The Australian Wine Research Institute , Post Office Box 197, Glen Osmond , Adelaide 5064 , Australia.
J Agric Food Chem. 2019 Dec 11;67(49):13487-13495. doi: 10.1021/acs.jafc.9b03228. Epub 2019 Aug 13.
The occurrence in Riesling wine of the potent odorant 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) is dependent upon vineyard and winemaking conditions, and TDN can have a prominent impact on the attributes of a wine after years in a bottle. As such, immediately assessing the impact of vineyard or winery treatments on future TDN formation requires forced creation of the aroma compound under non-wine-like conditions from other precursors. Here, we use a Box-Behnken approach and known TDN end points in commercial wines to optimize the conditions (pH, temperature, and time) of a "total TDN" hydrolytic assay for Riesling wine, which was intended to not interfere with yeast-derived formation pathways. The new assay (75 °C, pH 1.7, and 60 min) was used to determine the role of industry-relevant commercial yeasts as well as novel hybrid yeast strains on total TDN concentrations in young Riesling wines. While significant differences were observed between some yeasts, the impact of defoliation as a viticultural intervention outweighed yeast effects, suggesting that elevated TDN concentrations in wine are likely due to grape growing conditions and cannot be readily reduced or compensated for in the winery.
雷司令葡萄酒中强烈气味的 1,1,6-三甲基-1,2-二氢萘（TDN）的出现取决于葡萄园和酿酒条件，并且 TDN 在瓶中陈年后会对葡萄酒的特性产生显著影响。因此，立即评估葡萄园或酿酒厂处理对未来 TDN 形成的影响需要在非葡萄酒样条件下使用其他前体强制生成香气化合物。在这里，我们使用 Box-Behnken 方法和商业葡萄酒中的已知 TDN 终点来优化 Riesling 葡萄酒的“总 TDN”水解分析的条件（pH 值、温度和时间），该分析旨在不干扰酵母衍生的形成途径。新的分析方法（75°C、pH 值 1.7 和 60 分钟）用于确定行业相关商业酵母以及新型杂交酵母菌株对年轻 Riesling 葡萄酒中总 TDN 浓度的影响。虽然一些酵母之间存在显著差异，但作为一种葡萄栽培干预措施的除叶作用的影响大于酵母的影响，这表明葡萄酒中 TDN 浓度升高很可能是由于葡萄种植条件造成的，并且在酿酒厂中不容易降低或补偿。
