基于分子感官科学的柑橘果酒风味形成机理研究

The final organoleptic quality of citrus wine is identified as the key driver of consumer liking and satisfaction, but the molecular basis of the formation of the off flavor, such as high bitterness and undesirable aroma changes, is still unclear. To reveal the scientific problem of the formation of the fruity characters and bitterness in the citrus wine, the method of molecular sensory science is to be developed. In this project, the volatiles and phenolic compounds are quantified by GC-MS and HPLC-MS, separately. Citrus wine aroma characters and bitterness are described by intensity scales. Partial least squares regression is used to build sensory character with one group of compounds. The results will interpret the chemical base of wine aroma quality change and bitterness and its regulation in theory, which will improve sensory quality of citrus. This study will provide a theoretical basis for solving the flavor change during the citrus wine production process, which has an important guiding significance for citrus production.

感官品质是柑橘果酒质量的重要评价指标，但目前对影响柑橘果酒感官品质的因素，如果香弱、味苦等产生的物质基础尚不清楚。我们拟采用分子感官科学的方法，以高效液相色谱、气相色谱-质谱连用等技术为手段量化分析酿造过程中果香特征及果酒苦味形成的化学基础，利用“感官量化品尝法”量化柑橘果酒的香气特征和苦味，化学成分和感官特征之间的数学联系通过“偏最小二乘回归法”建立，研究果香特征和苦味形成和调控的机制。本研究将为解决柑橘果酒生产过程中风味变化问题提供理论依据，对柑橘工厂化生产具有重要指导意义。

柑橘果酒风味特征的化学基础是由含量超过感官阈值的味觉及嗅觉物质共同作用而构成的。本项目针对构成柑橘风味的香气成分和苦味物质展开研究，通过分析不同来源的柑橘果酒样品的香气、苦味成分及含量，计算气味和味觉活性值，对应分析柑橘果酒感官量化数据，阐明柑橘果酒特征香气和苦味形成的化学分子机制。以柑橘果实原料为基础，并通过原料处理、酿造工艺的优化，研究低苦柑橘果酒酿造关键控制点。 研究结果如下：（1）建立以果肉出汁率、糖酸及苦味物质相结合的综合体系，以评价柑橘原料酿酒可适性。（2）利用SPME-GC-MS定量出供试酒样中的91种香气成分，其中仅有13种具有气味活性。结合主成分分析和感官量化分析得出柑橘果酒的主要香气成分和典型香气特征。（3）以苦味物质活性值为基础，建立柑橘果酒苦味指数模型，通过检验，柑橘果酒苦味指数和苦味感官评价分值之间有理想的拟合效果，相关系数达到了0.8686。（4）低苦柑橘酒的工艺要点：控制原料本身苦味物质含量，利用果汁发酵，并选择对果肉组织破坏小的取汁方式；推荐用1.0g/L 的壳聚糖作为澄清剂，选择商业酿酒酵母RV171进行柑橘酒的酿造。