This paper reports the results of a study on the ambiguous behaviour of substances with lmaxat 280 nm in the determination of total flavonoids in whole grape skin extracts made from a hydroalcoholicSO2-rich solvent, apparently not eluted with methanol after absorption on a C18 cartridgeemployed for sample pre-concentration and SO2 removal. After rejecting the hypothesis thatthey were irreversibly absorbed on the C18 cartridge, it seemed that they reacted with other phenolics during passage through the C18 cartridge and were totally eluted with methanol in this new combined form. This new hypothesis seems very probable and is in accord with the more recent acquisition about the synthesis of anthocyanins and flavanols.
|Numero di pagine||5|
|Rivista||Italian Journal of Food Science|
|Stato di pubblicazione||Published - 2010|