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Free amino acids in grape juice are important as nitrogen source for yeast strains during alcoholic fermentation. The aim of this research was to determine amino acid profiles in musts from nine grapevine cultivars (six white and three red). The cultivars were located in a homogeneous soil and climatic zone of Bilogora growing hill (West continental region, Prigorje–bilogora subregion), grown on the same training system. The experiment was conducted in vintage 2015. The results showed significant influence of grape cultivar on the amino acids composition in musts of white and red grape cultivars. Arginine was dominant in most analyzed varieties of amino acids. The highest concentration of arginine in white cultivars was measured in Chardonnay must (470.18 mg/L) and in red cultivar must from Saint Laurent (280.65 mg/L). Statistically significant difference was also found in the total amino acid composition of white and red cultivars. The highest concentration of total amino acids in white cultivars was determined in Manzoni juice (1639.51 mg/L) and among the red cultivars in Pinot noir juice (1173.12 mg/L).

Slobodne aminokiseline u moštu su važan izvor dušika za kvasce tijekom alkoholne fermentacije. Cilj ovog istraživanja bio je odrediti aminokiselinski profil mošteva devet sorata vinove loze (šest bijelih i tri crne). Sorte vinove loze zasađene su u ujednačenim uvjetima tla i klime vinogorja Bilogora (Regija Kontinentalne Hrvatske, podregija Prigorje-bilogora) te su imale iste agrotehničke uvjete uzgoja. Pokus je postavljen 2015. godine. Rezultati su pokazali signifikantan utjecaj sorte na aminokiselinski sastav u moštevima bijelih i crnih sorti. Najzastupljenija aminokiselina u moštevima devet sorata vinove loze bila je arginin. Najveća koncentracija arginina kod bijelih sorata bila je u moštu Chardonnay (470,18 mg/l), a kod crnih sorata u moštu Lovrijenca (280,65 mg/l). Statistički značajne razlike nađene su između koncentracije ukupnih aminokiselina bijelih i crnih sorata. Najveća koncentracija ukupnih aminokiselina kod bijelih sorata bila je u moštu sorte Manzoni (1639,51 mg/l), a kod crnih sorata u moštu sorte Pinot crni (1173,12 mg/l)

Aim of this study was to monitor the influence of drying method (naturally and chamber drying) and different sample preparation on supercritical CO2 extraction of oil from three grape seed varieties (Graševina, Zweigelt, Cabernet Sauvignon). The highest oil content was obtained from naturally dried screened and washed seeds of red variety Cabernet Sauvignon (14.85%) and lowest from chamber dried screened seeds of white variety Graševina (7.67%). Peroxide value ranged from 0.36 to 1.77 mmol O2/kg oil, free fatty acids 0.28-8.0%, and insoluble impurities 0.05-0.28%. Determined fatty acids were palmitic (6.98-11.58%), stearic (3.82-6.59%), oleic (14.90-19.97%) and linoleic acid (61.82-71.96%) in oil obtained from naturally dried seeds and 6.84-8.68%, 4.12-5.73%, 15.10-20.18% and 67.88-70.76% in oil from chamber dried seeds, respectively. In defatted cakes after supercritical CO2 extraction, protein and fibre content ranged from 8.17 to 9.85% and 34.58 to 43.96%, respectively. According to ANOVA results, sample preparation and drying method had statistically significant influence on grape seed oil extraction.

The research on forming atypical aging off-flavor in wines (UTA) was revealed a significant correlation between the UTA , the concentration of 2-aminoacetophenones (AAP) and the wines produced from grapes affected by stress (lack of water or nitrogen supply), wines from grapes grown in high yielding vineyards or earlier harvested grapes. The aim of this study was to explore the different grape ripeness and synthesis of indole-3-acetic acid and tryptophan in must and wine of white cultivar Rhine Rieslin (Vitis vinifera L.). Treatments in the research have been the two periods of the grape harvesting dates (regular and late harvesting) from two different locations (Mladice and Hrnjevac). Indole-3-acetic acid and tryptophan in must and wine were determined by high performance liquid chromatography with fluorescence detector. As the process of ripening was going on the concentration of indole-3-acetic acid and tryptophan in must and wines have been reduced regardless the year of research and vineyards positions. Wines produced from late harvested grapes have a lower possibility of the appearance of atypical aroma aging effect compared to the regular harvest.

Quantities of sugar and acid in the must of Riesling Rhine of Kutjevo vineyard area were observed on the Jakobovic Family Estate in the period of five years, from 1999 to 2003. The analysis shows varying quality of must and wine due to climatic conditions of a particular year. In the year 2000 and 2003 the quantities of sugar were exceptionally high and the content of all acids considerably lower which reflected later on the quantity of alcohol and acid in wine, as well as on organoleptic traits of wine.