Optimization of preparation conditions of eucalyptus essential oil microcapsules by response surface methodology

In order to improve the microencapsulation efficiency of the eucalyptus essential oil (EEO) microcapsules, the preparation process was optimized using response surface methodology (RSM). The preferred key factors were chosen firstly by Plackett–Burman design (PBD) experiments, steepest ascent experiments results which were used to determine the central level of the RSM experiment. A three-level-three-variable Box–Behnken design was used to further optimize the synthesis parameters. The results of PBD experiments showed that the ratio of wall to core, encapsulation temperature and encapsulation time were the key factors affecting the microencapsulation efficiency of the EEO microcapsules. Through the RSM, the optimal preparation process of the EEO microcapsules was as follows: encapsulation temperature 46°C, encapsulation time 108 min, ratio of wall to core 9.59, ratio of ethanol to essential oil 20:1, and ratio of water to β-cyclodextrin 10:1. The microencapsulation efficiency of the EEO microcapsules prepared under these conditions was 71.17%. Practical applications In order to expand the application range of liquid eucalyptus leaves essential oil, the essential oil was prepared into solid for use and preservation. By optimizing the preparation conditions of eucalyptus leaves essential oil microcapsules, the encapsulation efficiency of microcapsules was improved. There was great potential in the research and development of new natural antibacterial and antiseptic products.