Investigating the impact of sugar type and nitrogen source on Maillard-associated flavors in sparkling wine.

传统的起泡葡萄酒，即香槟，是在顾客购买的实际瓶子里进行第二次酒精发酵而生产的。低温二次发酵需要在原酒中加入糖，通常伴随着酵母营养物质(酵母可同化氮{燕镁N/L})。这对于在高酸度、低pH值、高酒精浓度(10-11.5%v/v)、二氧化硫(SO2)和二氧化碳(CO2)的压力下进行健康发酵是必要的。第一次发酵后的残糖水平(g/L)通常低于1g/L，且果糖水平高于葡萄糖。如今，在生产的这个阶段使用的糖通常是颗粒糖，或者是特制的浓缩葡萄汁。近年来，人们对食品生产中的糖替代品的兴趣有所增加，这主要是因为对健康的担忧，但尚未对其对起泡葡萄酒风味的影响进行审查，特别是赋予焦糖、坚果和烘烤风味的与美拉德相关的化合物。因此，我的五年计划旨在研究有机和无机氮二次发酵产生的化合物的动力学。此外，计划将颗粒糖与不同类型的糖进行比较，其中将包括：液体糖、甜叶菊、葡萄糖、葡萄糖、浆果糖和黄糖。在后期生产阶段(酵母去除)，将进一步研究不同类型的糖对焦糖、坚果和烘焙风味的感官贡献，并进行化学分析。新的糖与一种以前从未研究过的创新的起泡葡萄酒方法相结合，将被用来检测起泡葡萄酒中不同糖与氨基酸的相互作用。根据葡萄酒行业的惯例，葡萄酒的化学和感官分析将持续数年，直到葡萄酒准备好投入商业销售。使用起泡葡萄酒作为媒介来研究与美拉德相关的风味化合物将带来关于形成的新信息。增加对酸性饮料中这些化合物的合成和稳定性的了解，最终可能导致它们对特定口味的控制，并加快风味开发，这也将对制造商产生财务影响。因此，我的研究计划的长期目标是通过模拟化学成分的感官结果来预测起泡葡萄酒的风味特征，从而加速风味的发展，以减少酒窖陈化时间和生产过程中的能量输入。短期目标是确定糖类、糖源、酸度和氮源对起泡葡萄酒中美拉德相关化合物的影响，包括二次发酵和最终葡萄酒的甜度。

Traditional method sparkling wine i.e., Champagne, is produced from a second alcoholic fermentation in the actual bottle that customer buys. The low temperature second fermentation requires sugar addition to the base wine, usually alongside yeast nutrients (yeast assimilable nitrogen {YAN mg N/L}). This is necessary for a healthy fermentation in the stressful base wine environment that includes high acid levels, low pH levels, high alcohol levels (10-11.5% v/v), sulfur dioxide (SO2) and carbon dioxide (CO2). The residual sugar level (g/L) after the first fermentation is usually below 1 g/L, and consists of higher fructose levels than glucose. Nowadays, the sugars used at this stage of production are usually granulated sugar, or specially prepared concentrated grape juice. Interest in sugar alternatives in food production has increased in recent years primarily due to health concerns yet examination of their effect on sparkling wine flavor, specifically Maillard-associated compounds that bestow caramel, nutty and roasted flavor, has yet to be undertaken. Therefore, my five year project has been designed to investigate the kinetics of compounds that result from the second fermentation with organic and inorganic nitrogen. Additionally, a comparison of granulated sugar to different types of sugar is planned, which will include: liquid sugar, stevia, dextrose, glucose, berry fruit sugar and yellow sugar. Further investigation regarding the contribution, at the later stage production (yeast removal), of different types of sugars to the caramel, nutty and roasted flavors by sensory, and chemical analysis will take place. Novel sugars combined with an innovative sparkling wine method never studied before, will be utilized to examine amino acids interaction with different sugars in sparkling wine. Chemical and sensory analysis of wines will continue over several years until the wines are ready for commercial release in accordance with wine industry practice. The use of sparkling wine as a medium to study Maillard-associated flavor compounds will lead to new information regarding formation. An increased understanding of the synthesis and stability of these compounds in acidic beverages could ultimately lead to their control for specific flavors, and acceleration of flavor development that will also have financial implications to the manufacturer. Therefore, the long-term objective of my research program is to predict the flavor profile of sparkling wine by modelling sensory outcomes from chemical composition to enable the acceleration of flavor development to reduce cellar aging time, and energy input during production. The short-term objectives are to establish the influence of sugar type, the source of sugar, acid level, and nitrogen source on Maillard-associated compounds in sparkling wine for both the second fermentation, and sweetening of the final wine.