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1.
J Sci Food Agric ; 100(3): 1301-1310, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31743440

RESUMO

BACKGROUND: Grape berries exhibit various beneficial health effects due to the potent antioxidant roles of their phenolic compounds. A new Vitis vinifera grape cultivar (Karaerik) grown in Turkey has attracted growing interest due to its antioxidant phenolic compounds, which have still not been investigated. The phenolic/anthocyanin profile needs to be investigated to ascertain its potential health benefits and market value in the region. The present study therefore involves a detailed characterization of the anthocyanin composition of 'Karaerik' grape berries in conjunction with a determination of the antioxidant capacity value of the phenolics present in the skin and the whole berry. RESULTS: Total phenolic compounds (average 8.56 and 2.88 g gallic acid equivalent kg-1 fresh weight) and anthocyanin (7.48 and 1.66 g mv-3-glc equivalent kg-1 fresh weight) contents varied significantly in the skin and whole berry. Malvidin-based anthocyanins made the highest contribution to the pigment content of the berry. Accordingly, the major anthocyanin in the skin (average 42.08 mol%) and whole berry (39.98 mol%) was malvidin-3-glucoside (mv-3-glc). In addition, we found strong evidence of the occurrence of sometimes reported malvidin-3-pentoside and particularly of the not previously reported feruloyl derivative of malvidin-3-(6″-feruloyl)-glucoside (mv-3-ferglc) for V. vinifera grapes. CONCLUSION: The current study is the first report to profile the anthocyanins of the grape with a detailed description of the rare and novel anthocyanin in V. vinifera grapes. The berry is also a potential source of phenolics/anthocyanins with a high antioxidant capacity value and is worthy of comparison with other V. vinifera grapes. © 2019 Society of Chemical Industry.


Assuntos
Antocianinas/química , Extratos Vegetais/química , Vitis/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Frutas/química , Fenóis/química , Espectrometria de Massas por Ionização por Electrospray , Turquia
2.
Food Chem ; 309: 125778, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31704071

RESUMO

This study investigated the evolution of both free and bound volatile compounds in 'Shine Muscat' grape from post-fruit set to post-maturity and limiting factors of the lipoxygenase (LOX) pathway. C6 compounds and terpenes were the main free and bound volatile compounds, respectively. At pre-softening, volatile compounds concentrations were mainly regulated by expansion dilution, and terpene concentrations decreased significantly, which resulted in the minimum terpene concentrations occurred at softening. The volatile compounds were mainly regulated by metabolic synthesis at post-softening, and the production of C6 compounds, terpenes and esters largely began at 10, 12 weeks post-flowering and maturity stages, respectively. In the LOX pathway, LOX, alcohol dehydrogenase and the substrate alcohols were the limiting factors. The aroma maturity stages occurred at 15.4 weeks post-flowering. Finally, the developmental patterns of the volatile compounds in grape were summarized considering previous results in neutral and non-Muscat aromatic varieties.


Assuntos
Evolução Molecular , Vitis/química , Compostos Orgânicos Voláteis/análise , Álcool Desidrogenase/metabolismo , Frutas/química , Frutas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Lipoxigenase/metabolismo , Microextração em Fase Sólida , Especificidade por Substrato , Terpenos/análise , Terpenos/isolamento & purificação , Vitis/crescimento & desenvolvimento , Vitis/metabolismo , Compostos Orgânicos Voláteis/isolamento & purificação , Compostos Orgânicos Voláteis/metabolismo
3.
J Agric Food Chem ; 68(4): 1071-1078, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31841622

RESUMO

Grapes are among the most popular fruits globally, and various fungicides are widely applied to grape crops. As such, the presence of multiple fungicide residues and dietary risks in grapes has become the focus of significant attention. In this study, an easy-to-implement and sensitive UPLC-MS/MS approach was developed to simultaneously determine pyraclostrobin, dimethomorph, cymoxanil, cyazofamid and its metabolite CCIM in grapes via QuEChERS. This approach achieved 78.1-106.0% recovery and a 0.01 mg kg-1 limit of quantitation (LOQ). Field trials revealed that these compounds had degradation half-lives ranging from 0.9 to 13.3 days. And their terminal residues ranging from < LOQ to 1.36 mg kg-1 were below the official maximum residue limit (MRL) in China. The short-term risk for each tested fungicide was below 54%. The long-term risk of individual chemicals ranged from 0.0086% to 3.1%, and their cumulative risk was 4.4%. Results indicated that the dietary risk of these fungicides in grapes was minor.


Assuntos
Fungicidas Industriais/química , Resíduos de Praguicidas/química , Vitis/química , China , Contaminação de Alimentos/análise , Frutas/química , Meia-Vida , Imidazóis/química , Medição de Risco , Estrobilurinas/química , Sulfonamidas/química
4.
Food Chem ; 305: 125506, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31606690

RESUMO

Grapes are known to contain high quantity of polyphenolic compounds, including caffeic, coumaric and ferulic acids esterified with tartaric acid, to yield caftaric, coutaric and fertaric acids, respectively. These acids are more abundant in unripe grapes, which can be processed into verjuice, a product that shows intrinsic resistance against microbial growth and significant antioxidant activity. In the present work, the isolation of hydroxycinnamoyl tartaric acids from unripe grape juice by chromatographic techniques was described. Moreover, the capability of caftaric acid to inhibit tyrosinase activity was evaluated by spectrophotometric assays. According to the kinetics parameters calculated, caftaric acid was shown to be a competitive inhibitor of tyrosinase, more potent than the related caffeic and chlorogenic acids, suggesting that it can be used in cosmetic and food industries for the development of natural skin whitening formulations and as an agent able to counteract the enzymatic browning of food.


Assuntos
Sucos de Frutas e Vegetais/análise , Monofenol Mono-Oxigenase/antagonistas & inibidores , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Espectrofotometria , Vitis/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia
5.
Food Chem ; 302: 125347, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31430631

RESUMO

This work aims to prolong the storage stability of polyphenols, obtained from grape pomace, using a spray drying-based microencapsulation technique. The microcapsules obtained under optimal conditions were stored at two different relative humidities (33% and 52%) during 75 days. The analyses of total phenolic content, antioxidant activity, and individual phenolic compounds were carried out every 15 days, and the most stable microcapsules were achieved with maltodextrin DE4-7 prepared by adding gum Arabic to the wall material at a ratio of 8:2. The phenolic content loss rate was found to be in a range of 0.93-5.42 % depending on phenolic compound. The decrease in the content of rutin, chlorogenic acid, epicatechin, caffeic acid, gallic acid, caftaric acid and catechin was only 0.93, 2.09, 2.13, 2.27, 2.41, 3.40 and 5.42%, respectively. These results indicate more efficient storage conditions than those of previously reported studies.


Assuntos
Cápsulas/química , Armazenamento de Alimentos , Polifenóis/química , Vitis/química , Antioxidantes/análise , Antioxidantes/química , Catequina/análise , Catequina/química , Ácido Clorogênico/análise , Ácido Clorogênico/química , Composição de Medicamentos/métodos , Goma Arábica/química , Umidade , Fenóis/análise , Fenóis/química , Extratos Vegetais/química , Polifenóis/análise , Polissacarídeos/química , Rutina/análise , Rutina/química
6.
Food Chem ; 305: 125484, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514048

RESUMO

Grape pathogenesis-related proteins can cause haze in wine that is undesirable for consumers. Bentonite is used to remove these proteins but is a non-renewable natural material and reduces wine volume due to poor settling. As a potential bentonite alternative, grape seeds powder (GSP) was added to four wines and two grape juice varieties. Addition to wine required high doses (25-32 g/L) for protein removal and haze prevention and this induced changes to wine composition. By contrast, addition to grape juice prior to fermentation required substantially lower doses of GSP (5 g/L) to prevent haze formation. Further 20 g/L of GSP added to the must induced less changes to wine composition than direct addition of GSP to the wine. No changes were recorded in the efficacy of protein removal by changing the GSP source (red or white grape marc), or by using grape seed roasting. Despite the need for additional trials, these preliminary results suggest that GSP may be considered as a viable alternative to bentonite especially when added to juice prior to fermentation.


Assuntos
Pós/química , Vitis/química , Adsorção , Bentonita/química , Cor , Estudos de Viabilidade , Qualidade dos Alimentos , Sucos de Frutas e Vegetais/análise , Proteínas de Plantas/química , Sementes/química , Sementes/metabolismo , Vitis/metabolismo , Vinho/análise
7.
Food Chem ; 308: 125571, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655480

RESUMO

Grape seed maturation involves the gradual oxidation of tannins, decreasing excessive bitterness and astringency in wine. In cool climates, this process is limited by the short growing season, affecting wine quality. A "freeze-thaw" treatment on seeds of red vinifera cultivars at veraison and harvest was used to evaluate the effect of oxidation and extractability on seed phenolic fractions. Freezing increased the extraction of total phenolics and o-diphenols quantified from fractionation (fraction 1, vacuolar tannins; fraction 2, hydrogen bonded tannins; fraction 3, covalently bonded tannins), especially at harvest. Despite this, colorimetry, microscopy, oxidation reactivity index (ORI), and correlations between the color index and fractions indicated that freezing disrupted vacuole integrity, enhancing oxidation in the seed coat. In conclusion, vacuolar tannins (which are the main seed phenolics extracted during fermentation) were highly correlated with seed color change, potentially providing information for winemaking in cool climate regions.


Assuntos
Extratos Vegetais/química , Taninos/isolamento & purificação , Vitis/química , Vinho/análise , Clima , Fermentação , Congelamento , Oxirredução , Fenóis/química , Sementes/química
8.
Food Chem ; 308: 125552, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31677598

RESUMO

The influence of different combinations of Syrah grape maturation degree (19, 21 and 23 °Brix) and maceration times (10, 20 and 30 days) on the volatile profile and aroma potential was evaluated for the first time through different chromatographic platforms (GC × GC/TOFMS, GC-O-OSME, GC-FID and GC/MS). GC × GC/TOFMS analyses resulted in 145 identified compounds and among these 29 were determined to be the most important for wine differentiation. The aroma compounds allowed the discrimination of Syrah wines made with grapes macerated for a shorter time (ten days) due to the higher levels of volatile compounds. The evaluation of these wines through GC-O-OSME together with GC-FID, MS resulted in the designation of 19 °Brix as the most appropriate grape maturation degree to obtain a greater number of volatiles with pleasant odor and higher intensity and persistence. GC × GC/TOFMS allowed five and six co-elutions to be resolved, involving, respectively, ten and twelve important wine compounds.


Assuntos
Odorantes/análise , Vitis/química , Vinho/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Olfatometria , Compostos Orgânicos Voláteis/análise
9.
Food Chem ; 307: 125518, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31644976

RESUMO

The Greek vineyard is home to many minor, indigenous grape cultivar whose diverse polyphenolic content has remained largely unexploited. The study aimed at assaying and assessing the polyphenolic content and antioxidant capacity of: (a) five obscure cultivars; (b) Six biotypes of cultivar 'Liatiko'; (c) Five prominent cultivars; and (d) three French varieties included for comparison reasons. Results revealed all samples exhibiting high polyphenol content and antioxidant capacity levels. 'Vertzami' recorded the highest concentrations in berry skins total anthocyanins, flavanols, flavonols, antioxidant capacity. 'Mandilaria' scored the highest value in seed total flavanols compared to all biotypes and cultivars. All 'Liatiko' biotypes scored the highest concentrations in seed total flavonoids and flavonols. 'Liatiko' and its biotypes exhibited different polyphenolic profiles between them. Owing to the climate change, those indigenous varieties' substantial polyphenol amounts, and the differences between biotypes, will allow viticulturists to select the varieties/biotypes most appropriate for obtaining higher quality products.


Assuntos
Antioxidantes/química , Polifenóis/química , Vitis/química , Antocianinas/análise , Mudança Climática , Flavonoides/análise , Flavonóis/análise , Frutas/química , Frutas/metabolismo , Grécia , Polifenóis/análise , Sementes/química , Sementes/metabolismo , Vitis/metabolismo
10.
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
11.
Food Chem ; 305: 125512, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610422

RESUMO

This study represents the first attempt to combine mid infrared (MIR) spectroscopy and multivariate data processing for prediction of alcohol degree, sugars content and total acidity in straw wine. 302 Italian samples, representing different vintages, production regions and grape varieties, were analysed using FT-MIR spectroscopy and reference methods. New regression functions based on a combination of Orthogonal Signal Correction and Partial Least Squares regression are proposed for prediction of quality parameters: this approach allows overcoming the issue of matrix complexity, reducing spectral interferences and enhancing the information embodied in fingerprinting data. The models proposed are characterised by an excellent reliability, with low error in prediction (alcohol: 0.28%; sugars: 9.9 g/L; acidity: 0.29 g/L) comparable both to reference methods and table wine models. Results demonstrate that vibrational spectroscopy, combined with a proper multivariate data strategy, represents a suitable strategy for the quick and non-destructive assessment of quality parameters of straw wine.


Assuntos
Qualidade dos Alimentos , Informática/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Vinho/análise , Análise dos Mínimos Quadrados , Análise Multivariada , Reprodutibilidade dos Testes , Vitis/química
12.
J Sci Food Agric ; 100(2): 465-482, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31452209

RESUMO

In contrast with the general trend of producing wine from the most famous grapevine varieties, associated with the French paradigm, such as Cabernet-Sauvignon, Merlot, Pinot Noir, Syrah, Sauvignon Blanc, and Chardonnay, there is a tendency to revalorize and preserve minority or autochthonous grapevine varieties worldwide. The South American wine region, where most of the varieties derived from varieties brought after European colonization, is not exempt from this. This has allowed new wines to be provided with distinctive identities that are markedly different from the current homogeneous wine production. Moreover, varietal homogenization increases vineyard genetic vulnerability in relation to the emergence of grapevine diseases, to which the commonly cultivated varieties are not resistant. This review summarizes the oenological potential of minority or autochthonous grapevine varieties cultivated within the South American wine region, focusing on Argentina, Chile, and Bolivia. © 2019 Society of Chemical Industry.


Assuntos
Vitis/química , Vinho/análise , América do Sul , Vitis/classificação , Vitis/genética , Vitis/crescimento & desenvolvimento , Vinho/classificação
13.
J Sci Food Agric ; 100(2): 885-890, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31483055

RESUMO

BACKGROUND: The research focused on the evaluation of the impact of cover cropping on trace metals (Fe, Mn, Cu, Zn, Pb, Co and Cd) and nutrients in vineyard soils and Vitis vinifera L. For this purpose, two types of cover crops (Lolium perenne L. and Medicago sativa L.) and their mixture were planted between vine rows of Muscat white in the vineyard in South Crimea. Trace elements, nutrients and other parameters were analyzed in the soil layers, leaves and grapevines of control and cover cropped plots. RESULTS: The effect of cover cropping was dependent on applied plant species. Ryegrass (L. perenne L.) seems to compete with V. vinifera L. for nutrients - these were lower in the soil and vines of the treated plot. In parallel, lead (Pb) bioconcentration in grapevines was reduced. In contrast, under lucerne (M. sativa L.), nitrogen in the soil and vines, and trace metal bioconcentration (Fe, Pb and Co) were higher. CONCLUSIONS: Our results indicate that cover cropping can influence the chemical composition of soil and vines. This should be considered when selecting cover crops. © 2019 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Lolium/crescimento & desenvolvimento , Medicago/crescimento & desenvolvimento , Oligoelementos/análise , Vitis/química , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Lolium/metabolismo , Medicago/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Solo/química , Especificidade da Espécie , Oligoelementos/metabolismo , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
14.
J Sci Food Agric ; 100(1): 376-383, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31595514

RESUMO

BACKGROUND: Every year, the viticulture activity generates considerable amounts of underused lignocellulosic residues as grape cane, which are generally composted or burned despite their potential value as a source of bioactive compounds. Determination of their phytochemical composition and total antioxidant capacity (TAC) may be a useful way of exploiting different high-added value applications. RESULTS: Twenty-one phenolic compounds (PC) and two carotenoids (Car) were quantified by high performance-liquid chromatography-diode array detection in eight grape varieties from different locations in Mendoza, Argentina. The maximum concentrations corresponded to the stilbene ϵ-viniferin [10 552 µg g-1 dry weight (DW)], followed by the flavanols (+)-catechin (3718 µg g-1 DW) and (-)-epicatechin (2486 µg g-1 DW). In addition, lutein and ß-carotene were quantified at levels ranging between 350 and 2400 ng g-1 DW. The TAC of the extracts was assessed by oxygen radical absorbance capacity, 2,20-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid and 1,1-diphenyl-2-picrylhydrazyl assays, with a good correlation between TAC and total PC for each sample (r ≥ 0.82). CONCLUSION: Samples of cv. Malbec, the most representative variety of Argentina's winemaking industry, presented high contents of PC, particularly ϵ-viniferin, (+)-catechin and (-)-epicatechin. Quercetin-3-galactoside, OH-tyrosol and Car were reported for the first time in grape canes of the eight varieties. The results add to the existing knowledge related to this inexpensive source of high-value bioactive compounds, which could be used as functional ingredients. © 2019 Society of Chemical Industry.


Assuntos
Antioxidantes/química , Extratos Vegetais/química , Polifenóis/química , Vitis/química , Resíduos/análise , Cromatografia Líquida de Alta Pressão , Compostos Fitoquímicos/química , Caules de Planta/química , Vitis/classificação
15.
J Sci Food Agric ; 100(1): 401-409, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31637723

RESUMO

BACKGROUND: It is widely recognized that ambient levels of solar ultraviolet (UV) radiation strongly influence the phenolic composition of grape skins. However, it is unknown to what extent this influence is reflected in the resulting wines. RESULTS: Tempranillo grapevines were exposed or non-exposed to close-to-ambient solar UV levels using appropriate filters, and the phenolic profiles and antioxidant capacity of both grape skins and the resulting wines were analyzed. In total, 47 phenolic compounds were identified in skins and wines, including flavonols, anthocyanins, flavanols, stilbenes, and hydroxycinnamic and hydroxybenzoic acids. In UV-exposed grape skins, flavonols and anthocyanins increased, whereas flavanols and hydroxybenzoic acids showed no significant change. These characteristics were conserved in the resulting wines. However, for stilbenes, hydroxycinnamic acids and antioxidant capacity, the effect of UV on grape skins was not conserved in wines, probably as a result of changes during winemaking. In addition, color intensity, total phenols and total polyphenol index of wines elaborated from UV-exposed grapes increased (although non-significantly) compared to those made from non-UV-exposed grapes. CONCLUSION: The phenolic composition of grape skins exposed to close-to-ambient solar UV could predict, to some extent, the phenolic composition of the resulting wines, particularly regarding higher contents of flavonols and anthocyanins. Thus, manipulating the UV radiation received by grape skins could improve wine quality by positively influencing color stability and healthy properties. To our knowledge, this is the first study in which the effects of solar UV radiation on phenolic composition have been assessed from grape skins to wine. © 2019 Society of Chemical Industry.


Assuntos
Frutas/efeitos da radiação , Fenóis/química , Vitis/química , Vinho/análise , Antocianinas/química , Antioxidantes/química , Flavonóis/química , Frutas/química , Polifenóis/química , Estilbenos/química , Raios Ultravioleta , Vitis/efeitos da radiação
16.
J Sci Food Agric ; 100(2): 836-845, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31646641

RESUMO

BACKGROUND: A classical postulate of viticulture declares that small grape berries produce the best red wines. The popularity of this postulate among winemakers leads them to consider berry size at harvest as a tool to measure the grape's potential to obtain great red wines. To address this issue, two vineyards from the same cultivar and subjected to the same physiological conditions during growing were selected for their difference in average grape berry size at harvest. Grapes from both origins were characterized and used for red winemaking by the same way. Release of volatile compounds and phenolic compounds during the alcoholic fermentation was monitored, and the finished wines were chemically characterized. RESULTS: Larger grapes have a lower theoretical surface-to-volume ratio but have thicker skins and a greater proportion of skins (m/m). Wines made from grapes with a greater proportion of skins contain higher amounts of phenolic compounds, terpenes, volatile acids, acetate esters and polysaccharides. CONCLUSION: According to the results, it seems that grape skin extraction is more related to skin proportion than to berry size. Thus not always smaller grapes produce darker red wines. © 2019 Society of Chemical Industry.


Assuntos
Frutas/química , Vitis/crescimento & desenvolvimento , Vinho/análise , Ésteres , Manipulação de Alimentos , Frutas/crescimento & desenvolvimento , Fenóis/química , Terpenos/química , Vitis/química , Compostos Orgânicos Voláteis/química
17.
J Sci Food Agric ; 100(2): 825-835, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31646642

RESUMO

BACKGROUND: Seaweeds are defined as novel elicitors in many crops, allowing the synthesis of secondary metabolites to be triggered in different plant tissues. Currently, the phenolic composition of Tempranillo Blanco grapes and wines is unreported. The present study aimed to investigate the effects of an Ascophyllum nodosum seaweed extract applied to Tempranillo Blanco grapevines, at low (Ld) and high (Hd) dosages, on grape and wine phenolic compounds during two consecutive seasons (2017-2018). RESULTS: The results obtained showed that catechin was the most abundant phenolic compound in Tempranillo Blanco grapes and wines. Season affected the weight of 100 berries and some enological parameters. Catechin and flavonols concentrations in grapes were increased after Hd application to grapevines, independently of season. The concentration of hydroxycinnamic and hydroxybenzoic acids in wines was affected by vintage, probably as a result of oxidation reactions, as well as pinking phenomena, whereas the stilbenes content in wines was conditioned by the affect of cryptogamic diseases in grapes. CONCLUSION: Seaweeds might act as an elicitor of several phenolic compounds in grapes, enhancing the content of some phenolic compounds in wines. © 2019 Society of Chemical Industry.


Assuntos
Feófitas/química , Fenóis/química , Extratos Vegetais/farmacologia , Alga Marinha/química , Vitis/química , Cromatografia Líquida de Alta Pressão , Fertilizantes/análise , Flavonóis/análise , Flavonóis/metabolismo , Frutas/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Fenóis/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Estilbenos/análise , Estilbenos/metabolismo , Vitis/efeitos dos fármacos , Vitis/metabolismo , Vinho/análise
18.
J Agric Food Chem ; 67(51): 14137-14142, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31802665

RESUMO

Smoke-taint is a wine defect that may occur when ripening grape crops absorb volatile phenols (VPs), compounds associated with the negative sensory attributes of smoke-taint, due to exposure of grapes to wildfire smoke. This study examined potential methods to reduce the impact that smoke-exposure has on wine grapes. Specifically, agricultural sprays normally used to protect grapes from fungal pathogens and a spray used to prevent cracking in soft-fleshed fruits were assessed for their capacity to inhibit increases in VP concentrations in wine grapes following on-vine smoke-exposure. The results indicated that an artificial grape cuticle applied 1 week before exposure to simulated forest fire smoke (at 1-2 weeks after veraison) can significantly hinder an increase in VP concentrations in smoke-exposed grapes at commercial maturity. This reduction in VP concentrations may mitigate crop losses experienced globally by the wine industry due to exposure of grapes on-vine (at key phenological stages) to wildfire smoke.


Assuntos
Produção Agrícola/métodos , Frutas/efeitos dos fármacos , Fumaça/efeitos adversos , Vitis/crescimento & desenvolvimento , Vinho/análise , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Fenóis/metabolismo , Fumaça/análise , Vitis/química , Vitis/efeitos dos fármacos , Vitis/metabolismo , Incêndios Florestais
19.
J Agric Food Chem ; 67(49): 13496-13505, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31724402

RESUMO

Despite being used chiefly for fermenting the sugars of grape must to alcohol, wine yeasts (most prominently Saccharomyces cerevisiae) play a pivotal role in the final aroma profiles of wines. Strain selection, intentionally incorporating non-Saccharomyces yeast in so-called mixed-culture fermentations, and genetic modifications of S. cerevisiae have all been shown to greatly enhance the chemical composition and sensory profile of wines. In this Review, we highlight how wine researchers employ fermenting yeasts to expand on the aroma profiles of the wines they study.


Assuntos
Aromatizantes/metabolismo , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Fermentação , Aromatizantes/química , Odorantes/análise , Saccharomyces cerevisiae/genética , Vitis/química , Vitis/microbiologia
20.
J Chem Ecol ; 45(11-12): 946-958, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31755018

RESUMO

There are contrasting hypotheses regarding the role of plant volatiles in host plant location. We used the grape berry moth (GBM; Paralobesia viteana)-grape plant (Vitis spp.) complex as a model for studying the proximate mechanisms of long distance olfactory-mediated, host-plant location and selection by a specialist phytophagous insect. We used flight tunnel assays to observe GBM female in-flight responses to host (V. riparia) and non-host (apple, Malus domestica; and gray dogwood, Cornus racimosa,) odor sources in the form of plant shoots, extracts of shoots, and synthetic blends. Gas chromatography-electroantennographic detection and gas chromatography/mass spectrometry analyses were used to identify antennal-active volatile compounds. All antennal-active compounds found in grape shoots were also present in dogwood and apple shoots. Female GBM flew upwind to host and non-host extracts and synthetic blends at similar levels, suggesting discrimination is not occurring at long distance from the plant. Further, females did not land on sources releasing plant extracts and synthetic blends, suggesting not all landing cues were present. Additionally, mated and unmated moths displayed similar levels of upwind flight responses to all odor sources, supporting the idea that plant volatiles are not functioning solely as ovipositional cues. The results of this study support a hypothesis that GBM females are using volatile blends to locate a favorable habitat rather than a specific host plant, and that discrimination is occurring within the habitat, or even post-landing.


Assuntos
Mariposas/fisiologia , Oviposição/efeitos dos fármacos , Extratos Vegetais/química , Vitis/química , Compostos Orgânicos Voláteis/química , Animais , Comportamento Animal , Cornus/química , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Controle de Insetos/métodos , Malus/química , Odorantes/análise , Brotos de Planta/química , Olfato , Vitis/parasitologia , Compostos Orgânicos Voláteis/metabolismo
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