Biolaffort, Bordeaux, France; UMR 1366 Œnologie, Université de Bordeaux, INRAE, Bordeaux INP, BSA, ISVV, France.
UMR 1366 Œnologie, Université de Bordeaux, INRAE, Bordeaux INP, BSA, ISVV, France.
Food Microbiol. 2023 Jun;112:104209. doi: 10.1016/j.fm.2022.104209. Epub 2022 Dec 14.
In the context of climate change, the chemical composition of wines is characterized by a massive drop of malic acid concentration in grape berries. Then wine professionals have to find out physical and/or microbiological solutions to manage wine acidity. The aim of this study is to develop wine Saccharomyces cerevisiae strains able to produce significant amount of malic acid during the alcoholic fermentation. By applying a large phenotypic survey in small scale fermentations, the production level of malic acid in seven grape juices confirmed the importance of the grape juice in the production of malic acid during the alcoholic fermentation. Beside the grape juice effect, our results demonstrated that extreme individuals able to produce up to 3 g/L of malic acid can be selected by crossing together appropriate parental strains. A multivariate analysis of the dataset generated illustrate that the initial the amount of malic acid produced by yeast is a determining exogenous factor for controlling the final pH of wine. Interestingly most of the acidifying strains selected are particularly enriched in alleles that have been previously reported for increasing the level of malic acid at the end of the alcoholic fermentation. A small set of acidifying strains were compared with strains able to consume a large amount of malic acid previously selected. The total acidity of resulting wines was statistically different and a panelist of 28 judges was able to discriminate the two groups of strains during a free sorting task analysis.
在气候变化的背景下，葡萄酒的化学成分特点是葡萄浆果中苹果酸浓度大幅下降。然后，葡萄酒专业人员必须找到物理和/或微生物学解决方案来管理葡萄酒的酸度。本研究的目的是开发能够在酒精发酵过程中产生大量苹果酸的酿酒酵母菌株。通过在小规模发酵中进行大规模表型调查，在七种葡萄汁中的苹果酸产量水平证实了葡萄汁在酒精发酵过程中产生苹果酸的重要性。除了葡萄汁的影响外，我们的结果表明，通过将合适的亲本菌株杂交，可以选择出能够产生高达 3g/L 苹果酸的极端个体。对生成的数据集进行的多元分析表明，酵母最初产生的苹果酸量是控制葡萄酒最终 pH 值的决定性外源因素。有趣的是，大多数选择的酸化菌株特别富含以前报道的增加酒精发酵结束时苹果酸水平的等位基因。一小部分酸化菌株与之前选择的能够消耗大量苹果酸的菌株进行了比较。结果葡萄酒的总酸度存在统计学差异，在自由分类任务分析中，28 名评审员中有 28 名能够区分这两组菌株。
