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1.
J Agric Food Chem ; 68(1): 279-291, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31802659

RESUMO

This study aimed to identify the key aroma-active volatiles in cranberry wines through three vinification methods (White, Red and Thermo) using GC-MS/O to identify the important aroma compounds. A total of 70 compounds were detected, with 67 in wines and 61 in juices. The esters was the most diversified class, while alcohols and acids were the most abundant, especially 3-methylbutanol, methylbutyric acid, and benzoic acid. The volatile profiles of cranberry wines are distinctive from their source juices. Most alcohols, esters, and acids are fermentation-derived, while terpenes, phenols, aldehydes and ketones are varietal. The Red vinification retained the most varietal volatiles from the must, while the White and Thermo vinifications produced more volatiles during fermentation. Thermovinification reduced the yield of benzoic acid and its derivatives after fermentation. Olfactory analysis identified 47 aroma-active compounds, among which 41 were considered as the major aroma contributors (ethyl benzoate had the highest modified detection frequency).


Assuntos
Aromatizantes/química , Sucos de Frutas e Vegetais/análise , Vaccinium macrocarpon/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Fermentação , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise
2.
J Sci Food Agric ; 100(3): 1012-1021, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31646636

RESUMO

BACKGROUND: Wines are produced via the alcoholic fermentation of suitable substrates, usually sugar (sugar cane, grapes) and carbohydrates (wheat, grain). However, conventional alcoholic fermentation is limited by the inhibition of yeast by ethanol produced, usually at approximately 13-14%. Aside from that, soursop fruit is a very nutritious fruit, although it is highly perishable, and thus produces a lot of wastage. Therefore, the present study aimed to produce fermented soursop juice (soursop wine), using combination of two starter cultures, namely mushroom (Pleurotus pulmonarius) and yeast (Saccharomyces cerevisiae), as well as to determine the effects of fermentation on the physicochemical and antioxidant activities of fermented soursop juice. Optimisation of four factors (pH, temperature, time and culture ratio) using response surface methodology were performed to maximise ethanol production. RESULTS: The optimised values for alcoholic fermentation were pH 4.99, 28.29 °C, 131 h and a 0.42 culture ratio (42:58, P. pulmonarius mycelia:S. cerevisiae) with a predicted ethanol concentration of 22.25%. Through a verification test, soursop wine with 22.29 ± 0.52% ethanol was produced. The antioxidant activities (1,1-diphenyl-2-picrylhydrazyl and ferric reducing antioxidant power) showed a significant (P < 0.05) increase from the soursop juice to soursop wine. CONCLUSION: The alternative fermentation technique using yeast and mushroom has successfully been optimised, with an increased ethanol production in soursop wine and higher antioxidant activities. Ultimately, this finding has high potential for application in the brewing industry to enhance the fermentation process, as well as in the development of an innovative niche product, reducing wastage by converting the highly-perishable fruit into wine with a more stable and longer shelf-life. © 2019 Society of Chemical Industry.


Assuntos
Annona/microbiologia , Microbiologia de Alimentos/métodos , Pleurotus/metabolismo , Saccharomyces cerevisiae/metabolismo , Annona/metabolismo , Antioxidantes/análise , Antioxidantes/metabolismo , Etanol/análise , Etanol/metabolismo , Fermentação , Vinho/análise
3.
J Agric Food Chem ; 68(3): 876-883, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31670510

RESUMO

A chemical-derivatization-triggered aggregation-induced emission (AIE) method for the highly selective determination of hydrogen sulfide (H2S) in wine matrices by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was developed. The detection strategy was developed based on the chemical derivatization of H2S using a low-cost AIE-active fluorescence derivatization reagent, N-(3-iodine-2-oxopropyl)pyrene methamine (NIPM), to trigger specific AIE at 475 nm, which was red-shifted sharply to the maximum emission wavelength as compared with NIPM monomers of 375 nm, effectively quenching the interference from other thiol-containing compounds. With the aid of specific AIE and the effective separation of HPLC, the proposed method showed high selectivity and sensitivity toward H2S. The limits of detection (LODs) at the sub-nM level of 0.25 nmol/L in the wine-beer sample and 0.30 nmol/L in red wine sample were obtained. To certify its applicability, this proposed strategy was successfully applied for the determination of H2S in wine matrices.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Sulfeto de Hidrogênio/análise , Vinho/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Fluorescência , Limite de Detecção
4.
Chemosphere ; 240: 124881, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574438

RESUMO

Phyto- and myco-remediation have been identified as sustainable options for treatment of petroleum-contaminated soils. To appraise the benefits thereof, the potentials of 3 sunflower species, 2 palm wine types and P. ostreatus to treat petroleum-contaminated soils was investigated. The study involved sampling of petroleum-contaminated soils and treatment with the phyto- and myco-remediation agents for a period of 90-days. Agents used for the remediation were 3 species of sunflowers (Helianthus annus-pacino gold, Helianthus sunsation &Helianthus annus-sunny dwarf), fermented palm wine (from 2 species of palm trees -Elaeis guineensis &Raffia africana), and oyster mushroom (Pleurotus ostreatus). The study further investigated variation in remediation efficiency among the sunflower and palm wine species, as well as different substrates and conditions for optimal application of P. ostreatus. The results obtained revealed up to 340 g/kg dry weight of Total petroleum hydrocarbons (TPHs) in the soils, with remediation outcomes of up to 69% by the sunflower- Helianthus annus (Pacino gold), 70% by fermented palm wine, and 85% by P. ostreatus. While the remediation efficiency of sunflower species was proportional to biomass, there was no significant difference in remediation efficiency of the palm wines. It was also found that substrates type and method of application has a significant impact on the remediation efficiency of P. ostreatus. The study further revealed available nitrate and electrical conductivity as possible useful indicators of TPHs concentration and remediation progress in soils.


Assuntos
Biodegradação Ambiental , Helianthus/química , Petróleo/metabolismo , Pleurotus/química , Poluentes do Solo/metabolismo , Solo/química , Vinho/análise , Fermentação , Petróleo/análise , Poluentes do Solo/análise
5.
Food Chem ; 307: 125553, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654952

RESUMO

Aroma contribution of individual esters has been studied in complex mixtures mimicking red wine models. A mixture containing 14 ethyl esters at concentrations found in wine (V1) was prepared and kept as reference. Isointense and qualitatively similar aroma vectors with a reduced number of esters (V2-V7) were prepared. Those vectors were introduced in two reconstituted wines to assess whether simpler vectors could replace V1 without compromising wine quality. In the simpler young wine model, V1 could be replaced by a vector containing just 3 odorants (ethyl 2-methylbutyrate, ethyl butyrate and hexanoate). In the oaky model, a vector containing just ethyl 2-methylbutyrate (V7) could replace V1 without any discernible sensory change. Results also reveal that sub- or perithreshold odorants play outstanding roles on the overall odour intensity of the mixture and that aroma simplification concomitantly implies an increase in the amount of odorant required to keep the intensity of the aroma vector.


Assuntos
Ésteres/análise , Odorantes/análise , Vinho/análise
6.
Food Chem ; 306: 125623, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606633

RESUMO

In this study, apple juice was fermented using Hanseniaspora osmophila X25-5 in pure culture as well as mixed culture with Torulaspora quercuum X24-4, which was inoculated simultaneously or sequentially. H. osmophila inhibited the growth of T. quercuum, while T. quercuum had little effect on the growth of H. osmophila. The simultaneous fermentation consumed relatively more sugar and resulted in the highest ethanol content. The production of organic acids varied depending on the yeast species employed and inoculation modality. Esters and alcohols were the main volatile families produced during fermentation, while ethyl esters and terpenes contributed most to the temperate fruity aroma. Gas chromatography-olfactometry (GC-O) showed that 3-methyl-1-butanol, ethyl 2-methylbutanoate, phenylethyl alcohol, ß-phenethyl acetate, and ß-damascenone were the most potent odorants in all samples. This study suggested that simultaneous fermentation with H. osmophila and T. quercuum might represent a novel strategy for the future production of cider.


Assuntos
Acetatos/análise , Fermentação , Hanseniaspora/metabolismo , Malus/metabolismo , Odorantes/análise , Torulaspora/metabolismo , Bebidas Alcoólicas , Cromatografia Gasosa , Ésteres/análise , Frutas/química , Norisoprenoides/análise , Olfatometria , Vinho/análise
7.
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
8.
Food Chem ; 308: 125665, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655473

RESUMO

The effects of different dissolved oxygen concentrations (DOC) on the browning degree, amino acids, total phenols, reducing sugars, polyphenoloxidase (PPO), peroxidase (POD), phenylalanine ammonia-lyase (PAL) of pear wine, and the relationship between various quality indicators and browning degree were investigated. Dynamic model fitting analysis of the changes of physiochemical indicators of pear wine in the storage process were performed. The importance of the physiochemical indicators effect on the browning of pear wine during the storage process was analyzed by OPLS (orthogonal partial least squares discriminant analysis), and the effect of dissolved oxygen on the browning of pear wine was systematically revealed. The results showed that dissolved oxygen, total phenols and amino acids had the greatest influence on the browning degree of pear wine. It provided a theoretical basis for revealing the browning mechanism and inhibiting the browning of pear wine.


Assuntos
Pyrus/metabolismo , Vinho/análise , Aminoácidos/metabolismo , Catecol Oxidase/metabolismo , Fermentação , Frutas/química , Frutas/metabolismo , Oxirredutases/metabolismo , Peroxidase/metabolismo , Fenóis/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Pyrus/química
9.
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
10.
Food Chem ; 305: 125486, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31520920

RESUMO

The formation of 3-methyl-2,4-nonanedione (MND) during red wine aging can contribute to the premature evolution of aroma, characterized by the loss of fresh fruit and development of dried fruit flavors. The identification of two new hydroxy ketones, 2-hydroxy-3-methylnonan-4-one (syn- and anti-ketol diastereoisomers) and 3-hydroxy-3-methyl-2,4-nonanedione (HMND), prompted the investigation of the precursors and pathways through which MND is produced and evolves. An HS-SPME-GC-MS method was optimized for their quantitation in numerous must and wine samples, providing insight into the evolution of MND, HMND, and ketols through alcoholic fermentation and wine aging. Alcoholic fermentation resulted in a significant decrease in MND and HMND and the simultaneous appearance of ketol diastereoisomers. The analysis of 167 dry red wines revealed significant increases in MND and anti-ketol contents through aging and a significant positive correlation between MND and anti-ketols. Additional experiments demonstrated that ketols are precursors to MND during red wine oxidation.


Assuntos
Alcanos/química , Diacetil/análogos & derivados , Sucos de Frutas e Vegetais/análise , Cetonas/análise , Vinho/análise , Alcanos/metabolismo , Diacetil/química , Diacetil/metabolismo , Etanol/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Concentração de Íons de Hidrogênio , Cetonas/isolamento & purificação , Limite de Detecção , Microextração em Fase Sólida , Estereoisomerismo , Fatores de Tempo
11.
J Sci Food Agric ; 100(1): 59-73, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31435933

RESUMO

BACKGROUND: Jiuzao is the residue after Bajiu distillation which is usually used as forage for livestock. However, it is not fully utilized yet considering the content of protein remained. The present study aimed to isolate antioxidant peptides from Jiuzao protein hydrolysates, then add these peptides into Baijiu product to enhance the healthy value of Baiju. Meanwhile environmental pollution caused by massive Jiuzao can be mitigated indirectly. RESULTS: Four peptides Ala-Tyr-Ile(Leu) (AYI(L)) and Asp-Arg-Glu-Ile(Leu) (DREI(L)) were identified from Jiuzao protein hydrolysates, the extraction contents of AYI + AYL and DREI + DREL were 896.10 and 110.51 mg kg-1 Jiuzao, respectively. On the one hand, antioxidant activities of these peptides were investigated. For in vitro antioxidant assays, AYI, AYL and DREI exhibited strong capacities in oxygen radical absorbance capacity (ORAC) assay. Furthermore, three levels of four peptides were assessed by 2,2'-azobis(2-methylpropanimidamidine) (AAPH)-induced HepG2 cells model. The results showed that these peptides exerted a degree of antioxidant activities in cells. Meanwhile, selected peptides concentrations according to cell assays remined at effective doses after in vitro digestion. On the other hand, the influence of these four peptides on the characteristic aroma compounds in Baijiu was studied. Most characteristic aroma compounds releases were increased with the addition of peptides. CONCLUSION: In the study, antioxidant activities of peptides were evaluated, the feasibility of utilizing Jiuzao protein hydrolysates to obtain beneficial peptides was also proved. Healthy effect of Baijiu or other food can be increased by adding these functional substances. The findings might contribute to food application and Baijiu industries. © 2019 Society of Chemical Industry.


Assuntos
Antioxidantes/química , Peptídeos/química , Hidrolisados de Proteína/química , Resíduos/análise , Vinho/análise , Antioxidantes/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Peptídeos/farmacologia , Hidrolisados de Proteína/farmacologia
12.
J Sci Food Agric ; 100(1): 38-49, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31435935

RESUMO

BACKGROUND: Aromatic compounds are responsible for the final quality of wines. A semi-quantitative analysis was carried out during two consecutive seasons aiming to determine the volatile composition of 12 new white crosses obtained between Monastrell (M) and other varieties, such as Cabernet Sauvignon (C), Syrah (S) and Tempranillo (T) (MC10, MC180, MC9, MC69, MS30, MS33, MS82, MT103, MT19, MV11, MV67 and MV7), using a methodology based on gas chromatography-solid phase microextraction-mass spectrometry. RESULTS: On the one hand, 30 aromatic compounds were identified belonging to different chemical groups (alcohols, acids, terpenes, norisoprenoids and esters). The results showed how some crosses presented significant differences with respect to their parental. For example, in 2016, Monastrell and Cabernet Sauvignon showed high concentration of alcohols, acids and some terpenes, whereas the corresponding crosses showed a predominance of aromas belonging to esters. In 2017, as a result of edaphoclimatic conditions, the white crosses had higher concentrations of esters and acids. In addition, Monastrell and Cabernet Sauvignon showed similar concentrations of alcohols compared to 2016. On the other hand, sensorial analyses confirmed these results, so that mint and peppermint aromas and a fresh quality were detected in MC69 wine, especially in 2016, and fruity and acid aromas were detected in MC180 wine, which gave it a wide ranging complexity and aromatic potential. CONCLUSION: The present study reports the first investigation of the volatile composition and sensory characteristics of directed crosses white wines obtained from Monastrell and other varieties, such as Cabernet Sauvignon, Syrah, Tempranillo and Verdejo. The results obtained indicate that the use of some of these white crosses could be a good option for growing them in this Mediterranean area as a result of the contribution of a good quality in the wine aroma. © 2019 Society of Chemical Industry.


Assuntos
Aromatizantes/química , Compostos Orgânicos Voláteis/química , Vinho/análise , Aromatizantes/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Odorantes/análise , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/isolamento & purificação , Vinho/classificação
13.
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
14.
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
15.
Food Chem ; 308: 125555, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655483

RESUMO

Saccharomyces cerevisiae flor yeast is used for the first time in sparkling wine-making. Twenty-six oenological variables and fifty-three volatile metabolites are quantified in the middle (P = 3 bar) and at the end (P = 6 bar) of the second fermentation, carried out in open and closed bottles. A heat-map of volatiles and the fingerprints obtained for ten chemical families and ten odorant series visualize the changes for each condition. Terpenes, fatty acids and volatile phenols increased their contents by pressure effect at the end of the study by 25.0, 7.8 and 2.2%, respectively. The remaining families decrease between 17.4% and 30.1% for furanic compounds and esters in the same stage. A Principal Component Analysis established that nine volatiles are mainly affected by pressure and five by fermentation stage. The use of ethanol-tolerant flor yeasts constitutes an innovative procedure for the enhancement of the sparkling wines diversification.


Assuntos
Dióxido de Carbono/química , Fermentação , Saccharomyces cerevisiae/metabolismo , Vinho/análise , Dióxido de Carbono/análise , Ésteres/análise , Odorantes/análise , Pressão
16.
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
17.
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
18.
Food Chem ; 302: 125340, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419775

RESUMO

In this study, 83 wines representating four commercial categories: "Argentinean Malbec", "Brazilian Merlot", "Uruguayan Tannat" and "Chilean Carménère" were analyzed according to their phenolic and volatile compounds. The objective was to identify the chemical compounds that would typify each category. From approximately about 600 peaks obtained by chromatographic techniques, 169 were identified and 53 of them were selected for multivariate statistical analysis. Chilean Carménère was the best discriminated group by the methods applied in our study, followed by Argentinean Malbec. Brazilian Merlot mixed mainly with some Carménère, whileTannat mixed with all wines categories, especially Malbec. In general, Chilean Carménère wines can be characterized by a bluish color, higher amounts of sulphur dioxide, higher content of octanoic acid, isobutanol, ethyl isoamyl succinate and catechin and a smaller amount of quercetin. These data can contribute for further process of authenticity or typification of South American red wines.


Assuntos
Análise de Alimentos/estatística & dados numéricos , Fenóis/análise , Compostos Orgânicos Voláteis/análise , Vinho/análise , Butanóis/análise , Caprilatos/análise , Catequina/análise , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/estatística & dados numéricos , Análise Multivariada , Quercetina/análise , América do Sul , Dióxido de Enxofre/análise , Vinho/classificação
19.
Food Chem ; 303: 125277, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473460

RESUMO

Lead concentrations and lead isotope ratios of 43 authentic Bordeaux wines from prestigious châteaux and 14 suspicious Bordeaux origin were determined to evaluate their potential for authenticity and geographical origin assessment. Results have shown that the total Pb concentrations in Bordeaux wines drastically decreased over the previous 50 years with a clear shift of isotopic signatures towards geogenic values corresponding to an overall trend of European environmental lead monitoring. The Pb isotopic ratios determined in both series of samples clearly demonstrated that suspicious Bordeaux wines displayed Pb isotopic signatures statistically distinctive from those obtained for authentic wines. This observation was confirmed by the three-isotope mixing lines obtained between the geogenic and the anthropogenic Pb isotopes data that characterize European and Asian sources. The use these specific three-isotope plots allows a non-ambiguous discrimination between authentic Pauillac AOC and the counterfeited ones.


Assuntos
Qualidade dos Alimentos , Geografia , Chumbo/análise , Chumbo/química , Vinho/análise , Fraude , Isótopos
20.
Int J Food Microbiol ; 312: 108373, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31654841

RESUMO

The use of non-Saccharomyces yeast in conjunction with Saccharomyces cerevisiae in wine fermentation is a growing trend in the wine industry. Non-Saccharomyces, through their distinctive production of secondary metabolites, have the potential to positively contribute to wine sensory profile. To discover new candidate strains for development as starter cultures, indigenous non-Saccharomyces were isolated from un-inoculated fermenting Shiraz musts from a South Australian vineyard (McLaren Vale wine region) and characterised. Among the 77 isolates, 7 species belonging to 5 genera (Kazachstania, Aureobasidium, Meyerozyma, Wickerhamomyces and Torulaspora) were identified by sequencing the internal transcribed spacer regions of the 5.8S rRNA gene (ITS1-5.8S-ITS2 region). The indigenous isolates were evaluated for oenological properties, namely, ethanol tolerance, enzyme activity, and H2S production. To determine their potential industrial use as starter cultures, representative isolates of each species were assessed in a sterile chemically defined grape juice and Viognier grape juice to evaluate their contribution to fermentation kinetics and production of key metabolites, including volatile compounds.


Assuntos
Saccharomycetales/genética , Saccharomycetales/metabolismo , Vitis/metabolismo , Vinho/microbiologia , Leveduras/metabolismo , Austrália , DNA Intergênico/genética , Fazendas , Fermentação , RNA Ribossômico 5,8S/genética , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , Austrália do Sul , Vinho/análise
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