FREE AND GLYCOSIDICALLY BOUND AROMA COMPOUNDS IN GRAPE MUST OF 4 NON-FLORAL VITIS-VINIFERA VARIETIES

Free and glycosidically bound compounds of the four Vitis vinifera cul tivar grapes, Chenin, Colombard, Riesling and Semillon, were determine d qualitatively and quantitatively. To carry out the isolation and sep aration of these compounds, a selective non-ionic resin, amberlite XAD -2 was used. Free and bound fractions were analyzed by capillary gas-c hromatography (GC) equipped with a flame ionization detector (FID) and capillary gas-chromatography coupled to mass-spectrometry (GC-MS). Bo und fraction was determined indirectly through release of aglycons by enzymatic hydrolysis or directly after trifluoroacetylation (TFA). Som e glycosidic compounds, glucosides, arabinosylglucosides and rutinosid es, were identified and quantified in some of these Varieties for the first time. Chenin and Colombard grapes were mainly characterized by t heir low content of monoterpenols and high concentrations of free C-6 compounds. Riesling and Semillon varieties, with the highest content o f free and bound terpenes, contained a high level of 2-phenylethanol a s diglycoside compounds.