Flavone luteolin was detected only in brewed black teas in the
range of 0.006–0.010 mg/L. Amongst flavonols, quercetin
and traces of myricetin (about 0.014 mg/L) were present
only in black tea infusions. Kaempferol as aglycone has not
been found in all studied teas, although its presence in the
forms of different glycosides was determined in several tea
and herbal infusions [16