Fermentation, of wine

Tartaric acid [526-83-0] (2,3-dihydroxybutanedioic acid, 2,3-dihydroxysuccinic acid), C H O, is a dihydroxy dicarboxyhc acid with two chiral centers. It exists as the dextro- and levorotatory acid the meso form (which is inactive owing to internal compensation), and the racemic mixture (which is commonly known as racemic acid). The commercial product in the United States is the natural, dextrorotatory form, (R-R, R )-tartaric acid (L(+)-tartaric acid) [87-69-4]. This enantiomer occurs in grapes as its acid potassium salt (cream of tartar). In the fermentation of wine (qv), this salt forms deposits in the vats free crystallized tartaric acid was first obtained from such fermentation residues by Scheele in 1769. 

The optimum temperature of fermentation of wine depends on the type, red wines working best at about 29°C while the white wines require a cooler condition of around 16°C. Heat is given off by the chemical process of fermentation. They are then traditionally matured and stored in caves or cellars at about 10°C. Much of the manufacture... 

Cruess, W.V. Fermentation of Wines at Lower Temperatures," Wines Vines... 

Pure enantiomers of optically active compounds are often obtained by isolation from biological sources. Most optically active molecules are found as only one enantiomer in living organisms. For example, pure (+ )-tartaric acid can be isolated from the precipitate formed by yeast during the fermentation of wine. Pure ( + )-glucose is obtained from... 

Malolactic fermentation (MLF) in wine is by definition the enzymatic conversion of L-malic acid to L-lactic acid, a secondary process which usually follows primary (alcoholic) fermentation of wine but may also occur concurrently. This reduction of malic acid to lactic acid is not a true fermentation, but rather an enzymatic reaction performed by lactic acid bacteria (LAB) after their exponential growth phase. MLF is mainly performed by Oenococcus oeni, a species that can withstand the low pFi (<3.5), high ethanol (>10 vol.%) and high SO2 levels (50 mg/L) found in wine. More resistant strains of Lactobacillus, Leuconostoc and Pediococcus can also grow in wine and contribute to MLF especially if the wine pH exceeds 3.5 (Davis et al. 1986 Wibowo et al. 1985). The most important benefits of MLF are the deacidification of high acid wines mainly produced in cool climates, LAB contribute to wine flavour and aroma complexify and improve microbial sfabilify (Lonvaud-Funel 1999 Moreno-Arribas and Polo 2005). 

Davis, C.R., Wibowo, D.J., Lee, T.H. Eleet, G.H. (1986). Growth and metabolism of lactic acid bacteria during and after malolactic fermentation of wines at different pH. Appl. Environ. Microbiol, 51, 539-545. 

Mass spectrometry (MS) is one sophisticated technique that has been applied relatively recently for monitoring biotechnological processes, but mainly for the on-line detection and quantification of gases [27], MS is described in section 2.10.2. One drawback with MS is that is requires expensive equipment and is not as easy to handle as HPLC coupled to an UV-detector. Diode-array detectors (DAD) have most recently begins to be to be used for monitoring of the fermentation of wines and ethanol [28-30],... 

Figure 1.19 Mass spectra of acetaldehyde PFB-oxime (a), diacetyl mono PFB-oxime (b), acetoin PFB-oxime derivative (c), and o-chlorobenzaldehyde PFB-oxime (d) recorded in the GC/MS analysis of standard solution performed in positive ion chemical ionization mode using methane as reagent gas (reagent gas flow 1 mL/min ion source temperature 200 °C). Flamini et al., (2005) Monitoring of the principal carbonyl compounds involved in malolactic fermentation of wine by synthesis of 0-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine derivatives and solid-phase-microextraction positive-ion-chemical-ionization mass spectrometry analysis, Journal of Mass Spectrometry, 40, p. 1561. Copyright John Wiley Sons, Ltd. Reproduced with permission...

Flamini, R. and Dalla Vedova, A. (2003) Glyoxal/glycolaldehyde a redox system involved in malolactic fermentation of wine, /. Agric. Food Chem., 51(8), 2300-2303. 

Lonvaud-Funel, A., Joyeux, A., and Desens, C. 1988. Inhibition of malolactic fermentation of wines by products of yeast metabolism. J. Sci. Food Agric. 44, 183-191. 

Severe, life-threatening asthmatic reactions following consumption of restaurant meals and wine have occurred secondary to ingestion of the food preservative potassium metabisulfite. Sulfites have been used for centuries as preservatives in wine and food. As antioxidants, they prevent fermentation of wine and discoloration of fruits and vegeta-... 

PROBLEM 3.6 During the fermentation of wine, a buffer system consisting of tartaric acid and potassium hydrogen tartrate is produced by a biochemical reaction. Assuming that at some time the concentration of potassium hydrogen tartrate is twice that of tartaric acid, calculate the pH of the wine. The pKa of tartaric acid is 2.96. Solution IT , [hydrogen tartrate] P - P a + °g [tartaric acid] = 2.96 + log 2 = 2.96 + 0.30 = 3.26... 

Pyruvic acid (pyruvate) is a product of yeast glycolysis. The decarboxylation of this compound leads to the formation of acetaldehyde, which in turn is reduced to ethanol. In the fermentation of wine, the maximum concentration of pyruvic acid occurs approximately when half of the sugars have been fermented (Whiting and Coggins, 1960). These pyruvate molecules are later metabolized by the yeast. 

These chemicals are prepared from crude potassium acid tartrates known as argots, which are precipitated during the fermentation of wines. The crude salt is slightly soluble and can be purified by recrystallization to produce the cream of tartar of commerce. The use of activated carbon gives a higher yield of crystals and usually eliminates the need of more than one recrystallization. 

Agouridis N., Kopsahelis N., Plessas S., Koutinas A. A. and KaneUaki M. Oenococcus oeni cells immobilized on delignilied cellulosic material for malolactic fermentation of wine. Bioresource Technology 99 (18) (2008) 9017-9020. 

Vaillant, H. and Formisyn, P. (1996) Purification of the malolactic enzyme from a Leuconostoc oenos strain and use in a membrane reactor for achieving the malolactic fermentation of wine. Biotechnol Appl. Biochem., 24, 217-223. 

L-lactate is the intermediate prodnct of carbohydrate metabolism. The rapid, accurate and selective assay of L-lactate and pyrnvate is necessary in clinical biology where it is important in the growth of certain cells and in fermenters. L-lactate also plays an important role in food industries engaged in fermentation of wine and dairy products. The lactate concentration level in blood indicates various pathological states, including shock, respiratory insufficiencies and heart diseases, and finds immense importance in neonatology and sports medicine. 

Ethyl Alcohol Alcohol produced during the fermentation of wine that is responsible for the wine s intoxicating effect. 

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