Wine is a complex mixture of chemical compounds in a hydro-alcoholic solution with a pH around 4.
Types of natural molecules present in wineEdit
- Acids in wine
- Phenolic compounds in wine
- Proteins in wine
- Sugars in wine
- Yeast assimilable nitrogen
- Dissolved gas (CO2)
- Monoterpenes and sesquiterpenes such as linalool and α-terpineol
- Glutathione (reduced and oxidized)
- Esters : Ethyl acetate is the most common ester in wine, being the product of the most common volatile organic acid — acetic acid, and the ethyl alcohol generated during the fermentation.
- Norisoprenoids, such as C13-norisoprenoids found in grape (Vitis vinifera) or wine, can be produced by fungal peroxidases or glycosidases.
Other molecules found in wineEdit
List of additives permitted for use in the production of wine under European Union law:
|Type or purpose of addition||Permitted additives|
neutral potassium tartrate
|Enrichment||concentrated grape must|
rectified concentrated grape must
A wine fault or defect is an unpleasant characteristic of a wine often resulting from poor winemaking practices or storage conditions, and leading to wine spoilage. Many of the compounds that cause wine faults are already naturally present in wine but at insufficient concentrations to adversely affect it. However, when the concentration of these compounds greatly exceeds the sensory threshold, they replace or obscure the flavors and aromas that the wine should be expressing (or that the winemaker wants the wine to express). Ultimately the quality of the wine is reduced, making it less appealing and sometimes undrinkable.
The yeast Brettanomyces produces an array of metabolites when growing in wine, some of which are volatile phenolic compounds. Brettanomyces converts p-coumaric acid to 4-vinylphenol via the enzyme cinnamate decarboxylase. 4-Vinylphenol is further reduced to 4-ethylphenol by the enzyme vinyl phenol reductase. 4-Ethylphenol causes a wine fault at a concentration of greater than 140 µg/L. Other compounds produced by Brettanomyces that cause wine faults include 4-ethylguaiacol and isovaleric acid.
Fusel alcohols are a mixture of several alcohols (chiefly amyl alcohol) produced as a by-product of alcoholic fermentation.
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- Straightforward Method To Quantify GSH, GSSG, GRP, and Hydroxycinnamic Acids in Wines by UPLC-MRM-MS. Anna Vallverdú-Queralt, Arnaud Verbaere, Emmanuelle Meudec, Veronique Cheynier and Nicolas Sommerer, J. Agric. Food Chem. 2015, 63, 142−149, doi:10.1021/jf504383g
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- Zelena, Kateryna; Hardebusch, Björn; Hülsdau, BäRbel; Berger, Ralf G.; Zorn, Holger (2009). "Generation of Norisoprenoid Flavors from Carotenoids by Fungal Peroxidases". Journal of Agricultural and Food Chemistry. 57 (21): 9951–5. doi:10.1021/jf901438m. PMID 19817422.
- Cabaroglu, Turgut; Selli, Serkan; Canbas, Ahmet; Lepoutre, Jean-Paul; Günata, Ziya (2003). "Wine flavor enhancement through the use of exogenous fungal glycosidases". Enzyme and Microbial Technology. 33 (5): 581. doi:10.1016/S0141-0229(03)00179-0.
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- Lamont, Kim T.; Somers, Sarin; Lacerda, Lydia; Opie, Lionel H.; Lecour, Sandrine (2011). "Is red wine a SAFE sip away from cardioprotection? Mechanisms involved in resveratrol- and melatonin-induced cardioprotection". Journal of Pineal Research. 50 (4): 374–80. doi:10.1111/j.1600-079X.2010.00853.x. PMID 21342247.
- M. Baldy "The University Wine Course" Third Edition pgs 37-39, 69-80, 134-140 The Wine Appreciation Guild 2009 ISBN 0-932664-69-5
- Brettanomyces Monitoring by Analysis of 4-ethylphenol and 4-ethylguaiacol at etslabs.com
- Wine Chemistry and Biochemistry, by M. Victoria Moreno-Arribas,Carmen Polo and María Carmen Polo, on Google books
- Mass Spectrometry in Grape and Wine Chemistry, by Riccardo Flamini and Pietro Traldi, on Google books
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