Method for analysis of TAG formed by reaction of fish oil with hydrogenated soybean oil

An HPLC method was developed for analysis of the TAG formed during interesterification of a fish oil rich in DHA residues and of a fully hydrogenated soybean oil. TAG species were separated using a three‐phase (acetone/acetonitrile/chloroform) solvent system. Peak identities were assigned on the basis of a multiple linear regression analysis by using factors such as carbon number, number of double bonds, and number of PUFA in the molecule as predictors for TAG retention time. Good agreement between experimental and predicted retention times was observed when the effect of the PUFA was separated in the regression model from that of the monounsaturated FA. In addition, the new method permits one to determine tristearin at concentrations up to 3 mg/mL without encountering the problem of partial retention of this TAG in the column that was observed when chloroform is not incorporated in the mobile phase.