Enzymes, in winemaking

The addition of enzymes during winemaking is a common practice to improve the extraction of colour and aroma compounds, the clarification of the white wines and the filtration processes of musts and wines (Doco et al. 2007). More information about the behaviour of enzymes during winemaking is described in Chapter 4 (Enzymes in winemaking). 

VAN Rensburg, P. and I.S. Pretorius. 2000. Enzymes in winemaking harnessing natural catalysts for efficient biotransformations irreview. S. Afr. J. Enol. Vitic. 21 52-73. 

Canal-Llauberes R.M. (1992) Enzymes in winemaking. In Wine Microbiology and Biotechnology (ed. 

Glycosidases may also be used to promote extraction of terpenic aromas—particularly useful in making Muscat wines. Care must be taken in traditional red winemaking to avoid producing off-aromas. The use of enzymes in winemaking requires further scientific research. 

In enzymes, this folding process is crucial to their activity as catalysts, with part of the structure as the center of reactivity. Heating enzymes (or other treatments) destroys their three-dimensional structure so stops further action. For example, in winemaking, the rising alcohol content eventually denatures the enzymes responsible for turning sugar into alcohol, and fermentation stops. 

Giinata, Z., Dugelay, 1., Sapis, J.C., Baumes, R., Bayonove, C. (1993). Role of the enzymes in the use of the flavour potential from grape glycosides in winemaking. In P. Schreier P. Winterhalter (Eds.), Progress in flavor precursors studies (pp. 219-234). Carol Stream Ils. AUured Publishing. 

Clarification of the must in winemaking is made by treatments with silica gel, filtration, centrifugation, or by the use of enzymes. During filtration and centrifugation, oxidation of polyphenols may occur loss of protective colloids occurring with enzymes can promote precipitation of potassium bitartrate affecting the tartaric acid, pH and total acidity data. For determination of organic acids either in skins or in the... 

Glycosldases in winemaking. Enzyme treatment of juices or wines to increase the concentrations of volatile monoterpene flavorants could, if successful, provide considerable benefit to winemaking. 

The findings thus far indicate that there are several constraints to be overcome before commercial use of enzymes for volatile monoterpene enhancement in winemaking can be developed. 

Urea is assayed using urease, and ammonium carbonate is formed. Wine contains less than 1 mg/1, and it is certainly of microbial origin. Urea is significant in winemaking as it may be a precursor of ethyl carbamate. In spite of certain reservations, L Office International de la Vigne et du Vin (OIV) authorize the treatment of wines by active urease in an acid medium. This enzyme is extracted from Lactobacillus fermentum. The objective is to reduce excessive urea concentrations in wine to avoid the formation of ethyl carbamate as the wine ages. 

The use of proteolytic enzymes seems, theoretically, to be the most appropriate tool for selectively eliminating proteins from wine. The first proteinases demonstrated in winemaking were initially studied in grapes. The role of these enzymes in protein breakdown in must during fermentation... 

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