Extracts were injected and separated by HPLC-DAD. Under the optimum conditions, calibration
curves were obtained by injecting standard solutions at ten different concentrations. Each point on the
calibration graph corresponded to the mean value obtained from three independent peak area
measurements. Calibration curves were y = 8.824x − 2.54 for capsaicin and y = 14.312x − 2.12 for
dihydrocapsaicin. The calibration curves exhibited excellent linear behavior over the concentration
range of 1.5–1,200 μg mL−1 for capsaicin and 1.25–500 μg mL−1 for dihydrocapsaicin with a
correlation coefficient (r) 0.9999 and 1, respectively.