Laboratorio de Aromas y Sustancias Naturales, Estación Experimental Agropecuaria Mendoza, Instituto Nacional de Tecnología Agropecuaria (INTA), San Martín 3853, 5507 Luján de Cuyo, Mendoza, Argentina.
J Agric Food Chem. 2011 Jun 8;59(11):6120-36. doi: 10.1021/jf200073k. Epub 2011 May 6.
The phenolic composition of Malbec (Vitis vinifera L.) grape skins and seeds during ripening and the effect of cluster thinning (CT) in two consecutive seasons (2008-2009) were evaluated by high-performance liquid chromatography-diode array detection/electrospray ionization-mass spectrometry (HPLC-DAD/ESI-MS). Removal of 50% of clusters was performed at 40 days (T1), 80 days (T2), and 100 days after flowering (T3) in a vineyard located in southern Mendoza (Argentina). Yield components, with the exception of cluster weight, were significantly affected by CT in both seasons, but no statistically significant differences were found among treatments. Cluster thinning and its timing had little or no influence on physical parameters and fruit chemical composition, and the differences with respect to the control were mainly due to the season. At harvest in 2008, T1 encouraged the biosynthesis of individual anthocyanins in skins, generating 44.0, 39.6, and 41.2% more glucosylated, acetylated, and total anthocyanins, respectively, as compared to the control, whereas in seeds, T1 and T2 mainly changed the concentrations of (+)-catechin, epicatechin-3-gallate, procyanidin B4, dimer gallate 1, trimer gallate 2, and tetramer. Conversely in 2009, T1 significantly affected the content of flavanols and flavonols in skins, whereas in seeds, T1 and T2 modified the level of (+)-catechin, procyanidins B4 and B6, and trimer gallate 2. Moreover, in 2008 the grapes had a higher concentration of most phenolic compounds, indicating a greater potential for more complex wines. Finally, dihydroquercetin-3-glucoside was the major compound among all nonanthocyanin phenolics detected in Malbec skins and represented 25.7% (2008) and 39.9% (2009) of the total content of those compounds at harvest. This finding could represent a distinctive feature of this grape variety.
采用高效液相色谱-二极管阵列检测/电喷雾电离质谱联用（HPLC-DAD/ESI-MS）分析了马尔贝克（Vitis vinifera L.）葡萄果皮和种子在成熟过程中的酚类成分，以及连续两个季节（2008-2009 年）中整穗疏果（CT）的影响。在位于阿根廷南部门多萨的葡萄园里，在开花后第 40 天（T1）、第 80 天（T2）和第 100 天（T3），去除了 50%的果穗。在两个季节中，CT 对产量构成因素（除了果穗重量外）均有显著影响，但处理间无统计学差异。整穗疏果及其时间对果实的物理参数和化学组成几乎没有影响，与对照相比，差异主要是由于季节造成的。2008 年收获时，T1 促进了果皮中单宁的生物合成，与对照相比，分别增加了 44.0%、39.6%和 41.2%的葡萄糖苷化、乙酰化和总花青素；而在种子中，T1 和 T2 主要改变了（+）-儿茶素、表儿茶素-3-没食子酸酯、原花青素 B4、二聚没食子酸 1、三聚没食子酸 2 和四聚没食子酸的浓度。相反，在 2009 年，T1 显著影响了果皮中黄烷醇和黄酮醇的含量，而在种子中，T1 和 T2 改变了（+）-儿茶素、原花青素 B4 和 B6 以及三聚没食子酸 2 的水平。此外，在 2008 年，葡萄中含有更多的酚类化合物，表明具有酿造更复杂葡萄酒的更大潜力。最后，二氢槲皮素-3-葡萄糖苷是在马尔贝克果皮中检测到的所有非花青素类酚类化合物中的主要化合物，占这些化合物总含量的 25.7%（2008 年）和 39.9%（2009 年）。这一发现可能是该葡萄品种的一个显著特征。
