| Phosphatidyl choline (PC) was an important physiological in the lecithin, which could strengthen the body energy, metabolize, immunity and avoid cardiovascular cerebrovascular disease, fatty liver, alcohol liver, etc. It was widely used in pharmacy industry and health protection. At present the primary commercial source of lecithin comes from the soybean. Lecithin obtained from different source is different from copponent, the physiological activity of egg yolk is best. Recently, the technology of extracting soybean phospholipids which contains 20% PC was relatively perfect; however the technology of extracting egg yolk lecithin which contains 70% PC was still scarce. Recently, the demand for egg yolk lecithin has increased in the fields of food additive, nourishment, cosmetic and pharmaceutical. As a food additive, lecithin is primarily utilized as emulsification agents, stabilization agents and wetting agents.At present, the processing techniques of lecithin were as follows: mixture solvent (ethanol-water) extraction, columniation chromatogram, acetylized reaction, high pressure liquid chromatography (HPLC), membrane ultration, supercritical CO2 extraction. By far, lecithin was 90% obtained from soybean and only a few researched egg yolk lecithin.In this study, we used ultrasonic assistant extraction technique and columniation chromatogram technique to obtained egg yolk lecithin with high content Acetone Insoluble (AI %). Egg yolk phospholipids were analyzed by ultraviolet technique, infrared spectrum technique and HPLC. The purity of prepared PC was all above 97.53%, which was determined by HPLC. The configuration was confirmed by the IR and UT analysis.In the investigation of crude lecithin which using egg yolk powder as raw materials, the common nutritional ingredient was analyzed. The main contents in egg yolk powder are: protein 36.65%, fat 57.5%, water 2.4%, total phospholipids 21.53%, and cholesterol 1.824%. The egg yolk lecithin with high content Acetone Insoluble was obtained using organic solvent method and supersonic wave technique. In the organic solvent method, many influence factors for lecithin enrichment such as the ethanol concentration, ethanol volume, and extract temperature and extract time were analyzed. On the base of Single-factor experimental and the orthogonal experiment, we optimized the parameters in the extraction. Parallel results, the solvent extraction liquid were operated by Supersonic wave technique (SWT). Many effective factors for lecithin enrichment such as the supersonic frequency, the supersonic time, and the ratio of ethanol and egg yolk powder were analyzed. Then the organic solvent method was based on L4 (23) orthogonal experiment, a group of suitable operation conditions of ethanol extraction were finally settle down, in which, ethanol concentration was 90%, and the ethanol volume was 7mL/g yolk, extract time was 50min,extract temperature was 50℃. The 87% lecithin content was obtained by using these conditions. And then the SWT-extraction liquid was operated by follow conditions: the supersonic frequency was 800W and the supersonic time was 9min, the ratio of ethanol and egg yolk powder was 6:1. The SWT-extraction liquid was operated by chromatography and the PC content of extract was increased to 97.53%.In the investigation of crude lecithin deoxidized which using egg yolk powder extraction liquid as raw materials, the decolorment and dry method was analyzed. In the decolor method, there are two kind of it which are physico-decolor and chemical-decolor. There are many influence factors for decolorment such as temperature, time, concentration, and application of sample amounts. The conditions of physico-decolor were temperature 55℃, time 30min, and application of sample amounts 2.5%. And the conditions of chemical-decolor were: temperature 30℃, time 70min, concentration 70% and application of sample amounts 3%. The physico-decolor was the better method for the reason of peroxide value. And then we investigated the common dry method in the lecithin such as infrared drying, centrifugal spray drying ,hot air drying, vacuum freeze-drying, and vacuo heating drying. Finally, we choose the vacuo heating drying was the best method for the reason of peroxide value.In the investigation of purify lecithin which using crude egg yolk lecithin as raw materials, the chromatography method was analyzed. In the chromatography method, there are many influence factors such as flow rate, solvent concentration,and the rate of sample in the column volume. We choosed the conditions by the principal component analysis method: flow rate 0.1ml/min, solvent concentration 95%, and the rate of sample in the column volume 5%. And the PC content of extract was increased to 97.53%.In the investigation of Phosphatidylcholine configuration confirmed and quantitative method of Phosphatidylcholine which using purity egg yolk lecithin as raw materials, the HPLC, IR, and UT method were analyzed. The ultraviolet spectra working curve regression equation was A=0.92917C+0.14811, R=0.9995,average recovery 97.06%,RSD bellow 5%;And the HPLC working curve regression equation was Y=248648.1X+32846.4 ,r=0.9995,average recovery 111.97%, RSD bellow 2%. In the IR and UT method, the configuration was confirmed and in the HPLC method, the purity of prepared PC was all above 97.53%.Besides, the effect of medium, water contents of solvent, pH etc. on lecithin stability was also studied. Experimental results showed that solvent can isolate the system from atmosphere, phospholipids solution was more stable than solid; pH played an important role in stability of phospholipids solution, here hydro sis was facilely occurred. It was indicated using of solvent will not accelerate the oxidation process; simultaneously water contents need be controlled.
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