Importantly, water has been used to extract flavonoids
from bitter melon . However, if water is to be the
solvent of choice, the optimal conditions for the aqueous
extraction of flavonoids from bitter melon need to be
determined. The aqueous extraction of bioactive compounds
from plant matrices is known to be dependent on
several extraction parameters. For example, the
temperature and length (time) of the extraction, the ratio
of the water to the plant material and how many times the
same material is extracted can have significant impacts
on the extraction of bioactive compounds from plant materials.
Furthermore, in the case of flavonoids,
because they occur as aglycones and glycosides, the extraction
efficiency obtained with optimal aqueous conditions
also needs to be compared with that of less polar
solvents.