Influence of rainfall and number of sunny days in three consecutive years of harvesting on the content of color and aroma components in white wines from vineyard Mandićevac

Abstract

Aroma vina predstavlja kemijski kompleks koji sadrži preko tisuću hlapljivih spojeva, na osnovu kojih se može odrediti i kvaliteta vina, a igra i veliku ulogu kod odabira vina od strane potrošača. Dio tih spojeva potječe od same sorte grožđa, dok se ostali oslobađaju tijekom procesa fermentacije i tijekom odležavanja i dozrijevanja vina. Dosadašnja istraživanja utvrdila su pozitivan utjecaj umjerene konzumacije crnih vina na ljudsko zdravlje zbog većeg sadržaja polifenola. Međutim, novija istraživanja pokazuju da polifenoli u bijelim vinima imaju jače antioksidativno djelovanje. Ovisno o sorti grožđa i načinu prerade, sadržaj polifenola je različit, a najčešće su to spojevi iz grupe tanina i tvari boje. Danas se pažnja posvećuje njihovoj nutritivnoj i zdravstvenoj vrijednosti, antioksidacijskom, antibakterijskom, antikancerogenom djelovanju i dr. Cilj ovog istraživanja je bio utvrditi sadržaj aromatičnih spojeva, polifenola, flavonoida te antioksidacijsku aktivnost u bijelim vinima đakovačkog vinogorja Mandićevac (uzorci: Chardonnay, Graševina i Traminac berbe 2011, 2012. i 2013.). Rezultati su pokazali da sorta, geografski položaj te količina oborina i broj sunčanih dana u godini utječu na sadržaj navedenih spojeva. Sva tri vina su imala najveći sadržaj polifenolnih tvari i tvari arome u godini berbe 2011. koja je imala najmanju količinu oborina i najveći broj sunčanih sati i dana.The aroma of wine represents a chemical complex that contains over one thousand volatile compounds, based on which the quality of wine can be determined, and plays a major role in selecting wines from consumers. Some of these compounds originate from grape varieties, while others are released during the fermentation process and during the aging and maturation of wine. Previous research has determined the positive impact of moderate consumption of black wines on human health due to the increased content of polyphenols. However, recent studies have showed that polyphenols in white wines have higher antioxidant activity. Depending on the grape varieties and the method of processing, the polyphenol content is different, and most commonly these are tannin compounds and aroma components. Today, the most attention is observed to their nutritional and health value, antioxidative, antibacterial, anticancerogenic impact and other. The aim of this study was to determine the content of aroma components, polyphenols, flavonoids and antioxidant activity in white wines of the Đakovo wine district Mandicevac (samples: Chardonnay, Graševina and Traminac, year of harvest 2011, 2012 and 2013). The results showed that the variety, the geographic position, the rainfall and number of sunny days per year had impact on content of the above mentioned compounds. All three wines had the highest content of total polyphenols and aroma components in 2011 vintage, which had the smallest rainfall and the highest number of sunny hours and days