Impact of ecological production on antioxidant activity and organoleptic properties of wine

Polifenoli prisutni u vinu, kojima su osobito bogate crne sorte vina, puno su istraživani zbog svojih brojnih bioloških učinaka. Na udio polifenola u vinu primarno utječu sorta, klimatski uvjeti i lokalitet, dok je važnost utjecaja načina proizvodnje još uvijek upitna. U okviru ovog istraživanja pokušao se utvrditi utjecaj načina proizvodnje vina (ekološki ili konvencionalni) na udio polifenola i antioksidativnu aktivnost vina te neka organoleptička svojstva. Analizirani su uzorci ukupno 38 crnih i bijelih vina s područja Republike Hrvatske. Udio ukupnih polifenola, određen Folin – Ciocalteu metodom, kretao se od 0,38 do 2,73 mg/mL u crnim vinima, te 0,19 do 0,47 mg GAE/mL u bijelim vinima. Antioksidativna aktivnost vina određena je DPPH metodom; vrijednosti su se kretale od 19,71 do 208,5 mmol AAE/L u crnim, te 2,84 do 26,05 mmol AAE/L u bijelim vinima. Spektrofotometrijski određivan udio antocijana kretao se od 1,20 do 5,16 mg/L u crnim i od 0,60 do 1,25 mg/L u bijelim vinima. Nakon provedenih istraživanja, utvrđeno je da način uzgoja i proizvodnje vina ne utječe bitno na koncentracije ukupnih fenola, antocijana i na antiradikalnu aktivnosti u crnim vinima. Kod bijelih vina, utvrđene su značajno više vrijednosti udjela polifenola i antiradikalne aktivnosti u ekološki proizvedenim vinima. Usporedbom kemijskog sastava crnih i bijelih vina, utvrđeno je da su crna vina, bez obzira na način proizvodnje, bogatija polifenolima i antocijanima, te imaju veću antioksidativnu aktivnost. Ispitivanjem organoleptičkih svojstava vina, utvrđena je značajna korelacija između udjela polifenola u vinima i intenziteta boje vina.Phenolics present in wines, particularly abundant in red wine cultivars, have been extensively researched due to wide range of their biological activities. The total phenolic content of wine is primarily affected by climate, wine cultivar and locality, while the influence of production method has not yet been investigated. The aim of this research was to determine the impact of production method (ecological or conventional) on the total phenolic content, antioxidative activity and some organoleptic properties of wine. A total of 38 wine samples, both red and white cultivars from Croatian territory, have been studied. The total phenolics content, determined by Folin – Ciocalteu method, varied from 0,38 to 2,73 mg GAE/mL in red wines, and from 0,19 to 0,47 mg GAE/mL in white wines. The antioxidative effects of wine phenolics were determined according to DPPH method. Results varied from 19,71 to 208,5 mmol AAE/L in red wines, and from 2,84 to 26,05 mmol AAE/L in white wines. The total content of anthocyanins, determined by spectrophotometric method, varied from 1,20 to 5,16 mg/L in red wines, and from 0,60 to 1,25 mg/L in white wines. Results of conducted research showed that the impact of production method on the total phenolics content, total anthocyanins content and antioxidative effects of wine phenolics is not statistically significant in red wines. However, in white wine samples, the ecological production resulted in significantly higher total phenolic content and antioxidative activity. Comparison of red and white wines showed that red wines contain significantly higher amounts of total phenolics and anthocyanins, regardless of the production method. Investigation of organoleptic properties of wine showed significant correlation between total phenolic content and color intensity of wines