Pereira G E, Gaudillere J-P, Pieri P, Hilbert G, Maucourt M, Deborde C, Moing A, Rolin D
UMR Oenologie-Ampélologie, Ecophysiologie et Agronomie Viticole, INRA-ENITA Bordeaux-Université Bordeaux 2, BP 81, 33883 Villenave d'Ornon Cedex, France.
J Agric Food Chem. 2006 Sep 6;54(18):6765-75. doi: 10.1021/jf061013k.
The grape berry microclimate is known to influence berry quality. The effects of the light exposure of grape berry clusters on the composition of berry tissues were studied on the "Merlot" variety grown in a vineyard in Bordeaux, France. The light exposure of the fruiting zone was modified using different intensities of leaf removal, cluster position relative to azimuth, and berry position in the cluster. Light exposures were identified and classified by in situ measurements of berry temperatures. Berries were sampled at maturity (>19 Brix) for determination of skin and/or pulp chemical and metabolic profiles based on (1) chemical and physicochemical measurement of minerals (N, P, K, Ca, Mg), (2) untargeted 1H NMR metabolic fingerprints, and HPLC targeted analyses of (3) amino acids and (4) phenolics. Each profile defined by partial least-square discriminant analysis allowed us to discriminate berries from different light exposure. Discriminant compounds between shaded and light-exposed berries were quercetin-3-glucoside, kaempferol-3-glucoside, myricetin-3-glucoside, and isorhamnetin-3-glucoside for the phenolics, histidine, valine, GABA, alanine, and arginine for the amino acids, and malate for the organic acids. Capacities of the different profiling techniques to discriminate berries were compared. Although the proportion of explained variance from the 1H NMR fingerprint was lower compared to that of chemical measurements, NMR spectroscopy allowed us to identify lit and shaded berries. Light exposure of berries increased the skin and pulp flavonols, histidine and valine contents, and reduced the organic acids, GABA, and alanine contents. All the targeted and nontargeted analytical data sets used made it possible to discriminate sun-exposed and shaded berries. The skin phenolics pattern was the most discriminating and allowed us to sort sun from shade berries. These metabolite classes can be used to qualify berries collected in an undetermined environment. The physiological significance of light and temperature effects on berry composition is discussed.
已知葡萄果实微气候会影响果实品质。在法国波尔多一个葡萄园种植的“梅洛”品种上，研究了葡萄果穗光照对果实组织成分的影响。通过不同强度的疏叶、果穗相对于方位的位置以及果穗中果实的位置来改变结果区的光照。通过原位测量果实温度来识别和分类光照情况。在果实成熟时（>19°波美度）采样，基于以下方面测定果皮和/或果肉的化学和代谢谱：(1) 矿物质（氮、磷、钾、钙、镁）的化学和物理化学测量；(2) 非靶向1H NMR代谢指纹图谱；以及HPLC靶向分析 (3) 氨基酸和 (4) 酚类物质。通过偏最小二乘判别分析定义的每个谱图使我们能够区分来自不同光照条件的果实。遮光和光照果实之间的判别化合物，酚类物质方面有槲皮素-3-葡萄糖苷、山奈酚-3-葡萄糖苷、杨梅素-3-葡萄糖苷和异鼠李素-3-葡萄糖苷；氨基酸方面有组氨酸、缬氨酸、γ-氨基丁酸、丙氨酸和精氨酸；有机酸方面有苹果酸。比较了不同分析技术区分果实的能力。尽管1H NMR指纹图谱解释的方差比例低于化学测量，但核磁共振光谱使我们能够识别光照和遮光的果实。果实光照增加了果皮和果肉中黄酮醇、组氨酸和缬氨酸的含量，并降低了有机酸、γ-氨基丁酸和丙氨酸的含量。所有使用的靶向和非靶向分析数据集都能够区分日晒和遮光的果实。果皮酚类物质模式的区分能力最强，使我们能够将日晒果实与遮光果实区分开来。这些代谢物类别可用于鉴定在不确定环境中采集的果实。讨论了光照和温度对果实成分影响的生理意义。
