Supercritical CO₂ Fluid Extract The Perilla Oil And Study Its Phase Equilibrium Process

Supercritical CO₂ fluid extraction technology is a kind of green, environmental protection, high efficiency, clean separation technology, it has been widely used in the field of the natural products’ extraction. Perilla seed is an edible and medicinal natural product, the Perilla oil in the seed account for about 45%-60% of the whole Perilla seed quality. The alpha linolenic acid account for about 50%-70% of the Perilla oil, which can be used in food, medicine, health products development, etc. In this paper, the supercritical CO₂ fluid extraction technology was applied in the extraction of Perilla oil, studied the extraction technology, solubility phase equilibrium and detected the content of alpha linolenic acid in Perilla oil rapidly non-destructive testing, concretly study the following four aspects’ content:（1）The technology research of supercritical CO₂ fluid extraction of Perilla oil: Determinated the appearance, color, smell, acid value, peroxide value, iodine value of Perilla oil extracted by three methods of squeezing method, soxhlet extraction and supercritical CO₂ fluid extraction primarily, the result showed that the quality of Perilla oil extracted by supercritical CO₂ fluid extraction was better than the rest of the two methods, so choosed supercritical CO₂ fluid extraction to extracte the Perilla oil in the Perilla seed. Then selected temperature, pressure, time, loading coefficient four factors, respectively selected levels for 6, 3, 3, 2, used to design mixing experiment. Use the DPS date processing software to fit the experimental data by quadratic polynomial stepwise regression to get the oil yield model equation of four factors and the best extraction conditions: extraction temperature is 42 ℃, extraction pressure is 27 MPa, extraction time is 4 h, the loading coefficient is 0.8. The maximum yield efficiency was 55.23% in the best extraction conditions, the parallel test for three times, the average yield efficiency was 54.62%, the relative standard deviation was 1.1%.（2）Establish and validate the solubility algorithm: selected 10 kinds of solid solubility in supercritical CO₂ fluid’s experiment data in literature, combined with the compiled solubility algorithm program, in Mathematica computing platforms, respectively used RK, SRK and PR three state equations to associate and calculate the solubility data, the average calculated deviation ware under 10%.（3） Associate and compute the alpha linolenic acid’s solubility in supercritical CO₂ fluid: selecte pressure and temperature two factors, respectively three levels, got alpha linolenic acid’s solubility experiment data in supercritical CO₂ fluid, then used Aspen Plus to simulate and estimate the physical property parameters of alpha linolenic acid, combined the established algorithm to associate the solubility experimental data, the average correlation calculation deviation was below 5%, correlation calculation results was satisfied.（4） Identificate the Perilla oil’s quality nondestructivly by Raman spectroscopy: The alpha linolenic acid’s content in Perilla oil is the main indicator for evaluating the oil’s quality.Transforme the Perilla oil samples’ Raman spectral intensity value matrix to Angle value matrix, used the classical PRESS criterion combined interaction validation method to calibrate the principal components, used partial least squares and Angle measurement method respectively to establish the determination method of alpha linolenic acid content in Perilla oil. The results showed that the method of Angle measurement model was more stable, which the largest relative error of the prediction was 4.28%, RSD was 2.79%. This method can realize the Perilla oil’s identification of quality rapid, accurate, real-time on the site.