Validation of a method for the quantification of cocoa butter equivalents in cocoa butter and plain chocolate : report on the validation study

A European collaborative study has been conducted to validate an analytical procedure for the quantification of cocoa butter equivalents in cocoa butter and plain chocolate. In principle, the fat obtained from plain chocolate according to the Soxhlet principle is separated by high-resolution gas chromatography into triglyceride fractions according to their acyl-C-numbers, and within a given number, also according to unsaturation. The amount of cocoa butter equivalents in cocoa butter is estimated by Partial Least Squares regression analysis applied to the relative proportions of the five main triglycerides present in cocoa butter. Fifteen laboratories participated in the validation study. For all test samples the predicted cocoa butter equivalent amounts were in close agreement with the true values. The results of the ring test clearly demonstrated that the applied method performs well at the level of the statutory limit of 5% cocoa butter equivalent addition to chocolate with a prediction error of 0.4% to 0.6%, assuming a chocolate fat content of 20% to 30%.