Determination of red wine flavonoids by HPLC and effect of aging

A new method for simultaneous determination of 10 flavonols and 2 flavones by high performance liquid chromatography was developed in this paper. The identified compounds contained quercetin, kaempferol, myricetin, rhamnetin, isorhamnetin, quercetrin, rutin, morin, galangin, fisetin, apigenin and luteolin. The chromatographic separation of these flavonoids was performed in a single run by using the mobile phase gradient elution of acetonitrile–methanol–water mixture (1% tetrahydrofuran, THF) at 20 °C, with the flow rate at 1.0 ml/min and the detection wavelength at 360 nm. With direct injection of wine samples, seven red wine samples, differing in their origin of producing places and time, were analyzed for flavonoids content by this method. The results showed the presence of myricetin, luteolin, quercetin, kaempferol, isorhamnetin and galanin. Additionally, the changes of flavonoids in red wines stored in the three types of oak barrels with aging time were investigated, which indicated that the component of flavonoids in red wine is related to wine aging greatly. These provide a substantial basis for the further research on control of flavonoids during winemaking.