Calibration curves of 5-caffeoylquinic acid (5-CQA) and caffeine standard were used for quantifying. Coefficients of linearity for the calibration curves were typically R2 > 0.99. Quantification of the other chlorogenic acids was carried out using the area of 5-CQA standard combined with molar extinction coefficients of the respective chlorogenic acid as reported by Trugo and Macrae (1984) and Farah et al. (2005).