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: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=524477
• 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。 它仍然是至关重要的加拿大葡萄酒行业，冰酒批准销售在2011年价值1亿美元。生产这些葡萄酒对进行发酵的葡萄酒酵母提出了许多挑战。 冰酒汁中的溶质使葡萄酒酵母处于高渗压力下，导致新陈代谢改变，发酵困难，并且在餐桌葡萄酒中发现的乙酸浓度是十倍。 冰酒中高浓度的乙酸是一个问题，因为它与葡萄酒腐败有关。 葡萄酒酵母菌株显示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然未知。 该计划的中心研究目标是在分子水平上更全面地了解影响浓缩葡萄汁发酵过程中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，有机酸生产和整体葡萄酒质量的关系。 我们将研究这种影响，而酵母适应首先从浓缩冰酒汁的高渗应力，然后乙醇和乙酸应力发酵进行。 一旦我们理解了为什么在这种反应过程中会形成某些代谢物，就应该有可能控制酵母的代谢，以避免或最大限度地减少不需要的化合物，如乙酸。 这项研究将为开发最适合冰酒和基于高白利糖度果汁的葡萄酒风格的酵母菌株提供关键信息，例如在新兴的加拿大appassimento葡萄酒风格中发现的葡萄成熟的葡萄藤。这些信息将适用于酿酒师，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，并支持他们的需求，因为他们分支进入涉及高糖果汁的新葡萄酒风格。