HPLC METHOD FOR THE ANALYSIS OF ORGANIC-ACIDS, SUGARS, AND ALCOHOL IN EXTRACTS OF FERMENTING COCOA BEANS

A cation-exchange HPLC column was evaluated for the analysis of sugars (sucrose, glucose, fructose), acids (citric, lactic and acetic) and ethanol in extracts of cocoa, preserved in a solution of benzoic acid (0,2 % w/v). Optimum sensitivity, precision and selectivity was achieved when the column was operated at a temperature of 25 °C and the combination of a refractive index detector and peak height measured peaks was employed. The limit of detection was 3.5 ng acetic acid, 5.5 ng sucrose, 6.3 ng fructose and lactic acid, 7.3 ng citric acid, 10.5 ng glucose and 12.4 ng ethanol. The extracts of cocoa were stable over a 10 week period, permitting the analysis of large numbers of samples without degradation of the analytes. © 1990 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.