FRACTIONATION AND PARTIAL CHARACTERIZATION OF PROTEIN-FRACTIONS PRESENT AT DIFFERENT STAGES OF THE PRODUCTION OF SPARKLING WINES

Soluble proteins from sparkling wines (var. Chardonnay) manufactured i ndustrially following the Champenoise method were analysed by analytic al anion-exchange FPLC (fast protein liquid chromatography). Samples o f the must, the unfined wine, the fined wine and the sparkling wines a fter 3, 6, 9, 12, 15 and 18 months of ageing with yeast lees were take n. Eight main must protein fractions were collected and characterized by isoelectric focusing and capillary electrophoresis. Six fractions c onsisted of proteins with isoelectric points (pIs) from 4.27 to 3.04. Two fractions, according to their UV spectra, seemed to contain phenol ic compounds. A comparison of FPLC profiles of the must, the unfined w ine and the fined wine indicated that both fermentation and stabilizat ion processes decrease the concentration of those proteins with less a ffinity for the anion-exchange column and with a higher pi. No changes in the protein profiles of sparkling wines were observed during the f irst 18 months of ageing with yeast. (C) 1998 Elsevier Science Ltd, Al l rights reserved.