Macrowine 2021
IVES 9 IVES Conference Series 9 Impact of drought stress on concentration and composition of wine proteins in Riesling

Impact of drought stress on concentration and composition of wine proteins in Riesling

Abstract

Protein haze in white wines is a major technological and economic problem of the wine industry. Field tests were carried out in steep slope vineyards planted with Riesling grapes over 3 dry growing seasons to study the effect of drought stress on the concentration of proteins in the resulting wines. Plots suffering from drought stress were compared with surrounding drip irrigated plots. Riesling grapes were processed into wines by conventional procedures. Protein amounts of the isolated wine colloids of the stressed samples were always higher than those of the watered samples(mean watered 13.8 ± 0.44, mean stressed 17.4 ± 0.40 g 100 g-1). As a consequence, higher bentonite doses were needed to achieve protein haze stability of the drought stressed treatments. Concerning the amino acid composition of the proteins, there were no significant differences between stressed and watered treatments. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed, that the molecular weights of proteins ranged from 12-75 kDa with an accumulation of chitinases and thaumatin-like proteins (TLPs) between 20-30 kDa. Concerning the protein bands, minor differences became obvious only between vintages but not between stressed and watered samples. In-solution digest of proteins from Riesling grapes 2008 followed by LCMSn and data base research identified 15 proteins originating from grapes and 10 from the yeast Saccharomyces cerevisiae.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Frank Will*, Heinz Decker, Helmut Dietrich, Manfred Stoll, Miriam Meier, Nadine Jäckels, Petra Fronk, Stefan Tenzer

*Hochschule Geisenheim University

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Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

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