The complexity of protein haze formation in wines

ABSTRACT Protein haze formation in bottled wines is a significant concern for the global wine industry, and wine clarification before bottling is therefore a common but expensive practice. Previous studies have shown that wine yeast strains can reduce haze formation through the secretion of certain mannoproteins, but it has been suggested that other yeast-dependent haze protective mechanisms exist. On the other hand, the addition of chitin has been shown to reduce haze formation, likely because grape chitinases have been shown to be the major contributors to haze. In this study, Chardonnay grape must fermented by various yeast strains resulted in wines with different protein haze levels, indicating differences in haze-protective capacities of the strains. The cell wall chitin levels of these strains were determined, and a strong correlation between cell wall chitin levels and haze protection capability was observed. To further evaluate the mechanism of haze protection, Escherichia coli -produced green fluorescent protein (GFP)-tagged grape chitinase was shown to bind efficiently to yeast cell walls in a cell wall chitin concentration-dependent manner, while commercial chitinase was removed from synthetic wine in quantities that also correlated with the cell wall chitin levels of the strains. Our findings suggest a new mechanism of reducing wine haze, and we propose a strategy for optimizing wine yeast strains to improve wine clarification. IMPORTANCE In this study, we establish a new mechanism by which wine yeast strains can impact the protein haze formation of wines, and we demonstrate that yeast cell wall chitin binds grape chitinase in a chitin concentration-dependent manner. We also show that yeast can remove this haze-forming protein from wine. Chitin has in the past been shown to efficiently reduce wine haze formation when added to the wine in high concentration as a clarifying agent. Our data suggest that the selection of yeast strains with high levels of cell wall chitin can reduce protein haze. We also investigate how yeast cell wall chitin levels are affected by environmental conditions.

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Predicting protein haze formation in white wines

Australian Journal of Grape and Wine Research ◽

10.1111/ajgw.12354 ◽

2018 ◽

Vol 24 (4) ◽

pp. 504-511 ◽

Cited By ~ 8

Author(s):

J.M. McRae ◽

V. Barricklow ◽

K.F. Pocock ◽

P.A. Smith

Keyword(s):

White Wines ◽

Protein Haze ◽

Haze Formation

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Protein Haze Formation in White Wines: Effect ofSaccharomyces cerevisiaeCell Wall Components Prepared with Different Procedures

Journal of Agricultural and Food Chemistry ◽

10.1021/jf0712550 ◽

2007 ◽

Vol 55 (21) ◽

pp. 8737-8744 ◽

Cited By ~ 18

Author(s):

Giovanna Lomolino ◽

Andrea Curioni

Keyword(s):

White Wines ◽

Protein Haze ◽

Haze Formation ◽

Wall Components

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Is caffeic acid, as the major metabolite present in Moscatel wine protein haze hydrolysate, involved in protein haze formation?

Food Research International ◽

10.1016/j.foodres.2016.09.007 ◽

2017 ◽

Vol 98 ◽

pp. 103-109 ◽

Cited By ~ 3

Author(s):

Ricardo Chagas ◽

Ana Maria Lourenço ◽

Sara Monteiro ◽

Ricardo Boavida Ferreira ◽

Luísa Maria Ferreira

Keyword(s):

Caffeic Acid ◽

Major Metabolite ◽

Protein Haze ◽

Haze Formation

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Identification and Partial Characterization of Extracellular Aspartic Protease Genes from Metschnikowia pulcherrima IWBT Y1123 and Candida apicola IWBT Y1384

Applied and Environmental Microbiology ◽

10.1128/aem.00505-12 ◽

2012 ◽

Vol 78 (19) ◽

pp. 6838-6849 ◽

Cited By ~ 26

Author(s):

Vernita J. Reid ◽

Louwrens W. Theron ◽

Maret du Toit ◽

Benoit Divol

Keyword(s):

Grape Juice ◽

Nitrogen Sources ◽

Aspartic Protease ◽

Available Nitrogen ◽

Content Type ◽

Metschnikowia Pulcherrima ◽

Genetic Level ◽

Candida Apicola ◽

Protein Haze ◽

Haze Formation

ABSTRACTThe extracellular acid proteases of non-Saccharomyceswine yeasts may fulfill a number of roles in winemaking, which include increasing the available nitrogen sources for the growth of fermentative microbes, affecting the aroma profile of the wine, and potentially reducing protein haze formation. These proteases, however, remain poorly characterized, especially at genetic level. In this study, two extracellular aspartic protease-encoding genes were identified and sequenced, from two yeast species of enological origin: one gene fromMetschnikowia pulcherrimaIWBT Y1123, namedMpAPr1, and the other gene fromCandida apicolaIWBT Y1384, namedCaAPr1.In silicoanalysis of these two genes revealed a number of features peculiar to aspartic protease genes, and both the MpAPr1 and CaAPr1 putative proteins showed homology to proteases of yeast genera. Heterologous expression ofMpAPr1inSaccharomyces cerevisiaeYHUM272 confirmed that it encodes an aspartic protease. MpAPr1 production, which was shown to be constitutive, and secretion were confirmed in the presence of bovine serum albumin (BSA), casein, and grape juice proteins. TheMpAPr1gene was found to be present in 12 otherM. pulcherrimastrains; however, plate assays revealed that the intensity of protease activity was strain dependent and unrelated to the gene sequence.

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Protein haze in bottled white wines: How well do stability tests and bentonite fining trials predict haze formation during storage and transport?

Australian Journal of Grape and Wine Research ◽

10.1111/j.1755-0238.2006.tb00061.x ◽

2006 ◽

Vol 12 (3) ◽

pp. 212-220 ◽

Cited By ~ 63

Author(s):

K.F. POCOCK ◽

E.J. WATERS

Keyword(s):

White Wines ◽

Stability Tests ◽

Protein Haze ◽

Haze Formation

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Hpf2 Glycan Structure Is Critical for Protection against Protein Haze Formation in White Wine

Journal of Agricultural and Food Chemistry ◽

10.1021/jf803254s ◽

2009 ◽

Vol 57 (8) ◽

pp. 3308-3315 ◽

Cited By ~ 13

Author(s):

Simon A. Schmidt ◽

Ee Leng Tan ◽

Shauna Brown ◽

Uli J. Nasution ◽

Filomena Pettolino ◽

...

Keyword(s):

White Wine ◽

Glycan Structure ◽

Protein Haze ◽

Haze Formation

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Influence of Applied Phytosanitary Treatments and Climatic Crop Year on Zinc Content in Wines from Tohani Vineyard

Revista de Chimie ◽

10.37358/rc.17.9.5830 ◽

2017 ◽

Vol 68 (9) ◽

pp. 2092-2097

Author(s):

Catalina Calin ◽

Gina Vasile Scaeteanu ◽

Roxana Maria Madjar ◽

Otilia Cangea

Keyword(s):

Zinc Content ◽

Soil Samples ◽

Limit Set ◽

Red Wines ◽

Metallic Ions ◽

Sauvignon Blanc ◽

Before And After ◽

Haze Formation ◽

Zinc Levels ◽

Concentration Levels

Metallic ions present a great importance in oenological practice and usually are present in wines in levels that are not hazardous. Among all metallic ions, zinc presents a great interest because may cause the persistence of the wine sour taste and by the side of Al, Cu, Fe and Ni, contribute to the haze formation and the change of color. The present study was focused on measuring the concentration levels of mobile zinc from vineyard soil before and after phytosanitary treatments and zinc content from white (Feteasca Alba - FA, Riesling Italian - RI, Sauvignon Blanc - SB, Tamaioasa Rom�neasca - TR), rose (Busuioaca de Bohotin - BB) and red (Feteasca Neagra - FN) wines within the wine-growing Tohani area, Romania. Other objective was to investigate of the influence of crop year and variety on zinc levels found in wine samples. Mobile zinc content for all analyzed soil samples is low ([1.5 mg/kg). Analyses indicated that zinc content found in wines was below 5 mg/L, limit set by Organisation Internationale of Vine and Wine (OIV). Also, it was found that red wines contain zinc in higher concentrations than white ones.

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