Screening of eighteen polyphenolic compounds in different carob pekmez by green capillary electrophoresis method

Carob pekmez, a traditional concentrate, has long been produced from Ceratonia siliqua L. for human consumption in Turkey. Although it is already known that carob pekmez contains several classes of polyphenolic substances, a comprehensive analysis of these compounds has not been conducted individually by capillary electrophoresis. Therefore, the polyphenolic compounds were extracted, and a sensitive, green, dependable, simple and rapid method based on capillary electrophoresis with diode array detection was developed for identification and determination of eighteen polyphenolic compounds in five different carob pekmez samples. The effect of separation voltage and pH of the buffer were investigated for determination of optimum conditions. The eighteen compounds were analyzed and fifteen compounds were determined within 17 min without using organic modifier. The developed method was successfully applied to the determination of polyphenolic compounds in five different carob pekmez samples with satisfactory recoveries. As a result of analyses, four major compounds could be determined (gallic acid, vanilic acid, gentisic acid and luteolin) in carob pekmez samples.