Characterization of triacylglycerols in unfermented cocoa beans by HPLC-ESI mass spectrometry

The nutritional value of cocoa butter is mainly determined by the composition of triacylglycerols (TAGs). In this paper we have developed a non-aqueous reversed-phase liquid chromatographic method, using ethanol as the mobile phase, coupled to electrospray ionization (ESI) tandem mass spectrometry to identify TAGs in raw cocoa beans from six different origins. Tandem mass spectrometry was adopted to facilitate the identification of TAGs using unique diacylglycerol product ions and neutral losses. Additionally, two-dimensional m/z retention time maps aided the identification of entire homologous series of TAGs. A total of 83 different TAGs were identified in unfermented cocoa beans, 58 of which were not previously reported in cocoa. Thirty-one of these compounds represent a new class of TAGs characterized by the presence of one to three hydroxyl groups on the unsaturated fatty acid chain. To date, this represents the largest number of TAGs identified in cocoa.