Impact of microbiological and technological factors on volatile phenols content in Montenegrin red winesRadonjić, Sanja (Avtor) Košmerl, Tatjana (Mentor) Prosen, Helena (Komentor) winevolatile phenolshydroxycinnamic acidsstarter culturesyeastslactic acid bacteriared wineautochthonous grape varietiesVranacKratošijaCabernet SauvignonThe aim of this research has been to examine the microbiological and technological parameters influencing volatile phenols (VP) production in wine of the autochthonous Montenegrin grape varieties Kratošija and Vranac and the international grape variety Cabernet Sauvignon. Within two consecutive vintages (2012 and 2013) grape must and wines have been analysed on the presence of Dekkera bruxellensis yeast and on hydroxycinnamic acids (HCA) as precursors of VP. Among technological parameters, the influence of commercial yeast and lactic acid bacteria (LAB) and the addition of oak alternatives on wine chemical composition and sensory profile has been examined. Caffeic acid represented the prevalent HCA compound for all varietal wines, with the exception of Kratošija in the 2012 vintage in which ferulic acid (93.2%) was the main HCA. Higher total content of all three examined HCA was observed in all varietal wines inoculated with commercial yeast in 2012, as compared to 2013, due to the high content of caffeic acid in the 2012 vintage. Statistically significant differences in VP content were found between commercial yeast, LAB and oak alternatives. The presence of Dekkera bruxellensis spp. has been noticed only in the 2013 vintage for Vranac control wine after alcoholic fermentation (AF), confirming that these yeasts are present in extremely low numbers at the beginning of AF only. Vranac wines, inoculated with commercial yeast, contained the highest content of p-coumaric acid in 2012 (1.54 mg/L), followed by Kratošija wines in the 2013 vintage (1.03 mg/L). The highest number of samples with detected VP from the vintage 2012 were found for Vranac wines (12 out of 28), while in 2013 vintage, Kratošija had the highest number of samples (18 out of 28). VP have appeared only in wines of autochthonous grape varieties, after long bottle aging and the number of infected samples were vintage dependent. Comparing autochthonous Montenegrin wines to Cabernet Sauvignon, it can be concluded that this international variety grown in agro-ecological conditions of Ćemovsko field does not show increased VP even after three or four years of aging in bottles. It has been concluded that VP are formed predominantly in wines with high alcohol content, low pH, low reducing sugars content, and even in wines with free SO2 above 30 mg/L[S. Radonjić]20202020-12-31 07:15:30Doktorsko delo/naloga124107sl