Identification of cocoa butter equivalents added to cocoa butter I. An approach by fatty acid composition of the triacylglycerol sub-fractions separated by Ag+-HPLC

 Separation of the six sub-fractions of triacylglycerols (TAG) from cocoa butter, three cocoa butter equivalents (CBEs: calvetta, choclin and coberine) and their mixtures was carried out by silver ion high-performance liquid chromatography. The percentage fatty acid composition of all these sub-fractions was then measured by high-resolution gas chromatographic analysis of the methyl esters of the constitutive fatty acids. In particular, the percentage quantities of all acids in the fully saturated sub-fraction of pure fats and some of their mixtures were evaluated as a function of the percentage CBEs added to cocoa butter in order to devise multiple regression models. The aim was to obtain statistical tools for the identification and/or quantification of added CBEs. The results obtained show the effectiveness of TAG sub-fraction percentage fatty acid composition data for the purposes of research, as well as the potential use of stereospecific analysis of the same sub-fractions. In fact, the stereospecific analysis of TAG fractions from cocoa butter and CBEs already carried out has enabled observation of the different distributions of various fatty acids in the glycerol backbone of TAG from cocoa butter and the CBEs under study, and this will certainly result in the development of more powerful and discriminating statistical models. Received: 12 August 1997 / Revised version: 19 December 1997