Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Food Chem ; 345: 128843, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33340888

RESUMO

The study of seaweeds is increasing in viticulture due to their implications on plant protection and grape quality. This trial aimed to study the effects of foliar applications of an Ascophyllum nodosum extract at low (0.25%, v v-1) and high (0.50%, v v-1) dosages on grape and wine phenolic compounds in 2017 and 2018. In grapes, seaweed biostimulation increased the content of malvidin-3-glc, myricetin-3-glc and myricetin-3-gal in 2017 season. Moreover, both treatments improved the synthesis of trans-piceid and total stilbenes in both seasons. Sensory analysis revealed that 2017 wines had more color than the 2018 wines, which coincided with color intensity parameters. Therefore, seaweed applications to grapevines improved stilbenes content in grapes independently of the season and its effects on the rest of phenolic compounds in grapes and wines depended strongly of season factor.


Assuntos
Fenóis/análise , Alga Marinha/química , Vitis/química , Vinho/análise , Ascophyllum/química , Cor , Frutas/química
2.
Food Res Int ; 130: 108918, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32156366

RESUMO

The effects of seaweed applications to grapevines on grape and wine volatile composition are currently unknown. The aim of this work was to study the influence of seaweed foliar applications (Ascophyllum nodosum) to a Tempranillo blanco vineyard on grape and wine volatile composition. A low (Ld) and a high dosage (Hd) of the seaweed fertilizer was applied in two consecutive seasons (2017-2018). The most abundant family of varietal volatile compounds in Tempranillo blanco grapes was C13 norisoprenoid. Hd treatment tended to increase the concentration of certain C6 compounds in grapes in both seasons, whereas Ld application tended to decrease 2-phenylethanol and 2-phenylethanal content in grapes with a season dependence. Season factor affected to the concentration of most of the volatile compounds in grapes due to the differences on rainfall, which affected to the weight of 100 berries and physico-chemical parameters. Yeast assimilable nitrogen (YAN) in musts could have affected the concentration of most of the wine volatile compounds. According to odor activity values (OAV), Tempranillo blanco wines were characterized as floral, fruity, banana, pear, among others aroma compounds.


Assuntos
Ascophyllum , Fertilizantes , Alga Marinha , Vitis/química , Compostos Orgânicos Voláteis/análise , Vinho/análise , Espanha
3.
Food Chem ; 308: 125605, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31648090

RESUMO

Recently, A.O.C. Rioja have selected and enlisted the Tempranillo blanco as a new grapevine variety to be cultivated in this area. This is the first report that studies amino acid and ammonium composition of grape juice and wine from Tempranillo blanco. The aim was to study the effect of foliar application of a seaweed extract to a Tempranillo blanco vineyard on must and wine amino acids and ammonium content. The results suggested that Tempranillo blanco behaved as an arginine accumulator variety. Biostimulation after seaweed applications at a high dosage (Hd) to the grapevines increased the concentration of several amino acids in the 2017 season, while scarcely affected their content in 2018. Phenylalanine, precursor of several volatile and phenolic compounds, was increased in both seasons after Hd applications. Season was the most important factor in the variability of the must and wine amino acids concentration, followed by treatment and its interaction.


Assuntos
Aminoácidos/química , Alga Marinha/química , Vitis/química , Vinho/análise , Fenóis/análise , Estações do Ano
4.
Food Chem ; 269: 380-386, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30100449

RESUMO

Photosynthetic pigments, including carotenoids are important secondary metabolites, which play a key role in photosynthesis. There is little information about the effects of nitrogen and elicitor applications on chlorophyll and carotenoid concentrations in grapes. The aim of this work was therefore to study the effects of the foliar application of nitrogen sources and elicitors to Tempranillo, Garnacha and Graciano (Vitis vinifera L.) grapevines on chlorophyll and carotenoid contents. The results showed that ß-carotene and lutein were the most abundant carotenoids in all the samples, ranging from 1336 and 227 to 7054 and 1382 µg/g, respectively. The applied treatments had greater impact on chlorophyll and carotenoid contents in Tempranillo grapes than in Graciano and Garnacha varieties. The content of chlorophyll was determined by the variety factor, while the concentration of carotenoids was influenced by the interaction of variety and treatment factors, depending on the type of foliar application.


Assuntos
Carotenoides/análise , Clorofila/análise , Nitrogênio/farmacologia , Vitis/química , Vinho/análise , Fazendas
5.
Food Res Int ; 105: 344-352, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29433223

RESUMO

Nitrogen compounds play a key role on grape and wine quality. Their composition in grapes depends mainly on variety, viticultural management, and terroir, and affects fermentation kinetics and the volatile compound formation. The aim of this work was to study grape and wine amino acid composition of ungrafted or grafted onto cv. País Carignan grapevines growing under rainfed conditions in ten sites of the Maule Valley (Chile). The results showed that proline was the most abundant amino acid in grapes and wines. In general, Carignan noir grapevines grafted over País showed lower grape amino acid content respect to ungrafted vines. Cool night index (CI) was inversely correlated to several amino acids, showing that their plant synthesis or accumulation increased with lower minimum temperatures during the last month before harvest. Truquilemu (Tru) and Ciénaga de Name (Cdn) sites showed the highest concentration for several amino acids and total amino acid content in grapes, which led to a faster alcoholic fermentation.


Assuntos
Aminoácidos/análise , Raízes de Plantas/química , Chuva , Vitis/química , Vinho/análise , Aminoácidos/química , Chile , Clima , Raízes de Plantas/metabolismo , Análise de Componente Principal
6.
Food Res Int ; 99(Pt 1): 688-692, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28784532

RESUMO

Elicitors play an important role in the defense against pathogens as an alternative to chemical pesticides by increasing secondary metabolites. Their effect on grape amino acid has been little investigated. Thus, the aim of this research was to study the influence of methyl jasmonate (MeJ), chitosan (CHT), and a yeast extract (YE) on grape amino acid composition, through foliar applications to grapevines. The must amino acid concentration was analyzed by HPLC. The results showed that CHT and YE treatments decreased the must concentration of several amino acids, affecting total amino acid content (from 2364 to 1961, and 1818mg/L, respectively). However, MeJ treatment had a slight effect on grape amino acid content, increasing the concentration of Met (from 8.95 to 12.13mg/L) and Phe (from 7.96 to 9.29mg/L). It seems to be that, the resistance induction through CHT and YE treatments results in physiological costs to grapevines associated with a decrease on grape amino acid concentration. Consequently, MeJ applications, as a viticultural practice, could be a better tool than CHT and YE treatments, because did not affect grape amino acid concentration.


Assuntos
Acetatos/metabolismo , Aminoácidos/análise , Aminoácidos/metabolismo , Quitosana/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Vitis/química , Leveduras/metabolismo , Aminoácidos/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão
7.
J Agric Food Chem ; 65(34): 7379-7386, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28759217

RESUMO

Copper fungicide use is limited by the European regulation; therefore, new strategies have been developed to prevent grapevine downy mildew (GDM). However, there is poor information about their effects on grape amino acid composition. This field trial aimed to evaluate the effect on grape amino acid composition of chitosan and of a mixture of laminarin and Saccharomyces extracts (LamE), applied in different strategies with copper hydroxide. The results showed that all the treatments applied to grapevines decreased the concentration of several amino acids. Moreover, treatments that have mostly decreased these compounds are those with copper hydroxide, especially when applied individually. LamE applied individually or alternately with copper hydroxide had the least negative effect on grape amino acid content. These results provide further information about the negative effects of copper on grape quality, which can be reduced when it is used in strategy with LamE or chitosan in GDM control.


Assuntos
Quitosana/farmacologia , Cobre/farmacologia , Fungicidas Industriais/farmacologia , Glucanos/farmacologia , Oomicetos/efeitos dos fármacos , Doenças das Plantas/microbiologia , Vitis/microbiologia , Aminoácidos/metabolismo , Oomicetos/metabolismo , Oomicetos/fisiologia , Vitis/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA