Quantification of capsaicinoids in acetone and acetonitrile extracts by HPLC
Five µl aliquot of the sample was used for each HPLC injection. The capsaicinoids were identified with reference to retention time of standards and by spiking the samples with standards. The major capsaicinoids in peppers, capsaicin and dihydrocapsaicin, were determined by comparison to external reference standards injected under the same conditions. Their identification was based on the retention times measured under identical HPLC conditions while the quantitative determination in the different peppers samples was carried out using the peak areas. The ratio between these capsaicinoids was calculated by dividing capsaicin and dihydrocapsaicin contents by the total capsaicinoids26.
The capsaicinoids concentrations in samples were expressed as µg/g pepper.