Preparation of aroma microcapsules with sodium alginate and tetradecylallyldimethylammonium bromide (TADAB) and its potential applications in cosmetics

Abstract

The formation of apple aroma microcapsules was achieved by sodium alginate (SA) and tetradecylallydimethylammonium bromide (TADAB) as shells based on complex coacervation-emulsion polymerization. Alkyl alcohol polyoxyethylene ether was employed as emulsifier. Pentaerythritol tetraacrylate (PETRA) was used as a crosslinking agent and methyl methacrylate (MMA) was applied as comonomer to copolymerize with TADAB. The aroma microcapsules were characterized by scanning electron microscopy (SEM). Results showed that the aroma microcapsules prepared under optimal conditions were core-shell structure. The aroma microcapsules were sphere-like shape with particle size between 20 to 50 μm. FT-IR analysis results showed that the electrostatic interactions and polymerization occurred assuredly. TG-DTA study indicated that the thermal stability of the aroma microcapsules crosslinked with MMA shell was improved, and the thermal resistant temperature was up to 110°C. Moreover, the encapsulation efficiency of aroma microcapsules was measured by ultraviolet–visible near-infrared spectrophotometer. In the surfactant solution, the release of aroma was quick during the first 8 hours, losing ca. 10.8% aroma encapsulated, however, there was no more else aroma dissolving out from the 9th hour. In open conditions, the encapsulation efficiency of the aroma microcapsules kept 66.57% after 48 hours, compared with the encapsulation efficiency going down alone if the microcapsules were milled.