Study of capsaicin content in various parts of pepper fruit by liquid chromatography with electrochemical detection

Abstract

The burning taste of pepper is induced by six chemically related compounds derived from phenylalkylamide alkaloid (capsaicinoids) group. Capsaicin and its derivative dihydrocapsaicin have the strongest burning effects from them. The aim of this work was to determine capsaicin content in different fruit parts (ovary, lower flesh, upper flesh and seeds). For these purposes, we optimized high performance liquid chromatography with electrochemical detection. The most suitable conditions for capsaicin determination were as follows: working electrode potential of 750 mV, mobile phase of acetate buffer (pH 4) and methanol in ratio 40: 60 (v/v, %). At these conditions we were able to detect picomoles of capsaicin per injection. Finally, we utilized this technique to determine capsaicin in various cultivars of peppers. The highest content of capsaicin (227 mg per 100 g of fresh weight) was found in 'Takanotsume' cultivar.