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1.
J Agric Food Chem ; 68(8): 2562-2569, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-32003990

RESUMEN

This study was aimed to evaluate the level of furan and acrylamide contamination in cocoa and noncocoa raw materials, in masses from processing stages, and in chocolates originating from three factories. Acrylamide was determined by the gas chromatography-mass spectrometry (GC-MS) method using the QuEChERS procedure with dispersive solid-phase extraction clean-up and isotopic standard (2,3,3-d3-acrylamide). Furan was analyzed by the headspace solid-phase microextraction/GC-MS technique with the d4-furan marker. Both analytical methods were validated in terms of accuracy, precision, and linearity as well as the limit of detection (LOD) and limit of quantification (LOQ). Among all raw materials, the most abundant in acrylamide were cocoa masses and powders (83.0-127.5 ng g-1). Roasting of cocoa beans increased the content of acrylamide 2-3-fold. The obtained results indicate that acrylamide might be formed during wet conching. Only in cocoa powders and lecithin, it was possible to quantify furan (3.7-10.2 and 16.3 ng g-1, respectively). Roasting of cocoa beans increased the content of furan from

Asunto(s)
Acrilamida/análisis , Cacao/química , Chocolate/análisis , Furanos/análisis , Acrilamida/aislamiento & purificación , Contaminación de Alimentos/análisis , Manipulación de Alimentos , Furanos/aislamiento & purificación , Cromatografía de Gases y Espectrometría de Masas , Semillas/química , Microextracción en Fase Sólida
2.
J Agric Food Chem ; 68(8): 2554-2561, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-32027503

RESUMEN

Excessive use of antibiotics in aquatic products is a serious problem for food safety and human health, and on-site detection of antibiotics is highly demanded. Herein, we proposed multivalence aptamer probes, allowing sensitive, label-free, and homogeneous detection of antibiotics in different aquatic products. Compared to commonly used aptamers, multivalence aptamer probes can provide multiple binding sites and a higher affinity for target molecules, and the iterative binding on different binding sites contributes to an amplified recognition effect, sharply increasing the response and sensitivity of aptamer probes. The 2-valence aptamer probes conferred a limit of detection of 0.097 nM for kanamycin detection, where it is estimated that their sensitivity is enhanced 12 times compared to 1-valence aptamer probes. Meanwhile, multivalence aptamer probes allowed us to specifically identify kanamycin among other antibiotics. It could detect kanamycin residual in aquatic products including river eel and puffer fish, as well as tap water with high precision. A multivalence design strategy of aptamer probes would significantly improve the detection performance of aptamers, facilitating the translation of aptamer for food safety control.


Asunto(s)
Antibacterianos/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Residuos de Medicamentos/análisis , Alimentos Marinos/análisis , Animales , Aptámeros de Nucleótidos/síntesis química , Acuicultura , Técnicas Biosensibles/instrumentación , Peces/crecimiento & desarrollo , Contaminación de Alimentos/análisis , Agua Dulce/análisis , Kanamicina/análisis , Límite de Detección , Contaminantes Químicos del Agua/análisis
3.
J Agric Food Chem ; 68(9): 2826-2831, 2020 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-32045247

RESUMEN

In this work, we have developed an all-in-one aptasensor based on an enzyme-driven three-dimensional DNA walker for antibiotic detection. To overcome the drawback of time-consuming methods, high-density substrate strands were anchored on the walking interface that accelerated the signal amplification efficiency. Such an all-in-one design integrated the functionality of target recognition, signal amplification, as well as signal output into a single probe. Upon addition of kanamycin, the activated walking strand moved along the track by the stepwise cleavage of a nicking enzyme, which resulted in the enhancement of the fluorescence intensity of the solution. Under the optimized conditions, the detection process was accomplished in 40 min with a low detection limit of 1.23 pM. This aptasensor was also applied in spiked milk samples with satisfactory recoveries of 97.76% to 105.33%, demonstrating an excellent stability and accuracy. Therefore, this all-in-one aptasensor shows great potential for applications in food safety.


Asunto(s)
Antibacterianos/análisis , Técnicas Biosensibles/métodos , Animales , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Bovinos , Contaminación de Alimentos/análisis , Oro/química , Kanamicina/análisis , Límite de Detección , Leche/química
4.
Environ Pollut ; 259: 113878, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32032983

RESUMEN

Eating fish provides numerous health benefits, but it is also a dominant pathway for human exposure to contaminants. Many studies have examined mercury (Hg) accumulation in fish, but fewer have considered other elements, such as arsenic (As) and chromium (Cr). Recently, freshwater fish from several pristine boreal systems across northern Ontario, Canada, have been reported with elevated concentrations of As and Cr for reasons that are not well understood. Our goal was to investigate the ecological and environmental influences over concentrations of As, Cr, and other elements in these fish to better understand what affects metal uptake and the risk to consumers. We measured 10 elements (including As, Cr, Hg) as well as carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) stable isotopes in 388 fish from 25 lake and river sites across this remote region. These data were used to determine the effect of: 1) trophic ecology; and 2) watershed geology on piscine elemental content. Overall, most element concentrations were low, often below provincial advisory benchmarks (ABs). However, traces of Hg, As, Cr, and selenium (Se) were detected in most fish. Based on their exceedance of their respective ABs, the most restrictive elements on fish consumption in these boreal systems were Hg > As > Cr. Arsenic and Se, but not Cr concentrations were related to fish size and trophic ecology (inferred from δ13C and δ15N), suggesting bioaccumulation of the former elements. Fish with enriched δ34S values, suggestive of anadromous behaviour, had marginally lower Hg but higher Se concentrations. Modeling results suggested a strong effect of site-specific factors, though we found weak trends between piscine elemental content and geological features (e.g., mafic intrusions), potentially due to the broad spatial scale of this study. Results from this study address gaps in our understanding of As and Cr bioaccumulation and will help to inform fish consumption guidelines.


Asunto(s)
Arsénico , Cromo , Peces , Contaminación de Alimentos , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Cadena Alimentaria , Contaminación de Alimentos/análisis , Humanos , Lagos , Mercurio , Ontario , Ríos , Contaminantes Químicos del Agua/análisis
5.
J Agric Food Chem ; 68(10): 3260-3266, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32050063

RESUMEN

One of the main challenges for analytical laboratories and food safety authorities is the control of food contaminants hazardous to human health. For the first time, a simple, fast, and cost-effective sample preparation method is proposed as an extraction technique to determine 12 brominated flame retardants (BFRs) (seven polybrominated diphenyl ether (PBDE) congeners and five novel BFRs) in Capsicum cultivars. Different QuEChERS and dispersive solid-phase extract (d-SPE) sorbent compositions were evaluated in terms of recovery and matrix effects. The best results were obtained with citrate-buffered version QuEChERS and a cleanup step, with 150 mg of MgSO4, 50 mg of primary secondary amine (PSA), 50 mg of C18, and 5 mg of carbon. The limit of detection (LOD) was between 1.4 and 9.3 µg/kg and R2 > 0.99. Recoveries and matrix effects were between 66 and 104% and 0.58 and 2.18, respectively. The relative standard deviations from repeatability and reproducibility studies and estimation of measurement uncertainty were lower than 20%. Gas chromatography coupled with a mass spectrometer was used to confirm the presence of BFRs in the samples. Novel BFRs were detected lower than the LOD.


Asunto(s)
Capsicum/química , Retardadores de Llama/análisis , Retardadores de Llama/aislamiento & purificación , Éteres Difenilos Halogenados/química , Éteres Difenilos Halogenados/aislamiento & purificación , Extracción en Fase Sólida/métodos , Contaminación de Alimentos/análisis , Frutas/química , Cromatografía de Gases y Espectrometría de Masas , Humanos , Límite de Detección , Extracción en Fase Sólida/instrumentación
6.
J Agric Food Chem ; 68(7): 2201-2213, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-32023042

RESUMEN

A feeding study was carried out to investigate the kinetics in cow milk of the 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), the 12 dioxin-like polychlorinated biphenyls (DL-PCBs), and the 6 non-dioxin-like PCBs (NDL-PCBs) regulated by the European (EU) legislation. A fortified ration (ΣPCDD/Fs and DL-PCBs: 24.68 ng TEQ/day/cow; ΣNDL-PCBs: 163.99 µg/day/cow) was given to the animals for 49 days, followed by 42 days on clean feed. EU maximum limit for TEQPCDD/F+DL-PCB was exceeded in milk after 1 week of exposure, while for ΣNDL-PCBs, after 5 weeks. Milk compliance was restored after 1 week on clean feed, but to return to the basal TEQPCDD/F+DL-PCB it took 42 days. At the end of the study, ΣNDL-PCBs had not yet reached the basal level. The carryover rate of ΣNDL-PCBs was 25.4%, while the carryover rate of TEQPCDD/F+DL-PCB was 36.9%. The latter was mainly affected by the 12 congeners contributing most to the toxic equivalent (TEQ) level, explaining the fast overcome of the maximum limit in milk.


Asunto(s)
Dibenzofuranos/análisis , Contaminación de Alimentos/análisis , Leche/química , Bifenilos Policlorados/análisis , Dibenzodioxinas Policloradas/análisis , Alimentación Animal/análisis , Animales , Bovinos , Dioxinas/análisis , Femenino
7.
Environ Monit Assess ; 192(2): 126, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31960162

RESUMEN

This study evaluates the concentrations of lead (Pb) in 6 selected vegetables and drinking water samples taken from an agricultural/mining town Ishiagu. This evaluation is important because these vegetables and water are major gateway of lead exposure through ingestion, especially children in the Pb mining environment. Pb at even very low concentrations has been shown to have adverse effect on developing brain and hence children's intellectual ability. The impact of lead-contaminated food/water intake on the cognitive function was focused on school children whose parents have lived in the Pb mining town for over 25 years before they were born. Non-invasive, "target risk quotient" (TRQ) methodology, based on the principle of predictive toxicology was adopted for our analysis. Samples of these vegetables harvested in July and August 2015, and water taken from homes at 4 different villages in Ishiagu town and neighbouring community Akaeze (control), were subjected to appropriate chemical treatment/digestion procedures and the concentrations of Pb determined using AA-700 Shimadzu model atomic absorption spectrophotometer. From 642 structured questionnaire administered to the teachers/children, the daily vegetable ingestion rates for each vegetable (mg/child/day) and estimated daily intakes (EDI) of lead were obtained. The results show that the concentrations of Pb in water samples and the 6 vegetables harvested from the lead mining town vary as distances increase from the mining sites while the total target hazard quotients (TTHQs) for the vegetable crops were greater than one (˃ 1). The cognitive functions of 160 school children (aged 6-8 years), sampled from 265 families based on their meeting the criteria for distances away from the mining site, were evaluated using Raven's Standard Progressive Matrices and psychometrics. The data generated were analysed using (SPSS) version 21.0 and results expressed as mean ± standard deviation of intelligent quotient (IQ). Students' t tests for independent samples were used to compare the IQ results for children in the lead mining area and non-mining area. A model based on predictive toxicology paradigm which can show a relationship between concentrations of lead in vegetables/water and cognitive function was developed. This model shows that there is a positive correlation between total lead concentrations in vegetables/water and children's cognitive function.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Plomo/análisis , Contaminantes del Suelo/análisis , Verduras/química , Agricultura , Niño , Ciudades , Productos Agrícolas , Agua Potable/análisis , Agua Potable/química , Monitoreo del Ambiente , Femenino , Contaminación de Alimentos/análisis , Humanos , Masculino , Metales Pesados/análisis , Minería , Medición de Riesgo
8.
J Agric Food Chem ; 68(5): 1213-1225, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31903748

RESUMEN

Organically farmed rice is believed to be healthier, safer, and eco-friendlier than its conventionally farmed counterparts and sells for a premium price in global markets. Deliberate mislabeling of organic rice has become a critical consumer concern in China and elsewhere, and there is an increased risk of buying fraudulent organic rice in the market place. In this study, stable isotopic and multielemental analysis combined with chemometrics was used to differentiate organically farmed rice from green and conventional rice in a 4-year experimental field trial from 2014 to 2017. A total of 108 rice samples and their associated soils were collected during the study from three farming (fertilization) systems to investigate whether there are long-term changes in the rice farming classification accuracy from climate effects. Stable carbon and nitrogen isotopic ratios (i.e., δ13C and δ15N) and 27 elemental contents (e.g., Na, K, Ca, Fe, and Zn) of rice and soil samples were determined and then evaluated using statistical analysis [i.e., one-way analysis of variance, multivariable correlation analysis, and modeling of partial least-squares discriminant analysis]. Although δ15N values can be an effective indicator for organic rice authentication during one crop rotation, both δ13C and δ15N values of rice were easily affected by rice cultivar and interannual soil fertilization and localized agroclimatic variations. These two isotopes were not able to separate organic rice from green and conventional rice accurately. Elemental contents of green and conventional rice (especially K and Ca) were found at higher levels due to the abundant application of synthetic fertilizers (e.g., KNO3, KH2PO4, and CaHPO4), unlike organically farmed rice, which primarily used animal manure and composts. Partial least-squares discriminant analysis modeling combined isotopic and elemental signatures to correctly differentiate organic rice from green and conventional counterparts, with an accuracy up to 100% over the 4-year study. Therefore, this multi-isotope and -element strategy proposes a more rigorous, alternative tool to combat fraudulent mislabeling of organic rice, increasing the trust of organically labeled rice products and supporting the integrity of the organic sector worldwide.


Asunto(s)
Isótopos de Carbono/análisis , Contaminación de Alimentos/análisis , Alimentos Orgánicos/análisis , Isótopos de Nitrógeno/análisis , Oryza/química , Oligoelementos/análisis , China , Análisis Discriminante , Fertilizantes/análisis , Oryza/clasificación , Suelo/química
9.
Anal Bioanal Chem ; 412(3): 621-633, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31907590

RESUMEN

We produced a prometryn-specific monoclonal antibody and propose a strategy for convenient on-site detection of prometryn residues in herbs for the first time. This strategy has perfect applicability in a complex herbal medicine matrix. The strategy combines a semiquantitative immunochromatographic strip assay with a heterologous indirect competitive ELISA. When there was no matrix interference, the ELISA had a half-maximal inhibitory concentration of 2.6 ng·mL-1 and a limit of detection of 0.2 ng·mL-1. The immunochromatographic strip assay can be completed within 5 min with a visual limit of detection of 1 ng·mL-1. Although the sample matrix had different effects on the sensitivity of the antibody, excellent repeatability and accuracy were achieved. The method was successfully applied for the screening and determination of prometryn residue in multiple complex herb samples for the first time, and the results were in good agreement with those obtained by liquid chromatography-tandem mass spectrometry. The proposed strategy is rapid, of high-throughput, and of low cost, and may be a promising choice for on-site detection of prometryn in different kinds of herbs. Graphical abstract.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Herbicidas/análisis , Plantas Medicinales/química , Prometrina/análisis , Animales , Anticuerpos Monoclonales/química , Ensayo de Inmunoadsorción Enzimática/instrumentación , Diseño de Equipo , Femenino , Contaminación de Alimentos/análisis , Oro Coloide/química , Inmunoconjugados/química , Límite de Detección , Ratones Endogámicos BALB C , Tiras Reactivas/análisis
10.
Artículo en Inglés | MEDLINE | ID: mdl-31931332

RESUMEN

A rapid, simple, and generic analytical method that could simultaneously determine 291 undesirable low molecular weight chemical contaminants from different drug families in protein powder, such as veterinary drugs and pesticides, etc, had been developed. This method comprised the extraction with acetonitrile-dimethyl sulfoxide (DMSO), clean-up through dispersive solid phase extraction (D-SPE) and low temperature filtration, and analysis by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry at multiple-reaction monitoring mode. Acetonitrile-DMSO was more generic than acetonitrile or methanol for the extraction of large-scale organic chemical contaminants with different polarities in protein powder. Most interferences in the extract were eliminated by the combination of D-SPE and low temperature filtration, which simultaneously provided satisfactory recoveries of both hydrophobic and hydrophilic analytes. In particular, besides the purification function, the sorbent of D-SPE also played an important role in grinding samples to improve extraction efficiency during homogenization. This streamlined approach allowed the processes of extraction and the main purification were carried out in one-step, and dramatically reduced sample preparation turnaround times and solvent consumption. For quantification, matrix-fortified calibration curves showed competent linearity for most of the target compounds with linear regression coefficients (r) higher than 0.9900, except for two analytes. The limits of quantification ranged from 0.1 µg/kg to 50 µg/kg, which was usually sufficient to verify the compliance of products with legal tolerances. The average recoveries for spiked protein powder ranged from 65.6% to 142.2% with associated RSD values between 0.5% and 28.5%. For over 90% of the analytes, the recoveries were between 70% and 120% with RSD values in the range of 1%-15%. Applying this method in routine monitoring programs would drastically reduce both effort and time.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Proteínas en la Dieta , Residuos de Medicamentos/análisis , Contaminación de Alimentos/análisis , Espectrometría de Masas en Tándem/métodos , Proteínas en la Dieta/análisis , Proteínas en la Dieta/normas , Suplementos Dietéticos/análisis , Suplementos Dietéticos/normas , Modelos Lineales , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
11.
J Agric Food Chem ; 68(4): 1110-1117, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31891498

RESUMEN

Select cultivars of table olives have more desirable traits and a higher economic value. There are suspected issues with cultivar mislabeling and traceability in the supply chain. Here, we describe a method to identify cultivars by genotyping of processed olives. DNA was extracted from leaves and California-style olives of seven commonly packed cultivars. Processed olive fruits yielded relatively low DNA concentrations (0.04-0.86 µg/g), and extracts had more impurities compared with leaves. From 15 candidate SSRs, five markers showing the highest number of unique allele combinations and discriminatory power were selected. These SSRs were successfully amplified and analyzed in all cultivars of olives except one. When directly comparing any two cultivars, different allele combinations were typically present for at least four of the five SSRs. Microsatellite analysis shows potential as a simple yet robust diagnostic tool. The method can be expanded to include other cultivars, styles of table olives, and potentially other processed plant-based foods.


Asunto(s)
Repeticiones de Microsatélite , Olea/genética , Alelos , Contaminación de Alimentos/análisis , Frutas/química , Frutas/clasificación , Frutas/genética , Genotipo , Olea/química , Olea/clasificación
12.
J Agric Food Chem ; 68(4): 943-960, 2020 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-31913614

RESUMEN

Diet, especially seafood, is the main source of arsenic exposure for humans. The total arsenic content of a diet offers inadequate information for assessment of the toxicological consequences of arsenic intake, which has impeded progress in the establishment of regulatory limits for arsenic in food. Toxicity assessments are mainly based on inorganic arsenic, a well-characterized carcinogen, and arsenobetaine, the main organoarsenical in seafood. Scarcity of toxicity data for organoarsenicals, and the predominance of arsenobetaine as an organic arsenic species in seafood, has led to the assumption of their nontoxicity. Recent toxicokinetic studies show that some organoarsenicals are bioaccessible and cytotoxic with demonstrated toxicities like that of pernicious trivalent inorganic arsenic, underpinning the need for speciation analysis. The need to investigate and compare the bioavailability, metabolic transformation, and elimination from the body of organoarsenicals to the well-established physiological consequences of inorganic arsenic and arsenobetaine exposure is apparent. This review provides an overview of the occurrence and assessment of human exposure to arsenic toxicity associated with the consumption of seafood.


Asunto(s)
Arsenicales/análisis , Exposición Dietética/efectos adversos , Contaminación de Alimentos/análisis , Alimentos Marinos/análisis , Animales , Arsenicales/metabolismo , Exposición Dietética/análisis , Humanos , Medición de Riesgo
13.
J Agric Food Chem ; 68(5): 1427-1435, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31913622

RESUMEN

A number of new C-11 hydroxyl metabolites (so-called M-toxins) of paralytic shellfish toxins (PSTs) have been discovered in contaminated shellfish, and trace amounts have also been detected in some strains of PST-producing microalgae. To investigate the chemical conversion and stability of M-toxins, mussel extracts were purified with solid-phase extraction cartridges (Oasis HLB) and Biogel P-2 resin columns and four partially purified M-toxin fractions were stored at different temperatures (-20, 4, and 20 °C) and pH values (3, 4, and 5). The concentrations and profiles of M-toxins in these fractions were analyzed using liquid chromatography coupled with tandem mass spectrometry for 27 weeks. Results further confirmed the chemical conversion pathway M1 → M3 → M5 and determined for the first time two new transformation pathways: M2 → M4 → M6 and neosaxitoxin (NEO) → M10. The half-lives of M1, M2, M4, and M10 were calculated using a first-order degradation kinetics model, which indicated that the degradation of all M-toxins was dependent upon the temperature and pH, increasing with rising temperature and pH. In comparison to M4 and M10, M1 was more sensitive to the temperature, followed by M2. Results suggest that M-toxins should be maintained at a low temperature (-20 °C) and low pH (3) for their prolonged storage. M-toxins were less stable than all of the common analogues of PSTs, which may be beneficial for shellfish to achieve rapid detoxification through transformation of PSTs to M-toxins. These new findings are of significance because they enable further understanding of the metabolism of PSTs and their detoxification mechanisms in contaminated shellfish.


Asunto(s)
Bivalvos/química , Toxinas Marinas/química , Mariscos/toxicidad , Animales , Cromatografía Líquida de Alta Presión , Contaminación de Alimentos/análisis , Concentración de Iones de Hidrógeno , Toxinas Marinas/toxicidad , Estructura Molecular , Mariscos/análisis , Espectrometría de Masas en Tándem , Temperatura Ambiental
14.
J Agric Food Chem ; 68(5): 1468-1479, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31945291

RESUMEN

In this study, sample processing of bulk commodities using an efficient one-step comminution procedure with liquid nitrogen (LN2) was devised and assessed in the analysis of pesticide residues in fruits and vegetables. LN2 was added to the fresh samples from a tank by opening a valve, and the standard food chopper was kept in a laboratory hood to reduce safety risks. Test portions of four replicates each of 0.25, 0.5, 1, 2, 5, 10, and 15 g were taken from eight fruits and vegetables (tomato, squash, broccoli, apple, grape, peach, green bean, and cucumber) individually comminuted with LN2. For comparison without comminution, similar test portions of a reconstituted freeze-dried certified reference material of pesticides in cucumber were also analyzed by the same method. More than 100 pesticides were monitored by both ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and instrument top sample preparation (ITSP) + fast low-pressure gas chromatography-tandem mass spectrometry (LPGC-MS/MS). A new version of QuEChERS-based sample preparation was followed, in which 5 mL of 4:1 (v/v) acetonitrile/water per gram of sample is used for extraction and 200 µL of initial extract is quickly evaporated, reconstituted in water, and ultracentrifuged for UHPLC-MS/MS analysis. For ITSP+LPGC-MS/MS, another portion of the initial extract undergoes salt-out partitioning with 4:1 (w/w) anhydrous MgSO4/NaCl and the upper layer extract is transferred to an autosampler vial for automated cleanup and analysis in parallel. Quality control spikes were made during the comminution, extraction, cleanup, and analysis steps to isolate and estimate the individual and overall measurement uncertainties of the approach. The recommended test portion size is 2 g for routine monitoring by this approach, but results demonstrated that subsamples as low as 0.5 g typically gave overall biases and relative standard deviations of <10% for nearly all pesticides, commodities, and methods, which is 3-5% lower than previously evaluated sample processing and analytical methods. This approach can be used to improve data quality, laboratory efficiency, and sample throughput in routine monitoring programs for regulatory, risk assessment, and other purposes.


Asunto(s)
Contaminación de Alimentos/análisis , Frutas/química , Ensayos Analíticos de Alto Rendimiento/métodos , Nitrógeno/química , Residuos de Plaguicidas/análisis , Verduras/química , Cromatografía Líquida de Alta Presión , Control de Calidad , Tamaño de la Muestra , Espectrometría de Masas en Tándem
15.
J Agric Food Chem ; 68(3): 856-868, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-31891502

RESUMEN

Biogenic amines (BAs) are low molecular weight organic bases. BAs occurring naturally in living organisms are responsible for a number of vital functions, including (in humans) secretion of gastric acids, controlling body temperature, differentiation and growth of cells, immune reactions, and brain activity. However, if oversupplied with food, BAs may cause food poisoning and produce undesirable effects. Nine BAs and eight free amino acids (FAAs) were determined in 85 samples of 19 different varieties of fermented vegetables available on the Polish retail market. Both BA and FAA levels differed significantly among various varieties of the studied fermented vegetables. Averages for the sum of all tested BAs ranged from 30.29 ± 16.43 mg·kg-1 in fermented olives to 612.1 ± 359.33 mg·kg-1 in fermented Brussels sprout. BA profiles were dominated by putrescine (42%), tyramine (20%), cadaverine (18%), and histamine (8%); jointly, the four amines amounted to 88% of all nine studied BAs. The combined level of the latter four BAs was calculated for each vegetable variety as the so-called BA index (BAI). On that basis, the risk of BA-related adverse health effects has been assessed as high/medium/low in 6/3/10 of all 19 studied varieties of fermented vegetables. Brussels sprout and broccoli turned out to be the most risky vegetables from that point of view (BAI above 400 mg·kg-1). FAA levels ranged from 54.8 ± 12.76 (fermented olives) to 3917.42 ± 1528.73 mg·kg-1 (fermented garlic). The high content of FAAs may increase the risk of forming toxic amounts of BAs, depending on characteristics of the current and added microflora as well as on environmental and technological conditions the product is subjected to.


Asunto(s)
Aminoácidos/análisis , Aminas Biogénicas/análisis , Verduras/química , Aminas Biogénicas/toxicidad , Brassica/química , Fermentación , Contaminación de Alimentos/análisis , Factores de Riesgo
16.
J Agric Food Chem ; 68(7): 2193-2200, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31976658

RESUMEN

Various mycotoxins widely co-exist in agro-products, and their combined effects cause toxicity and potential carcinogenicity to humans and animals. In this work, we developed an economical and sensitive quantum dots (QDs)/QD microbead (QDs/QB)-based multiplex immunochromatographic assay (mICA) for the rapid detection of fumonisin B1 (FB1), zearalenone (ZEN), and ochratoxin A (OTA) without the building-up process of mycotoxin conjugates. QDs and QBs were selected as fluorescent reporters and conjugated with antimycotoxin monoclonal antibodies for improving sensitivity. Furthermore, phage-displayed FB1, ZEN, and OTA mimotope peptide-based soluble and monovalent fusions to maltose-binding protein (MBP) were applied onto the test line of the mICA as the mimetic coating antigen. Under the optimized conditions, the visual detection limits (vLODs) of peptide-MBP-based mICA could be obtained as 0.25 ng/mL for FB1, 3.0 ng/mL for ZEN, and 0.5 ng/mL for OTA within 10 min. The results for spiked real sample detection indicate good accuracy, reproducibility, and practicability. In addition, the proposed mICA was comparable with ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) in terms of reliability in detecting FB1, ZEN, and OTA using natural samples. From the point of promoting commercial production, these time-saving and low-cost peptide-MBP antigens applied in ICA might provide promising potential for promoting productivity and decreasing the cost of production.


Asunto(s)
Fumonisinas/análisis , Inmunoensayo/métodos , Ocratoxinas/análisis , Zearalenona/análisis , Contaminación de Alimentos/análisis , Inmunoensayo/economía , Inmunoensayo/instrumentación , Límite de Detección , Proteínas de Unión a Maltosa/química , Puntos Cuánticos/química
17.
J Agric Food Chem ; 68(7): 2263-2275, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31986019

RESUMEN

The growth conditions and age of Panax ginseng are vital for determining the quality of the ginseng plant. However, the considerable difference in price according to the cultivation method and period of P. ginseng leads to its adulteration in the trade market. We herein focused on ginseng peptides and the possibility of these peptides to be used as biomarker(s) for discrimination of P. ginseng. We applied an ultraperformance liquid chromatography-high resolution mass spectrometry-based peptidomics approach to characterize ginseng peptides and discover novel peptide biomarkers for authentication of mountain-cultivated ginseng (MCG). We identified 52 high-confidence peptides and screened 20 characteristic peptides differentially expressed between MCG and cultivated ginseng (CG). Intriguingly, 6 differential peptides were expressed significantly in MCG and originated from dehydrins that accumulated during cold or drought conditions. In addition, 14 other differential peptides that were significantly expressed in CG derived from ginseng major protein, an essential protein for nitrogen storage. These biological associations confirmed the reliability and credibility of the differential peptides. Additionally, we determined several robust peptide biomarkers for discrimination of MCG through a precise selection process. These findings demonstrate the potential of peptide biomarkers for identification and quality control of P. ginseng in addition to ginsenoside analysis.


Asunto(s)
Panax/química , Péptidos/química , Secuencia de Aminoácidos , Biomarcadores/química , Cromatografía Líquida de Alta Presión , Análisis Discriminante , Contaminación de Alimentos/análisis , Espectrometría de Masas , Panax/crecimiento & desarrollo , Mapeo Peptídico , Raíces de Plantas/química , Raíces de Plantas/crecimiento & desarrollo , Control de Calidad
18.
J Agric Food Chem ; 68(7): 2249-2255, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31986034

RESUMEN

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.


Asunto(s)
Aptámeros de Nucleótidos/química , Transferencia Resonante de Energía de Fluorescencia/métodos , Ocratoxinas/análisis , Vino/análisis , Transferencia Resonante de Energía de Fluorescencia/instrumentación , Contaminación de Alimentos/análisis , Límite de Detección
19.
J Agric Food Chem ; 68(6): 1634-1644, 2020 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-31961687

RESUMEN

A novel microbial consortium (NZDC-6) was screened and characterized to detoxify the estrogenic mycotoxin zearalenone (ZEA), which commonly contaminates maize and is a major threat to food and health security. We found NZDC-6 to be thermophilic and highly effective, with a 90.3% ZEA degradation ratio at an optimum temperature of 60 °C. NZDC-6 was also effective at degrading the more estrogenic ZEA cognates, α-zearalenol (α-ZAL) and ß-zearalenol (ß-ZAL), with >90% degradation ratios. To evaluate a practical application, ZEA-contaminated corncobs were treated with NZDC-6 via semisolid fermentation. Measurements of physicochemical parameters and 16S microbial diversity and redundancy analysis (RDA) indicated that ZEA removal was most efficient at a low corncob solid content (< 5%), as a high solid content overwhelmed the microbial metabolic load, leading to increased dissolved oxygen and lowered pH. Our results demonstrate that the control of environmental variables is crucial for effective ZEA microbial removal in practical applications.


Asunto(s)
Bacterias/metabolismo , Consorcios Microbianos , Zea mays/microbiología , Zearalenona/metabolismo , Bacterias/genética , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Biodegradación Ambiental , Fermentación , Contaminación de Alimentos/análisis
20.
Anal Bioanal Chem ; 412(1): 81-91, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31953713

RESUMEN

Methods for detecting mycotoxins are very important because of the great health hazards of mycotoxins. However, there is a high background and low signal-to-noise ratio in real-time sensing, and therefore it is difficult to meet the fast, accurate, and convenient requirements for control of food quality. Here we constructed a quantitative fluorescence image analysis based on multicolor upconversion nanocrystal (UCN)-encoded microspheres for detection of ochratoxin A and zearalenone. The background-free encoding image signal of UCN-doped microspheres was captured by fluorescence microscopy under near-infrared excitation, whereas the detection image signal of phycoerythrin-labeled secondary antibodies conjugated to the microspheres was captured under blue light excitation. We custom-wrote an algorithm to analyze the two images for the same sample in 10 s, and only the gray value in the red channel of the secondary probe confirmed the quantity. The results showed that this novel detection platform performed feasible and reliable fluorescence image measurements by this method. Additionally, the limit of detection of was 0.34721 ng/mL for ochratoxin A and 0.41162 ng/mL for zearalenone. We envision that this UCN encoding strategy will be usefully applied for fast, accurate, and convenient testing of multiple food contaminants to ensure the safety of the food.


Asunto(s)
Microesferas , Ocratoxinas/análisis , Zearalenona/análisis , Contaminación de Alimentos/análisis , Inmunoensayo/métodos , Límite de Detección , Nanopartículas/química , Relación Señal-Ruido
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