Influence of high voltage electrical discharge on the composition of polyphenolic and volatile compounds of wine during ageing

Cilj ovog rada je bio utvrditi utjecaj visokonaponskog električnog pražnjenja i dodatka antioksidansa (standardna koncentracija SO2, snižena koncentracija SO2 uz dodatak glutationa i snižena koncentracija SO2) na sastav polifenolnih i hlapivih spojeva nakon 12 mjeseci starenja bijelog vina Graševina i crnog vina Cabernet Sauvignon. Za tretman vina hladnom plazmom korištena je tekućinska hladna plazma generirana pulsnim visokonaponskim generatorom uz upuhivanje mjehurića plina argona pri pozitivnom polaritetu. Koncentracija ukupnih fenola, tanina i antocijana određena je primjenom spektrofotometrijskih metoda. Sastav slobodnih antocijana, fenolnih kiselina i flavanola određen je primjenom tekućinske kromatografije visoke djelotvornosti (HPLC). Sastav hlapivih spojeva vina određen je primjenom plinske kromatografije s masenom detekcijom (GC/MS) uz prethodnu mikroekstrakciju na čvrstoj fazi (SPME). Tretman visokonaponskim električnim pražnjenjem utjecao je na blago smanjenje koncentracije polifenolnih i hlapivih spojeva u bijelom vinu. S druge strane, navedeni tretman u crnom vinu utjecao je na značajno smanjenje polifenolnih spojeva te porast koncentracije hlapivih spojeva u vinima sa sniženom koncentracijom SO2. Dodatak antioksidansa u vino utjecao je na stabilnost analiziranih polifenolnih spojeva.The aim of this study was to determine the effect of high voltage electrical discharge and antioxidant addition (standard SO2 concentration, reduced SO2 concentration with glutathione addition and reduced SO2 concentration) on the composition of polyphenolic and volatile compounds of Graševina and Cabernet Sauvignon wine after 12 months of ageing. Liquid cold plasma generated by a pulse high-voltage generator was used for the treatment of cold plasma wine with blowing argon gas bubbles at positive polarity. The concentration of total phenols, tannins and anthocyanins was determined using spectrophotometric methods. The composition of free anthocyanins, phenolic acids and flavonols were determined using high performance liquid chromatography (HPLC). The composition of the volatile compounds of the wine was determined using gas chromatography with mass detection (GC/MS) with previous solid phase microextraction (SPME). Treatment with high voltage electrical discharge resulted in a slight decrease in the concentration of polyphenolic and volatile compounds in white wine. On the other hand, the mentioned treatment in red wine resulted in a significant decrease in polyphenolic compounds and an increase in the concentration of volatile compounds in wines with reduced SO2 concentration. The addition of antioxidants to wine contributed to the stability of the analyzed polyphenolic compounds