葡萄酒典型香气特征形成机制

Most of impact odorants contributed to the whole aroma character of wine origin from the aroma glycosides in grape skins. The free aroma components are released from the glycosides by hydrolysis release in winemaking, and then they form typical varietal wine characteristics. In this project, the hydrolysis reaction of these aroma glycosides is to be studied to reveal its regulation mechanism. The common picking wine grape berries are selected as research samples from Yangling districts. The library of aroma glycosides is adjusted by the pre-fermentative freezing extraction. The method system of instrument analysis is developed to study the aroma glycoside library. And then the program of exogenous glycodidase treatment is designed to improve the hydrolysis release of aroma glycosides and to regulate the formation of wine varietal aroma characteristics. Aroma components are detected by SBSE-GC-MS, SBSE-GC-O and OAV. Wine aroma characteristics are quantified by wine aroma quantification method. In the results, the key influence factors on freezing extracting aroma glycosides and their optimal combination are to be studied, and the library of grape aroma glycosides and its analyzing system are to be built. The inactivation kinetics of exogenous glycodidase in winemaking and the kinetic process of enzyme catalyzed reaction for the important aroma glycosides are to be revealed, and the mathematic forming model of the typical aroma characteristics and its regulation mechanism by exogenous glycosidase is to be explained.

对葡萄酒香气特征起重要贡献的活性成分绝大多数来源于葡萄果皮上的香气糖苷，在酿酒过程中这些香气糖苷水解释放游离香气成分，形成葡萄酒典型的品种香气特征。本项目针对这些香气糖苷在酿酒过程中的水解反应进行调控，阐明葡萄酒典型香气特征形成的调控机制。实验以本单位酿酒葡萄示范园的正常采摘葡萄为材料，优化冷冻浸提技术调整葡萄汁香气糖苷库，研发香气糖苷库的仪器分析方法体系，设计外源糖苷酶添加方案，促进香气糖苷的水解，调控酿造过程中葡萄酒典型香气特征的形成。香气成分采用SBSE-GC-MS、SBSE-GC-O和OAV分析，香气特征运用"感官量化分析法"量化。研究冷冻浸提技术调整葡萄汁中香气糖苷的关键影响因素及其优化组合，建立葡萄香气糖苷库及其研究方法体系，揭示酿酒过程中外源糖苷酶的失活动力学过程和重要香气糖苷的酶解反应动力学过程，阐明糖苷酶处理调控葡萄酒典型香气特征形成的机制。

葡萄酒典型香气特征的化学基础是含量超过其嗅觉阈值的香气成分，尤其是来源于葡萄原料中的品种香气成分。本项目针对葡萄香气糖苷前体在葡萄酒酿造过程中的水解反应展开研究，通过冷浸渍提取、纯化、分析定量，优化设计葡萄与葡萄酒中香气糖苷前体的仪器分析方法，并通过酒精发酵过程中外源糖苷酶的添加方案，促进香气前体物质的水解，研究葡萄酒典型香气特征的形成机制。研究结果如下：1）提出了葡萄香气糖苷仪器分析的可行性策略；2）揭示了人工贵腐葡萄酒典型香气特征形成的化学机制；3）阐明了优选酵母及其糖苷酶增香酿造的风味化学基础；4）建立了优选酵母及其糖苷酶不同接种策略影响下的果香特征形成机制；5）开发了人工贵腐葡萄酒酿造和优选酵母混合酒精发酵的实用技术。项目研究结果为开发葡萄酒增香酿造技术方案提供了必要的理论依据和实践支持。