THE DEVELOPMENT AND EVALUATION OF CAPILLARY ELECTROPHORETIC METHODS FOR THE DETERMINATION OF THE MAJOR PHENOLIC CONSTITUENTS OF POTATO (SOLANUM-TUBEROSUM) TUBERS

A range of capillary electrophoretic methods utilizing both capillary zone (CZE) and micellar electrokinetic techniques were developed for t he separation of 15 compounds consisting of a complex micture of couma rins, cinnamic and phenolic acids, Factors influencing their migration times are evaluated and discussed, and conditions optimized for their quantitative analyses, These techniques were applied to potato extrac ts, in which chlorogenic acid and caffeic acids were identified and si multaneously quantified. A CZE method was also developed for the separ ation of chlorogenic acid isomers, These techniques were utilized in a preliminary study to evaluate the effect of light on both the isomeri c ratios and total chlorogenic acid content of potato tubers, The resu lts indicated that prolonged exposure to light resulted not only in an increase in total chlorogenic acid content but also in a significant change in the relative proportions of the two major chlorogenic isomer s present in the tubers.