Degumming of soybean oil: Quantitative analysis of phospholipids in crude and degummed oil1

Abstract Phospholipids of crude and degummed soybean oils were isolated and separated by column chromatography and thin layer chromatography. Standards and specific spray reagents were used to identify the phospholipids. Phospholipids identified in the crude and degummed oils were phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, lysophosphatidylcholine and lysophosphatidylethanolamine. Several unknown phosphorus‐containing compounds were present. Samples of crude and degummed oil were collected from four soybean oil processors over four consecutive days. Total and individual phospholipids were quantitated by determining the phosphorus content. The total phosphorus content of crude oil varied among companies, with the average ranging from 453 to 676 ppm. The average total phosphorus content of the degummed oil of the four processors ranged from 12 to 84 ppm. Processors removed an average of 86‐98% of the phosphorus present in the crude oil during the degumming process. There was also a daily variation in phosphorus removal within the individual companies. During the degumming process, the proportion of phosphatidylcholine decreased and the proportion of unknown, nonpolar phosphorus compounds increased in samples from all companies. Significantly higher proportions of phosphatidic acid and lyso compounds were found in the degummed oil of some but not all companies.