Preparation and characterization of cinnamon essential oil extracted by deep eutectic solvent and its microencapsulation

In this paper, the effect of different deep eutectic solvents (DESs) on the yield of cinnamon oil was studied, and the extraction conditions were optimized. Then, the cinnamon essential oil microcapsule was prepared by complex coacervation method. The morphology, chemical structure, and thermal stability were characterized by Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA). The research results showed that the optimum DES for the cinnamon oil extraction was choline chloride: 1,2-propanediol, their molar ratio was 1:3 and the water content of 40%. The optimal extraction conditions were the solid–liquid ratio was 1:6, the extraction temperature was 70 °C, the extraction time was 10 min, and the distillation time was 50 min. The optimal extraction rate was 4.464%, which was higher than that of the conventional hydrodistillation (HD) method (1.581%). It was found by the characterizations that the microcapsules were full spherical under SEM. The FTIR showed the interaction of the gelatin, gum Arabic acid, and tannic acid. The TGA result showed that microencapsulated essential oil could improve the thermal stability of essential oil. This study provides some ideas for the extraction and application of cinnamon essential oil.