Wine proteins

Proteins Wine Gels on reacting with tannin Clarification of wines, removes colloidal matter... 

Minerals, particularly Bentonite, ate used to remove proteins that tend to cause haze in white wines. The natural tannin of ted wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyttohdone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen ate often used to fine ted wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

Caseins are used in wine making to clarify the wine by causing fine particles to coagulate with the protein so they can be easily filtered out or precipitated. 

Schad SG. Trcka J, Vieth S. Scheurer S. Conti A. Brbcker EB. Trautmann A Wine anaphylaxis in a German patient IgE-mediated allergy against a lipid transfer protein of grapes. Int Arch Allergy Immunol 2005 136 159-164. 

Sami-Manchado, P. et al.. Analysis and characterization of wine condensed tannins precipitated by proteins used as fining agent in enology. Am. J. Enol. Viticult., 50, 81, 1999. 

A similar problem occurs with beer stabilization. A serious problem in the brewing industry is the tendency of some beers to develop hazes during long-term storage due to protein precipitation that is usually stimulated by small quantities of naturally occurring proanthocyanidin polyphenols. In the same way as observed for wine, the excess polyphenols are traditionally removed by treatment with insoluble PVPP, with the same resulting problems. To resolve the problems, several authors have proposed the use of laccase, which forms polyphenol complexes that may be removed by filtration or other separation means. 

Tyramine is an amino acid which is present in large quantities in protein rich, fermented and stored products like some cheeses, sausages, red wines, beers etcetera. Tyramine is metabolized into nor-adrenaline by the enzyme mono-amino-oxidase (MAO). If MAO is inhibited by drags nor-adrenaline is accumulated and can give hypertensive crises. 

White wines were uniformly low in HA protein, while red wines were quite variable (Siebert et al., 1996b). Vitis vinifera white wines had very low levels of HA polyphenols, while Vitis labrusca white wines had higher and vinifera-labrusca hybrids had intermediate levels (Siebert et al., 1996b). All red wines had high levels of HA polyphenols, and most had low levels of HA protein the two exceptions were both hybrids. 

The removal of macromolecules by ultrafiltration has often been used in the production of clear fruit juices and wine (Girard and Fukumoto, 2000). This treatment removes both proteins and polysaccharides. Ultrafiltration through a 10,000 Da cut-off membrane has been shown to stabilize wines against haze formation (Flores, 1990). 

Dizy, M. and Bisson, L. F. (1999). White wine protein analysis by capillary zone electrophoresis. Am. J. Enol. Vitic. 50,120-127. 

Duncan, B. (1992). Varietal differences in white grape protein Implications for bentonite fining. Aus. New Zealand Wine Ind.. 7,189-193. 

Hsu, J. C. and Heatherbell, D. A. (1987). Heat-unstable proteins in wine. I. Characterization and removal by bentonite fining and heat treatment. Am. J. Enol. Vitic. 38,11-16. 

Pocock, K. F. and Rankine, B. C. (1973). Heat test for detecting protein instability in wine. 

Siebert, K. J., Lynn, P. Y., and Carrasco, A. (1996b). Analysis of haze-active polyphenols and proteins in grape juices and wines. In "4th International Symposium on Cool Climate Viticulture and Enology," pp. VII-18-VII-21. Rochester, New York. 

Waters, E. J., Peng, Z., Pocock, K. F., and Williams, P. J. (1995). Proteins in white wine, I Procyanidin occurrence in soluble proteins and insoluble protein hazes and its relationship to protein instability. Aust. ]. Grape Wine Res. 1, 86-93. 

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