New enzymatic method for estimating fumaric acid in wines

• Main Authors: Daniel Fernández-Vázquez, Nicolas Rozès, Joan Miquel Canals, Albert Bordons, Cristina Reguant, Fernando Zamora
• Format: Article
• Language: English
• Published: International Viticulture and Enology Society 2021-09-01
• Series: OENO One
• Subjects: fumaric acid; L-malic acid; enzymatic method
• Online Access: https://oeno-one.eu/article/view/4825

This work aims to develop a new enzymatic method for analysing fumaric acid in wines. Fumaric acid is a very effective lactic acid bacteria inhibitor that is widely used in the food industry as an additive (E297). Using it to inhibit malolactic fermentation has recently been authorized by the International Organisation of Vine and Wine (OIV). However, the official analytical method for fumaric acid involves the classical HPLC method for organic acids, which is overly complicated for use in wineries. This research proposes a very simple and efficient enzymatic method that allows the simultaneous determination of L-malic acid and fumaric acid. The method uses a commercial enzymatic kit for L-malic acid and adds a supplementary step in which the fumarase enzyme is added to transform fumaric acid into L-malic acid. The results obtained show that this method could be used in different media (synthetic solution, white wine, red wine and white grape juice). This article also proposes a modification of the enzymatic method to be applied when the L-malic acid concentration of the sample is very high.