Lipase-catalyzed interesterification of egg-yolk phosphatidylcholine and plant oils

The incorporation of polyunsaturated fatty acids into the sn-1 position of egg-yolk phosphatidylcholine (PC) in the process of lipase-catalyzed interesterification was investigated. For this purpose plant oils containing these acids in the triacylglycerol (TAG) form were used as acyl donors and three commercially available immobilized lipases were examined as biocatalysts. In all the experiments the best results were obtained using Novozym 435. After 72 h of the reaction of PC with linseed oil the maximum incorporation of a-linolenic acid into PC was 34%. The result of this reaction was also a reduction in the n-6/n-3 ratio in egg-yolk PC from 24.5 to 0.7. The highest incorporation n-6 PUFAs into PC were obtained with evening primrose oil as the acyl donor, and in this case, 50.7% of n-6 PUFA as the sum of linoleic and gamma-linolenic was achieved. The highest content of gamma-linolenic acid in modified PC (7.3%) was achieved in the reaction of PC with borage oil.