Phenolic Compounds in Macedonian Grapes and Wines

This study evaluates the phenolic content of red (Vranec and Merlo) and white (Smederevka and Chardonnay) wines produced under different vinifications and grapes at different ripening phases. HPLC-DAD-MS, MALDI-TOF-MS and spectrophotometry were used for analysis of phenolics (anthocyanins, hydroxycinnamic acids and proanthocyanidins) in the samples, observing that their content varied greatly with the winemaking conditions and ripening. The effect of pH of the sample and mobile phase on anthocyanin analysis was explored. Maximum flavylium response was obtained in the samples acidified to pH 1.2 and elution using 1 % (V/V) formic acid in the HPLC mobile phase, allowing proper separation and detection of anthocyanins and phenolic acids as well as lower current in the MS source. Several MALDI matrices were tested: α-cyano-4-hydroxycinnamic acid (CHCA), sinapic acid (SA), 2,5- hydroxybenzoic acid (2,5-DHB) and C70. 2,5-DHB was superior with respect to all the matrices tested. For the first time, fullerene was introduced as a new possible matrix for MALDI-TOF-MS analysis of anthocyanins in wines and grapes.