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1.
J Agric Food Chem ; 68(10): 3220-3227, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32066240

RESUMO

Monoterpenes are aromatic compounds that are of great interest to wine as they are related to the quality of varietal wines. However, there is little information available about the impact of monoterpenes on wine odor perception at sub- or peri-threshold concentrations. The aim of this study was to investigate odor perception of monoterpene isomers in Pinot Gris wine and determine compositional matrix effects. Monoterpene isomers were quantitated in 46 Pinot Gris wines using headspace solid-phase microextraction-multidimensional gas chromatography-mass spectrometry, and sensory analysis was conducted using three different model wines. Results show that the nonvolatile composition of Pinot Gris wine strongly increased the volatility of monoterpene isomers. However, aromatic compounds suppressed odor perception, especially with the more complex monoterpene profiles. Monoterpenes were found to influence some fruity aromas in Pinot Gris. The knowledge of these interactions will further help in the development of wine styles and our understanding of wine quality.


Assuntos
Monoterpenos/química , Odorantes/análise , Percepção Olfatória , Vinho/análise , Adulto , Feminino , Aromatizantes/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Isomerismo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
2.
Food Chem ; 313: 126062, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31931422

RESUMO

In sparkling wine, foam characteristics are one of the major attributes. The foam quality depends on wine components. Bentonite is added to the base wine to facilitate the riddling process, but causes a loss of foamability. Acacia gum can be used as additive in wine. We have studied if the addition of Acacia senegal gum (AsenG), Acacia seyal gum (AseyG) and different AsenG fractions could improve the foamability of different base wines treated with bentonite. The foamability differs depending on the gum or the gum fraction treatment but also on the wine, being these differences linked to some aspects of their respective compositions and molecular parameters. AsenG and AseyG increase the foamability (by Mosalux - sparging procedure), respectively, in five and seven out of eight base wines treated with bentonite. Therefore, AsenG and AseyG are potential treatments increasing the foamability of these wines.


Assuntos
Goma Arábica/química , Vinho/análise , Bentonita/química , Cromatografia Líquida de Alta Pressão , Gases/química
3.
Food Chem ; 313: 126045, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31954278

RESUMO

The polyphenolic content and the antioxidant capacity of seven tannins with different botanical origin were measured with spectrophotometric methods (Folin-Ciocalteu, Total Polyphenols Index, DPPH, FRAP), HPLC (phloroglucinolysis), voltammetric analysis (Linear Sweep Voltammetry, LSV). The oxygen consumption rate (OCR) was measured in an oxygen saturated model wine solution, containing transition metals and metabisulphite, with a noninvasive luminescence-based technology. The results showed a high variability in polyphenolic concentration related to the botanical origin of tannins. The OCR determined over 21 days was described by quadratic equations, with coefficients varying with tannin botanical origin, dose and SO2 concentration. The tannins ranked differently for antioxidant capacity, depending on the kind of test. The oxygen consumption parameters were positively correlated only with the LSV data measured with anodic current between 100 and 1200 mV (LSV1200mV) and with the FRAP index.


Assuntos
Antioxidantes/química , Polifenóis/química , Taninos/química , Vinho/análise , Cromatografia Líquida de Alta Pressão , Oxigênio/química , Consumo de Oxigênio , Espectrofotometria
4.
J Agric Food Chem ; 68(7): 2249-2255, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31986034

RESUMO

Ochratoxin A (OTA) is an intrinsically fluorescent phenolic mycotoxin that contaminates a wide range of food products and is a serious health threat to animals and humans. An OTA binding aptamer (OTABA) that folds into an antiparallel G-quadruplex (GQ) in the absence and presence of target OTA has been incorporated into a vast variety of aptasensor platforms for OTA detection. The development of a simple, aptamer-based approach would allow for detection of the toxin without the use of complex analytical instrumentation, which has been the gold standard for OTA detection thus far. However, to date, none of the aptasensor platforms have utilized the natural fluorescence of the phenolic toxin for detection. Herein, we report that OTA binding to OTABA involves π-stacking interactions that lead to GQ-to-toxin energy transfer (ET), which affords a "turn-on" fluorescence self-signaling platform in which the emission of the aptamer-target complex is enhanced in comparison to the free toxin alone. Selective excitation of the GQ-OTA complex at 256 nm leads to a 4-fold enhancement in OTA fluorescence. The GQ-OTA ET detection platform boasts a limit of detection ∼2 ng/mL, which is comparable to a previously demonstrated fluorescence resonance energy transfer immunoassay platform for OTA detection, and displays excellent OTA selectivity and recovery from red wine samples.


Assuntos
Aptâmeros de Nucleotídeos/química , Transferência Ressonante de Energia de Fluorescência/métodos , Ocratoxinas/análise , Vinho/análise , Transferência Ressonante de Energia de Fluorescência/instrumentação , Contaminação de Alimentos/análise , Limite de Detecção
5.
J Agric Food Chem ; 68(6): 1666-1677, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31957444

RESUMO

A potent unpleasant aroma presenting a pickle-like off-odor in Moutai-aroma type Baijiu was studied by comparative aroma extract dilution analysis (AEDA). Two Moutai-aroma type Baijiu samples, one having no off-odor (A) and the other one presenting pickle-like off-odor (B), were selected for chemical analysis and sensory evaluation. The aroma compounds were isolated by headspace solid-phase microextraction and liquid-liquid extraction. AEDA, quantitative analysis, and odor activity value calculation were performed in both the A and B samples. The main differences between the two samples were obtained for 12 compounds, presenting significantly higher concentrations in the off-odor sample. A total of 30 Moutai-aroma type Baijiu samples having different intensities of pickle-like sensory defect were analyzed to confirm the differences. An aroma addition test indicated that the 12 compounds with higher concentrations contributed to the pickle-like off-odor when spiked into sample A. Finally, a triangle test involving omission of the aroma compounds from the spiked A sample proved that 2-methyl-3-furanthiol, methional, methyl 2-methyl-3-furyl disulfide, dimethyl trisulfide, 2-furfurylthiol, methanethiol, dimethyl disulfide, and bis(2-methyl-3-furyl)disulfide with higher concentrations were generally responsible for the pickle-like off-odor in Moutai-aroma type Baijiu.


Assuntos
Aromatizantes/análise , Odorantes/análise , Vinho/análise , Aromatizantes/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Olfato , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação
6.
Food Microbiol ; 87: 103358, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948613

RESUMO

Microbes influence the quality of agricultural commodities and contribute to their distinctive sensorial attributes. Increasingly studies have demonstrated not only differential geographic patterns in microbial communities and populations, but that these contribute to valuable regionally distinct agricultural product identities, the most well-known example being wine. However, little is understood about microbial geographic patterns at scales of less than 100 km. For wine, single vineyards are the smallest (and most valuable) scale at which wine is asserted to differ; however, it is unknown whether microbes play any role in agricultural produce differentiation at this scale. Here we investigate whether vineyard fungal communities and yeast populations driving the spontaneous fermentation of fruit from these same vineyards are differentiated using metagenomics and population genetics. Significant differentiation of fungal communities was revealed between four Central Otago (New Zealand) Pinot Noir vineyard sites. However, there was no vineyard demarcation between fermenting populations of S. cerevisiae. Overall, this provides evidence that vineyard microbiomes potentially contribute to vineyard specific attributes in wine. Understanding the scale at which microbial communities are differentiated, and how these communities influence food product attributes has direct economic implications for industry and could inform sustainable management practices that maintain and enhance microbial diversity.


Assuntos
Fungos/isolamento & purificação , Micobioma , Vitis/microbiologia , Vinho/análise , Análise Discriminante , Fermentação , Frutas/microbiologia , Fungos/classificação , Fungos/genética , Nova Zelândia , Vinho/microbiologia
7.
Food Microbiol ; 87: 103379, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948620

RESUMO

Brettanomyces bruxellensis is a yeast species found in many fermented matrices. A high level of genetic diversity prevails in this species and was recently connected with tolerance to sulfur dioxide, the main preservative used in wine. We therefore examine other phenotypes that may modulate the ability of the species to spoil wine, in a selection of representative strains. The species shows a fairly high homogeneity with respect to the carbohydrates that can support growth, but more diverse behaviors regarding tolerance to low pH or ethanol. Thought no clear link can be drawn with genotype, some strains appear more tolerant than the others, mainly in the AWRI1499 like genetic group. Volatile phenol production is ubiquitous within the species, independent from yeast growth profile and not affected by the nature of the growth substrate. The specific production. n rate of volatile phenol production raises in case of increased aeration. It is little affected by pH decrease until 3.0 or by ethanol concentration increase up to 12% vol, but it decreased in case of increased constraint (pH < 3.0, Ethanol ≥14% vol) or combination of constraints. All the strain studied have thus the ability to spoil wine but some outstanding dangerous strains can even spoil the wine with high level of constrainst.


Assuntos
Brettanomyces/isolamento & purificação , Vinho/microbiologia , Brettanomyces/efeitos dos fármacos , Brettanomyces/crescimento & desenvolvimento , Brettanomyces/metabolismo , Etanol/metabolismo , Conservantes de Alimentos/farmacologia , Genótipo , Concentração de Íons de Hidrogênio , Fenótipo , Dióxido de Enxofre/farmacologia , Vinho/análise
8.
J Agric Food Chem ; 68(6): 1707-1713, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31999112

RESUMO

The potential of different natural antioxidants to inhibit the 1-hydroxyethyl radical formation in SO2-free wines was analyzed by electron paramagnetic resonance (EPR). Chitosan, glutathione, inactive dry yeast, oak and grape seed extracts, and ascorbic acid were tested in white and red wines. The ability of these substances to prevent the formation of acetaldehyde after the Fenton reaction and the oxygen consumption capacity were measured. Ascorbic acid was the antioxidant substance that offered higher percentages of 1-hydroxyethyl radical inhibition at 30 min of reaction. However, wines with ascorbic acid showed higher concentrations of acetaldehyde after the Fenton reaction. Grape seed extract and chitosan provided higher percentages of radical inhibition in red wine than those in white wine, in contrast to the inactive dry yeast that only produced radical inhibition in white wine. Although oak extract did not produce changes in the 1-hydroxyethyl radical, wines with that extract had lower concentrations of acetaldehyde.


Assuntos
Antioxidantes/química , Etanol/química , Aditivos Alimentares/química , Vinho/análise , Acetaldeído/análise , Manipulação de Alimentos
9.
Food Chem ; 312: 126100, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901826

RESUMO

'Nebbiolo' (Vitis vinifera L.) is renowned for its use in producing monovarietal high-quality red wines, such Barolo and Barbaresco. The fight against fraud to safeguard high-quality productions requires an effective varietal identification system applicable in musts and wines. 'Nebbiolo'-specific single-nucleotide polymorphisms (SNPs) were identified starting from available databases and 260 genotypes analysed by Vitis18kSNP array. Two SNPs were sufficient to identify 'Nebbiolo' from 1157 genotypes. The SNP TaqMan® genotyping assays developed in this work successfully identified 'Nebbiolo' in all musts and wines collected at different experimental wine-making steps. The high sensitivity of the assays allowed identification of must mixtures at 1% and wine mixtures at 10-20% with non-'Nebbiolo' genotypes. In commercial wines, the amplification efficiency was limited by the low amount of grapevine DNA and the presence of PCR inhibitors. The TaqMan® genotyping assay is a rapid, highly sensitive and specific methodology with remarkable potential for varietal identification in wines.


Assuntos
Polimorfismo de Nucleotídeo Único , Vitis/genética , Vinho/análise , Genótipo , Reação em Cadeia da Polimerase
10.
Anal Bioanal Chem ; 412(5): 1137-1149, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31925488

RESUMO

The significance of wood odors beyond flavoring effects for barbecues and wine aged in barrels has recently been under discussion. Wood has an immense influence on our physical and mental condition through our palate, such as positive health and mood-stimulating effects. As a result of increased public interest, the key odorants from various natural wood species were recently decoded. To gain profound insights into the contribution of single odorants to the overall scent of distinct wood types, this study compares several softwood species (Scots pine, incense cedar, European larch, Norway spruce, and white fir) by odor profile analysis. Nine odor-active constituents, which were previously detected in those woods, were quantified using stable isotope dilution analysis (SIDA). Odor activity values (OAVs) calculated on the basis of odor thresholds (OTs) determined in cellulose revealed hexanal, octanal, (E)-non-2-enal, p-cresol, vanillin, and thymoquinone as dominant odorants for wood odor. Recombination experiments by mixing the odorants in their naturally occurring concentrations in a cellulose matrix confirmed the successful characterization of the key odorants for Scots pine and incense cedar wood.


Assuntos
Odorantes/análise , Olfato , Madeira/química , Aromatizantes/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Limite de Detecção , Padrões de Referência , Vinho/análise
11.
Food Chem ; 312: 126060, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31891884

RESUMO

This work proposes the development of a simple, fast, and inexpensive methodology based on color histograms (obtained from digital images), and supervised pattern recognition techniques to classify red wines produced in the São Francisco Valley (SFV) region to trace geographic origin, winemaker, and grape variety. PCA-LDA coupled with HSI histograms correctly differentiated all of the SFV samples from the other geographic regions in the test set; SPA-LDA selecting just 10 variables in the Grayscale + HSI histogram achieved 100% accuracy in the test set when classifying three different SFV winemakers. Regarding the three grape varieties, SPA-LDA selected 15 variables in the RGB histogram to obtain the best result, misclassifying only 2 samples in the test set. Pairwise grape variety classification was also performed with only 1 misclassification. Besides following the principles of Green Chemistry, the proposed methodology is a suitable analytical tool; for tracing origins, grape type, and even (SFV) winemakers.


Assuntos
Vitis/química , Vinho/análise , Cor
12.
Food Chem ; 312: 126046, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31911354

RESUMO

The impact of crop level and leaf removal on Istrian Malvasia (Vitis vinifera L.) white wine aroma and phenolic acids composition was studied over two vine-growing seasons. Two crop levels were combined with leaf removal or untreated control in two-factorial design. Crop level showed limited impact on aroma compounds in wine and the concentration of some esters was increased by higher crop level. In contrast, leaf removal increased the concentration of several aroma compounds and especially monoterpenes and esters. The concentration of hydroxycinnamic acids in wine was enhanced only by leaf removal, while no consistent impact of the investigated factors on hydroxybenzoic acids was observed. The obtained results suggest that in cases where environmental conditions are not limiting, increasing the crop level under adequate microclimate in fruit zone has no detrimental effects on white wine aroma and hydroxycinnamic acids composition, potentially leading to economically more sustainable grape production.


Assuntos
Hidroxibenzoatos/análise , Odorantes/análise , Vitis/química , Vinho/análise , Éteres/análise , Frutas/química , Monoterpenos/análise
13.
Waste Manag ; 104: 119-129, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31978830

RESUMO

The residual biomass of winter vine prunings (WVPs) in the Chinese and global grape and wine industries was investigated and estimated, and the physicochemical characteristics of Chinese WVPs were analyzed. The eight regions investigated within China showed a total annual regional WVP yield of 201-842 kt FW, with R1 and R6 region showing the highest and the lowest region yields, respectively. The R4 and R2 regions showed the highest and the lowest yield per tree. Table grapes showed considerably higher WVP yields than wine grapes, whereas the pergola systems showed considerably higher WVP yields than the hedge systems. In addition, older vines showed higher WVP yields than younger vines. Overall, the average WVP yield in China was 2.35 kg/tree FW with a range of 1.33-3.21 kg/tree FW. Globally, the estimated WVP yield has decreased gradually from 2000 to 2017 to 42.31 million ton FW; in contrast, estimated WVP yield in China has increased substantially over the same period to 6.04 million ton FW. Winter vine pruning was the leading source of solid grape waste in the grape and wine industry, both absolutely and proportionally, and was characterized by such properties as a high dry matter content, mild acidity, high levels of organic matter and nutrients, and low fat. It is clear that WVP represents a resource of immense value for generating additional wealth in China and in the global grape and wine industry.


Assuntos
Vitis , Vinho , Biomassa , China , Frutas
14.
Int J Food Microbiol ; 314: 108415, 2020 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-31707175

RESUMO

Dekkera bruxellensis, considered the major microbial contaminant in wine production, produces 4-ethylphenol, a cause of unpleasant odors. Thus, identification of this yeast before wine spoilage is crucial. Although challenging, it could be achieved using a simple technique: RNA-FISH. To reach it is necessary to design probes that allow specific detection/identification of D. bruxellensis among the wine microorganisms and in the wine environment and, if possible, using low formamide concentrations. Therefore, this study was focused on: a) designing a DNA-FISH probe to identify D. bruxellensis that matches these requirements and b) determining the applicability of the RNA-FISH procedure after the end of the alcoholic fermentation and in wine. A novel DNA-FISH D. bruxellensis probe with good performance and specificity was designed. The application of this probe using an in-suspension RNA-FISH protocol (applying only 5% of formamide) allowed the early detection/identification of D. bruxellensis at low cell densities (5 × 102 cell/mL). This was possible by flow cytometry independently of the growth stage of the target cells, both at the end of the alcoholic fermentation and in wine even in the presence of high S. cerevisiae cell densities. Thus, this study aims to contribute to facilitate the identification of D. bruxellensis before wine spoilage occurs, preventing economic losses to the wine industry.


Assuntos
Dekkera/isolamento & purificação , Microbiologia de Alimentos/métodos , RNA Fúngico/análise , Vinho/microbiologia , Dekkera/genética , Fermentação , Citometria de Fluxo , Hibridização in Situ Fluorescente , Sondas de Ácido Nucleico/genética , RNA Fúngico/genética , Especificidade da Espécie
15.
Food Chem ; 310: 125801, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31711813

RESUMO

The influence on aroma compounds chips or staves and toasting degree have been analyzed in red wines aged for two periods of time. Ethyl propanoate, ethyl butanoate, ethyl octanoate, ethyl acetate, isoamyl acetate, isobutanol, 2-methyl-1-butanol, 2-phenylethanol, E-2-hexenol, octanal, nonanal, decanal, γ-nonalactone, furfural, 5-methylfurfural, 2-methoxy-4-vinylphenol and cis-whiskey lactone were the compounds that contribute the most to the aroma series profile. By means of principal components analysis, esters were related to the aging time; cis-whiskey lactone with the type of wood pieces and octanal, 5-methyl furfural and cis-whiskey lactone with the toasting degree. Star plot show that woody aroma compounds are dominant in wines aged with low toasting degree oak pieces, whereas medium plus toasted pieces increased the concentration of aroma compounds with fruity aroma descriptors. Wines with prominent fruity or woody aromas can be obtained depending upon the degree of toasting of wood pieces used for aging.


Assuntos
Compostos Orgânicos Voláteis/análise , Vinho/análise , Madeira , Análise de Alimentos , Indústria de Processamento de Alimentos/instrumentação , Indústria de Processamento de Alimentos/métodos , Furaldeído/análogos & derivados , Furaldeído/análise , Guaiacol/análogos & derivados , Guaiacol/análise , Lactonas/análise , Odorantes/análise , Romênia , Fatores de Tempo , Compostos de Vinila/análise , Madeira/química
16.
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
17.
J Sci Food Agric ; 100(4): 1547-1557, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31769027

RESUMO

BACKGROUND: It is important to increase productivity and improve plant quality at the same time as preserving the principles of safety and productivity. The present study aimed to evaluate the effects of different concentrations of sodium metasilicate and calcium chloride, applied as fertilizers, on the productivity and phytochemical characteristics of Sauvignon Blanc grapes and their respective wines. RESULTS: The experiments were conducted using 2017 and 2018 vintages of commercial Sauvignon Blanc grapes. The treatments consisted of applying separately different concentrations of sodium metasilicate (0, 4, 8 and 12 g L-1 ) or calcium chloride (0, 5, 10 and 15 g L-1 ). The treatments were carried out during four phenological phases. The grapes were harvested at technical maturity and white wines were elaborated. The application of inorganic salts, silicon and calcium to the grapes had a significant effect on the vineyard productivity. The best results were obtained with 4 and 8 g L-1 silicon and 15 g L-1 calcium. An increase in the concentration of phenolics in the grapes was noted. These compounds have antioxidant capacity, which is one of the factors responsible for the resistance of the grapes to pathogens. CONCLUSION: The application of 4 and 8 g L-1 silicon and 15 g L-1 calcium to the grapes represents a potential alternative fertilizing strategy, which could increase the plant yield without damaging the phytochemical characteristics of the fruit and its derivatives. © 2020 Society of Chemical Industry.


Assuntos
Cálcio/metabolismo , Produção Agrícola/métodos , Frutas/química , Compostos Fitoquímicos/química , Silício/metabolismo , Vitis/metabolismo , Vinho/análise , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Compostos Fitoquímicos/metabolismo , Vitis/química , Vitis/crescimento & desenvolvimento
18.
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
19.
J Sci Food Agric ; 100(4): 1436-1447, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31742703

RESUMO

BACKGROUND: Grapevine red blotch virus (GRBV) is a recently discovered DNA virus, which was demonstrated to be responsible for grapevine red blotch disease (GRBD). Its presence has been confirmed in the United States, Canada, Mexico, and South Korea in white and red Vitis vinifera cultivars, including Chardonnay. It has been shown that the three-cornered alfalfa treehopper (Spissistilus festinus) was able to both acquire the GRBV from a grapevine infected and transmit it to healthy grapevines in glasshouse conditions. Studies found that GRBD impacts fruit price, grapevine physiology, and grape berry composition and metabolism in red cultivars. This study evaluated the impact of GRBD on V. vinifera L. Chardonnay grape and wine composition and sensory properties from one vineyard during the 2014, 2015 and 2016 seasons. RESULTS: Grapes from symptomatic red blotch diseased grapevines were lower in total soluble solids, flavan-3-ol, and total phenolic content, and higher in flavonol content when compared to grapes from healthy grapevines. Wines made with grapes from symptomatic grapevines resulted mostly in lower ethanol content and higher pH when compared to wines made from healthy grapevines. Analysis of volatile compounds and descriptive analysis demonstrated that GRBD can impact wine style by altering aroma, flavor, and mouthfeel attributes. CONCLUSIONS: The impacts of GRBD on grape composition directly influenced wine chemistry. The decreased ethanol content impacted not only the levels of volatile compounds but the sensory perception during descriptive analysis. The extent of GRBD impact on the grape composition and wine composition and sensory attributes varied between seasons. © 2019 Society of Chemical Industry.


Assuntos
Frutas/química , Geminiviridae/fisiologia , Doenças das Plantas/virologia , Vitis/virologia , Vinho/análise , Vinho/virologia , Antocianinas/química , Antocianinas/metabolismo , Aromatizantes/química , Aromatizantes/metabolismo , Frutas/metabolismo , Humanos , Fenóis/química , Fenóis/metabolismo , Estações do Ano , Paladar , Vitis/química , Vitis/metabolismo
20.
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
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