Redox balance in wine yeast under hyperosmotic stress and the relation to wine quality

高渗胁迫下葡萄酒酵母的氧化还原平衡及其与葡萄酒品质的关系

• 批准号: 238872-2012
• 负责人: Inglis, Debra
• 金额: $ 1.82万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570510
• 关键词: Redox; balance; wine; yeast; under

Icewine is the flagship wine of Canada that spearheaded international trade for Canadian wines. It continues to be of critical importance to the Canadian wine industry, with Icewines approved for sale in 2011 worth $100 million. Producing these wines offers many challenges to wine yeast carrying out the fermentations. Solutes in Icewine juice place wine yeast under increased hyperosmotic stress, leading to altered metabolism, fermentation difficulties and ten-times the concentration of acetic acid found in table wines. A high concentration of acetic acid in Icewine is a concern due to its association with wine spoilage. Wine yeast strains display properties that are distinct from well-studied laboratory yeast strains, and these differences can impact on the organoleptic properties of wine. However, the molecular basis of these differences remains largely unknown. The central research goal of this program is to gain a more comprehensive understanding, at the molecular level, of factors influencing wine yeast stress responses during fermentation of concentrated grape juices and how these responses relate to cellular redox balance, glycerol, organic acid production and overall wine quality. We will examine such influences while yeast adapt first to the hyperosmotic stress from concentrated Icewine juice, and then to ethanol and acetic acid stress as fermentation proceeds. Once we understand why certain metabolites are formed during this response, it should be possible to control yeast metabolism to avoid or minimize unwanted compounds such as acetic acid. This research will provide critical information for the development of yeast strains best suited for Icewine and wine styles based on high Brix juice, such as that found in the emerging Canadian appassimento wine style produced from grapes ripened off-vine. This information will be applicable to winemakers, assisting them in maintaining and expanding Canada's global dominance in Icewine quality and supporting their needs as they branch into new wine styles involving high sugar juices.

冰酒是加拿大的旗舰葡萄酒，引领了加拿大葡萄酒的国际贸易。它对加拿大葡萄酒行业仍然至关重要，2011年批准销售的冰酒价值1亿美元。生产这些葡萄酒给进行发酵的葡萄酒酵母带来了许多挑战。冰酒果汁中的溶质使葡萄酒酵母处于高渗透压力下，导致新陈代谢改变，发酵困难，并使食用葡萄酒中的醋酸浓度增加十倍。冰酒中的高浓度醋酸是一个令人担忧的问题，因为它与葡萄酒的变质有关。葡萄酒酵母菌株表现出与经过充分研究的实验室酵母菌株不同的特性，这些差异可能会影响葡萄酒的感官特性。然而，这些差异的分子基础在很大程度上仍不清楚。该项目的中心研究目标是在分子水平上更全面地了解浓缩葡萄汁发酵过程中影响葡萄酒酵母应激反应的因素，以及这些反应与细胞氧化还原平衡、甘油、有机酸产生和葡萄酒整体质量的关系。我们将在酵母菌首先适应浓缩冰酒汁的高渗胁迫，然后随着发酵的进行而适应乙醇和醋酸胁迫的过程中，研究这些影响。一旦我们了解了为什么在这种反应中会形成某些代谢物，就应该有可能控制酵母的新陈代谢，以避免或最大限度地减少不需要的化合物，如醋酸。这项研究将为开发最适合冰酒和基于高糖度果汁的葡萄酒风格的酵母菌株提供关键信息，例如由葡萄在藤外成熟生产的新兴加拿大阿帕西门托葡萄酒风格。这些信息将适用于酿酒商，帮助他们保持和扩大加拿大在冰酒质量方面的全球主导地位，并支持他们进入涉及高糖汁的新葡萄酒风格的需求。