2.5.13. Caffeine and CGA
The procedure was performed according to Del Castillo, Ames,
and Gordon (2002). Separation was carried out in a capillary
electrophoresis system with an ultraviolet–visible detection.
Calibration curves of caffeine (0.25–5.15 mmol/l) and CGA(0.15–2.5 mmol/l) were constructed. The analyses were performed
in triplicate. Results were expressed as% 3-CGA (w/w) and %
caffeine (w/w).
2.5.14. Total phenolic content
Total phenolic content (TPC) was determined by the Folin–Ciocalteu
method as described by Contini, Baccelloni, Massantini, and
Anelli (2008) adapted to a micro-method format. CGA calibration
curve (0.1–0.8 mg/ml) was used for quantification. Measurements
were performed in triplicate and results were expressed as %
CGA equivalent (eq.) (w/w).