Tronchoni Jordi, Gonzalez Ramon, Guindal Andrea M, Calleja Elena, Morales Pilar
Instituto de Ciencias de La Vid y Del Vino (CSIC, Gobierno de La Rioja, Universidad de La Rioja), Finca La Grajera, Carretera de Burgos Km 6, 26007, Logroño, La Rioja, Spain; Universidad Internacional de Valencia - VIU, C/ Pintor Sorolla 21, 46002, Valencia, Spain.
Instituto de Ciencias de La Vid y Del Vino (CSIC, Gobierno de La Rioja, Universidad de La Rioja), Finca La Grajera, Carretera de Burgos Km 6, 26007, Logroño, La Rioja, Spain.
Food Microbiol. 2022 Feb;101:103893. doi: 10.1016/j.fm.2021.103893. Epub 2021 Aug 25.
Aerobic fermentation was previously proposed to reduce the ethanol content of wine. The main constraint found for Saccharomyces cerevisiae to be used under these conditions was the high levels of acetic acid produced by all S. cerevisiae strains previously tested. This work addressed the identification of S. cerevisiae wine yeast strains suitable for aerobic fermentation and the optimization of fermentation conditions to obtain a reduced ethanol yield with acceptable volatile acidity. This approach unveiled a great diversity in acetic acid yield for different S. cerevisiae strains under aerobic conditions, with some strains showing very low volatile acidity. Three strains were selected for further characterization in bioreactors, with natural grape must, under aerobic and anaerobic conditions. Ethanol yields were lower under aerobic than under anaerobic conditions for all strains, and acetic acid levels were low for two of them. Strain-dependent changes in volatile compounds were also observed between aerobic and anaerobic conditions. Finally, the process was optimized at laboratory scale for one strain. This is the first report of S. cerevisiae wine strains showing low acetic acid production under aerobic conditions and paves the way for simplified aerobic fermentation protocols aimed to reducing the alcohol content of wines.
有氧发酵此前被提议用于降低葡萄酒中的乙醇含量。在这些条件下使用酿酒酵母发现的主要限制因素是此前测试的所有酿酒酵母菌株产生的乙酸水平过高。这项工作旨在鉴定适合有氧发酵的酿酒酵母葡萄酒酵母菌株，并优化发酵条件，以获得乙醇产量降低且挥发性酸度可接受的葡萄酒。该方法揭示了不同酿酒酵母菌株在有氧条件下乙酸产量的巨大差异，一些菌株的挥发性酸度非常低。选择了三个菌株在生物反应器中使用天然葡萄汁在有氧和厌氧条件下进行进一步表征。所有菌株在有氧条件下的乙醇产量均低于厌氧条件下，其中两个菌株的乙酸水平较低。在有氧和厌氧条件之间还观察到了挥发性化合物的菌株依赖性变化。最后，在实验室规模上对一个菌株的工艺进行了优化。这是关于酿酒酵母葡萄酒菌株在有氧条件下乙酸产量低的首次报道，并为旨在降低葡萄酒酒精含量的简化有氧发酵方案铺平了道路。
