Table 1 shows that FOG might be effectively recovered with 60%
methanol, and about 96% absorbance was collected in the solution.
The HPLC–MS test had proved that all the FOG are in this part and
the other two parts didn’t contain any FOG compounds. Although
the absorbance at 287 nm is not exclusively due to catechins, we
could deduce when catechins were washed out based on their
absorbance spectra and their retention time on HPLC. From
Table 1 it can be withdrawn that most catechins were eluted by
100% methanol and not by 60% methanol, so that FOG compounds
could be separated from most catechins by this step. This was also
confirmed by analyzing catechins by HPLC in these eluates.