Box-Behnken效应面法优化柠檬桉叶油微囊的制备工艺

Optimizing Preparation of Microcapsules of Eucalyptus Citriodora Oil by Bex-Behnken Design and Response Surface Method

目的优选柠檬桉叶油微囊的制备工艺,并考察其热稳定性。方法以明胶作为囊材,采用单凝聚法制备微囊。以包封率为指标,在单因素试验的基础上,选取明胶浓度、芯壁比、制备温度3个影响因素,采用Box-Behnken效应面法优化柠檬桉叶油微囊的制备工艺,并应用Design-Expert 8.0.6软件分析试验结果。结果柠檬桉叶油微囊的最佳制备工艺条件是明胶浓度为3.27%,芯壁比为2.5∶1,制备温度为50℃。采用优选后的制备工艺制备的柠檬桉叶油微囊包封率可达67.50%,与模型预测值(65.68%)误差为2.77%;粒径在75μm左右,大小相对均匀,表面较为光滑;热分析显示柠檬桉叶油微囊化后可显著提高其热稳定性。结论运用Box-Behnken效应面法优化柠檬桉叶油微囊的制备工艺是准确、有效、可行的,微囊化可改善柠檬桉叶油的热稳定性。

OBJECTIVE To optimize the preparation process of microcapsules of eucalyptus citriodora oil, and to investigate its thermal stability. METHODS Using gelatin as the capsule materials, the microcapsules were prepared by simple coacervation. Base on single factor experiments, three factors including the concentration of gelatin, the core-wall ratio and the reaction temperature were selected to study the preparation conditions by Box-Behnken design and response surface method with its encapsulation efficiency as index. The test results were analyzed by Design-Expert 8.0.6 software. RESULTS The optimal preparation process was as follows: gelatin solution concentration 3.27%, core-wall ratio 2.5∶1, preparation temperature 50 ℃. Under the optimized preparation process, the encapsulation rate was 67.50%, which was different from the model prediction value (65.68%) by 2.77%. The particle size was about 75 μm and relatively uniform, and the surface was relatively smooth. Moreover, thermal analysis showed that microencapsulation of eucalyptus citriodora oil could significantly increase its thermal stability. CONCLUSION Using Box-Behnken design and response surface method to optimize the preparation process of eucalyptus citriodora oil microcapsule is accurate, effective and feasible. Microencapsulation can improve the thermal stability of eucalyptus citriodora oil.