Chemical profile and antioxidative activity of red wines obtained from autochthonous and international grape clone varieties

Ova doktorska disertacija fokusirana je na hemijsku i biološku karakterizaciju odabranih uzoraka crvenih vina. Akcenat je stavljen na hemijsku karakterizaciju klonskih sortnih vina vranac i merlo, kao i na procenu antioksidativne aktivnosti vina sorte merlo u ćelijama kvasca. Pored uobičajenih spektrofotometrijskih metoda, primenjene su elektrohemijske metode (ciklična voltametrija i klasična polarografija), kao i EPR spektroskopija. Tečnom hromatografijom sa ultraljubičastim detektorom sa nizom dioda (PDA) i masenim detektorom sa tri analizatora – trostruki kvadrupol (QQQ) određen je fenolni profil analiziranih uzoraka vina. Njihov elementalni profil je okarakterisan pomoću induktivno spregnute plazme kuplovane sa optičkom emsionom spektroskopijom (ICP-OES) ili masenom spektrometrijom (ICP-MS). Antiradikalske aktivnosti ispitane su i na fiziološki relevantnim slobodnim radikalima (hidroksil i superoksid anjon). Osim toga, utvrđena je i ukupna antioksidativnost, kao i druge biološke aktivnosti (citotoksična i antibakterijska aktivnost) odgovarajućih uzoraka vina. Eksperiment na bazi vinskog kvasca je obuhvatio određivanje koncentracije proteina, ukupnih grupa –SH, kao i enzimskih aktivnosti (glutation peroksidaza, glutation reduktaza i katalaza). Eksperimentalno dobijeni podaci za klonska sortna vina merlo ukazuju na poseban doprinos glutation peroksidaze preživljavanju ćelija kvasca u uslovima oksidativnog stresa. Konačno, primenom veštačke neuronske mreže (ANN) razvijena je brza i precizna metoda za predviđanje uticaja malih promena u vinskom fenolnom profilu na aktivnosti istaknutih enzima antioksidativne zaštite. Svi protokoli u okviru ove disertacije mogu se primeniti kako na crvena, tako i na bela i roze vina.This doctoral dissertation focuses on the chemical and biological characterisation of selected red wine samples. Emphasis is placed on the chemical characterisation of clonal wines of Vranac and Merlot varieties, as well as on the evaluation of the antioxidant activity of Merlot wines in yeast cells. In addition to the usual spectrophotometric methods, electrochemical methods (cyclic voltammetry and classical polarography) as well as EPR spectroscopy were also applied. Phenolic profile of the analysed wine samples was determined using liquid chromatography with a multi-diode (PDA) ultraviolet detector and a triple quadrupole (QQQ) mass detector. The elemental profile is characterised by inductively coupled plasma coupled with optical emission spectroscopy (ICP-OES) or mass spectrometry (ICP-MS). Antiradical activities were also screened for physiologically relevant free radicals (hydroxyl and superoxide anion). In addition, total antioxidant activity as well as other biological activities (cytotoxic and antibacterial activity) of the respective wine samples were determined. The wine yeast experiment involved determining the concentration of proteins, total groups –SH, as well as enzymatic activities (glutathione peroxidase, glutathione reductase and catalase). The experimentally obtained data for clonal Merlot wine varieties indicate a particular contribution of glutathione peroxidase to the survival of yeast cells under oxidative stress conditions. Finally, using an artificial neural network (ANN), a rapid and accurate method was developed to predict the effect of small changes in the wine phenolic profile on the activities of prominent antioxidant enzymes. All protocols within this dissertation can be applied on white and rose wines as well