Analysis of capsaicin and dihydrocapsaicin from sweet-to-very hot chilli peppers using an ultrasound-assisted extraction followed by RP-HPLC-PDA

In the present study, the optimal conditions of an ultrasound assisted extraction for both capsaicin and dihydrocapsaicin in hot chilli samples were developed. The parameters affecting the yield of the capsaicinoids such as extraction solvents (methanol, ethanol, acetonitrile and water), solvent to sample ratio, extraction temperature and extraction time were investigated. The capsaicinoid extracts were analyzed by reversed phase-HPLC with photodiode array detector (RP-HPLC-PDA). The optimum extraction conditions consist of 20 mL of 80% (v/v) methanol and water as the extraction solvents and 20 min extraction time at 50oC. The method was applied to determine seven varieties of sweet-to-very hot chilli peppers cultivated. The concentration of the capsaicinoids ranging from 573.44-15220 µg/g was widely found in these samples.