ANALYSES OF VEGETABLE OIL TRIGLYCERIDE MOLECULAR-SPECIES BY REVERSED PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Triglyceride molecular species (TGMS) of 10 vegetable oils (olive, soybean, sunflower, corn, cottonseed, pumpkin seed, peanut, safflower, canola and palm oil) were separated and analyzed quantitatively by gradient, reversed phase high performance liquid chromatography with a flame ionization detector (FID). Identification of TGMS was made by comparison of experimental and calculated theoretical carbon numbers (TCN). The relationship between elution time and calculated TCN of each TGMS was linear. The FID response (area percent) was determined to be linear or proportional to weight percent. Nine of the oils showed significant differences between observed TGMS composition and composition expected or calculated from an assumption of random fatty acid distribution. Results indicate preferential or genetically controlled distribution of fatty acids in TGMS of these oils and a random distribution for sunflower oil. TGMS composition was determined for a 1:1 blend of soybean oil with fully hydrogenated soybean oil before and after interesterification.