Microclimate Influence on Mineral and Metabolic Profiles of Grape Berries

Abstract

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.

Microbial biogeography of wine grapes is conditioned by cultivar, vintage, and climate

“…However, unlike biogeographical patterns, nonrandom microbial patterns linked to grape variety may also represent the influence of viticultural practices. Many cultivars receive specific treatments, including trellising and canopy management strategies, which alter grape microclimate, composition (41,42), and hence possibly microbial community patterns.…”

Effect of Ambient Sunlight Intensity on the Temporal Phenolic Profiles of Vitis Vinifera L. Cv. Chardonnay During the Ripening Season – A Field Study

“…Similarly, to avoid the effect of vineyard orientation and/or microclimatic influences inside the vineyard itself (Pereira et al, 2006), the sampling setup was adapted according to the experiment's purpose (see materials and methods). Average ambient light intensity (Fig.…”

NMR spectroscopy evaluation of direct relationship between soils and molecular composition of red wines from Aglianico grapes

“…Moreover, wines of Montepulciano d'Abruzzo (Italy) were satisfactorily depending on production years, yeast strains, and winemaking processes [8]. The applicability of a polyphasic approach was further confirmed when wines deriving from different cultivars, as grown on three different soils, were discriminated [7].…”

“…The flavours and chemical composition of wine are usually related to the general environmental conditions insisting on vineyards from which wine is produced [2] Many geographical factors such as climate, soil geology and composition, wild yeasts [3,4] and lactic acid bacteria [5], are able to synergistically influence wine molecular characteristics [6]. The relationship between wine quality and its specific site of production is commonly described by the French term "terroir" [7].…”