Institut des Nutraceutiques et des Aliments Fonctionnels, Université Laval, Quebec City, QC, Canada G1V 0A6.
J Agric Food Chem. 2013 Nov 6;61(44):10418-38. doi: 10.1021/jf402473u. Epub 2013 Oct 24.
Since the arrival on the market of high-quality cold-hardy grape varieties, northern winemaking has been developing tremendously in countries traditionally unsuited for grape and wine production. Cold-hardy grapes are mainly interspecific hybrids of Vitis vinifera with Vitis labrusca and Vitis riparia , making their chemical composition distinct from that of V. vinifera varieties traditionally used for winemaking and therefore limiting the use of current knowledge about V. vinifera varieties in the assessment of grape maturity. Consequently, to evaluate the flavor development of cold-hardy grapes in the province of Quebec, Canada, the ripening of Frontenac and Marquette berries in two vineyards located in the southwest (SW) and northeast (NE) areas of the province, starting at the beginning of veraison, was studied. Quality attributes, phenolic compounds, and aroma profiles showed significant changes during maturation. Although full maturity was reached for both Frontenac and Marquette in the SW vineyard (1380 accumulated growing degree days, based on 10 °C), the accumulation of 1035 growing degree days was not sufficient to fully ripen Frontenac and Marquette in the NE vineyard. Principal component analysis showed different ripening patterns for the two studied locations. The longer veraison in the SW vineyard resulted in higher quality attributes and higher flavor development for both Frontenac and Marquette. Under the colder conditions in the NE vineyard, metabolite accumulation was driven primarily by berry growth, and flavor development was limited. Besides growing degree days and technological parameters (total soluble solids, pH, titratable acidity), which provide significant guidelines for maturity assessment in cold climate, phenolic maturity may be followed by the accumulation of hydroxycinnamic esters and flavonoids, although the impact of these compound classes on quality remains to be determined in cold-climate wines. In both Frontenac and Marquette, aromatic maturity was best assessed using the ratio of cis-3-hexenol to trans-2-hexenal, which showed a constant decrease until maturity. Interestingly, a shift in C6 compound profile, illustrated by the progression of the sum of C6 compounds respectively produced from linoleic (C18:2; hexanal and 1-hexanol) and α-linolenic (C18:3; trans-2-hexenol and cis-3-hexenol) acids occurred during ripening, with α-linolenic acid (C18:3) degradation products decreasing in both varieties as maturation approached. At harvest, aroma profiles of both Frontenac and Marquette were dominated by C6 compounds (hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, and hexanoic acid), acetic acid, β-damascenone, and 2-phenylethanol, with Marquette additionally showing significant levels of monoterpenes (linalool, geraniol, and α-citral) and 1-octen-3-ol.
自高质量抗寒葡萄品种上市以来，在传统上不适合葡萄和葡萄酒生产的国家，北方酿酒业发展迅猛。抗寒葡萄主要是欧亚葡萄与美洲葡萄和河岸葡萄的种间杂种，其化学成分与传统用于酿酒的欧亚葡萄品种明显不同，因此限制了当前对欧亚葡萄品种的了解在葡萄成熟度评估中的使用。因此，为了评估加拿大魁北克省耐寒葡萄的风味发展，研究了位于该省西南部 (SW) 和东北部 (NE) 的两个葡萄园的 Frontenac 和 Marquette 浆果从转色期开始的成熟情况。质量属性、酚类化合物和香气特征在成熟过程中均发生显著变化。尽管在 SW 葡萄园（基于 10°C 的 1380 个累积生长度日）中，Frontenac 和 Marquette 均达到完全成熟，但在 NE 葡萄园，积累 1035 个生长度日不足以完全成熟 Frontenac 和 Marquette。主成分分析表明，两个研究地点的成熟模式不同。SW 葡萄园较长的转色期导致 Frontenac 和 Marquette 的质量属性更高，风味发展更好。在 NE 葡萄园较冷的条件下，代谢物的积累主要由浆果生长驱动，风味发展受限。除了生长度日和技术参数（总可溶性固形物、pH 值、可滴定酸度）为寒冷气候下的成熟评估提供了重要指导外，酚类成熟度可能伴随着羟基肉桂酸酯和类黄酮的积累，尽管这些化合物类别的质量影响仍需在寒冷气候葡萄酒中确定。在 Frontenac 和 Marquette 中，使用顺式-3-己烯醇与反式-2-己烯醛的比值来评估香气成熟度，结果表明该比值在成熟前持续下降。有趣的是，在成熟过程中，C6 化合物谱的变化（由亚油酸（C18:2；己醛和 1-己醇）和α-亚麻酸（C18:3；反式-2-己烯醇和顺式-3-己烯醇）产生的 C6 化合物的总和分别说明），两种品种中 α-亚麻酸（C18:3）降解产物随着成熟的临近而减少。在收获时，Frontenac 和 Marquette 的香气特征均由 C6 化合物（己醛、反式-2-己烯醛、1-己醇、顺式-3-己烯醇和己酸）、乙酸、β-大马酮和 2-苯乙醇主导，其中 Marquette 还显示出显著水平的单萜（芳樟醇、香叶醇和α-柠檬醛）和 1-辛烯-3-醇。
