Study of low molecular weight phenolic compounds during the aging of sparkling wines manufactured with red and white grape varieties.

Thirty-two phenolic compounds of low molecular weight were identified in 36 white, blanc de noir, and rosé sparkling wines by using HPLC with photodiode array and mass spectrometry detection. Some of the identified compounds, such as cis- and trans-ethylcaftaric, cis- and trans-ethylcaffeic, and cis- or trans-ethyl-p-coumaric acids, 2R,3R-dihydroquercetin, 2R,3R-dihydrokaempferol 3-O-beta-d-glucoside, and a lignan derivative are described for the first time in sparkling wines manufactured with grapes of red varieties. This is also the first time that cis- or trans-diethylfertaric acids have been identified in wines. When cluster analysis was applied to the data of 19 of the 32 identified compounds, the greatest differences found in the low molecular weight phenolic compounds in sparkling wines were due to the grape variety from which they were manufactured, whereas aging time did not significantly influence phenolic composition. Nine phenolic compounds, that is, trans-p-coumaric and trans-caftaric acids, trans-resveratrol glucoside, cis-coutaric, trans-coutaric, cis-p-coumaric, and cis-caftaric acids, tryptophol, and syringic acid, permit the wines to be classified correctly in accordance with the grape variety from which they were manufactured.