甲氧基吡嗪(MPs)是一类独特的挥发性化合物,含有含氮杂环,赋予绿色钟罩,红葡萄浆果和葡萄酒的植物和草药气味。在这项研究中,连续两年对6个具有代表性的红葡萄酒品种的浆果品质和MPs水平进行了测定。结果表明,成熟时,连续两年在PetitVerdot葡萄浆果中观察到最高的总可溶性固体。虽然2018年Marselan浆果的花青素含量最高,但2019年,PetitVerdot浆果的花青素含量最高。此外,2-甲氧基吡嗪(MOMP),3-甲基-2-甲氧基吡嗪(MEMP)和3-乙基-2-甲氧基吡嗪(ETMP)水平相对较低,在成熟的浆果中几乎没有检测到。在赤霞珠中观察到相对较高的3-异丁基-2-甲氧基吡嗪(IBMP)含量,Marselan,梅洛,和马尔贝克浆果。然而,3-仲丁基-2-甲氧基吡嗪(SBMP)和IBMP仅在六种葡萄酒中检测到,它们的含量高于葡萄浆果中的含量。此外,相关分析表明,VvOMT1和VvOMT3的表达水平与葡萄果实中MPs含量呈正相关,而在VvOMT2中发现最低的关联。这些发现为选择最合适的葡萄品种以提高葡萄酒品质提供了依据。
Methoxypyrazines (MPs) are a unique class of volatile compounds containing nitrogenous heterocyclics that impart green bell, vegetal and herbal odors to red grape berries and wines. In this study, the quality and MPs levels of grape berries from six representative red wine grape varieties were determined in the two consecutive years. The results showed that, at maturity, the highest total soluble solid was observed in Petit Verdot grape berries in the two consecutive years. While the anthocyanin content showed the highest in Marselan berries in 2018, in 2019, Petit Verdot berries had the highest anthocyanin content. Moreover, 2-
methoxypyrazine (MOMP), 3-methyl-2-
methoxypyrazine (MEMP) and 3-ethyl-2-
methoxypyrazine (ETMP) levels were relatively lower, with almost no detectable in berries at maturity. The relative higher 3-isobutyl-2-
methoxypyrazine (IBMP) content was observed in Cabernet Sauvignon, Marselan, Merlot, and Malbec berries. However, 3-sec-butyl-2-
methoxypyrazine (SBMP) and IBMP were only detected in six wines, and their levels were higher than those in the grape berries. Furthermore, correlation analysis showed that there was a statistically positive correlation between the expression levels of VvOMT1 and VvOMT3 and MPs content in grape berries, while the lowest association was found in the VvOMT2. These findings provide a basis for selecting the most suitable grape varieties to improve wine quality.