Abstract:Objective: In order to overcome the disadvantageous volatility and degradability of essential oil, microsphere was prepared with polymer as wall material to encapsulate essential oil for sustaining release. Methods: The Lemon essential oil was extracted from the steam distillation, the essential oil microspheres were prepared by emulsion cross-linking method taking sodium alginate/gelatin used as the wall material, and solvent evaporating technique Polylactic acid-Glycolic Acid copolymer (PLGA) as the wall material. The properties of the microspheres were compared by yield rate, entrapment efficiency and slow release behavior, and their thermal stability was tested by thermogravimetric analysis. Results: The diameter of the microspheres was less than 10 μm. By comparing the yield rate and encapsulation efficiency of the two kinds of microspheres, it was found that sodium Alginate/gelatin microspheres had better encapsulation effect on lemon essential oil. With the release of essential oil, the ability of scavenging free radical DPPH from the microspheres increased gradually. The thermal stability analysis showed that the PLGA microsphere had better thermal stability. Conclusion: Both kinds of microspheres prepared by different methods have smaller diameter and are easy to disperse. According to their different characteristics, they can be used in different food fields.