Malic acid in wine : origin, function and metabolism during vinification

Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
South African Society for Enology and Viticulture
Abstract
The production of quality wines requires a judicious balance between the sugar, acid and flavour components of wine. L-Malic and tartaric acids are the most prominent organic acids in wine and play a crucial role in the winemaking process, including the organoleptic quality and the physical, biochemical and microbial stability of wine. Deacidification of grape must and wine is often required for the production of well-balanced wines. Malolactic fermentation induced by the addition of malolactic starter cultures, regarded as the preferred method for naturally reducing wine acidity, efficiently decreases the acidic taste of wine, improves the microbial stability and modifies to some extent the organoleptic character of wine. However, the recurrent phenomenon of delayed or sluggish malolactic fermentation often causes interruption of cellar operations, while the malolactic fermentation is not always compatible with certain styles of wine. Commercial wine yeast strains of Saccharomyces are generally unable to degrade L-malic acid effectively in grape must during alcoholic fermentation, with relatively minor modifications in total acidity during vinification. Functional expression of the malolactic pathway genes, i.e. the malate transporter (mae1) of Schizosaccharomyces pombe and the malolactic enzyme (mleA) from Oenococcus oeni in wine yeasts, has paved the way for the construction of malate-degrading strains of Saccharomyces for commercial winemaking.
Description
CITATION: Volschenk, H., Van Vuuren, H. J. J. & Viljoen-Bloom, M. 2006. Malic acid in wine : origin, function and metabolism during vinification. South African Journal of Enology & Viticulture, 27(2):123-136, doi:10.21548/27-2-1613.
The original publication is available at http://www.journals.ac.za/index.php/sajev
Keywords
Wine and wine making, Malic acid metabolism, Tartaric acid, Malolactic fermentation, Grape must -- Deacidification
Citation
Volschenk, H., Van Vuuren, H. J. J. & Viljoen-Bloom, M. 2006. Malic acid in wine : origin, function and metabolism during vinification. South African Journal of Enology & Viticulture, 27(2):123-136, doi:10.21548/27-2-1613