Polyphenolic substances in wine

Grožđe je bogat izvor različitih organskih kiselina, ugljikohidrata, fenola, minerala, dušikovih spojeva i vode. Za boju vina odgovorni su fenolni spojevi, odnosno polifenoli koji iz kožice i opne sjemenke prelaze u vino. Dijelimo ih na flavonoide i neflavonoide. Od flavonoida najvažniji su antocijani koji su odgovorni za plavu, crvenu i ljubičastu boju vina. Oni tijekom fermentacije prelaze u vino i vrlo su podložni degradaciji. Uz njih je vezan i fenomen kopigmentacije koji određuje prvotnu boju antocijana. Tanini su spojevi koje ubrajamo i u neflavonoide i flavonide te su odgovorni za trpkost i gorčinu vina. Stilbeni su neflavonoidni spojevi koji, osim što su odgovorni za boju crnih vina, imaju antioksidativna svojstva. Povoljno utječu na zdravlje ljudi, posebice na sprječavanje kardiovaskularnih bolesti. Maceracija je najvažniji proces kojim polifenoli iz kožice grožđa prelaze u vino. Također utječe i na oslobađanje voćnih aroma i prekursora arome. Bijela vina se dobivaju postupkom hladne maceracije, a crna vina klasičnom maceracijom. Najveći utjecaj na maceraciju ima temperatura i o njoj ovisi količina ekstrahiranih bojenih tvari. Osim maceracije, na boju vina također utječu i postupci bistrenja vina te sumporenje. S obzirom na različite postupke prerade grožđa i sorte, dobivamo i različite boje vina. Tako prema boji vina dijelimo na: crna, rose i bijela.Grapes is a rich source of different organic acid, carbohydrates, pfenols, minerals, nitrogen compounds and water. Phenolic compounds or polyphenols are responsible for the color of the wine, which turn into wine from skin and membranes seeds. We share them on flavonoids and nonflavonoids. Of flavonoids, anthocyanins are the most important which responsible for blue, red and purple color of the wine. They cross during fermentation in wine and are very susceptible to degradation. Linked to this is the phenomenon copigmentation which determines the original color of anthocyanins. Tannins are compounds that include flavonoids and nonflavonoids and they are responsible for astringency and bitterness of wine. Stilbenes are nonfalvonoids compounds which are responsible of the color of the wine and also have antioxidant properties. They have good influence on health of people, especially on cardiovascular diseases. The maceration is the most important process by which polyphenols from grape skins turn into wine. It also affects the release of fruity flavor and aroma precursors. White wines are obtained by cold maceration and red wine by classic maceration. The biggest impact on a maceration have temperature and it conditions the quantity extracted the coloring matter. Besides maceration, wine clarification and sulfurize also affect the color of the wine. Due to different methods of processing of grapes and varieties, we get different colors of wine. So we have black, rose and white color of wine