Analysis of Volatile Compounds in White Wines: A Comparative Study of Slovenian and Spanish VarietiesŠegina, Tina (Avtor) Marolt, Gregor (Mentor) Rodríguez Bencom, Juan José (Komentor) Volatile CompoundsWhite WineGC–MSPCATwo-Way ANOVAWhite wine aroma is determined by a complex mixture of volatile compounds whose composition is influenced by grape variety, geographical origin, grape maturity, fermentation, ageing, and other winemaking practices. The aim of this master’s thesis was to compare the volatile profiles of selected Slovenian and Spanish white wines and to evaluate whether the observed differences could be associated with grape variety and country of origin. A total of 50 wine samples representing five varieties – Chardonnay, Sauvignon Blanc, Malvasia, Riesling, and Muscat – were included, with five samples of each variety from each country. Volatile compounds were isolated from the wine samples by liquid-liquid extraction with dichloromethane and analysed by gas chromatography coupled with mass spectrometry (GC-MS). Based on their frequency of occurrence in the obtained chromatograms, 54 volatile compounds were selected for further data analysis. Their analytical responses were expressed as relative peak area equivalents using four internal standards, while the label-declared alcohol content was included as an additional variable. The resulting dataset of 55 variables was evaluated using principal component analysis (PCA) to investigate correlations and differences among the wine samples. Two-way ANOVA was then applied to identify variables significantly associated with country of origin, grape variety, and the country  variety interaction. Initial PCA of all 55 analytes revealed considerable overlap between Slovenian and Spanish samples. Country-related separation became more apparent when individual varieties were analysed separately, suggesting that varietal differences partly masked the effect of geographical origin. The clearest country-related separation was obtained using 19 variables selected by two-way ANOVA, although complete separation was not achieved. In the variety-based analyses, Muscat was the main driver of sample separation because of its characteristic terpene-related composition. Chardonnay, Sauvignon Blanc, Malvasia, and Riesling showed a considerable overlap, even after ANOVA-based variable selection. Therefore, Muscat was excluded from the PCA and ANOVA analyses to allow the remaining varieties to be examined in more detail, but only partial differentiation was observed. The analysis of combined variety-country groups likewise showed incomplete separation, further indicating that the two factors had overlapping effects on the volatile profiles. Overall, the results demonstrate that GC-MS combined with PCA and two-way ANOVA provides useful information for investigating differences in the volatile composition of white wines. The observed profiles reflected a combination of varietal, geographical, and production-related influences rather than a single dominant source of variation. Consequently, larger and more balanced sample set, including wines from different producers, regions, and harvest years, together with the information on production conditions, would be required to confirm the observed trends and enable more reliable differentiation of the wines.20262026-09-03 12:15:10Magistrsko delo/naloga186616VisID: 25713sl