Precise size-controllable generation of alginate encapsulated menthol microcapsules by active flow-focusing microfluidic technology

The encapsulation of menthol by polymer particles is an attempt to decrease its volatilization loss during the drying process when used in tobacco, cosmetics, and food applications. To generate precise size-controllable menthol microcapsules with high menthol loading, this work encapsulated menthol with alginate using a new active flow-focusing microfluidic technology. The size of the alginate-encapsulated menthol microcapsules can be precisely controlled by adjusting the diameters of the nozzles. The results showed that the size difference scale could be controlled below 5%, and the encapsulation efficiency was higher than 80%. Additionally, alginate encapsulated menthol microcapsules exhibited a sustained-release effect. The presence of an alginate shell can effectively protect menthol from rapid volatilization, which is conducive to avoiding menthol loss for tobacco, cosmetics, and food applications.