Supercritical CO_2 Extraction of Tea Seed Oil from Camellia Seeds and Composition Analysis of Tea Seed Oil Extracts

摘要

The extraction of tea seed oil obtained from wild camellia seed using supercritical CO_2 extraction has been investigated. The extraction was carried out under operation pressures of 20, 30, 35, 40 and 50 MPas at 45°C, with a supercritical fluid flow rate of 5mL-min~(-1). The collected extracts were analyzed and the relative compositions of the tea oil were determined by gas chromatography-mass spectrometry(GC-MS). The purpose of this work was to investigate the effect of operation pressure on the extraction yield, extraction time, and extract composition. The results from supercritical CO_2 fluid extraction (SFE) showed that the extraction pressure positively related to the extraction yield and negatively and linearly related to the extraction time. Only 5 constituents were found in the extract under the pressure of 20 MPa. However, about 20 constituents in the extract were obtained under the pressure of 35 MPa, approximately the same as those under 50 MPa. The curve of the extraction pressure versus the extraction yield demonstrated that the extractable constituents of wide camellia seeds have two states: a free state and a bound state. In the bound state, extractable constituents can only be extracted under an extraction pressure above the threshold. Taking into consideration of the extraction yield, equipment, and operation, the appropriate pressure of the SFE is between 36.4 MPa and 40 MPa.