Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.151
Filtrar
1.
Food Chem ; 351: 129304, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33657499

RESUMO

Trifluoroacetate (TFA) is an ultrashort-chain perfluoroalkyl substance, which is ubiquitously present in the aqueous environment. Due to its high mobility, it accumulates in plant material. The study presented here shows for the first time that TFA is a widely spread contaminant in beer and tea / herbal infusions. In 104beer samples from 23countries, TFA was detected up to 51 µg/L with a median concentration of 6.1 µg/L. An indicative brewing test and a correlation approach with potassium (K) indicate that the main source of TFA in beer is most likely the applied malt. It could be proven that the impact of the applied water is negligible in terms of TFA, which was supported by the analysis of numerous tap water samples from different countries. The unintended extraction of TFA was also demonstrated for tea / herbal infusions with a median concentration of 2.4 µg/L.


Assuntos
Cerveja/análise , Fluorcarbonetos/análise , Chá/química , Ácido Trifluoracético/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise
2.
Food Chem ; 348: 129147, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-33508607

RESUMO

To simultaneously determine the enantiomers of prothioconazole and its chiral metabolite prothioconazole-desthio in water, beer, Baijiu, and vinegar samples by HPLC, a simple, fast, environmentally-friendly popping candy-assisted dispersive liquid-liquid microextraction technique was developed. A green medium-chain fatty acid (decanoic acid) and popping candy could be used as the extractant and solid dispersant respectively to avoid the use of toxic organic solvents. Decanoic acid was collected after extraction by solidification at room temperature. The linear range of this technique was from 27.1 to 1000 µg L-1. The limits of detection and quantification were within the ranges of 8.1-11.2 µg L-1 and 27.1-37.3 µg L-1, respectively. The extraction recovery was 80.8% to 102.5% with the relative standard deviation ranged from 1.1 to 7.1%. This technique has been successfully applied to enantioselectively determine the residues of prothioconazole and prothioconazole-desthio in water, beer, Baijiu, and vinegar samples.


Assuntos
Ácido Acético/química , Cerveja/análise , Cromatografia Líquida de Alta Pressão , Microextração em Fase Líquida/métodos , Triazóis/análise , Água/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Análise de Componente Principal , Cloreto de Sódio/química , Estereoisomerismo , Temperatura , Triazóis/isolamento & purificação
3.
Food Chem ; 346: 128804, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33418411

RESUMO

Fruity beers can be promoted through production of flavoring compounds during fermentation by partial replacement of brewing yeast by non-conventional-yeasts with high aroma production abilities. We evaluated here the use of a wild Saprochaete suaveolens strain, producing atypical aroma compounds, to produce new natural fruity beer, while keeping classical production conditions used in brewing industry. S. suaveolens was inoculated as starter of culture during beer fermentation and the fermentation performance was evaluated through measurement of several physicochemical parameters. The aroma profile of the engineered beers was monitored using HS-SPME GC/MS. The results showed that high fruity aroma and low-ethanol content beers were obtained through single-fermentation using S. suaveolens. We also demonstrated that during mixed-fermentation, S. suaveolens maintained high metabolic activity and allowed production of beer enriched with fruity aroma. Production of high or low ethanol content fruity beer could be achieved by varying the composition of the starter of culture.


Assuntos
Fermentação , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Cerveja/análise , Aromatizantes/análise , Frutas/química , Geotrichum/metabolismo , Odorantes/análise
4.
Food Chem ; 346: 128924, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33429297

RESUMO

The increasing interest of consumers in the still-developing craft beer market and the strict tax-related legal regulations concerning alcoholic beverages require precise methods for quality control. Determination of ethyl alcohol concentration was performed in 167 samples of alcoholic beverages (craft beers, soft drinks, wines, and cider). We applied headspace gas chromatography using a dual column/dual flame ionization detector (HS-GC-FID/FID), a technique routinely used in forensic toxicology. The method was linear in range, from 0.01 to 20.0%, with a coefficient of determination of 0.999 (R2). The limit of quantification was 0.01%; the detection limit was 0.003%. Furthermore, very good validation parameters were achieved (precision and accuracy below 5%). The samples were analyzed for compliance with EU standards and recommendations of The Beer Judge Certification Program. Moreover, the content of trace quantities of volatile compounds and fusel alcohols (1-propanol, 2-propanol, acetone, and acetaldehyde) was found in the majority of alcoholic beverages.


Assuntos
Cerveja/análise , Bebidas Gaseificadas/análise , Cromatografia Gasosa/métodos , Etanol/análise , Análise de Alimentos/métodos , Vinho/análise , Ionização de Chama , Humanos
5.
Food Chem ; 338: 127801, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798820

RESUMO

A fast high performance liquid chromatography tandem mass spectrometry multi-method based on an ACN-precipitation extraction was developed for the analysis of 41 (modified) mycotoxins in beer. Validation according to the performance criteria defined by the European Commission (EC) in Commission Decision no. 657/2002 revealed good linearity (R2 > 0.99), repeatability (RSDr < 15%), reproducibility (RSDR < 15%), and recovery (79-100%). Limits of quantification ranging from 0.04 to 75 µg/L were obtained. Matrix effects varied from -67 to +319% and were compensated for using standard addition. In total, 87 beer samples, produced worldwide, were analyzed for the presence of mycotoxins with a focus on modified mycotoxins, whereof 76% of the samples were contaminated with at least one mycotoxin. The most prevalent mycotoxins were deoxynivalenol-3-glucoside (63%), HT-2 toxin (15%), and tenuazonic acid (13%). Exposure estimates of deoxynivalenol and its metabolites for German beer revealed no significant contribution to intake of deoxynivalenol.


Assuntos
Cerveja/análise , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Micotoxinas/análise , Espectrometria de Massas em Tandem/métodos , Exposição Dietética/análise , Contaminação de Alimentos/análise , Glucosídeos/análise , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Toxina T-2/análogos & derivados , Toxina T-2/análise , Ácido Tenuazônico/análise , Tricotecenos/análise
6.
Food Chem ; 345: 128744, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33333360

RESUMO

The combination of QuEChERS-LC-QTOFMS and matrix-matched calibration (MMC) to simultaneously determinate legislated and emerging mycotoxins in malt and beer was evaluated for the first time. The method performance was satisfactory displaying suitable linearity (R2 >0.99) and recovery (71-102%). The lowest values (in µg kg-1) of LOD (0.01) and LOQ (0.05) were found for enniatins, while the highest LOD (15) and LOQ (50) were reported for fumonisin B1. Precision and sensitivity (RSD <10%) were in accordance with the different guidelines of method validation. MMC was important to avoid inaccurate quantification of all mycotoxins due to signal enhancement or suppression. Another advantage was the enhanced throughput, requiring 1.2 min of analysis per analyte. The detection of legislated (aflatoxins, ochratoxin A, deoxynivalenol, fumonisin B1, zearalanone, T-2 and HT-2 toxin) and emerging mycotoxins (enniatins, beauvericin, moniliformin and sterigmatocystin) allowed verifying compliance with legislation and generating data to support the establishment of limits for emerging mycotoxins.


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Hordeum/química , Micotoxinas/análise , Espectrometria de Massas em Tandem/métodos , Calibragem , Cromatografia Líquida de Alta Pressão/métodos
7.
Food Chem ; 346: 128871, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33360845

RESUMO

An analytical method for the simultaneous determination of ethylene glycol and diethylene glycol in beer was developed and validated according to current legislation. This method includes the application of sample dilution with ethanol followed by quantification using gas chromatography coupled to mass spectrometry. All figures of merit were within the limits established by regulation. The recoveries of the analytes, expressed as mean recovery, were between 91.9% and 108.9%. Precision, in terms of repeatability and intermediate precision, was established (relative standard deviations were lower than or equal to 10%). The limits of detection (10.0 and 5.0 mg.L-1 for ethylene glycol and diethylene glycol, respectively) and quantification (15.0 mg.L-1 for ethylene glycol and diethylene glycol) obtained were appropriate. Finally, the present method was applied for determination of ethylene glycol and diethylene glycol in 701 beer samples (from 67 different brands and 128 different labels), proving to be reliable.


Assuntos
Cerveja/análise , Etilenoglicol/análise , Etilenoglicóis/análise , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes
8.
Food Chem ; 340: 127900, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32871359

RESUMO

The development of innovative and more cost-effective approaches of making beer throughout continuous fermentation process remains a challenging problem, which is worthy of serious exploration. The current work focuses on the application of a commercial brewing yeast (S. cerevisiae Nottingham Ale), entrapped into chitosan-calcium alginate double layer microcapsules, for the production of a Pale Ale beer. During the primary alcoholic fermentation, the consumption rate of fermentable brewing sugars and dissolved O2, estimated by the Gompertz equation, was halved in the beer obtained by encapsulated yeast in comparison with the free cell. The physical-chemical parameters of beer (i.e. pH, alcohol content, color and bitterness) were not remarkably affected by the different yeast-inoculating form. However, the volatile profiles identified by means of HS-SPME-GC-MS analysis, significantly differed in terms of terpenes, esters and alcohols content, thus proving that the yeast-inoculating form may typify the odor and flavor descriptors of the green beer.


Assuntos
Cerveja/análise , Cerveja/microbiologia , Saccharomyces cerevisiae , Compostos Orgânicos Voláteis/análise , Adulto , Álcoois/análise , Encapsulamento de Células , Ésteres/análise , Feminino , Fermentação , Microbiologia de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Cinética , Masculino , Pessoa de Meia-Idade , Odorantes/análise , Saccharomyces cerevisiae/química , Paladar
9.
Food Chem ; 340: 128208, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33022558

RESUMO

Oligosaccharides analysis is crucial for brewing technology. Herein, we reported a rapid and highly reproducible method for profiling of oligosaccharides in beer using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) by employing a reasonably designed reactive-matrix, 2-phenyl-3-(p-aminophenyl) acrylonitrile (PAPAN). The PAPAN enhanced ionization efficiency of oligosaccharides and improved reproducibility comparing to the use of conventional matrix, 2,5-dihydroxybenzoic acid (DHB). After optimization of sample dilution factor and cationization agents, the distributions of maltooligosaccharides in different brands of beers were unambiguously identified. Since the PAPAN selectively reacts with the reducing end of oligosaccharides, the interferences from matrixes are effectively eliminated. Therefore, the method shows potentials for analysis of oligosaccharides in other foods.


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Oligossacarídeos/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Limite de Detecção , Oligossacarídeos/química , Reprodutibilidade dos Testes , Fatores de Tempo
10.
Food Chem ; 340: 128156, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33011465

RESUMO

The Berthelot reaction for ammonia is revisited with the aim of miniaturization and addressing interferences as encountered with food and water samples. Headspace single drop microextraction of ammonia in phosphoric acid served to attain selectivity in complex matrices, and liquid-liquid microextraction of red or blue indophenol species into 1-octanol-isooctane (60:40, v/v) resulted into high sensitivity. Fiber-optics-based cuvetteless micro-spectrophotometry has been used for colorimetric determination on microliter volumes of extract. The linear dynamic range, limit of detection and enrichment factor have been found to be 0.2-3 mg kg-1, 0.14 mg kg-1 and 38, respectively, measuring red species for milk, cheese and beer (4.9-5.5% error; 4.8-6.3% RSD; n = 5); and 5-400 µg L-1, 0.4 µg L-1 and 137, respectively, measuring blue species for water samples (3.3-5.7% error; 3.6-6.8% RSD; n = 5). A plausible reaction scheme has been proposed for nitroprusside catalysis in indophenol reaction.


Assuntos
Amônia/análise , Indofenol/química , Espectrofotometria/métodos , Água/química , Amônia/isolamento & purificação , Cerveja/análise , Tecnologia de Fibra Óptica , Análise de Alimentos/métodos , Limite de Detecção , Microextração em Fase Líquida , Teoria Quântica
11.
Int J Food Microbiol ; 337: 108953, 2021 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-33161347

RESUMO

Recently, the increase in microbreweries and the consequent production of craft beers have reached exponential growth. The interest in non-conventional yeasts for innovation and a unique selling feature in beer fermentation is increasing. This work studied the autochthonous Saccharomyces and non-Saccharomyces yeasts, isolated from various food sources, with the ability to modify and improve the fermentative and aromatic profiles during alcoholic fermentation. The ability to ferment maltose and produce desirable aroma compounds were considered as the key characters for the screening selection. A synthetic beer wort was developed for this purpose, to simulate beer wort composition. A total of forty-seven yeast strains belonging to different genera were analysed according to their fermentation profile, volatile compounds production and sensory analysis. Three native strains of Saccharomyces cerevisiae, Zygoascus meyerae and Pichia anomala were selected to evaluate their aromatic profile in single and mixed fermentations. The strains produced 4-vinylguaiacol, ß-phenylethyl alcohol, and isoamyl alcohol at levels significantly above the sensory threshold, making them interesting for wheat and blond craft beer styles. The native Hanseniaspora vineae was also included in a co-fermentation treatment, resulting in a promising yeast to produce fruity beers.


Assuntos
Cerveja/análise , Cerveja/microbiologia , Odorantes/análise , Leveduras/metabolismo , Fermentação , Microbiologia de Alimentos , Saccharomyces/classificação , Saccharomyces/metabolismo , Paladar , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/metabolismo , Leveduras/classificação , Leveduras/isolamento & purificação
12.
Int J Food Microbiol ; 333: 108777, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32745828

RESUMO

This study aimed to model the aflatoxin B1 (AFB1) production by A. flavus in wheat grains during malting for craft beer. A total of sixty-four different combinations of grains steeping degree (ST; 41, 43, 45 and 47%), temperature (13, 15, 17 and 19 °C) and time of germination (48, 72, 96 and 120 h), comprising the range of malting conditions that allow the production of quality malt, were assayed. AFB1 was produced in a range of 15.78 ± 3.54 µg/kg (41% ST, 13 °C for 48 h) to 284.66 ± 44.34 µg/kg (47% ST, 19 °C for 120 h). The regression model showing an acceptable fit to the experimental data (adjusted R2 0.84) for AFB1 as a function of grains steeping degree, temperature and time of germination. Results showed that AFB1 levels in wheat malt increase with increase of the temperature or time of germination. Within the range of tested malting conditions, no significant effects were observed for steeping degree on AFB1 levels in wheat malt. The generated model is useful to estimate the AFB1 levels in wheat malt. Findings highlight overall that if wheat grains are contaminated with A. flavus, AFB1 might be produced in malt in levels above the limits set by regulatory agencies, regardless the steeping conditions used.


Assuntos
Aflatoxina B1/biossíntese , Aspergillus flavus/metabolismo , Cerveja/microbiologia , Modelos Biológicos , Triticum/microbiologia , Cerveja/análise , Fermentação/fisiologia , Germinação/fisiologia , Sementes/microbiologia , Temperatura
13.
J Chromatogr A ; 1628: 461475, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822995

RESUMO

For successful profiling of aroma carriers in food samples, a highly efficient extraction method is mandatory. A two-step stir bar sorptive extraction (SBSE) approach, namely fractionated SBSE (Fr-SBSE), was developed to improve both the organoleptic and the chemical identification of aroma compounds in beverages. Fr-SBSE consists of two multi-SBSE procedures (mSBSE) performed sequentially on the same sample. The first extraction consists of a conventional mSBSE using three polydimethylsiloxane (PDMS) stir bars (1stmSBSE). This is followed by a solvent-assisted mSBSE performed on the same sample using three solvent-swollen PDMS stir bars (2nd SA-mSBSE). The 1stmSBSE mainly extracts apolar/medium polar solutes with log Kow values >2, while the 2nd SA-mSBSE mainly extracts polar solutes with log Kow values <2. After this two-step fractionation procedure, either thermal desorption (TD) or liquid desorption - large volume injection (LD-LVI), followed by GC-MS is performed on each set of three stir bars. A real-life sample of roasted green tea was used for method development. The performance of the Fr-SBSE method is further illustrated with sensory evaluations and GC-MS analysis for a stout beer sample. Compared to an extraction procedure with SA-mSBSE only, Fr-SBSE including a 1stmSBSE and a 2nd SA-mSBSE reduced co-elution of aroma compounds in the chromatograms and was capable of providing improved mass spectral quality for identification of 17 additional compounds in roasted green tea, and 12 additional compounds in stout beer, respectively. Moreover, odor description and characterization were clearly improved.


Assuntos
Bebidas/análise , Fracionamento Químico/métodos , Odorantes/análise , Solventes/química , Cerveja/análise , Cromatografia Gasosa-Espectrometria de Massas , Compostos Orgânicos/análise , Reprodutibilidade dos Testes , Chá/química
14.
J Biosci Bioeng ; 130(5): 496-502, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32758402

RESUMO

Four different pesticide residues used in barley planting were selected to investigate their effects on simulated beer brewing. The influences were found to be different by varied agricultural chemicals. Among the four types of pesticides, at 25 µg/mL, triadimefon or carbendazim barely affected the brewing progress. However, ethametsulfuron-methyl and carbaryl (15 µg/mL and 2.5 µg/mL, respectively) exhibited slightly inhibition on saccharification and significantly negative impacts on yeast growth and alcohol fermentation. After pretreated by 50 µL carbaryl-degrading enzyme with the Kcat value of 2.12 s-1 at 30°C for 90 min, the negative influence on simulated beer brewing brought by carbaryl can be eliminated in the fermentation system containing 2.5 µg/mL carbaryl. The efficiency of ethanol fermentation was improved, and the removal rate of carbaryl in the brewing system was greatly accelerated. Taken together, this study suggested a potential method for solving the fermentation inhibition by pesticide residues.


Assuntos
Cerveja/análise , Enzimas/metabolismo , Resíduos de Praguicidas/metabolismo , Resíduos de Praguicidas/farmacologia , Cerveja/microbiologia , Benzimidazóis/metabolismo , Benzimidazóis/farmacologia , Carbamatos/metabolismo , Carbamatos/farmacologia , Fermentação/efeitos dos fármacos , Hordeum/química , Triazóis/metabolismo , Triazóis/farmacologia
15.
Food Chem ; 333: 127518, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32712545

RESUMO

A multifunctional visual observation of magnetic ionic liquid (MIL) benzyltrioctylammonium thiocyanatecobalt (II) [N8,8,8,B+]2[Co(SCN)42-] with the long-chain alkyl and benzyl group structures was designed and synthesized as microextraction phase. Designed new structural MIL displays good hydrophobicity, high extraction capacity for both aromatic and aliphatic compounds, and has obvious color markers (blue color) which is easy visual separation from aqueous solution through a magnet. In the present work, a green, efficient and rapid samples pretreatment method based on simultaneous derivatization and extraction of aromatic (tyramine, histamine, phenylethylamine, tryptamine) and aliphatic (spermidine and spermine) biogenic amines (BAs) were performed. Microwave-assisted derivatization coupled with MIL-dispersive liquid-liquid microextraction (DLLME) was established for the determination of six BAs in different food samples via HPLC. The method was successfully applied for the analysis of beer and milk samples, and the recoveries of analytes were 93.0-110.3% and 91.2-111.6%, respectively. The limits of detection (LODs) were 0.51-1.49 µg L-1 for six BAs. These results have demonstrated that the proposed method has offered an effective, accurate, and sensitive methodology for BAs residue detection in food sample, and this method has great potential for the routine analysis of large numbers of samples on measuring different kinds of compounds.


Assuntos
Aminas Biogênicas/isolamento & purificação , Líquidos Iônicos/química , Microextração em Fase Líquida/métodos , Magnetismo , Micro-Ondas , Animais , Cerveja/análise , Aminas Biogênicas/análise , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Leite/química
16.
Food Chem ; 333: 127379, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653678

RESUMO

The safety and regulatory status of fermented products derived from gluten-containing grains for patients with celiac disease remains controversial. Bottom-up mass spectrometry (MS) has complemented immunoassays for the compositional and immunogenic analyses of wheat beers. However, uncharacterized proteolysis during brewing followed by the secondary digestion for MS has made the analysis and data interpretation complicated. In this study, the composition and immunogenic potential of seven commercially available wheat beers were evaluated using bottom-up MS with the aid of fractionation and a multi-step peptide search strategy to identify peptides generated by various types of proteolysis. Gluten-derived peptides accounted for approximately 50% and 20% of the total number of wheat-derived and barley-derived peptides, respectively, in the investigated beers. Although relatively large polypeptides cannot be thoroughly characterized using traditional bottom-up proteomics, up to 50% of peptides identified contained celiac-immunogenic motifs, and consumption of wheat beers would pose risks for celiac patients.


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Espectrometria de Massas , Triticum/química , Triticum/imunologia , Fermentação , Glutens/química , Humanos , Peptídeos/análise , Peptídeos/imunologia
17.
J Chromatogr A ; 1625: 461226, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709310

RESUMO

In this work, an easy and fast procedure for the selective multiresidue determination of 14 highly polar pesticides (including glyphosate, glufosinate, ethephon and fosetyl) and metabolites in beverages is presented. After an initial sample dilution (1:1, v/v), the extract is shaken and centrifuged, further diluted and then injected directly into the LC-MS/MS system, using hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry. No clean-up procedure was needed. The method was validated according to the current European guidelines for pesticide residue analysis in food and feed and linearity, limits of detection and quantification, matrix effects, trueness and precision were assessed. For plant-based milk, wine and beer samples, 10, 11 and 12 analytes, respectively, out of 14 were fully validated at 10 µg kg-1, the lowest spike level tested. The matrix effect was negative in most of the cases, showing for some compounds, such as HEPA, up to 80% suppression when compared to the response from standards in solvent. The use of isotopically labelled internal standards is required for the optimal quantification, as it compensates for high and varying matrix effects and also for recovery losses during extraction.


Assuntos
Cerveja/análise , Cromatografia Líquida de Alta Pressão/métodos , Substitutos do Leite/química , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Vinho/análise , Animais , Ânions/química , Interações Hidrofóbicas e Hidrofílicas , Leite de Soja/química
18.
Food Chem ; 331: 127192, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569963

RESUMO

Melatonin and serotonin are bioactive compounds present in foods and beverages and related to neuroprotection and anti-angiogenesis, among other activities. They have been described in wines and the role of yeast in their formation is clear. Thus, this study evaluates the content of these bioactives and other related indolic compounds in beer. For this purpose, commercial beers were analyzed by a validated UHPLC-HRMS method and sample treatment optimized due to the low concentrations expected. Moreover, a wort was fermented with different commercial beer yeast (Abbaye, Diamond, SafAle, SafLager) in order to monitor the formation of these bioactives during the elaboration process. Results show that indolic compounds such as N-acetylserotonin and 3-indoleacetic acid are produced during the alcoholic fermentation of wort. Moreover, the occurrence of four indolic compounds (5-hydroxytryptophan, N-acetylserotonin, 3-indoleacetic acid, l-tryptophan ethyl ester) in commercial beers is reported for the first time.


Assuntos
Cerveja/análise , Cerveja/microbiologia , Indóis/metabolismo , Melatonina/metabolismo , Triptofano/metabolismo , Bebidas , Cromatografia Líquida de Alta Pressão/métodos , Fermentação , Análise de Alimentos/métodos , Armazenamento de Alimentos , Indóis/análise , Melatonina/análise , Saccharomyces cerevisiae/metabolismo , Serotonina/análogos & derivados , Temperatura , Triptofano/análogos & derivados
19.
J Stud Alcohol Drugs ; 81(3): 320-330, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32527384

RESUMO

OBJECTIVE: The Anglo-Celtic colonists of Australia and New Zealand brought with them heavy beer-drinking customs, and each country later developed similar temperance movements and alcohol policies. Yet their beer markets differed throughout the 20th century; for example, Australian men typically drank lager with 5% alcohol-by-volume (ABV), whereas New Zealand men drank ale with 4%ABV. We investigated the public health implications of recent developments in product availability, marketing, and country-level consumption patterns. METHOD: We analyzed official data reporting beverage- and strength-specific volumes of ethanol available for sale in beer from 2000 to 2016, a period in which the countries had similar consumption trends; and did a thematic analysis of "market intelligence" reports. RESULTS: Per capita ethanol beer sales fell in both countries, accompanied by increases in market share of higher %ABV categories. Different definitions of beer strength hampered comparison between countries. In Australia, consumption of ethanol in mid-strength beer (3.01%-3.5%ABV) increased, whereas consumption of low-strength beer (<3%ABV) decreased. In New Zealand, consumption of high-strength beer (4.351%-5%ABV) increased whereas that of traditional mid-strength beer (2.501%-4.35%ABV) decreased substantially. Market reports cited consumer health concerns and demand for "craft beer" (typically high-strength) as competing influences in both markets, and reduced-alcohol beer as "the alcoholic drinks industry's-potentially lucrative-shield against accusations of irresponsibility." CONCLUSIONS: Declines in both high- and low-strength beer in Australia have potentially important implications. In New Zealand, the failure of low-strength beer to establish significant market share, along with increased consumption of high-strength beer, are noteworthy developments. Trend data on product ethanol content warrants scrutiny in public health surveillance globally, whereas research is needed on the role of ethanol content within industry strategy.


Assuntos
Consumo de Bebidas Alcoólicas/tendências , Cerveja/análise , Etanol/análise , Indústrias/tendências , Marketing/estatística & dados numéricos , Austrália , Comércio/tendências , Humanos , Nova Zelândia , Saúde Pública
20.
J Appl Microbiol ; 129(5): 1309-1320, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32478894

RESUMO

AIMS: Beer is a harsh medium for bacteria to survive, however, lactic acid bacteria including Lactobacillus brevis have evolved the ability to grow in beer. Here, the influence of environmental factors such as low pH, ethanol or hop content was assessed. METHODS AND RESULTS: A transcriptomic analysis of two Lact. brevis beer-spoiling strains was performed comparing growth in nutritive media with or without the imposition of a stressor related to the beer environment. This allowed the identification of a manganese transporter encoding gene that contributes to low pH tolerance. CONCLUSIONS: We report on the importance of a manganese transporter associated with pH tolerance and beer spoilage in Lact. brevis. The importance of manganese for Lact. brevis growth in a low pH environment was highlighted. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial spoilage of beer may result in product withdrawal with concomitant economic losses for the brewing industry. A limited number of genes involved in beer spoilage have been identified but none of them are universal. It is clear that other molecular players are involved in beer spoilage. The study highlights the complexity of the genetic requirements to facilitate beer spoilage and the role of multiple key players in this process.


Assuntos
Cerveja/microbiologia , Homeostase , Lactobacillus brevis/metabolismo , Manganês/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cerveja/análise , Fermentação , Microbiologia de Alimentos , Perfilação da Expressão Gênica , Concentração de Íons de Hidrogênio , Lactobacillus brevis/genética , Lactobacillus brevis/crescimento & desenvolvimento , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...