and Dextran: Fabrication, Structure, and Controlled Release Characteristics

Vanilla is one of the most widely used flavors in the food and beverage industry; however, it is thermally unstable and volatile. In this study, microparticles consisting of ternary complexes of vanillin/γ-cyclodextrin/dextran (V/C/D) were prepared, in which vanillin served as a crosslink between the γ-cyclodextrin and dextran. One end of vanillin was inserted into the interior of γ-cyclodextrin through hydrophobic interactions and hydrogen bonding, while the other end was bound to dextran through hydrogen bonding. The encapsulation efficiency of vanillin in the microparticles increased from around 59 to 92% when the mass ratio of dextran in the complexes increased (V/C/D ratio ranging from 1:9:0 to 1:5:4). Moreover, the crystallization peak of vanillin disappeared in complexes with higher dextran contents. The dispersibility of vanillin in cold water (4 ℃) increased as the dextran content in the complexes increased, with the highest value being 15 mg/mL. Encapsulation of vanillin within the microparticles protected it from volatilization during storage, with more than 90% being retained after holding at 60 ℃ for a month, as well as increasing its resistance thermal processing. The release of vanillin during baking (200 ℃, 30 min) could be controlled by altering the composition of the microparticles. Our findings provide a novel strategy for improving the stability and controlling the release of aromas. Graphical Abstract