Preparation and Release of Vanillin from Sporopollenin Microcapsules

Abstract

Sporopollenin is a potential carrier for active ingredient due to its uniform size, central cavity, as well as chemical and thermal stability. Sporopollenin microcapsules were obtained by a series of processes on the pollens of Typhae angustfolia. Vanillin was embedded in sporopollenin using passive loading and evaporating techniques. Raw cattail pollen, sporopollenin, vanillin, and vanillin-loaded microcapsules were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The results show that sporopollenin exhibits structural integrity, porosity, and good thermal stability. The encapsulation efficiencies of the microcapsules prepared by passive loading technique and evaporating loading technique were found to be 7.2 ± 0.8% and 40.5 ± 1.6%, respectively. The release profile and kinetics of the vanillin-loaded sporopollenin microcages were conducted to evaluate the suitability of sporopollenin microcapsules for loading. Release behavior of vanillin from microcapsules was more aligned with Fickian diffusion, with an initial rapid cumulative release followed by a lower speed of release. These findings demonstrated that sporopollenin from the cattail pollen of T. angustfolia could be a suitable medium for sustained release of nutritional components.