Non-derivatized analysis of methiin and alliin in vegetables by capillary electrophoresis

Methiin and alliin are important components of flavors or the precursors of flavors and odors of Allium vegetables. Moreover, they are thought to be beneficial to health. A non-derivative method was developed to analyze these compounds in vegetables by capillary electrophoresis. These compounds in the extracts of Allium and Brassica vegetables were detected indirectly at 225 nm. The analysis of each sample required less than 25 min, and the linear detection range was 5-5000 mg/l. This method was simple compared to the other published methods using high performance liquid chromatography. Moreover, it was possible to detect the peak of pyruvate simultaneously with methiin and alliin using this method. The presence of pyruvate peak is a useful indicator if the blanching of the samples has been insufficient.