The Preparation Approach Of High Purity Egg Yolk Phosphatidylcholine

Phospholipids are well known as the basic material of life. Phosphatidylcholine, the most common and most important one, had been used in food, health products, pharmaceutical and other industries. Egg yolk phosphatidylcholine is considered superior to soy phosphatidylcholine because of its various functions and its high collection rate and good stability. Nature high-purity egg yolk phosphatidylcholine (EYPC) is being widely used in food, health care products, cosmetics, and pharmacy industry nowadays because it has strong emulsibility, no peculiar smell and it can be used in large quantity. Besides that, the price of high-purity egg yolk phosphatidylcholine is much higher than the crude phosphatidylcholine. Thus, the research and development of the high purity egg yolk phosphatidylcholine preparation approach is of great significance.This dissertation studied include the detection method of egg yolk phosphatidylcholine, organic solvent extraction process of egg yolk phosphatidylcholine, membrane recovery process, column chromatography process and their optimal choices.In this study, we proposed the optimized HPLC-ELSD operating conditions for analysis of EYPC:pure methanol as a mobile phase,1.0 mL/min flow rate, silica gel column (250 mm×4.6 mm,5μm, Inertsil GLTM), column temperature 30℃and low temperature evaporative light scattering detector (40℃,3.5 bar). This HPLC-ELSD method is feasible and reliable. The standard curve is logA=1.59381ogM+5.4271, R2= 0.9978.The organic solvent extraction process of egg yolk phosphatidylcholine was studied in this dissertation. The optimal conditions were as follows:acetone 14:1 (mL-acetone:g-egg yolk powder), extract 30min, ethanol 20:1 (mL-ethanol:g-egg yolk powder), temperature 50℃, extract 60min. The crude egg yolk phosphatidylcholine product had 73.7% purity,101.2% recovery.An alkali treatment which can purify egg yolk phosphatidylcholine was also proposed in this dissertation. The optimal conditions were as follows:crude egg yolk phosphatidylcholine product (PC purity 68.9%) 0.5g was soluted in 50mL n-hexane, lye solution (containing 5% NaCl and 2mol/L NaOH) purified the egg yolk phosphatidylcholine-n-hexane solution. Egg yolk phosphatidylcholine product's purity was 83.78% and recovery was 94.84%.Column chromatography purification process was studied in this dissertation. Silica gel was used as stationary phase, medium pressure column chromatography (MPLC) used for purification. The optimal conditions were as follows:QuikSep glass column (diameter 16mm, length 800mm) filled with silica gel, methanol or 85% ethanol-15% water as eluent, flow rate 20mL/min, maximum concentration of the sample was 400 mg/2mL methanol. The final egg yolk phosphatidylcholine product's purity was 90.56%.