Studies On Deacidification Of Egg Yolk Oil And Purification Of Egg Yolk Lecithin

Egg yolk has important dietary value and physiological function. In this paper, the egg yolk oil is deacidified and the egg yolk lecithin is purified.First of all, the egg yolk oil is deacidified with solvent extraction-alkali neutralization. The results showed that: 95% ethanol as extraction agent, the ratio of oil to alcohol was 1:2(g:ml), the extraction temperature was room temperature, extracting 2 times for once 10 min. The optimal process conditions of alkali neutralization were: the concentration sodium hydroxide was 8%, excess alkali amount was 0.1%, initial temperature was 50℃, final temperature was 65℃, neutralization time was 15min. Under these conditions, the acid value of egg yolk oil was reduced from 31.5mgKOH/g to 0.1mgKOH/g, 99.7% FFA was removed from the egg yolk oil, the yield of deacidification was 76.0%, the recovery rate of neutral oil was 89.6%.Secondly, the quality of crude egg yolk oil and deacidified egg yolk oil was compared and analyzed. The results showed that: the acid value of crude egg yolk oil was 31.5mgKOH/g; the content of unsaturated fatty acid of deacidified egg yolk oil was 71.73%, with oleic acid 54.45%. The acid value of deacidified egg yolk oil was 0.1mgKOH/g, all indicators of the deacidified egg yolk oil matched the second criterion of vegetable oil; the content of unsaturated fatty acid of deacidified egg yolk oil was 70.46%, with oleic acid 52.60%; the composition and content of fatty acid of egg yolk oil were not changed in deacidification procedure.Then, the crude egg yolk lecithin was purified with column chromatography. The results showed that: the 100-200 mesh Al2O3 can be chosen as the stationary phase, the mobile phase was pure ethanol, the flow rate was 30r/min, the sample loading amounts was 0.025g/(g Al2O3). Under these conditions, the purity of PC in the egg yolk lecithin was increased from 37.09% to 97.60%, the recovery rate of PC was 50.4%.Finally, the quality of crude egg yolk lecithin and refined egg yolk lecithin was compared and analyzed. The results showed that: the content of PC in crude egg yolk lecithin was 37.09%; the content of unsaturated fatty acid of crude egg yolk lecithin was 67.37%, with oleic acid 49.00%. The content of PC in crude egg yolk lecithin was 97.60%, all indicators of the refined egg yolk lecithin matched the first criterion of lecithin; the content of unsaturated fatty acid of refined egg yolk lecithin was 60.03%, with oleic acid 42.47%; the composition and content of fatty acid of egg yolk lecithin were not changed in deacidification procedure.