Free fatty acid profiles of emulsified lipids during in vitro digestion with pancreatic lipase.

Individual free fatty acids released from milk protein-stabilized emulsions prepared with milk fat, soya bean oil or tuna fish oil during in vitro digestion with pancreatic lipase were monitored using gas chromatography. The results showed that saturated fatty acids (C16:0 and C18:0) were released faster than unsaturated fatty acids (C18:1n9, C18:2n6 and C18:3n3) from soya bean oil emulsions; short chain fatty acids were released faster than long chain fatty acids from milk fat emulsions; long chain polyunsaturated fatty acids, such as eicosapentaenoic acid and docosahexaenoic acid, were released more slowly than other fatty acids from fish oil emulsions. The results confirm that the release behaviour of fatty acids from emulsions during digestion is related not only to the position of the fatty acids in the triglycerides in the fat/oil, but also to the length of the carbon chain of the fatty acid. The rates and the extents of the digestion of lipids consisting of short chain fatty acids are higher than those of lipids consisting of long chain fatty acids.