Characterization of Brazilian Syrah winter wines at bottling and after ageing

Double pruning extended the harvest season of wine grape (Vitis vinifera L.) to dry winter, enabling production of high quality wines in the southeastern Brazil. Winter harvest allows grapes to fulfill not only technological maturation, but also phenolic ripeness. Winter wines from Syrah grapes harvested from eight vineyards in southeastern Brazil during three harvests were analyzed for their chemical and aromatic composition after bottling and after ageing for 20, 30, and 42 months in bottle. Winter wines have high content of total phenolic compounds, which remained almost constant through ageing, as well as color intensity. Malvidin 3-O-glucoside stood out among anthocyanins, remaining 5-10 % after 39 months of ageing. Moreover, malvidin 3-O-glucoside-pyruvic acid was the main pyranoanthocyanin identified in winter wine. Polymerized pigments index ranged from 54 % at bottling to 80 % after 42 months of ageing. Young winter wines are rich in ester and monoterpene, as well as alcoholic volatile compounds responsible for ethereal, fruity, flowery, fresh and sweet aromas. Aged winter wines showed higher contents of furfural, geranyl ethyl ether, isoamyl decanoate, α-muurolene and α-calacorene, contributing to sweet, fruity and woody aromas. Syrah winter wines are characterized by high content of phenolic compounds and color stability, and keep good sensorial characteristics after ageing in bottle

Soil and climate effects on winter wine produced under the tropical environmental conditions of southeastern Brazil

Southeastern Brazil is an emergent region in terms of the production of high-quality fine wines. To contribute to typicity assessment, the soils (morphology, mineralogy, chemical and physical analyses), parent material (geologic maps and portable X-ray fluorescence spectrometry) and climate (temperature and precipitation) were characterized in seven vineyards located in the state of Minas Gerais and São Paulo, Brazil, by carrying out state-of-the-art terroir analysis and assessing the environmental variations of the study sites. A soil profile was described and sampled in the central part of each vineyard. Principal Component Analysis (PCA) biplots were used to analyze the relationships between these factors and the composition of wines (2016, 2017 and 2018 harvests) produced from Syrah in commercial vineyards in different municipalities of Três Corações (TC), Cordislândia (COR), Andradas (AND), São Sebastião do Paraíso (SSP), Três Pontas (TP), Espírito Santo do Pinhal (PIN) and Itobí (ITO). The vineyards were grouped according to soil and climate characteristics. Group A was composed of COR, AND and PIN vineyards, which exhibited the highest correlation with soil Al3+ content and accumulated rainfall. The group’s wines had the lowest ash alkalinity, total polyphenol index (TPI) and pH values and the highest fixed acidity. Group B consisted of the TP and TC vineyards, which had the highest soil organic matter and boron contents and the highest thermal amplitude with similar values (15.4 °C in TC and 15.2 °C in TP); their wines showed average composition. Group C comprised ITO alone, which was characterized by the shallowest and least developed soils. Its wine had the highest flavonol content and high dry extract, color intensity, TPI, alcohol content and sugar values. Group D contained the SSP vineyard, in which the soil subsurface horizons were correlated with the highest wine pH. Late harvest in this vineyard caused the most dehydration of grapes and consequent concentration of most wine compounds (human effect on terroir). The terroir information produced in this study adds substantial value to the wines produced under the tropical environmental conditions of southeastern Brazil, for which such studies are very rare. By characterizing the natural factors (soil, soil parent material and climate) and human factors (vineyard management and wine characteristics) related to terroir, this study can also provide historical information about the wine from this emergent region (the historical factors). In addition, its results can be used to guide producers in their choice of vineyard cultivation sites according to preference in wine composition

Volatile Composition of Sparkling Wines of cv. Chardonnay Cultivated under Different Training Systems in Serra da Mantiqueira (Brazil)

The grapevine is a climbing plant and allows for the manipulation of vegetative canopies to change the microclimate and exposure of leaves and clusters to solar radiation, affecting the primary and secondary metabolisms of plants. Thus, this work aimed to evaluate how the lyre and Geneva double-curtain (GDC) training systems could contribute to the volatile composition of sparkling wines in replicates of vinifications carried out in the Serra da Mantiqueira (Brazil) in two consecutive summer harvests (2017 and 2018). Fifty-four free volatile compounds were identified by HS-SPME/GC-MS in the wines in both systems and vintages. Multivariate analysis differentiated the vintages in component 1 (22.7%) and the training systems in component 2 (7.1%). The crops were differentiated by aldehydes in 2017 and in 2018 by isoamyl acetate ester, probably derived from the amino acid leucine, the season having been more humid, with lower temperatures and less radiation. For the training systems, besides the alcohol compounds, the GDC was differentiated by the terpenoid compounds geranylacetone and β-damascenone, which may contribute more pleasant aromas to sparkling wines. This work promotes additional research and enables winegrowers, through the management of their vineyards, to achieve sparkling wines with different volatile compositions

In-row spacing and shoot thinning for ‘Chardonnay’ grapevines in the south of Minas Gerais, Brazil

The quality of sparkling wine reflects the climate and management of vineyard, since these factors affect grape development, berry composition, and base wine composition. ‘Chardonnay’ vines were subjected to five in-row spacing distances (0.5; 0.75; 1.0; 1.50; and 2.0 m) combined with and without shoot thinning. For each in-row spacing, vines were thinned to 5, 8, 10, 15, and 20 shoots per plant. Vegetative growth, yield, berry composition and base wine composition were analyzed for two years. Vines with decreased in-row spacing, presented fewer clusters and malic acid content in berries, mostly related to the shading effect. Shoot thinning increased bud fruitfulness and decreased leaf area per meter, leaf area per plant, and leaf layer number. In-row spacing from 1.5 m to 0.5 m showed promising results for the Southeast Brazil with higher yield per hectare and sufficient acidity to provide freshness in sparkling wines

Identification of the potential inhibitors of malolactic fermentation in wines

<div><p>Abstract This exploratory work aims to identify the potential inhibitors of lactic bacterial growth and to propose enological practices to guarantee the occurrence of spontaneous malolactic fermentation (MLF) in wines from traditional and double-pruning management harvests in southeast Brazil. One white wine from a summer harvest and one red wine from a winter harvest that failed to complete MLF were utilized as comparative models to identify inhibitor compounds to lactic bacteria. Wine composition, alcoholic-fermentation temperature and bacterial strain contribute to the success or failure of MLF. Temperatures below 12 °C during alcoholic fermentation decrease lactic bacterial metabolism and may impair the bacteria’s growth after yeast cells lysis. A must pH below 3.2 in a summer harvest impairs bacterial growth, and the association of low pH with a free-SO2 concentration above 10 mg L-1 may inhibit MLF. For grapes with a high sugar content, harvested in the winter cycle, enologists should keep the alcohol content below 15% and control the alcoholic-fermentation temperature.</p></div

Bioactive compounds and juice quality from selected grape cultivars

<div><p>ABSTRACT Grape juices have been valued due to their potential health benefits, which have demanded increased grape productivity and quality. Five grape cultivars grown in Brazil, Isabel Precoce, Carmem, Violeta, Concord and Bordo were evaluated in 2013 and 2014 seasons for bioactive components and also for juice processing quality traits. Production cycle was the longest for Carmem but lower and similar for Violeta, Isabel, Bordo and Concord. Isabel showed higher productivity (5.4 kg∙plant-1) but lowest soluble solids content (16.9 °Brix), anthocyanins (26.7 mg∙100 g-1) and total phenolics (110.7 mg∙100 g-1). The highest anthocyanins contents were observed in Violeta (189.9 mg∙100 g-1) and Bordo (133.8 mg∙100 g-1). These cultivars were also rich in phenolics (356.1 and 239.5 mg∙100 g-1, respectively). The highest anthocyanin and total phenolics concentrations were found in Violeta juice (2.68 and 6.33 g∙L-1) followed by Bordo (1.44 and 2.86 g∙L-1). Isabel juice had the lowest content, 0.14 and 1.29 g∙L-1, respectively. Biogenic amines were found at low concentrations only in the juices. Putrescine and spermidine were the major amines detected in juices. Phenylethylamine was detected only in Bordo juice from 2013 season and tryptamine was detected only in 2014 season. Blends were preferred over varietal juices except for Carmem.</p></div