Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Preventing protein haze in bottled white wine
Author: Waters, E.
Alexander, G.
Muhlack, R.
Pocock, K.
Colby, C.
O'Neill, B.
Hoj, P.
Jones, P.
Citation: Australian Journal of Grape and Wine Research, 2005; 11(2):215-225
Publisher: Australian Society of Viticulture and Oenology
Issue Date: 2005
ISSN: 1322-7130
Statement of
E.J. Waters, G. Alexander, R. Muhlack, K.F. Pocock, C. Colby, B.K. O'Neill, P.B. Høp and P. Jones
Abstract: Slow denaturation of wine proteins is thought to lead to protein aggregation, flocculation into a hazy suspension and formation of precipitates. The majority of wine proteins responsible for haze are grapederived, have low isoelectric points and molecular weight. They are grape pathogenesis-related (PR) proteins that are expressed throughout the ripening period post véraison, and are highly resistant to low pH and enzymatic or non-enzymatic proteolysis. Protein levels in un-fined white wine differ by variety and range up to 300 mg/L. Infection with some common grapevine pathogens or skin contact, such as occurs during transport of mechanically harvested fruit, results in enhanced concentrations of some PR proteins in juice and wine. Oenological control of protein instability is achieved through adsorption of wine proteins onto bentonite. The adsorption of proteins onto bentonite occurs within several minutes, suggesting that a continuous contacting process could be developed. The addition of proteolytic enzyme during short term heat exposure, to induce PR protein denaturation, showed promise as an alternative to bentonite fining. The addition of haze-protective factors, yeast mannoproteins, to wines results in decreased particle size of haze, probably by competition with wine proteins for other non-proteinaceous wine components required for the formation of large insoluble aggregations of protein. Other wine components likely to influence haze formation are ethanol concentration, pH, metal ions and phenolic compounds.
Keywords: Haze; heat; protein instability; turbidity; sediment; protein; pathogenesis-related; thaumatin-like; chitinase; Botrytis; powdery mildew; Uncinula; bentonite; proteolytic enzymes; mechanical harvesting; ripening; maturity; heat test; grape; Vitis vinifera; white wine; haze protective factor; mannoprotein
Provenance: Published Online: 28 Jun 2008
Rights: Copyright © 2008 Australian Society of Viticulture and Oenology Inc.
RMID: 0020050787
DOI: 10.1111/j.1755-0238.2005.tb00289.x
Published version:
Appears in Collections:Agriculture, Food and Wine publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.