Application of advanced separation techniques in wine quality control

Wine is a very complex mixture of a large number of compounds, including phenolics (anthocyanins, flavan-3-ols, flavonols, phenolic acids, stilbenes), volatiles (alcohols, esters, aldehydes, volatile phenols), organic acids, carbohydrates, proteins, minerals, vitamins etc. All these compounds significantly influence the quality of wine, affecting the sensory perception such as flavor, aroma and colour, pH, chemical and microbiological stability of wines. Separation techniques have been applied for determination of the individual compounds from each group present in the wine such as gas chromatography, liquid chromatography and electrophoresis. For determination or aroma profile of wines, gas chromatography-mass spectrometry (GC-MS) is one of the most sensitive technique for qualitative and quantitative characterization of volatile compounds [1,2]. Reversed-phase liquid chromatography (RP-HPLC) coupled to photodiode array detector has been widely used for analysis of phenolic compounds, organic acids, carbohydrates and biogenic amines in wine [3,4,5]. In the last few years, capillary electrophoresis coupled to UV detection offers fast analysis and efficient resolution, or coupled to mass spectrometer (CE-MS) or accurate-mass quadrupole time-of-flight mass spectrometer (QTOF-MS) provides high separation sensitivity, high mass accuracy and resolution in a single analysis. This study reports optimized and validated separation methods, such as GC-MS, HPLC-DAD and CE-QTOF-MS for determination of aroma compounds, phenolic compounds and organic acids, respectively, in Macedonian red wines. Results provide important information for the organic acids concentration and aroma profile of wines from various red varieties and new evidence on the bioactive phenolic composition of the Stanušina wine, an autochthonous Macedonian variety