For a better interpretation of the results, graphic analysis of the
same was carried out, which was also undertaken independently
for the glucosides and for the acyl derivatives. The results are
shown in Fig. 2.
In the case of the glucoside type compounds (Fig. 2a), it can be
seen that the variables which have the most intense effect on recovery are the composition of the extraction solvent and the
extraction time.
In the case of the acyl derivatives (Fig. 2b), the composition of
the solvent is still equally important with regard to recovery. However,
the other significant variable is the temperature of the extraction,
not the extraction time. Given that the influence is negative,
i.e. the higher the temperature, the lower the recovery, it was
decided to study the interaction effects between the temperature
and the other variables in an attempt to explain this fact.
The most relevant interaction for temperature was that found
with the extraction volume.