College of Enology, Northwest A&F University, Yangling, Shaanxi 712100, China.
J Agric Food Chem. 2013 Feb 20;61(7):1542-53. doi: 10.1021/jf3043874. Epub 2013 Feb 11.
The influence of a prefermentative freezing process on changes of aromatic characteristics and volatile compounds in Meili wines was studied to optimize freezing parameters and reveal the mathematical relationship between aromatic characteristics and volatile compounds. The wines obtained were characterized by sensory evaluation and stir bar sorptive extraction (SBSE) followed by a thermal desorption-gas chromatography-mass spectrometry analysis. A total of 28 aromatic descriptors from 6 categories of wine aroma terminology were identified by judging with high "modified frequency (MF%)". In addition, 19 varietal aroma compounds and 36 fermentation aroma compounds were quantitated, followed by the determination of odor activity values (OAVs). On the basis of the data obtained, principal component analysis (PCA) was used to find the relationship between characteristic aroma terms and different freezing conditions, and then partial least-squares regression (PLSR) was proposed to establish the mathematical relationship between the resulting terms and impact odorants. Natural thawing treatment on frozen must resulted in higher aroma quality with higher extraction of varietal aroma compounds. Lower frozen maceration temperature contributed to higher esters and organic acids. Impact aroma compounds were related to models for floral, sweet fruit, temperate fruit, and vegetal, whereas the model of rose and strawberry contained only varietal volatile compounds, and temperate fruit could be regressed by impact fermentation aroma compounds.
研究了预冻处理过程对美乐葡萄酒香气特征和挥发性化合物变化的影响，以优化冷冻参数，并揭示香气特征与挥发性化合物之间的数学关系。通过感官评价和搅拌棒吸附萃取（SBSE）结合热解吸-气相色谱-质谱分析对获得的葡萄酒进行了表征。通过高“修正频率（MF%）”判断，从 6 类葡萄酒香气术语中确定了 28 个香气描述符。此外，定量了 19 种品种香气化合物和 36 种发酵香气化合物，并测定了气味活度值（OAV）。在此基础上，利用主成分分析（PCA）找出特征香气术语与不同冷冻条件之间的关系，然后提出偏最小二乘回归（PLSR），建立所得术语与关键气味物质之间的数学关系。对冷冻葡萄汁进行自然解冻处理，可提高香气质量，增加品种香气化合物的提取。较低的冷冻浸渍温度有利于提高酯类和有机酸的含量。关键香气化合物与花香、甜果、温和水果和蔬菜相关模型有关，而玫瑰和草莓模型仅包含品种挥发性化合物，而温和水果可以用关键发酵香气化合物进行回归。
