Rapid determination of flavonoids in green tea by synchronous fluorescence spectra coupled with chemometrics

Flavonoids are one of the most important antioxidant compounds of tea. It is necessary to determine flavonoid concentration of tea infusions and to understand how the storage condition and tea brewing processing impact on flavonoid content. The aim of this study is to analyze flavonoids' properties and predict flavonoid concentration using synchronous fluorescence spectra coupled with chemometrics. Different wavelength intervals were measured to develop an optimal model. Successive projection algorithms and interval partial least square regression were applied to extract informative wavelengths. The optimal interval partial least square regression model was obtained with the determination coefficient of calibration of 0.95, determination coefficient of cross-validation of 0.90.