Structure of unsaturated glycerides. Analysis by countercurrent distribution and lipase hydrolysis

The structure of highly unsaturated triglycerides isolated from soybean, linseed and safflower oils by countercurrent distribution has been determined by the pancreatic lipase hydrolysis technique. Compositions of positionally distinguishable glyceride isomers for the 5‐double bond fraction obtained from safflower oil, the 7‐double bond fraction from soybean oil and the 8‐double bond fraction from linseed oil agreed with the theoretical values calculated according to the VanderWal‐Coleman theory of 1,3‐random‐2‐random distribution. The fatty acid analyses for individual isomers of the unsaturated glycerides demonstrated that positional isomers of glycerides may be present in nonrandom amounts even though the compositionally distinguishable glycerides approximate a random pattern.