Preparation, Characterization, Release and Antibacterial Properties of Cinnamon Essential Oil Microcapsules

In this study, the antibacterial microcapsules of cinnamon essential oil (CEO) were prepared by complex condensation method. Chitosan quaternary ammonium salt (HACC) combined with gum arabic (GA) was selected as the coated wall material. The optimal preparation conditions of CEO microcapsules (CMSs) were determined by response surface methodology (RSM): the core/wall mass ratio was 1:1, the pH value was 4.5, the mass concentration of CaCl2 was 0.7 wt% and the actual encapsulation rate of microcapsules was 90.72% ± 1.89%. The morphology, size, composition and thermal stability of the prepared CMSs were characterized by scanning electron microscopy (SEM), laser particle size analysis (LPDA), Fourier transform infrared spectroscopy (FTIR), thermogravimetric differential thermal analysis (TG–DTA) and differential scanning calorimetry (DSC). In addition, the in vitro drug release and antibacterial properties of CMS were also evaluated. The results showed that CMS was spherical, with an average particle size of 6.31 µm. The obvious weight loss occurred at 269 °C and the corresponding DSC curve had an obvious exothermic peak at 265.5 °C, which had an increase compared with CEO. Microcapsules can achieve slow release, with the lowest and highest release rates being 19.66% and 49.79%, within 30 days. The drug release curve of essential oil of microcapsules was consistent with a first-order release model named ExpDec1. Based on the above research results, the CMS can effectively improve the stability of essential oil, achieve slow release and prolong the antibacterial effect, indicating its potential applications in food, cosmetics and medicine.