Microoxidation of pinot noir wine | Mikrooksidacija vina modri pinot

English. Under controlled conditions, young red wine can benefit from the exposure to oxygen. The process of microoxidation is basically a way to manipulate the phenolic structures in wine, which attempts to control the amount of oxygen added to wine to enhance colour stability, soften hard tannins, and decrease the perception of off-flavours. We examined the influence of microoxidation on colour changing and content of phenolic compounds in Pinot Noir wine. We determined the content of total phenols, tannins, non-tannins, flavonoids, non-flavonoids, anthocyanins, colour density, colour hue, degree of red pigment colouration at different wavelength (420, 520 and 620 nm), estimation of SO2 resistant pigments concentration, and comparison in chemical parameters between control and microoxidated sample (pH, free and bounded SO2, ethanol, total dry extract, total, titratable and volatile acids). Results showed that microoxidation caused changes in colour characteristics, improved the wine colour density as compared to the control, encouraged the formation of polymeric pigments and copigment complex as a result of softer tannins (polymerization of phenolic compounds) and more stable colour which is resistant to the bleaching effect of  SO2.

Slovenian. Mlada rdeča vina izpostavljena kisiku lahko pod določenimi pogoji pridobijo na kakovosti. Proces mikrooksidacije je osnovna metoda, s katero lahko vplivamo na fenolno strukturo vin, ki skuša prilagajati količino dodanega kisika vinu z namenom povečati stabilnost barve, zmehčanja trpkih taninov in zmanjšanja neprijetnih arom. Proučevali smo vpliv mikrooksidacije na spremembo barve in vsebnosti fenolnih spojin vina modri pinot. Analize so vključevale določanje skupnih fenolov, taninov, netaninov, flavonoidov in neflavonoidov, antocianov, intenzitete barve, tona barve, deleža rdeče barve pri posameznih valovnih dolžinah (420, 520 in 620 nm), oceno koncentracije pigmenta odpornega na SO2 ter primerjavo končnega in kontrolnega vzorca v kemijskih parametrih (pH, prosti in vezani SO2, alkohol, skupni suhi ekstrakt, skupne, titrabilne in hlapne kisline). Rezultati so pokazali, da je mikrooksidacija povzročila spremembo barvnega značaja, izboljšanje intenzitete barve procesiranega vzorca v primerjavi s kontrolnim, vzpodbudila tvorbo polimernih barvil in kopigmentiranih kompleksov, s tem pa mehčanje taninov (polimerizacija fenolnih spojin) in stabilizacijo barve, ki je odporna na vezavo z SO2.