After analyzing the green tea and oolong tea samples, besides 3
black tea samples from China, India and Kenya, the total amounts
of FOG compounds ranged from 2.32 to 5.67 g/kg dry weight (calculated
as aglycones). Comparing with their original aglycone
types, there are many kaempferol glycosides in green teas, more
quercetin glycosides and myricetin glycosides in oolong teas, and
dominated quercetin glycosides in black teas. Whether the difference
in their aglycones was caused by the tea cultivars or planting
area, should be further studied on more tea samples.