The Studies On Preparation Of High Content Phosphatidylcholine Phosphalipid From Powerded Phosphatide

In this paper, phosphatidylcholine was purified from soybean powdered phosphatide by a new method consisting of three stages: ethanol extraction, ethanol freeze-purify and column chromatography. The process conditions were investigated systematically and roundly. Fatty acid composition and glycolipid content of phosphatidylcholine samples from different stages were also determined. Mass transfer characteristic of phosphatidylcholine in alumina column was studied.The effects on extraction conditions were discussed with single factor and orthogonal(L9(34)) experiments. The factors included extraction time, extraction temperature, solid-liquid ratio and alcohol concentration. Best condition of Ethanol extraction: extraction time 30min, extraction temperature 35℃, alcohol concentration 97.5%, solid-liquid ratio 1:8(w/v), the results showed that the yield of phosphatidylcholine was 54.6%, and the purity of phosphatidylcholine was 47.8%. To improve the efficiency of the extraction, ultrasonic-assisted ethanol extraction conditions were also discussed with single factor and orthogonal experiments. And the optimal condition was: Ultrasonic frequency 45KHz, ultrasonic power 300w, extraction temperature 30℃, solid-liquid ratio 1:6 (w: v), alcohol concentration 95%, extraction time 10min, according the proof test the yield of phosphatidylcholine was52.5%, and the purity of phosphatidylcholine was 51.8%.To improve the purity of phosphatidylcholine, the effects on purity conditions of ethanol freeze-purify were investigated, phosphatidyl(PC45.1) was took as raw material. And optimal condition was : Solid to liquid ratio: 1:8 (w / v), freezing time: 6h, freezing temperature : -12℃, alcohol concentration: 97.5%. According to the proof test the yield of phosphatidylcholine was 69.2%, and the purity of phosphatidylcholine was 72.5%.The purification conditions of column chromatography were discussed, and the best condition was: 100~200 mesh alumina, alcohol concentration 95%, the sample concentration was 1:4(w/v), flow rate 8ml/min, loading 0.0238g/1g, yield of PC90 > 83.68%. Column parameters: packing height 65cm, column volume 220mL, column total voidage 0.63, number of plate (toluene) 111, plate height (toluene) 0.586cm, the effective number of plate (1gPC) 28, the effective plate height (1gPC) 2.32cm.By ultraviolet spectrophotometry and alkali-acid hydrolysis, an analytical method of glycolipid content was established: The total sugar content was determined. The steady color displaying time was 30-120min, galactose concentration showed positive correlation with absorbency(y =1.0175x-0.0531, R2=0.9914),the average recovery rate was 99.1% with RSD of 1.73%(n=6). The result of measurement showed: ethanol freeze-purify phosphatidylcholine had a highest content of total sugar (3.96%), concentrated soybean phospholipid:3.48%, powdered soybean phospholipid: 3.22%, phosphatidylcholine of ethanol extraction: 3.52%. column chromatography could effectively remove the glycolipid. Main glycolipids in phosphalipid were monogalactosyldiglyceride and monogalactosylmonoglyceride.Gas chromatography was used to analyze the fatty acid compositions of these phosphatidylcholine samples, and the results showed: the main fatty acid of phosphatidylcholine was linoleic, the content of Linoleic acid and palmitic acid showed positive correlation with the purity of phosphatidylcholine.Isothermal assorptive curves of phosphatidylcholine on 100~200 mesh alumina at different temperature were measured by static adsorptive method and conforms to Freundlich equation.. The general mass transfer, including axial dispersion, external-film mass transfer and pore diffusion, was futher applied to describe the adsorption process of phosphatidylcholine on fixed bed with alumina. The pore diffusion coefficient and external-film mass transfer coefficient were obtained by optimization the adsorption breakthrough of phosphatidylcholine. The result showed the model could predict the adsorption process of phosphatidylcholine in the fixed bed of alumina.