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1.
Food Chem ; 454: 139714, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38797105

RESUMO

Food safety issues have received much attention. Biogenic amines are considered important markers of food spoilage. Accurate detection of biogenic amines is important for food quality monitoring. Herein, we developed two coumarin-difluoroboron ß-diketonate hybrid probes, 1 and 2, for detection of amines. Both probes possess large conjugated structures and donor-acceptor-donor configuration, exhibiting solvatochromic effects due to intramolecular charge transfer mechanism. Upon reaction with amines, the boron atom in difluoroboron unit can interact with lone pair electrons of nitrogen atom, thus resulting in significant changes in absorption and fluorescence properties. These probes were successfully utilized to image amine in live cells and liver tissues. Moreover, by photographing probe-loaded food extract supernatant, we establish the relationship between color parameters and food storage time, which can easily indicate food spoilage process. This work and its findings hold promise for providing potential strategies for real-time and convenient detection of food freshness.


Assuntos
Aminas Biogênicas , Corantes Fluorescentes , Corantes Fluorescentes/química , Aminas Biogênicas/análise , Aminas Biogênicas/química , Humanos , Contaminação de Alimentos/análise , Animais , Imagem Óptica , Inocuidade dos Alimentos
2.
Int J Biol Macromol ; 261(Pt 1): 129647, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38281527

RESUMO

The limitation of conventional packaging in demonstrating accurate and real-time food expiration dates leads to food waste and foodborne diseases. Real-time food quality monitoring via intelligent packaging could be an effective solution to reduce food waste and foodborne illnesses. This review focuses on recent technological advances incorporated into food packaging for monitoring food spoilage, with a major focus on paper-based sensors and their combination with smartphone. This review paper offers a comprehensive exploration of advanced macromolecular technologies in biodegradable packaging, a general overview of paper-based probes and their incorporation into food packaging coupled with intelligent sensing mechanisms for monitoring food freshness. Given the escalating global concerns surrounding food waste, our manuscript serves as a pivotal resource, consolidating current research findings and highlighting the transformative potential of these innovative packaging solutions. We also highlight the current intelligent paper-based food freshness sensors and their various advantages and limitations. Examples of implementation of paper-based sensors/probes for food storage and their accuracy are presented. Finally, we examined how intelligent packaging can be an alternative to reduce food waste. Several technologies discussed here have good potential to be used in food packaging for real-time food monitoring, especially when combined with smartphone diagnosis.


Assuntos
Doenças Transmitidas por Alimentos , Eliminação de Resíduos , Humanos , Perda e Desperdício de Alimentos , Alimentos , Embalagem de Medicamentos , Embalagem de Alimentos
3.
Food Chem Toxicol ; 184: 114404, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142766

RESUMO

Total diet studies (TDS) and food monitoring programmes are different approaches for collecting occurrence data on substances in food. This case study evaluated the practical applicability of TDS data (BfR MEAL Study) and monitoring data for the assessment of long-term cadmium exposure in children in Germany. Cadmium data from both programmes were combined with food consumption data from the KiESEL study. Uncertainties associated with both assessments were systematically described. Using monitoring data resulted in cadmium intakes approximately 3 times higher than the use of BfR MEAL Study data. Incomplete data and neglect of market shares and consumption weights were considered by conservative data adjustments to the monitoring data and mainly explain the higher estimates. Fewer data adjustments were necessary for BfR MEAL Study data, which covered almost the entire diet and considered consumer behaviour during sample collection and sample preparation. In sum, the use of the BfR MEAL Study data resulted in less uncertainty and more reliable exposure estimates for chronic assessments over the entire diet. However, description of variability and upper tails of substance distributions in food remain essential features of monitoring data. The integration of both programmes into a complementary system further improves food safety.


Assuntos
Cádmio , Contaminação de Alimentos , Criança , Humanos , Cádmio/análise , Incerteza , Contaminação de Alimentos/análise , Inquéritos sobre Dietas , Medição de Risco , Alemanha , Dieta
4.
Sensors (Basel) ; 23(18)2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37765737

RESUMO

Sourdough can improve bakery products' shelf life, sensory properties, and nutrient composition. To ensure high-quality sourdough, the fermentation has to be monitored. The characteristic process variables for sourdough fermentation are pH and the degree of acidity measured as total titratable acidity (TTA). The time- and cost-intensive offline measurement of process variables can be improved by utilizing online gas measurements in prediction models. Therefore, a gas sensor array (GSA) system was used to monitor the fermentation process of sourdough online by correlation of exhaust gas data with offline measurement values of the process variables. Three methods were tested to utilize the extracted features from GSA to create the models. The most robust prediction models were achieved using a PCA (Principal Component Analysis) on all features and combined two fermentations. The calibrations with the extracted features had a percentage root mean square error (RMSE) from 1.4% to 12% for the pH and from 2.7% to 9.3% for the TTA. The coefficient of determination (R2) for these calibrations was 0.94 to 0.998 for the pH and 0.947 to 0.994 for the TTA. The obtained results indicate that the online measurement of exhaust gas from sourdough fermentations with gas sensor arrays can be a cheap and efficient application to predict pH and TTA.

5.
Int J Environ Health Res ; : 1-13, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37668001

RESUMO

Pesticides are dangerous chemicals that can harm to people and the environment when applied inappropriately or in excess. In this research, various pesticide residues were investigated in 48 pepper samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). All samples were collected randomly in two periods of time (September and December) from markets and greengrocers in four provinces (Siirt, Mardin, Diyarbakir, and Batman). Considering the means of the first and second periods, diclofop-methyl had the highest concentration of 29.4 ± 7.7 µg kg-1, and diazinon had the lowest of 21.1 ± 4.6 µg kg-1. Based on the maximum residue limits (MRLs) of pesticides specified in the Turkish Food Codex, pyrimethanil, bupirimate, and diclofop-methyl were found to be below the maximum acceptable residue limit, while pyridaphention, dinoseb, diazinon, and pirimiphos-methyl were found to be above the limit. Thus, the current study demonstrated the potential of LC-MS/MS as a crucial technique for accurate measurements and confirmations of pesticides in different pepper varieties.

6.
Foods ; 12(6)2023 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-36981231

RESUMO

Over 10 years have passed since the Fukushima Daiichi Nuclear Power Plant accident. This study verifies the efficacy of longitudinal regulation on internal exposure doses and analyzes food group contributions to radiation doses using accumulated monitoring test results. The committed effective doses in 10,000 virtual persons from fiscal year (FY) 2012 to 2021, with and without regulation, were estimated as products of radioactivity concentrations randomly sampled from the test results, food intake, and dose coefficient. The distributed values of food intake rather than a mean value in dose estimation were assumed to reflect food intake variations and avoid underestimation of internal exposure doses for high-intake consumers. Furthermore, the ingestion of radioactive cesium from the calculation was analyzed per food group. The 95th percentile of the internal exposure dose (the dose of a "representative person") was less than 1 mSv/year in both FYs. The regulation effect was substantial in FY 2012, and no noticeable difference in radiation doses was found between the regulation and no regulation conditions after FY 2016. Internal exposure doses decreased until approximately FY 2016 and then remained constant. It was also shown that not only radioactivity concentration but also food intake is a major factor affecting cesium intake. In summary, it was confirmed that Japan had ensured food safety regarding radioactive materials.

7.
J Expo Sci Environ Epidemiol ; 33(5): 794-804, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36725925

RESUMO

BACKGROUND: The German total diet study (TDS)-BfR MEAL Study-established its food list in 2016 based on food consumption data of children (0.5-<5 years) and adults (14-80 years). The list consists of 356 foods selected for analysis in order to ensure ≥90% coverage of the diet. Recently, new food consumption data for children (0.5-<6 and 6-<12 years) in Germany became available, which raised the opportunity to evaluate the applicability of the MEAL food list 2016 on new data. OBJECTIVE: We tested the hypotheses that the MEAL food list 2016 also covers ≥90% of the diet of the new collected food consumption data, and that the selection of foods from younger children and adults was sufficient to also cover the middle age group (6-<12 years). Strategies for updating the existing food list were assessed. METHODS: Three approaches evaluated the reusability and potential adjustment strategies of the existing food list. Approach 1 applied the existing food list to new food consumption data. Approach 2 allowed the extension of the existing food list to improve coverage of food consumption. Approach 3 set up a new food list based on the new data. RESULTS: The MEAL food list 2016 covered 94% of the overall diet of the new collected food consumption data. The diet of the middle age group was sufficiently covered with 91%. However, coverage on main food group or population subgroup level was <90% in some cases. Approach 3 most accurately identified relevant modifications to the existing food list. 94% of the MEAL food list 2016 could be re-used and 51 new foods were identified as potentially relevant. SIGNIFICANCE: The results suggest that a high investment in the coverage of a TDS food list will lower the effort and the resources to keep data updated in the long-term. IMPACT: There is no established approach to update a TDS food list. This study provides comparative approaches to handle newly collected food consumption data for follow-on TDS activities. The results provide useful information for institutions planning or updating a TDS. Furthermore, new food consumption data for children in Germany recently became available and are here presented for the first time.


Assuntos
Dieta , Alimentos , Adulto , Criança , Pessoa de Meia-Idade , Humanos , Alemanha , Contaminação de Alimentos/análise , Coleta de Dados
8.
Food Chem Toxicol ; 173: 113633, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36724847

RESUMO

A high variety of food contains low doses of ethanol which are sometimes difficult to identify by consumers (adults or children). However, even low doses of ethanol intake raises several toxicological concerns. In the present study, an enzymatic assay and an HS-GC/MS procedure were applied to determine the ethanol levels of 1260 samples from different food categories covering "nonalcoholic" beer, fruit juices/drinks, baked goods, bananas and baby foods. Based on these results, ethanol levels resulting from acute or chronic ethanol intake was calculated using consumption data from the EFSA Comprehensive European Food Consumption Database. Thus, health-based guidance values (HBGV) for ethanol intake were derived for acute or chronic exposure based on the available literature. For acute exposure, very few samples resulted in concerning ethanol uptake levels but following chronic exposure the here derived HBGV level was exceeded in several cases. This is mainly due to the following reasons: (1) certain amounts of ethanol are still tolerated in "nonalcoholic" beer and (2) presence of endogenous produced ethanol in bananas or baked goods via fermentation. Most analysed food samples, however, do not result in elevated ethanol doses linked with a potentially high risk following acute and chronic consumption by adults and children.


Assuntos
Bebidas , Etanol , Criança , Adulto , Humanos , Alimentos Infantis , Sucos de Frutas e Vegetais , Medição de Risco
9.
Int J Mol Sci ; 24(4)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36835492

RESUMO

The study aimed to investigate toxicity and the mechanism of toxicity of two Fusarium mycotoxins, deoxynivalenol (DON) and zearalenone (ZEA). DON and ZEA were applied to HepG2 cells as single compounds and in combination at low environmentally relevant concentrations. HepG2 cells were exposed to DON (0.5, 1, and 2 µM), ZEA (5, 10, and 20 µM) or their combinations (1 µM DON + 5 µM ZEA, 1 µM DON + 10 µM ZEA and 1 µM DON + 20 µM ZEA) for 24 h and cell viability, DNA damage, cell cycle and proliferation were assessed. Both mycotoxins reduced cell viability, however, combined treatment with DON and ZEA resulted in higher reduction of cell viability. DON (1 µM) induced primary DNA damage, while DON (1 µM) in combination with higher ZEA concentrations showed antagonistic effects compared to DON alone at 1 µM. DON arrested HepG2 cells in G2 phase and significantly inhibited cell proliferation, while ZEA had no significant effect on cell cycle. The combined treatment with DON and ZEA arrested cells in G2 phase to a higher extend compared to treatment with single mycotoxins. Potentiating effect observed after DON and ZEA co-exposure at environmentally relevant concentrations indicates that in risk assessment and setting governments' regulations, mixtures of mycotoxins should be considered.


Assuntos
Micotoxinas , Zearalenona , Humanos , Zearalenona/toxicidade , Células Hep G2 , Micotoxinas/farmacologia , Ciclo Celular , Proliferação de Células , DNA/farmacologia
10.
Food Chem ; 404(Pt B): 134653, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36327513

RESUMO

Accurate and fast on-site detection of harmful microorganisms in food products is a key preventive step to avoid food-borne illness and product recall. In this study, screen-printed electrodes (SPEs) were functionalized via a facile strategy with surface imprinted polymers (SIPs). The SIP-coated SPEs were used in combination with the heat transfer method (HTM) for the real-time detection of Escherichia coli. The sensor was tested in buffer, with a reproducible and sensitive response that attained a limit of detection of 180 CFU/mL. Furthermore, selectivity was assessed by analyzing the sensor's response to C. sakazakii, K. pneumoniae and S. aureus as analogue strains. Finally, the device was successfully used for the detection of E. coli in spiked milk as proof-of-application, requiring no additional sample preparation. These results suggest the proposed thermal biosensor possesses the potential of becoming a tool for routine, on-site monitoring of E. coli in food safety applications.


Assuntos
Técnicas Biossensoriais , Escherichia coli , Staphylococcus aureus , Eletrodos , Técnicas Biossensoriais/métodos , Laticínios , Limite de Detecção
11.
Food Chem ; 400: 134089, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36075167

RESUMO

In this work, the development of an analytical method for the evaluation of a wide variety of pesticide residues in cereals and pseudo-cereals widely consumed has been carried out. A QuEChERS method was used as extraction and clean-up procedure prior to separation and quantification of the target analytes by ultra-high performance liquid chromatography coupled to mass spectrometry using a single quadrupole-time-of-flight analyser. The methodology was validated for oat, rye, spelt, barley and quinoa matrices, following the European Commission guidelines (SANTE/11312/2021), achieving good absolute recovery values in the range 60-124% with relative standard deviation values lower than 20% and providing limits of quantification of the method in the low mg/kg range, in accordance with the maximum residue limits established by European policies. Finally, considering the importance of cereals in general population diet, the analysis of 60 samples was carried out in order to assure their safe consumption.


Assuntos
Resíduos de Praguicidas , Cromatografia Líquida de Alta Pressão/métodos , Grão Comestível/química , Contaminação de Alimentos/análise , Humanos , Resíduos de Praguicidas/análise , Espanha
12.
J Expo Sci Environ Epidemiol ; 33(5): 805-812, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36310320

RESUMO

The USDA's Pesticide Data Program (PDP) celebrated its 30th anniversary in 2021 and is one of the world's largest monitoring programs for pesticide residues. The PDP database contains over 42 million data points for a pesticide paired to a commodity that have resulted from the analysis of nearly 310,000 food samples of 126 different commodities. Over the decades of the program, sampling methods and infrastructure, major milestones, developments, and accomplishments have unfolded. Comparisons of data for four commodities that were in the program early on illustrate that over time pesticide residues on foods change, particularly when new pesticides are registered, and updated data, such as those provided by PDP, are key for exposure and risk assessment.


Assuntos
Resíduos de Praguicidas , Praguicidas , Humanos , Praguicidas/análise , Resíduos de Praguicidas/análise , Verduras/química , Frutas/química , Contaminação de Alimentos/análise
13.
Nanomaterials (Basel) ; 12(23)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36500739

RESUMO

Throughout the food supply chain, including production, storage, and distribution, food can be contaminated by harmful chemicals and microorganisms, resulting in a severe threat to human health. In recent years, the rapid advancement and development of nanotechnology proposed revolutionary solutions to solve several problems in scientific and industrial areas, including food monitoring. Nanotechnology can be incorporated into chemical and biological sensors to improve analytical performance, such as response time, sensitivity, selectivity, reliability, and accuracy. Based on the characteristics of the contaminants and the detection methods, nanotechnology can be applied in different ways in order to improve conventional techniques. Nanomaterials such as nanoparticles, nanorods, nanosheets, nanocomposites, nanotubes, and nanowires provide various functions for the immobilization and labeling of contaminants in electrochemical and optical detection. This review summarizes the recent advances in nanotechnology for detecting chemical and biological contaminations in the food supply chain.

14.
Sensors (Basel) ; 22(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36502240

RESUMO

The development of a robust surface functionalization method is indispensable in controlling the efficiency, sensitivity, and stability of a detection system. Polystyrene (PS) has been used as a support material in various biomedical fields. Here, we report various strategies of polystyrene surface functionalization using siloxane derivative, divinyl sulfone, cyanogen bromide, and carbonyl diimidazole for the immobilization of biological recognition elements (peptide developed to detect ochratoxin A) for a binding assay with ochratoxin A (OTA). Our objective is to develop future detection systems that would use polystyrene cuvettes such as immobilization support of biological recognition elements. The goal of this article is to demonstrate the proof of concept of this immobilization support. The results obtained reveal the successful modification of polystyrene surfaces with the coupling agents. Furthermore, the immobilization of biological recognition elements, for the OTA binding assay with horseradish peroxidase conjugated to ochratoxin A (OTA-HRP) also confirms that the characteristics of the functionalized peptide immobilized on polystyrene retains its ability to bind to its ligand. The presented strategies on the functionalization of polystyrene surfaces will offer alternatives to the possibilities of immobilizing biomolecules with excellent order- forming monolayers, due to their robust surface chemistries and validate a proof of concept for the development of highly efficient, sensitive, and stable future biosensors for food or water pollution monitoring.


Assuntos
Técnicas Biossensoriais , Poliestirenos , Poliestirenos/química , Peroxidase do Rábano Silvestre/química , Peptídeos/química , Ligantes
15.
Foods ; 11(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35885339

RESUMO

In 2019, SARS-CoV-2 was identified as the cause of an easily transmissible disease that was declared as a world pandemic. Foodborne transmission was never reported. However, early studies suggested that food could be involved in SARS-CoV-2 entry in the human gastrointestinal tract leading to possible infection, and highlighting the importance of further studies to inspect possible issues linked to food consumption. In this perspective, this work aimed at monitoring SARS-CoV-2 presence in some food and mains water samples in Northern Italy during the COVID-19 pandemic (2020-2022). A total of 1806 foods, 112 mains water samples, and 580 swabs on meat and dairy product surfaces were analyzed for SARS-CoV-2 RNA detection by Real-time PCR. All the analyzed samples were negative to viral RNA detection with the exception of one vegetable sample. Even if data on foodborne coronavirus transmission suggested a limited importance of this pathway, the impact of the current pandemic in Northern Italy deserved a rigorous investigation to rule out such possibility. Indeed, gaining insight on all SARS-CoV-2 possible transmission pathways, including the foodborne route, seemed of interest to maintain consumers' confidence and trust in food safety, and for the effective management of the current, and future, possible pandemics.

16.
Food Chem X ; 13: 100240, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35498969

RESUMO

Two different data sets of occurrence data are available in Germany at present: the German National Food Monitoring and the BfR MEAL Study. To determine the suitability of each data set for exposure assessment and to develop concepts for a target-oriented selection and application of data, possibilities, limitations and scope of substance as well as food selection is quantitatively compared. The National Monitoring data provides comprehensive information on the variability of substance levels. This enables short- and long-term exposure assessment and consumer-loyal scenarios. The BfR MEAL Study supplements the monitoring data set with > 100 substances or by complementing the food spectrum for substances already included in the National Monitoring. The study design benefits especially the long-term dietary exposure assessment for the German population including the total diet. Using both programmes enables case-dependent selection of the appropriate dataset and in combination both sets can contribute to enhanced consumer safety.

17.
Foods ; 11(8)2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35454738

RESUMO

Focusing on the importance of wild vegetables for local residents, this study aims to validate the effects of food regulations under the current criteria (e.g., 100 Bq/kg for general foods) established approximately a year after the Fukushima Dai-ichi Nuclear Power Plant accident. Over 2,500,000 monitoring tests were performed under the criteria until fiscal year (FY) 2020. We estimated changes in internal exposure dose using test results. The effective dose was estimated using the radioactive concentration randomly sampled from the results, food intake, and dose conversion factor. As a new attempt, dose estimation reflecting the intake of wild vegetables that may have irreplaceable value for local residents was conducted. The median, 95th, and 99th percentile of the estimated dose without reflecting the wild vegetables' intake were 0.0485, 0.183, and 10.6 mSv/year, respectively, in the estimation with all test results (no regulation) and 0.0431, 0.0786, and 0.236 mSv/year, respectively, in the estimation with results within the standard limits (regulated) in FY2012. These doses decreased with time. Although estimated doses with or without the reflection of wild vegetables' intake were similar, estimation that is more plausible is possible, particularly for a high percentile, by reflecting the wild vegetables' intake. Radiation doses (regulated) were significantly less than 1 mSv/year in different FYs. In Japan, food regulation measures benefit food safety.

18.
ACS Sens ; 6(10): 3685-3695, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34644058

RESUMO

The rapid advancement of internet of things (IoT)-enabled applications along with connected automation in sensing technologies is the heart of future intelligent systems. The probable applications have significant implications, from chemical process monitoring to agriculture, mining, space, wearable electronics, industrial manufacturing, smart cities, and point-of-care (PoC) diagnostics. Advancing sensor performance such as sensitivity to detect trace amounts (ppb-ppm) of analytes (gas/VOCs), selectivity, portability, and low cost is critical for many of these applications. These advancements are mainly achieved by selecting and optimizing sensing materials by their surface functionalization and/or structural optimization to achieve favorable transport characteristics or chemical binding/reaction sites. Surprisingly, the sensor geometry, shapes, and patterns were not considered as critical parameters, and most of these sensors were designed by following simple planar and interdigitated electrode geometry. In this study, we introduce a new bioinspired fractal approach to design chemoresistive sensors with fractal geometry, which grasp the architecture of fern leaves represented by the geometric group of space-filling curves of fractal patterns. These fractal sensors were printed by an extrusion process on a flexible substrate (PET) using specially formulated graphene ink as a sensing material, which provided significant enhancement of the active surface area to volume ratio and allowed high-resolution fractal patterning along with a reduced current transportation path. To demonstrate the advantages and influence of fractal geometry on sensor performance, here, three different kinds of sensors were fabricated based on different fractal geometrics (Sierpinski, Peano, and Hilbert), and the sensing performance was explored toward different VOC analytes (e.g., ethanol, methanol, and acetone). Among all these fractal-designed sensors including interdigitate sensors, the Hilbert-designed printed sensor shows enhanced sensing properties in terms of fast response time (6 s for 30 ppm), response value (14%), enhanced detection range (5-100 ppm), high selectivity, and low interference to humidity (up to RH 80%) for ethanol at room temperature (20 °C). Moreover, a significant improvement of this sensor performance was observed by applying the mechanical deformation (positive bending) technique. The practical application of this sensor was successfully demonstrated by monitoring food spoilage using a commercial box of strawberries as a model. Based on these presented results, this biofractal biomimetic VOC sensor is demonstrated for a prospective application in food monitoring.


Assuntos
Grafite , Dispositivos Eletrônicos Vestíveis , Eletrodos , Fractais , Umidade
19.
J Agric Food Chem ; 69(41): 12305-12313, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34633796

RESUMO

In this study, the residue data for conazole fungicides were collated and analyzed in all crop samples reported by the United States Department of Agriculture Pesticide Data Program over the period of 2009-2019. Considering all individual samples, the overall detection frequencies (DFs) of conazoles are less than 13%. Among the 18 conazoles, imazalil had the highest overall DF of 6%, followed by tebuconazole and myclobutanil, with 4% each. Conazoles were detected most frequently in raisins with 28% DF, followed by cherries (frozen and fresh) and grapes, with 12, 10, and 10%, respectively. The presence of multiple conazoles in single commodity samples is very low, below 2%. The analyses found no more than four conazoles present in any given sample. Out of the 18 conazoles, 8 of them were not detected in more than 99.9% of the commodity samples from 2009 to 2019 and, therefore, can be eliminated from screening-level cumulative risk assessment for dietary contributions from food items. While conazoles are widely used on food commodities, co-occurrence of conazole residues was observed only in a very limited number of food commodities, including raisins, grapes, cherries (frozen), nectarines, and peaches. Considering the remaining individual food commodities, the co-occurrence of conazole residues in single commodity samples is very low or not even present.


Assuntos
Fungicidas Industriais , Resíduos de Praguicidas , Praguicidas , Agricultura , Contaminação de Alimentos/análise , Frutas/química , Resíduos de Praguicidas/análise , Estados Unidos , United States Department of Agriculture
20.
ACS Nano ; 15(9): 13943-13969, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34524790

RESUMO

Since their discovery almost three decades ago, DNAzymes have been used extensively in biosensing. Depending on the type of DNAzyme being used, these functional oligonucleotides can act as molecular recognition elements within biosensors, offering high specificity to their target analyte, or as reporters capable of transducing a detectable signal. Several parameters need to be considered when designing a DNAzyme-based biosensor. In particular, given that many of these biosensors immobilize DNAzymes onto a sensing surface, selecting an appropriate immobilization strategy is vital. Suboptimal immobilization can result in both DNAzyme detachment and poor accessibility toward the target, leading to low sensing accuracy and sensitivity. Various approaches have been employed for DNAzyme immobilization within biosensors, ranging from amine and thiol-based covalent attachment to non-covalent strategies involving biotin-streptavidin interactions, DNA hybridization, electrostatic interactions, and physical entrapment. While the properties of each strategy inform its applicability within a proposed sensor, the selection of an appropriate strategy is largely dependent on the desired application. This is especially true given the diverse use of DNAzyme-based biosensors for the detection of pathogens, metal ions, and clinical biomarkers. In an effort to make the development of such sensors easier to navigate, this paper provides a comprehensive review of existing immobilization strategies, with a focus on their respective advantages, drawbacks, and optimal conditions for use. Next, common applications of existing DNAzyme-based biosensors are discussed. Last, emerging and future trends in the development of DNAzyme-based biosensors are discussed, and gaps in existing research worthy of exploration are identified.


Assuntos
Técnicas Biossensoriais , DNA Catalítico
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