Influence of high power ultrasound and addition of antioxidants on polyphenolic and aroma composition of wine during ageing

Cilj ovog rada bio je ispitati utjecaj ultrazvuka visokih snaga i dodatka antioksidansa (sumporov dioksid i glutation) na polifenolni i aromatski sastav vina Graševina i Cabernet Sauvignon nakon 12 mjeseci starenja u bocama. Koncentracija ukupnih fenola u bijelom i crnom vinu te koncentracije ukupnih tanina i antocijana u crnom vinu određene su primjenom spektrofotometrijskih metoda. Sastav fenolnih kiselina i flavanola u bijelom vinu te sastav slobodnih antocijana u crnom vinu određen je primjenom tekućinske kromatografije visoke djelotvornosti (HPLC). Spojevi arome analizirani su primjenom plinske kromatografije s masenom spektrometrijom uz mikroekstrakciju na čvrstoj fazi (SPME–GC/MS). U bijelom vinu navedeni tretman utjecao je na blago sniženje koncentracije ukupnih i pojedinačnih fenolnih spojeva (hidroksibenzojeve kiseline i flavan-3-ol monomeri) te spojeva arome (esteri i viši alkoholi), dok su crnom vinu utvrđene značajno niže koncentracije ukupnih i slobodnih antocijana posebno u vinima s nižim udjelom antioksidansa te više koncentracije etilnih estera i hlapivih masnih kiselina.The aim of this study was to investigate the effects of high power ultrasound and the addition of antioxidants (sulfur dioxide and glutathione) on the polyphenolic and aroma composition of Graševina and Cabernet Sauvignon after 12 months of bottle ageing. Concentration of total phenols in white and red wine and concentration of total tannins and anthocyanins in red wine was determined using spectrophotometric methods. The composition of phenolic acids and flavanols in white wine and the composition of free anthocyanins in red wine was determined by application of high performance liquid chromatography (HPLC). The aromatic compounds were analyzed by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC/MS). In white wine, application of high power ultrasound induced slight decrease in concentrations of total and some individual phenolic compounds (hydroxybenzoic acids and flavan-3-ol monomers) and aroma compounds (esters and higher alcohols). Also, significantly lower concentrations of total and free anthocyanins were determined in ultrasound treated red wine, especially in wine with a lower concentration of antioxidants; and increase in concentrations of ethyl esters and volatile fatty acids