Study on preparation, characterization and stability of β-cyclodextrin inclusion compound of Foeniculum vulgare volatile oil

Abstract

Objective: To Prepared of β-Cyclodextrin inclusion complex with Foeniculum vulgare（fennel） volatile ooil and study on its sstructural characterization and stability. Methods: Based on the inclusion rate, the inclusion yield and the content of trans-anethole in the inclusion compound, the comprehensive evaluation index was established, and the effects of the ratio of fennel volatile oil to β-cyclodextrin, inclusion temperature and inclusion time on it were explored. The preparation process was optimized by orthogonal test. It was characterized by scanning electron microscopy, thin layer chromatography, Fourier infrared spectroscopy and differential scanning calorimetry. Finally, the stability of the inclusion compound was investigated by light, high temperature and high humidity tests. Results: The optimum conditions obtained by saturated aqueous solution method were as follows: the ratio of volatile oil to β-cyclodextrin was 1∶8 (mL/g), the inclusion temperature was 40 ℃, the inclusion time was 60 min. Under these conditions, the inclusion rate of fennel volatile oil inclusion compound was 96.90%, the inclusion yield was 93. 61%, the content of trans-anethole was 6.81%, and the comprehensive score was 99.68. The inclusion compound was white powder with loose texture and good inclusion effect. The inclusion compound was characterized by scanning electron microscopy, thin layer chromatography, Fourier infrared spectroscopy and differential scanning calorimetry. Its stability was good within 5 days of illumination (4 000 lx), volatile components in the inclusion compound were easy to lose at high temperature (60 ℃) for a long time, and it would deliquesce and agglomerate when the relative humidity was more than 75%. Under the conditions of long illumination time, high temperature and high humidity, the inclusion rate and trans-anethole content were obviously reduced. Conclusion: The inclusion rate and inclusion yield of the above-mentioned optimal inclusion process are high, and the process is stable. When stored in a dry and sealed environment at room temperature, the β-cyclodextrin inclusion compound of fennel volatile oil has certain stability compared with the volatile oil.

Keywords

• foeniculum vulgare
• volatile oil
• inclusion compound
• β-cyclodextrin
• trans-anethole
• preparation technology