GRAPE MATURITY OF RHEIN RIESLING CULTIVAR AND SYNTHESIS OF ATYPICAL AGEING AROMA PRECURSORS

Istraživanja formiranja netipične arome starenja vina (UTA) otkrila su značajnu korela¬ciju između UTA, koncentracije 2-aminoacetofenona (AAP) i vina dobivena od grožđa, koje je bilo pod utjecajem stresa (nedostatak vode ili opskrbe dušikom), vina od grožđa iz vinograda s visokim prinosima ili od ranije branoga grožđa. Cilj ovog istraživanja bio je istražiti različitu dozrelost grožđa i sintezu indol-3-octene kiseline i triptofana u moštu i vinu kod bijeloga kultivara vinove loze Rizling rajnski (Vitis vinifera L.). Tretmani u istraživanju bili su dva roka berbe grožđa (redovna i kasna berba) s dva različita položaja (Mladice i Hrnjevac). Indol-3-octena kiselina i triptofan u moštu i vinu određeni su metodom tekućinskom kromatografijom visoke djelotvornosti, uz fluore¬scentni detektor. Dozrijevanjem grožđa koncentracije indol-3-octene kiseline i tripto-fana smanjivale su se nezavisno od godine istraživanja te ispitivanoga položaja. Vina dobivena od kasnije branoga grožđa imaju manju mogućnost pojave netipične arome starenja vina u odnosu na ona redovne berbe.The research on forming atypical aging off-flavor in wines (UTA) was revealed a significant correlation between the UTA , the concentration of 2-aminoacetophenones (AAP) and the wines produced from grapes affected by stress (lack of water or nitrogen supply), wines from grapes grown in high yielding vineyards or earlier harvested grapes. The aim of this study was to explore the different grape ripeness and synthesis of indole-3-acetic acid and tryptophan in must and wine of white cultivar Rhine Rieslin (Vitis vinifera L.). Treatments in the research have been the two periods of the grape harvesting dates (regular and late harvesting) from two different locations (Mladice and Hrnjevac). Indole-3-acetic acid and tryptophan in must and wine were determined by high performance liquid chromatography with fluorescence detector. As the process of ripening was going on the concentration of indole-3-acetic acid and tryptophan in must and wines have been reduced regardless the year of research and vineyards positions. Wines produced from late harvested grapes have a lower possibility of the appearance of atypical aroma aging effect compared to the regular harvest