Analysis of triacylglycerol isomers in Malaysian cocoa butter using HPLC-mass spectrometry

Chocolate is acclaimed for its unique and highly desirable flavor and its unusual melting characteristics (a narrow melting point range centered a few degrees below body temperature ∼32 to ∼35 °C). The triacylglycerol (TAG) composition of cocoa butter is responsible for this important melting behavior. The exact composition of the primary TAG in a Malaysian cocoa butter sample was elucidated by ESI/tandem mass spectroscopy. The cocoa butter sample consisted primarily of the TAG, POP, POS and SOS with smaller amounts of PLP, POO, PLS, and SOO, where P, O, S, and L indicated palmitic, oleic, stearic and linoleic acid, respectively. The use of tandem mass spectroscopy or MS/MS was critical for the identification of coeluted TAG, such as POO and PLS. The fragmentation pattern provided by diacylglycerol sodium adduct ions, enabled the identification of co-eluted TAG by the loss of a fatty acid fragment and the corresponding diacylglycerol sodium adduct ion.