Quantification of condensed tannins by precipitation with methyl cellulose: development and validation of an optimised tool for grape and wine analysis

Sarneckis, C.J.; Dambergs, Robert G.; Jones, Patrik R.; Mercurio, M; Herderich, Markus; Smith, Paul A.

doi:10.1111/j.1755-0238.2006.tb00042.x

Cited by 292 publications

(241 citation statements)

References 35 publications

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“…Para determinação de níveis de antocianinas e totais fenólicos foram colhidas amostras compostas de 50 bagas de uva, em cada tratamento. As bagas foram homogeneizadas com mixer e, sobre o macerado resultante, foi feita extração com etanol hidratado, sob agitação; posteriormente, adicionou-se HCl 1M às amostras e se fez a leitura em espectrofotômetro, seguindo-se procedimento descrito por Iland et al (2004); as determinações de taninos totais foram feitas utilizando-se a mesma amostragem anterior e sobre o macerado homogeneizado procedeu-se à precipitação dos taninos, através de metilcelulose, com posterior leitura em espectrofotômetro, seguindo-se metodologia descrita por Sarneckis et al (2006).…”

Section: Methodsunclassified

Parâmetros fitotécnicos e condições microclimáticas para videira vinífera conduzida sob dupla poda sequencial

Santos

Hernandes

Pedro

et al. 2011

Rev. bras. eng. agríc. ambient.

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R ESU M OA qualidade do vinho depende da qualidade da uva produzida. As condições microclimáticas incidentes no período de crescimento e desenvolvimento da videira, especialmente na fase do estabelecimento do fruto até a colheita, afetam a qualidade do fruto. A dinâmica da água no solo tem papel importante sobre a qualidade do mosto produzido à vinificação. Em São Paulo, nas bacias de maior concentração atual da vitivinicultura ocorre um período chuvoso que se estende de novembro a fevereiro, que alcança grande parte das variedades da região em fase de crescimento e maturação da baga, o que afeta negativamente a qualidade da uva e do vinho, na maioria das safras. Por outro lado, nas mesmas regiões ocorre um período mais favorável, que é o outono/inverno com potencial de soma térmica promissor para o crescimento da videira e com incidência de um longo período de baixa pluviometria, que vai de abril a outubro. Um experimento foi conduzido, objetivando estudar o cultivo da videira nas duas estações microclimáticas descritas. Avaliou-se a composição físico-química do fruto e a condições microclimáticas para maturação da baga da videira, de 2008 a 2010. Os resultados mostraram que as variedades de videira estudas desenvolveram maior potencial de qualidade da baga, quando cultivada no período de outono-inverno, sendo o efeito mais marcante sobre Vitis vinifera.Palavras-chave: Vitis, qualidade da uva, vinho Plant parameters and microclimatic conditions for wine grapes cultivated under sequential double pruning A B ST R A C T The wine quality depends on the quality grapes produced. Actual micrometeorological conditions occurring in the time frame of grapevine growth and development will impact berry quality, especially from berry set to the harvest. Soil-water dynamics plays an important role on the quality grape must achieved at the vinification. In the São Paulo State (Brasil) in the regions of greatest clustering of vintners, there is a marked rainy time-frame from November to February, which matches with the vine time-cycle when the majority of grape varieties are in the berry set to berry maturation bracket, which negatively affects the grape and wine quality in most of the harvests. In contrast, for the same region there is more favorable condition in the autumn/winter time, which has a promise heat summation for proper grape growing, characterized by a long time-frame of low pluviometric rate (April to October). An experiment was conducted aiming at study the cultivation o grapevines in both described "climatic windows". Physico-chemical composition of and microclimatic conditions for berry maturation during 2008 to 2010 were analysed. Results showed that the studied grape varieties developed better berry quality potential when cultivated in the autumn/winter time and this effect was more pronounced for Vitis vinifera.

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Section: Methodsunclassified

Parâmetros fitotécnicos e condições microclimáticas para videira vinífera conduzida sob dupla poda sequencial

Santos

Hernandes

Pedro

et al. 2011

Rev. bras. eng. agríc. ambient.

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“…A methyl cellulose precipitation assay developed by Sarneckis et al (2006) for grape extract and adapted by Maldonado (2008) for pine bark extract was used. Firstly, 0.5 mL of an aqueous solution of extract (1.0 mg/mL) was mixed with 1.5 mL of a 0.04% (w/w) aqueous solution of methyl cellulose (0.5 mL, 1 g/L).…”

Section: Pine Bark Extracts Tannin's Concentrationmentioning

confidence: 99%

EFFECT OF THE BENCH SCALE EXTRACTION CONDITIONS ON Pinus radiata BARK EXTRACT YIELD, ANTIOXIDANT PROPERTIES AND COMPOSITION

Ramos¹,

Bocalandro²,

Riquelme³

et al. 2013

Maderas, Cienc. tecnol.

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Many pine bark extracts have antioxidant properties. This work examined bench scale extraction on the yield, the composition and antioxidant properties of Pinus radiata. Acetone solvent (98.7% w/w at 120 °C) yielded maximum phenols concentration, tannins concentration, anti-radical activity (DPPH) and reducing activity (FRAP), although its extraction yield was the lowest. When the organic solvent in the mixture decreased, the chelating activity increased (ICA) and antiradical and reducing activities decreased. The extract largest yield was obtained with water at 120ºC, but the antioxidant properties were relatively poor. Taxifolin (dihydroquercetin) and catechin were the main extract components detected by RP-HPLC. The best extraction conditions for high extractive yield and antioxidant properties was achieved with ethanol/water at 120 °C.

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“…The most commonly used solvent for proanthocyanidin extraction from grape berries is 70% acetone in water (v/v), although 50% ethanol in water (v/v) has also been used (Sarneckis et al, 2006;Mercurio et al, 2007). Recently, published research comparing different analytical techniques for determining condensed tannin concentrations in grape skin reported significant discrepancies between analytical methods (Seddon & Downey, 2008;Harbertson & Downey, 2009).…”

Section: Introductionmentioning

confidence: 99%

“…The measurement of tannins in wine grapes before harvest gives an indication of the tannins that could be extracted into the wine during winemaking, and of the quality of the wine (Skogerson et al, 2007). There are a number of published methods for assessing tannin levels in grapes, ranging from the precipitation of tannins by protein (BSA) or methylcellulose (Harbertson et al, 2002;Sarneckis et al, 2006) to analysis by high-performance liquid chromatography (HPLC) (Kennedy & Jones, 2001;Peng et al, 2001). These approaches require the extraction of the condensed tannins from the grape tissue prior to analysis, regardless of the analytical method.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Ethanol and Acetone Mixtures for Extraction of Condensed Tannin from Grape Skin

Downey¹,

Hanlin²

2016

SAJEV

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Discrepancies in condensed tannin concentrations in grape skin determined by different analytical methods prompted the closer examination of aspects of the methodologies. One of these was the choice of extraction solvent. Condensed tannins were extracted from Shiraz grape skins using a range of aqueous solvent mixtures ranging from zero to 100% acetone and ethanol to examine the relative effectiveness of each solvent mixture and to determine whether different solvent mixtures extracted similar condensed tannin components. Acetone extracted more condensed tannin than ethanol. Mixtures of 50 to 70% acetone were equally effective. The most effective ethanol concentration was 50%. Epicatechin-gallate terminal subunits were not detected by HPLC following acid-catalysed cleavage in any of the extraction solvents. Extension subunit composition was similar between solvents across most mixtures. Polymers were generally shorter in the ethanol extracts than in the acetone extracts. Despite differences in tannin concentration and polymer length, the subunit composition was similar in 50% ethanol and 70% acetone. More tannin and tannins with longer polymer lengths were extracted with 70% acetone than with 50% ethanol. This suggests that all grape skin tannins are similar in composition, varying only in length. Thus, 50% ethanol and 70% acetone would give a fair indication of the grape skin tannin composition extracted into wine. However, both 50% ethanol and 70% acetone may overestimate the amount of tannin that is extracted into wine, as wine typically has a much lower solvent concentration, ranging between 10 and 15% ethanol.

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Quantification of condensed tannins by precipitation with methyl cellulose: development and validation of an optimised tool for grape and wine analysis

Cited by 292 publications

References 35 publications

Parâmetros fitotécnicos e condições microclimáticas para videira vinífera conduzida sob dupla poda sequencial

Parâmetros fitotécnicos e condições microclimáticas para videira vinífera conduzida sob dupla poda sequencial

EFFECT OF THE BENCH SCALE EXTRACTION CONDITIONS ON Pinus radiata BARK EXTRACT YIELD, ANTIOXIDANT PROPERTIES AND COMPOSITION

Comparison of Ethanol and Acetone Mixtures for Extraction of Condensed Tannin from Grape Skin

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