Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.718
Filtrar
1.
Food Chem ; 367: 130673, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34352693

RESUMEN

In this work, the use of a multisyringe flow injection analysis coupled to hydride generation atomic fluorescence spectrometry (MSFIA-HG-AFS) for inorganic selenium chemical speciation was proposed. A Doehlert design was applied to optimize the experimental conditions for hydride generation (NaBH4 and HCl concentrations). The limits of quantification (LoQ) obtained were 0.07 µg L-1, for total inorganic Se, and 0.08 µg L-1, for Se(IV). Accuracy and precision of the proposed analytical method were evaluated through analysis of standard reference material and addition and recovery tests. The optimized method was applied to analyses of eight samples of beer, produced in Spain, obtaining concentrations for Se(IV) (<0.08 - 0.46 ± 0.01 µg L-1), total inorganic Se (0.47 ± 0.01 - 3.04 ± 0.62 µg L-1) and Se(VI) (0.06 ± 0.01 - 3.00 ± 0.59 µg L-1). The proposed analytical method was accurate, precise and sensitivity for determination of selenium species in beer samples.


Asunto(s)
Selenio , Cerveza , Análisis de Inyección de Flujo , Selenio/análisis , Espectrometría de Fluorescencia , Espectrofotometría Atómica
2.
Food Chem ; 367: 130681, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34359005

RESUMEN

Parallel data analysis was investigated to improve performance in variable selection and to develop predictive models for beer quality control. A set of spectral near infrared (NIR) data from 60 beer samples and its primitive extracts as the original concentration was used. The dataset was distributed to Raspberry Pi 3 Model B devices connected to a network that was running a Machine Learning service. With more than 4 devices acting in parallel, it was possible to reduce time in 57% to find the best linear regression coefficient (0.999) with the lower RMSECV (0.216) if compared to a singular desktop computer. Thus, parallel processing can significantly reduce the time to indicate the best model fitted during the variable's selection.


Asunto(s)
Cerveza , Espectroscopía Infrarroja Corta , Análisis de los Mínimos Cuadrados , Modelos Lineales , Control de Calidad
3.
Food Chem ; 367: 130646, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34364146

RESUMEN

Main by-product of white wine production is white grape pomace (WGP). It has attracted attention of food scientists, because it possesses high concentration of nutrients and bioactive substances. In this study, WGP was added to the beer after primary fermentation in two different concentrations (10% w/w and 20% w/w) and two different pretreatments (pasteurised and unpasteurised) to determine, whether the most abundant waste from white wine industry could be used to modify the volatilome and phenolic content of the beer. The addition of white grape pomace increased the concentration of phenolic compounds in all of the tested beers (from 321.584 mg gallic acid equivalent (GAE)/dm3 to 501.459 mg GAE/dm3). Antioxidant activity of the beers with addition of WGP (tested with the ABTS+•, DPPH• and FRAP assays) also increased. The composition of volatiles in beers changed as WGP was added. The most significant difference was in the concentration of acetaldehyde - beers with WGP added had 4-7 times lower acetaldehyde content (17.425-31.425 mg/dm3) than the control sample (134.050 mg/dm3).


Asunto(s)
Vitis , Alcoholes , Antioxidantes/análisis , Cerveza , Ésteres , Tecnología
5.
Food Chem ; 369: 130917, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34464835

RESUMEN

The regulatory landscape of flavorings is evolving, thereby putting pressure on control laboratories to develop analytical methods for a wide range of compounds in various types of food and drinks. In order to improve the monitoring of flavoring substances, a versatile and accurate analytical method using the solvent-assisted flavor evaporation (SAFE) technique coupled to GC-MS(SIM) was developed and validated. Focus was put on authorized flavoring substances requiring specific attention due to a genotoxic concern based on information from European risks assessment reports. Thirty-seven (suspected) genotoxic flavoring substances were analyzed in a selection of ten alcohol-free beers. Five suspected genotoxic compounds (i.e. 1-(2-furyl)-2-propanone, 2-acetylfuran, 2-acetyl-5-methylfuran, 2-acetyl-3,5-dimethylfuran, hex-2-eno-1,4-lactone) as well as two confirmed genotoxic flavoring substances (p-mentha-1,8-dien-7-al, 2,4-pentanedione) were identified and quantified among the selected samples. Low concentrations and natural occurrences of the identified compounds suggested that these were not added as such but rather originated from heat-treatments or from plant-based extracts.


Asunto(s)
Cerveza , Aromatizantes , Bélgica , Daño del ADN , Aromatizantes/análisis , Cromatografía de Gases y Espectrometría de Masas
6.
Food Chem ; 369: 130926, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34474284

RESUMEN

Malting and brewing have previously been demonstrated to be risky procedures in terms of mycotoxins contamination. The goal of the study was to describe the fate of less investigated Fusarium and Alternaria mycotoxins, together with their conjugates, during these processes. The Pilsner malt producing process, together with double-mash brewing, were performed in a pilot-scale malting and brewery plants to simulate production of lager - the most popular type of central European beer. In addition, changes in temperature during barley germination were investigated to assess the influence of this critical step. QuEChERS-like extraction followed by UHPLC-HRMS/MS were utilized to quantify the mass balance of 13 mycotoxins and four of their conjugates. The results confirmed germination as the most determining malting step, followed by mashing of malt during brewing. Occurrence of type A trichothecenes, Alternaria mycotoxins and their conjugates in the final beer product indicates the need to take mitigation measures.


Asunto(s)
Fusarium , Micotoxinas , Alternaria , Cerveza/análisis , Contaminación de Alimentos/análisis , Micotoxinas/análisis
7.
Food Chem ; 372: 131093, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-34619521

RESUMEN

This review provides an overview on the influence of malting and brewing on the overall phenolic content of barley malt and beer. Beer phenolics are mainly originated from barley malt and can be found in free and bound forms, in concentrations up to 50% lower comparing to sweet wort. The use of roasted malts, in combination with proper milling and high mashing temperatures at low pH can lead to a release of bound phenolic forms and increased extraction. New technological strategies such as special yeasts, manipulation of enzymatic activity and dry-hopping may be relevant to improve the phenolic profile of beer and attain phenolic levels with benefits both for beer stability and consumer's health. As the content of free ferulic acid in beer only accounts up to approximately 15% of total content, further studies should put emphasis on its bound forms in different beer styles and non-alcoholic beers.


Asunto(s)
Cerveza , Hordeum , Cerveza/análisis , Fenoles , Plantones , Levaduras
8.
Food Chem ; 372: 131288, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-34655830

RESUMEN

Determination of ten biogenic amines in alcoholic beverages by HPLC coupled to a potentiometric detector for food quality control is herein presented. Biogenic amines were separated by ion-pair chromatography on a C18 column using a gradient mobile phase of acetic acid, acetonitrile, and butane-sulfonic acid. Detection was accomplished by a miniaturized amine-selective electrode. The method was validated following ICH and Eurachem guidelines. Linear regression models provided R2 values from 0.9870 ± 0.0019 to 0.9991 ± 0.0014 for tyramine and cadaverine, respectively. Detection and quantification limits depend on the molecular weight of BAs, ranging from 9.3 to 60.5 and from 31.1 to 202.3 µg L-1 for methylamine and spermine, respectively. Repeatability and intermediate precision showed RSD values lower than 5.8 and 8.3%, respectively. Accuracy of assays yielded recovery values from 86.4 to 109.9%. The biogenic amines content in red wine, white wine, and beer samples were 7.54, 5.24, and 4.58 mg L-1, respectively.


Asunto(s)
Aminas Biogénicas , Vino , Bebidas Alcohólicas/análisis , Cerveza/análisis , Aminas Biogénicas/análisis , Cromatografía Líquida de Alta Presión , Control de Calidad , Vino/análisis
9.
J Agric Food Chem ; 69(46): 14024-14036, 2021 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-34734707

RESUMEN

Beer is one of the most popular beverages in the world. The increased popularity of craft beers has led to the development of unique beers that are alcohol-free, gluten-free, low calorie, or with functional properties through fermentation with probiotic microorganisms. In this study, functional unhopped beers were evaluated by utilizing probiotics (Lacticaseibacillus paracasei Lpc-37 and ibSium Saccharomyces cerevisiae CNCM I-3856) as starter cultures. The metabolites produced by probiotics were investigated using a nontargeted metabolomics approach and identified against metabolomics databases (Kyoto Encyclopedia of Genes and Genomes (KEGG), Human Metabolome Database (HMDB), Yeast Metabolome Database (YMDB), METLIN tandem mass spectrometry (MS/MS)). Derivatives of branched-chain (leucine) and aromatic amino acids (phenylalanine, tryptophan, and tyrosine) were enriched (one-way analysis of variance (ANOVA) p < 0.05) in probiotic-fermented unhopped beers, especially tryptophan metabolites. In addition, the synergistic effects of yeast-lactic acid bacteria (LAB) interactions led to further enrichment of higher acids such as (S)-(-)-2-hydroxyisocaproic acid, phenyllactic acid, hydroxyphenyllactic acid, and indolelactic acid. The potential pathways for the formation of novel bioactive tryptophan metabolites (indole and indoleacrylic acid) by LAB were elucidated. Altogether, probiotic LAB-fermented unhopped beer showed the highest antioxidant capacity and total phenolic content. This work provides the basis for the discovery of bioactive metabolites in probiotic-fermented foods.


Asunto(s)
Cerveza , Probióticos , Aminoácidos , Cerveza/análisis , Cromatografía Liquida , Fermentación , Humanos , Metabolómica , Espectrometría de Masas en Tándem
10.
Artículo en Inglés | MEDLINE | ID: mdl-34639647

RESUMEN

Zero and low alcohol products, particularly beer, are gaining consideration as a method to reduce consumption of ethanol. We do not know if this approach is likely to increase or decrease health inequalities. The aim of the study was to determine if the purchase and consumption of zero and low alcohol beers differs by demographic and socio-economic characteristics of consumers. Based on British household purchase data from 79,411 households and on British survey data of more than 104,635 adult (18+) respondents, we estimated the likelihood of buying and drinking zero (ABV = 0.0%) and low alcohol (ABV > 0.0% and ≤ 3.5%) beer by a range of socio-demographic characteristics. We found that buying and consuming zero alcohol beer is much more likely to occur in younger age groups, in more affluent households, and in those with higher social grades, with gaps in buying zero alcohol beer between households in higher and lower social grades widening between 2015 and 2020. Buying and drinking low alcohol beer had less consistent relationships with socio-demographic characteristics, but was strongly driven by households that normally buy and drink the most alcohol. Common to many health-related behaviours, it seems that it is the more affluent that lead the way in choosing zero or low alcohol products. Whilst the increased availability of zero and low alcohol products might be a useful tool to reduce overall ethanol consumption in the more socially advantageous part of society, it may be less beneficial for the rest of the population. Other evidence-based alcohol policy measures that lessen health inequalities, need to go hand-in-hand with those promoting the uptake of zero and low alcohol beer.


Asunto(s)
Cerveza , Comportamiento del Consumidor , Etanol , Composición Familiar , Encuestas y Cuestionarios
11.
Molecules ; 26(19)2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34641609

RESUMEN

In recent years, the interest in the health-promoting effects of hop prenylflavonoids, especially its estrogenic effects, has grown. Unfortunately, one of the most potent phytoestrogens identified so far, 8-prenylnaringenin, is only a minor component of hops, so its isolation from hop materials for the production of estrogenically active food supplements has proved to be problematic. The aim of this study was to optimize the conditions (e.g., temperature, the length of the process and the amount of the catalyst) to produce 8-prenylnaringenin-rich material by the magnesium oxide-catalyzed thermal isomerization of desmethylxanthohumol. Under these optimized conditions, the yield of 8-prenylnaringenin was 29 mg per 100 gDW of product, corresponding to a >70% increase in its content relative to the starting material. This process may be applied in the production of functional foods or food supplements rich in 8-prenylnaringenin, which may then be utilized in therapeutic agents to help alleviate the symptoms of menopausal disorders.


Asunto(s)
Flavanonas/metabolismo , Flavonoides/metabolismo , Fitoestrógenos/metabolismo , Preparaciones de Plantas/metabolismo , Propiofenonas/metabolismo , Cerveza/análisis , Catálisis , Suplementos Dietéticos/análisis , Flavanonas/química , Flavonoides/química , Humanos , Humulus/química , Óxido de Magnesio/química , Óxido de Magnesio/metabolismo , Fitoestrógenos/química , Extractos Vegetales/metabolismo , Preparaciones de Plantas/química , Propiofenonas/química , Temperatura
12.
Appl Microbiol Biotechnol ; 105(21-22): 8359-8376, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34643787

RESUMEN

Yeast breeding is a powerful tool for developing and improving brewing yeast in a number of industry-relevant respects. However, breeding of industrial brewing yeast can be challenging, as strains are typically sterile and have large complex genomes. To facilitate breeding, we used the CRISPR/Cas9 system to generate double-stranded breaks in the MAT locus, generating transformants with a single specified mating type. The single mating type remained stable even after loss of the Cas9 plasmid, despite the strains being homothallic, and these strains could be readily mated with other brewing yeast transformants of opposite mating type. As a proof of concept, we applied this technology to generate yeast hybrids with an aim to increase ß-lyase activity for fermentation of beer with enhanced hop flavour. First, a genetic and phenotypic pre-screening of 38 strains was carried out in order to identify potential parent strains with high ß-lyase activity. Mating-competent transformants of eight parent strains were generated, and these were used to generate over 60 hybrids that were screened for ß-lyase activity. Selected phenolic off-flavour positive (POF +) hybrids were further sporulated to generate meiotic segregants with high ß-lyase activity, efficient wort fermentation, and lack of POF, all traits that are desirable in strains for the fermentation of modern hop-forward beers. Our study demonstrates the power of combining the CRISPR/Cas9 system with classic yeast breeding to facilitate development and diversification of brewing yeast. KEY POINTS: • CRISPR/Cas9-based mating-type switching was applied to industrial yeast strains. • Transformed strains could be readily mated to form intraspecific hybrids. • Hybrids exhibited heterosis for a number of brewing-relevant traits.


Asunto(s)
Sistemas CRISPR-Cas , Saccharomyces cerevisiae , Cerveza , Fermentación , Hibridación Genética , Saccharomyces cerevisiae/genética
13.
J Food Sci ; 86(11): 4991-5003, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34699076

RESUMEN

Craft beer because of its fresh flavor, unique taste, and rich nutrition is becoming more popular to consumers. Compared with industry beer, craft beer is often nonfiltered and nonpasteurized, for this reason, it has a short shelf life and is more susceptible to microbial spoilage, which may cause the quality deterioration of craft beer and the formation of biogenic amine as a harmful factor for consumer's health. In this study, the 23 beer-spoilage bacteria were isolated from craft beer, which were identified as 15 Lactobacillus (L.) brevis, 3 L. plantarum, 1 L. parabuchneri, 2 L. paracasei, and 2 Pediococcus damnosus. Among 23 beer-spoilage isolates, 20 representatives were able to form tyramine, histamine, putrescine, cadaverine, and/or tryptamine in MRS broth. The nine Lactobacillus strains were incubated in beer and produced tyramine, histamine, putrescine, cadaverine, and/or tryptamine during beer storage process. Logistic and Gompertz model could be adopted to respectively describe the kinetics of microorganism growth and biogenic amine formation. The relationship between the biogenic amines and biomass was simulated by Luedeking-Piret model very well, and showed that the formation of biogenic amine was mainly bacteria growth-associated in beer. These findings may be helpful for finding the preventive measures to control biogenic amine formation and for enhancing the safety of craft beer. PRACTICAL APPLICATION: The selection of the biogenic amine-producing spoilage bacteria from craft beer and the investigation their kinetics of the growth and biogenic amines production under beer environmental conditions was very helpful for finding preventive measures to eliminate or reduce biogenic amine formation and for appropriate increase in food safety.


Asunto(s)
Cerveza , Aminas Biogénicas , Bacterias , Cerveza/análisis , Aminas Biogénicas/análisis , Microbiología de Alimentos , Cinética , Pediococcus
14.
Artículo en Inglés | MEDLINE | ID: mdl-34682678

RESUMEN

This paper explores trends in beverage preference in adolescents, identifies related regional differences, and examines cluster differences in key drinking measures. Data were obtained from the European School Survey Project on Alcohol and Other Drugs (ESPAD), covering 24 European countries between 1999 and 2019. Trends in the distribution of alcoholic beverages on the participants' most recent drinking occasion were analysed by sex and country using fractional multinomial logit regression. Clusters of countries based on trends and predicted beverage proportions were compared regarding the prevalence of drinkers, mean alcohol volume and prevalence of heavy drinking. Four distinct clusters each among girls and boys emerged. Among girls, there was not one type of beverage that was preferred across clusters, but the proportion of cider/alcopops strongly increased over time in most clusters. Among boys, the proportion of beer decreased, but was dominant across time in all clusters. Only northern European countries formed a geographically defined region with the highest prevalence of heavy drinking and average alcohol volume in both genders. Adolescent beverage preferences are associated with mean alcohol volume and heavy drinking at a country-level. Future approaches to drinking cultures need to take subpopulations such as adolescents into account.


Asunto(s)
Conducta del Adolescente , Consumo de Bebidas Alcohólicas , Adolescente , Consumo de Bebidas Alcohólicas/epidemiología , Bebidas Alcohólicas , Cerveza , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino
15.
J Agric Food Chem ; 69(43): 12807-12817, 2021 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-34672546

RESUMEN

Glycation and caramelization reactions in malt lead to the formation of 1,2-dicarbonyl compounds, which come in contact with yeast during fermentation. In the present study, the metabolic fate of 5-hydroxymethylfurfural (HMF) and 1,2-dicarbonyl compounds (3-deoxyglucosone, 3-deoxygalactosone, 3-deoxypentosone, 3,4-dideoxyglucosone-3-ene) was assessed in the presence of Saccharomyces cerevisiae. HMF is degraded very fast by yeast with the formation of 2,5-bis(hydroxymethyl)furan (BHMF). By contrast, only 7-30% of 250 µM dicarbonyl compounds is degraded within 48 h. The respective deoxyketoses, 3-deoxyfructose (3-DF), 3-deoxytagatose, 3-deoxypentulose, and 3,4-dideoxyfructose, were identified as metabolites. While 17.8% of 3-deoxyglucosone was converted to 3-deoxyfructose, only about 0.1% of 3-deoxypentosone was converted to 3-deoxypentulose during 48 h. Starting with the parent dicarbonyl compounds, the synthesis of all deoxyketose metabolites was achieved by applying a metal-catalyzed reduction in the presence of molecular hydrogen. In a small set of commercial beer samples, BHMF and all deoxyketoses were qualitatively detected. 3-DF was quantitated in the four commercial beer samples at concentrations between 0.4 and 10.1 mg/L.


Asunto(s)
Cerveza , Saccharomyces cerevisiae , Cerveza/análisis , Fermentación , Furaldehído/análogos & derivados , Furaldehído/análisis
17.
Compr Rev Food Sci Food Saf ; 20(6): 5742-5764, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34668294

RESUMEN

Mycotoxins, including aflatoxins (AFs), ochratoxin A (OTA), deoxynivalenol (DON), fumonisins (FBs), and zearalenone (ZEN), have been reported as beer contaminants. This systematic review and meta-analysis provide the prevalence and concentration of mycotoxins in beers and their worldwide distribution. Mycotoxin's exposure and cancer risk through beer consumption were determined. The overall pooled prevalence of mycotoxins in beers was 31% (95% confidence interval [CI] = 28%-35%; I2  = 90%, p = .00). The most prevalent mycotoxins in beers were DON and its derivatives (53%), OTA (52%), FBs (47%), followed by AFs (12%). Iran (99%), Hungary (95%), Denmark (92%), Armenia (83%), and Cyprus (83%) had the highest mycotoxin prevalence in beers. The global mycotoxins average concentration in beers was 12.52 µg/L (95% CI = 10.70-14.75 µg/L; I2  = 100%, p = .00). DON and its derivatives showed the highest concentration (26.91 µg/L), followed by FBs (23.19 µg/L), ZEN and its derivatives (20.25 µg/L), and AFs (15.65 µg/L). African region had the highest mycotoxins concentration (73.95 µg/L) mostly due to the high levels reported in beers from Cameroon (293.02 µg/L), Malawi (132.34 µg/L), and Eastern Cape province (126.12 µg/L). The meta-regression indicated stability (p ≥ .05) of the global pooled concentration of mycotoxins in beers over the years, whereas FBs concentration increased. The intake of DON and its derivatives, FBs, ZEN and its derivatives, and OTA through beers is of concern in African countries. OTA is also of concern in Brazil and Belgium. Results show high mycotoxins concentration in beers worldwide and highlight the health risks through contaminated beer consumption.


Asunto(s)
Micotoxinas , Cerveza/análisis , Camerún , Contaminación de Alimentos/análisis , Micotoxinas/análisis , Medición de Riesgo
18.
Nutrients ; 13(10)2021 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-34684553

RESUMEN

The increasing global prevalence of overweight and obesity highlights an urgent need to explore modifiable obesogenic factors. This study investigated the impact of lifestyle factors, such as beer and wine drinking, cigarette smoking, and leisure time screen viewing activities, on body weight and the development of obesity. Individual level data were selected from a random sample of 3471 German adults using a two-stage disproportionate random sampling procedure. The empirical analysis employed a two-stage equations system and combined the endogenous treatment effects model with the quantile regression technique. Our estimations showed that the decisions to smoke and consume wine and beer were positively interrelated, especially in women. Frequent beer/wine drinkers of normal weight were found to have a lower BMI in the male subsample. Quantile regression estimates indicated a significant influence of smoking on BMI in both genders, with smokers' BMI following an upward trend, especially in the upper quantiles of the distribution. Leisure time screen activity was found to have a major impact on females' BMI. Prolonged television viewing and regular computer gaming had a strong relationship with weight increase in overweight women, whereas internet surfing was inversely correlated with the BMI of normal weight and slightly overweight female participants. Nutrition and health policies should direct individuals toward alternative recreational activities in order to substitute screen usage and reduce sedentary time. This study also raised doubts about the general belief that smokers have a lower body weight. As unhealthy behaviors usually co-occur or cluster together, obesity prevention interventions might also contribute to a decrease in smoking.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Índice de Masa Corporal , Fumar Cigarrillos/epidemiología , Obesidad/epidemiología , Tiempo de Pantalla , Adolescente , Adulto , Consumo de Bebidas Alcohólicas/efectos adversos , Cerveza , Peso Corporal , Fumar Cigarrillos/efectos adversos , Estudios Transversales , Femenino , Alemania/epidemiología , Humanos , Actividades Recreativas , Estilo de Vida , Masculino , Persona de Mediana Edad , Obesidad/etiología , Análisis de Regresión , Vino , Adulto Joven
19.
Analyst ; 146(18): 5732-5739, 2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34515698

RESUMEN

Developing a functional affinity monolithic column towards in-tube solid-phase microextraction (IT-SPME) for selective sample pretreatment is critical. Herein, a high-performance capillary affinity monolithic column with an ultra-high aptamer coverage density was rapidly fabricated via a simple adsorption strategy, in which aptamers with natural sequences were directly immobilized on an ammonium-based strongly cationic matrix. Limitations of the traditional biological or covalent methods such as time-consuming modification reactions, special requirement of active groups (e.g. -NH2 and -SH) on the aptamer, and low aptamer coverage density levels were avoided. An ultra-high coverage density of 8616 pmol µL-1 was achieved with excellent stability, and the highest aptamer-modification level among all the current methods was reached. Selective recognition and high recovery yields of the model mycotoxin ochratoxin A (OTA) were achieved in 95.9 ± 0.98%-97.9 ± 0.28% (n = 3). In particular, there was little cross-reactivity towards the OTB analogue of only 0.5% even in the case of 250 fold of the analogue OTB, which was not reported in previous affinity monoliths. Upon sample analysis, satisfactory discriminations of trace OTA were obtained at 93.7 ± 1.4%-95.5 ± 2.5% (n = 3) in beer and wheat. A facile and direct method for efficiently fabricating an aptamer-based affinity monolith towards online selective IT-SPME was proposed.


Asunto(s)
Aptámeros de Nucleótidos , Micotoxinas , Adsorción , Cerveza/análisis , Microextracción en Fase Sólida
20.
J Agric Food Chem ; 69(39): 11687-11695, 2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34559514

RESUMEN

The effect of nitrites in foods and beverages still raises discussion due to the possible formation of harmful nitroso compounds. However, as most of these compounds in beer were not structurally characterized yet, the research about their toxicological relevance for consumers is limited. This study is focused on identification of the products formed by nitrite (or isotopically labeled nitrite 15N) reactions in beer using gas chromatography with tandem mass spectrometry. In total, 19 products were identified, and some of them were structurally characterized and confirmed by comparing retention indices and mass spectra of standard/synthesized compounds. Identified compounds were representatives of nitroso, nitro, oxime, and even cyano compounds. For the peaks which were not structurally identified, primary structural characteristics were also listed. Found products were further screened in 16 authentic beer samples which showed the apparent occurrence of found compounds in non-treated beers.


Asunto(s)
Cerveza , Nitritos , Cerveza/análisis , Alimentos , Cromatografía de Gases y Espectrometría de Masas , Nitritos/análisis , Compuestos Nitrosos/análisis , Espectrometría de Masas en Tándem
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...