Dipartimento Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
The Australian Wine Research Institute, PO Box 197, Glen Osmond, Adelaide, South Australia, 5064, Australia.
Food Microbiol. 2019 Dec;84:103247. doi: 10.1016/j.fm.2019.103247. Epub 2019 Jun 22.
Over the last decades there has been an increase in ethanol concentration in wine. High ethanol concentration may impact negatively wine flavor and can be associated with harmful effects on human health. In this study, we investigated a microbiological approach to reduce wine ethanol concentration, using three non-Saccharomyces yeast strains (Metschnikowia pulcherrima, Torulaspora delbrueckii and Zygosaccharomyces bailii) in sequential fermentations with S. cerevisiae under different aeration conditions. At the same time, we evaluated the volatile profile of the resulting reduced alcohol Chardonnay wines. Results showed that the non-Saccharomyces yeasts tested were able to reduce wine ethanol concentration when oxygen was provided. Compared to S. cerevisiae wines, ethanol reduction was 1.6% v/v, 0.9% v/v and 1.0% v/v for M. pulcherrima, T. delbrueckii and Z. bailii sequential fermentations, respectively. Under the conditions evaluated here, aeration did not affect acetic acid production for any of the non-Saccharomyces strains tested. Although aeration affected wine volatile profiles, this was depended on yeast strain. Thus, wines produced with M. pulcherrima under aeration of 0.05 volume of air per volume of culture per minute (VVM) showed excessive ethyl acetate content, while Z. bailli wines produced with 0.05 VVM aeration had increased concentrations of higher alcohols and volatile acids. Increased concentrations of these compounds over their sensory thresholds, are likely to impact negatively on wine sensory profile. Contrarily, all three non-Saccharomyces strains under 0.025 VVM aeration conditions produced wines with reduced ethanol concentration and acceptable chemical volatile profiles.
在过去的几十年中，葡萄酒中的乙醇浓度不断增加。高乙醇浓度可能会对葡萄酒的风味产生负面影响，并可能对人体健康产生有害影响。在这项研究中，我们研究了一种使用三种非酿酒酵母菌株（Metschnikowia pulcherrima、Torulaspora delbrueckii 和 Zygosaccharomyces bailii）在不同通气条件下与酿酒酵母进行顺序发酵以降低葡萄酒乙醇浓度的微生物方法。同时，我们评估了所得低酒精霞多丽葡萄酒的挥发性特征。结果表明，在所测试的非酿酒酵母能够在提供氧气时降低葡萄酒的乙醇浓度。与酿酒酵母葡萄酒相比，M. pulcherrima、T. delbrueckii 和 Z. bailii 顺序发酵的乙醇减少量分别为 1.6% v/v、0.9% v/v 和 1.0% v/v。在评估的条件下，通气对所测试的任何非酿酒酵母菌株的乙酸产生都没有影响。尽管通气会影响葡萄酒的挥发性特征，但这取决于酵母菌株。因此，在每分钟每体积培养物 0.05 体积空气（VVM）的通气下用 M. pulcherrima 生产的葡萄酒表现出过高的乙酸乙酯含量，而在 0.05 VVM 通气下用 Z. bailii 生产的葡萄酒则具有更高的醇和挥发性酸浓度。这些化合物的浓度超过其感官阈值，可能会对葡萄酒的感官特征产生负面影响。相反，在每分钟每体积培养物 0.025 体积空气（VVM）的通气条件下，所有三种非酿酒酵母菌株都生产出了乙醇浓度降低且化学挥发性特征可接受的葡萄酒。
