The quality ofthe model regression can be observed in Fig. 1a–d,
in which the falling extraction rate period (FER) is depicted with
dashed lines. A comparison ofthe OECs corresponding to the different
supercritical fluids shows thatif no cosolvents are employed the
extraction entered the FER period at 54.5 min. Using the cosolvents,
the caffeine extraction rate is considerably higher at the beginning
of the extraction and thus, the FER period started at 23.6 min for
CO2 + EAC, 11.3 min for CO2 + ETOH and 7.5 min for CO2 + EL