THE INFLUENCE OF COMMERCIAL SACCHAROMYCES CEREVISIAE ON THE POLY-SACCHARIDES AND OTHER CHEMICAL PROFILES OF NEW ZEALAND PINOT NOIR WINES
Wine polysaccharides (PS) play an important role in balancing mouthfeel and stability of wine and even influence aroma volatility. Despite this, there is limited research into the effect of winemaking additives on the polysaccharide profile and other macromolecules of New Zealand (NZ) Pinot noir wine. In this study the influence of a selection of commercial S. cerevisiae strains on the chemical profile, including polysaccharides, of New Zealand Pinot noir (PN) wine was investigated. Research scale PN fermentations using five strains of commercially available S. cerevisiae (Lalvin EC1118 and RC212, Levuline BRG YSEO, Viallate Ferm R71 and R82) were undertaken. PS were qualified and quantified using HPLC-RID. Wine produced using Vialatte Ferm R71 had higher PS content than the uninoculated control, primarily for the high and medium molecular weight PS. Wine colour and tannins were spectrophotometrically analysed. R82 wines were found to have statistically higher colour density and lower hue than EC1118, R71 and control wines. Furthermore, R82 wines had statistically lower concentrations of tannins than BRG YSEO wines. The aroma profiles were examined using SPME-GC-MS and it was found that R82 wines had statistically higher concentrations of several aromatic esters and alcohols compounds than all other wines, including ethyl isobutyrate, ethyl octanoate, ethyl hexanoate and butanol. Varietal thiols and thiol precursors were measured using LC-MS/MS. There was no statistical difference between then concentration of 3SH in the wines, but some differences in concentrations of varietal precursors, Cys-3SH and GSH-3SH, were measured.
Issue: OENO Macrowine 2023
1. School of Chemical Sciences, University of Auckland, 23 Symonds St, Auckland, New Zealand
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Yeast, New Zealand Pinot noir, Polysaccharides, Chemical proﬁle