The oenological interest of fumaric acid: Stop malolactic fermentation and preserve the freshness of wines

One of the problems related to the increase in average temperatures in the wine-growing regions is the lower accumulation of organic acids in the berries. Wine freshness depends to a great extent on its acidity. In this study, the effectiveness of fumaric acid to inhibit malolactic fermentation or to stop it once initiated is evaluated. The main objective is to avoid the transformation of malic acid and thus preserve the freshness of wines made in warm areas. For this, different doses of fumaric acid (150, 300, 600 and 900 mg/L), lactic acid (2 and 4 g/L), SO 2 (50 and 100 mg/L), and lysozyme (200 and 500 mg/L) were tested. The ability of these compounds to inhibit bacterial development and stop the malic acid degradation was tested on a red wine of the variety Vitis vinifera L. cv. Tempranillo whose malic acid content was set at 1.5 g/L. The control wine inoculated with 6 log CFU / mL of Oenococus oeni finished the malolactic fermentation in 12 days. However, the use of doses equal to or greater than 300 mg/L of fumaric acid delayed the onset of malolactic fermentation for more than 50 days with little degradation of malic acid. In addition, fumaric acid proved to be effective in stopping a malolactic fermentation already started where the bacterial count was 7 log CFU/mL. Fumaric acid can be considered as a potent inhibitor of malolactic fermentation. This technological strategy allows the production of fresh wines with microbiological stability and low sulfur dioxide requirements

Non-Saccharomyces yeasts in ternary culture fermentations as a biotechnology to improve quality in warm climate wines = Fermentaciones ternarias con levaduras no-saccharomyces como estrategia biotecnológica para mejorar la calidad organoléptica de vinos de zonas cálidas

Changes in climate patterns have produced modifications in Vitis vinifera grapes maturation processes, especially in recent years, with an impact on the winemaking technology. Microbiological strategies may represent alternatives to mitigate the negative effects that climate change can produce on vines and grapes. Yeast species like Torulaspora delbrueckii and Metschnikowia pulcherrima with important enzymatic activity and, strains of the species Lachancea thermotolerans with the potential to produce large amounts of lactic acid during fermentation may be used in mixed cultures as starters in winemaking to modify the whole sensory perception after an increase in lactic acid production. The final alcoholic volume is achieved by the use of highfermentative power yeasts strains from the species Saccharomyces cerevisiae. The overall perception of these ongoing experimental wines is expected to be translated into less astringent and slightly more acidic wines with floral and fruity notes often not associated to these types of wine. Such sensory profile may be perceived as freshness by consumers. Important to mention is the fact that having wines with lower pH values may also imply the use of less dosages of SO2 as antimicrobial adjuvant also translated into the production of red wines with interesting color profiles

Non-Saccharomyces yeasts in ternary culture fermentations as a biotechnology to improve quality in warm climate wines = Fermentaciones ternarias con levaduras no-saccharomyces como estrategia biotecnológica para mejorar la calidad organoléptica de vinos de zonas cálidas

Changes in climate patterns have produced modifications in Vitis vinifera grapes maturation processes, especially in recent years, with an impact on the winemaking technology. Microbiological strategies may represent alternatives to mitigate the negative effects that climate change can produce on vines and grapes. Yeast species like Torulaspora delbrueckii and Metschnikowia pulcherrima with important enzymatic activity and, strains of the species Lachancea thermotolerans with the potential to produce large amounts of lactic acid during fermentation may be used in mixed cultures as starters in winemaking to modify the whole sensory perception after an increase in lactic acid production. The final alcoholic volume is achieved by the use of highfermentative power yeasts strains from the species Saccharomyces cerevisiae. The overall perception of these ongoing experimental wines is expected to be translated into less astringent and slightly more acidic wines with floral and fruity notes often not associated to these types of wine. Such sensory profile may be perceived as freshness by consumers. Important to mention is the fact that having wines with lower pH values may also imply the use of less dosages of SO2 as antimicrobial adjuvant also translated into the production of red wines with interesting color profiles