Extraction And Purification Of Soybean Phosphatidylcholine

Phosphatidylcholine(PC) is a kind of phospholipid, which has special character and physiological function. It widely used in food, cosmetic, and pharmaceutical industries. In particular, it is promising to prepare liposomes and pharmic emulsifier. At present, almost all of the high-pure PC used in our country is imported. In fact, our country is abundant in soybean resource. Hence it is a direction of soybean process to make use of soybean lecithin to prepare high-pure PC, which is cheaper and more valuable.In order to improve the PC content, a study has been carried out to obtain de-oiled powder phospholipid from soybean phospholipid with using acetone and supercritical fluid CO₂ (SF- CO₂). Their qualities were compared. A result showed that acetone insoluble residue and PC content were up to 98.3% and 20.6% by SF- CO₂ with extraction press 30Mpa, temperature 50℃, velocity of flow 301/h,time 3h. While acetone insoluble residue and PC content were up to 97.6% and 20.1% by acetone with 200ml, temperature 40℃, time 15min.Powder lecithin was fractionated with ethanol. Optimum condition was determined to get purified PC enrichment. The effects of alcohol concentration, lecithin/ alcohol, extraction time, temperature and times on the yield and PC content were evaluated. By the L₁6 4⁵ orthogonal test, it was found that the main influencing factors of the yield and PC content were temperature and alcohol concentration. Optimum condition obtained by the orthogonal tests was as follows: alcohol concentration 95%, soybean lecithin/ alcohol 10:200, extraction time 30 min, temperature 35℃, extract twice. The PC content and yield were 45.1% and 62.0% respectively.The separation of PC by the Al₂O₃ column chromatography method was researched. The effects of the eluting system, mode, sample weight and velocity of flow on yield were evaluated. Conditions were determined toobtain high-pure yellowish PC. Under the condition that sample weight 2.5%, velocity of flow 3ml/min, eluted with mobile phases of chloroform-methanol in a gradient mode, the PC content and final yield were 95.1% and 86.6% respectively. The PC content was analysised by thin layer chromagraphy and FTIR.