One of the most common techniques for wine analysis is gas chromatography coupled with the flame ionization detector and headspace autosampler (HSS-GC/FID) for the analysis of the volatile compounds in the wine samples. The main goal of this thesis was to develop the method for the analysis of volatiles (methanol, higher alcohols, and esters) in wine samples made of Cabernet Sauvignon and Merlot. Validation parameters were: r2 > 0.995; LOD (0.2–1.0 mg/L); CV (2.7–6.3%), and recovery (92–106%). Average contents of the methanol (198.0 mg/L and 150.5 mg/L), higher alcohols (398.5 mg/L and 335.8 mg/L), ethyl acetate (42.0 mg/L and 55.6 mg/L), and acetaldehyde (23.3 mg/L and 16.1 mg/L) were determined for Merlot and Cabernet Sauvignon, respectively. Based on the obtained results, it was concluded that the content of methanol is in direct connection with the type of grape used for preparation of the wine. It was also found that the duration of the maceration directly influenced the content of the methanol and higher alcohols. On the other hand, type of grape appeared not to have influence on the content of ethyl acetate and acetaldehyde in wines. The post hoc Tukey’s HSD test at 95% confidence limit showed significant differences between observed samples. Principal Component Analysis (PCA) was used for assessing the effect of different genotypes and extraction methods on wine samples. Using PCA of observed samples, the possible directions for improving the quality of product can be realized.

The phenolic compounds, which are rich in red wine, have gained considerable attention due to their antioxidant potential. Selected Serbian wines were analyzed for their antioxidant activity by DPPH test and the total content of phenolic compounds was determined by employing the Folin-Ciocalteu colorimetric method. The major polyphenols were determined by HPLC. The antioxidant activity was correlated with the amount of specific polyphenols (gallic acid, caffeic acid, catechin, epicatechin, myricetin, and kaempferol) by quantitative structure-activity relationship. The origin of the antioxidant potential of wines was discussed based on the individual activity of identified polyphenols and theoretical calculations (at APFD/6-311++G(d,p) level of theory). The thermodynamic parameters of free radical scavenging activity and reactivity towards DPPH • , HO • , and HOO • were explained with special emphasis on the effect of structure and intramolecular interactions in polyphenols. Based on the presented data, the positive effects of selected Serbian wines on humane health and biologically relevant free radicals are concluded.

In this study, HPLC-DAD rapid analysis of phenols in wine samples was performed. The recording was performed at different wavelengths: phenolic acid (254nm), flavan-3-ols and stilbene (280nm), flavonoids (340nm) and anthocyanins (520nm). In selected wines, the concentrations of the following compounds were determined and expressed in mg/l of wine. The isolated derivatives were: hydroxybenzoic acids, derivatives of caffeic, ferulic, syringic, and vanillic acids, catechin (flavanol), rutin, myricetin and quercetin (flavonols), and the stilbene derivative-resveratrol. The properties and quantities of phenolic compounds in organic wines were investigated. The results show the content of phenolic compounds in organic wines do not differ qualitatively and quantitatively from those in conventional wines. Wine samples have shown good antioxidative activity according to both DPPH and FRAP analysis, which indicates the good antioxidative potential and high antioxidant concentration in tested wines. Cabernet Sauvignon wines have shown better radical scavenging activity than Merlot, especially when the DPPH test was considered.