Phenolic profile of some fruit wines and their antioxidant properties/Fenolni profil nekih vocnih vina i njihova antioksidativna svojstva

The composition and content of individual phenolic compounds in various fruit wines and overall antioxidant properties of these fruit wines were studied. Phenolic compounds were separated by reverse phase (RP) HPLC techniques, and their content was determined by means of mass spectrometer (MS) with triple quadrupole (TQ) analyser, which recorded specific precursor-product transitions. Antioxidant activity was monitored by the following spectrophotometric methods: DPPH, FRAP and Folin-Ciocalteu assay, respectively. Four types of berries (raspberry, blackberry, chokeberry and blueberry), one type of pome (apple) and one type of stone fruit (cherries) were used for the production of fruit wines. Corresponding fruit wines were produced by microvinification with or without adding sugar into the must before fermentation. Increase in alcohol level was responsible for the increased content of phenolic compounds in fruit wine due to improved extraction conditions. Produced fruit wines were preserved by adding S[O.sub.2] which interferes with the determination of antioxidant activity of phenolic compounds. In this case, the development of a correlation method based on FRAP assay was introduced. Fruit wines are a rich source of substances which show beneficial effects on human health. Depending on the fruit type, different antioxidant compounds were predominant in wine samples. Keywords: fruit wines, phenolic compounds, antioxidant activity, DPPH, FRAP, HPLCMS/MS Antioksidansi polifenolne strukture su siroko rasprostranjeni u prirodi i to pogotovo u vocu i proizvodima od njega. Zbog toga je u razlicitim vocnim vinima ispitivan sadrzaj i sastav pojedinih polifenolnih jedinjenja, ali i ukupni antioksidantni potencijal tih vina. Fenolna jedinjenja su razdvojena reverzno-faznom (RF) HPLC tehnikom dok je njihov sadrzaj odrecen pomocu masenog spektrometra sa trostrukim kvadrupolnim (TQ) analizatorom koji je pratio specificne prekursor-produkt prelaze (tzv. MRM mod). Antioksidativna aktivnost je pracena spektrofotometrijskim metodama: DPPH, FRAP i Folinovom metodom. Za proizvodnju vocnih vina su primenjene cetiri vrste bobicastog voca (malina, kupina, aronija, borovnica), jedno jabucasto (jabuka) i jedno kostunjavo (visnja). Vina su proizvedena postupkom mikrovinifikacije bez i sa dodatkom secera u dezintegrisano voce pre fermentacije. Povecan nivo alkohola u vinima je uticao na povecanje sadrzaja fenolnih jedinjenja u analiziranim uzorcima zbog poboljsanja uslova ekstrakci