Magnetic aptamer copper nanoclusters fluorescent biosensor for the visual detection of zearalenone based on docking-aided rational tailoring.

To address the food safety issues caused by toxins, we established a fluorescent copper nanocluster biosensor based on magnetic aptamer for the visual and quantitative detection of ZEN. Specifically, we utilized the docking-aided rational tailoring (DART) strategy to analyze intermolecular force and interaction sites between zearalenone (ZEN) and the aptamer, and optimize the long-chain aptamer step by step to enhance the binding affinity by 3.4 times. The magnetic bead-modified aptamer underwent conformational changes when competing with complementary sequences to bind with ZEN. Then, the released complementary sequences will be amplified in template-free mode with the presence of the terminal deoxynucleotidyl transferase (TdT), and generating T-rich sequences as the core sequences for the luminescence of copper nanoclusters. The luminescence could be visualized and quantitatively detected through ultraviolet irradiation. The proposed label-free aptasensor exhibited high sensitivity and specificity, with a low limit of detection (LOD) of 0.1 ng/mL.

Selective adsorption of zearalenone by a novel magnetic molecularly imprinted carbon nanomaterial.

In this paper, the objective is to immobilize molecularly imprinted polymers (MIPs) onto the surface of magnetic carbon nanoparticles (Fe3O4@SiO2@C) to develop an effective method for the adsorption of zearalenone (ZEN). The prepared products were characterized by FT-IR, SEM, TEM, XRD, VSM, TGA, and BET. The content of zearalenone in corn samples was monitored by HPLC. The results indicate that the particle size of magnetic molecularly imprinted polymers (MMIPs) is approximately 200 nm. The adsorption mechanism of MMIPs was confirmed by static adsorption and dynamic adsorption experiments. The maximum adsorption capacity was 1.56 mg/g, and the adsorption equilibrium was reached within 50 min. The scatchard model showed that MMIPs had two binding sites, a high-affinity binding site and a low-affinity site. Kinetic second-order fitting indicates that MMIPs are mainly through chemisorption. In the actual sample application, the limit of detection (LOD) and limit of quantitation (LOQ) were 0.3 mg/L and 0.9 mg/L, respectively. The recovery of corn with the standard addition of ZEN was 73.6-88.1%, and the relative standard deviation (RSD) was 2.86-5.63%. The results demonstrated that MMIPs possess the advantages of straightforward operation, high precision, and cost-effectiveness, rendering them suitable for rapid ZEN detection.

Fabrication of amino- and hydroxyl dual-functionalized magnetic microporous organic network for extraction of zearalenone from traditional Chinese medicine prior to the HPLC determination.

Efficient enrichment of trace zearalenone (ZEN) from the complex traditional Chinese medicine (TCM) samples is quite difficult, but of great significance for TCM quality control. Herein, we reported a novel magnetic solid phase extraction (MSPE) strategy for ZEN enrichment using the amino- and hydroxyl dual-functionalized magnetic microporous organic network (Fe3O4@MON-NH2-OH) as an advanced adsorbent combined with the high-performance liquid chromatography (HPLC) determination. Efficient extraction of ZEN was achieved via the possible hydrogen bonding, hydrophobic, and π-π interactions between Fe3O4@MON-NH2-OH and ZEN. The adsorption capacity of Fe3O4@MON-NH2-OH for ZEN was 215.0 mg g-1 at the room temperature, which was much higher than most of the reported adsorbents. Under the optimal condition, the developed Fe3O4@MON-NH2-OH-MSPE-HPLC method exhibited wide linear range (5-2500 µg L-1), low limits of detection (1.4-35 µg L-1), less adsorbent consumption (5 mg), and large enhancement factor (95) for ZEN. The proposed method was successfully applied to detect trace ZEN from 10 kinds of real TCM samples. Conclusively, this work demonstrates the Fe3O4@MON-NH2-OH can effectively extract trace ZEN from the complex TCM matrices, which may open up a new way for the application of MONs in the enrichment and extraction of trace contaminants or active constituents from the complex TCM samples.

Biotransformation of zearalenone to non-estrogenic compounds with two novel recombinant lactonases from Gliocladium.

BACKGROUND: The mycotoxin zearalenone (ZEA) produced by toxigenic fungi is widely present in cereals and its downstream products. The danger of ZEA linked to various human health issues has attracted increasing attention. Thus, powerful ZEA-degrading or detoxifying strategies are urgently needed. Biology-based detoxification methods are specific, efficient, and environmentally friendly and do not lead to negative effects during cereal decontamination. Among these, ZEA detoxification using degrading enzymes was documented to be a promising strategy in broad research. Here, two efficient ZEA-degrading lactonases from the genus Gliocladium, ZHDR52 and ZHDP83, were identified for the first time. This work studied the degradation capacity and properties of ZEA using purified recombinant ZHDR52 and ZHDP83. RESULTS: According to the ZEA degradation study, transformed Escherichia coli BL21(DE3) PLySs cells harboring the zhdr52 or zhdp83 gene could transform 20 µg/mL ZEA within 2 h and degrade > 90% of ZEA toxic derivatives, α/ß-zearalanol and α/ß-zearalenol, within 6 h. Biochemical analysis demonstrated that the optimal pH was 9.0 for ZHDR52 and ZHDP83, and the optimum temperature was 45 °C. The purified recombinant ZHDR52 and ZHDP83 retained > 90% activity over a wide range of pH values and temperatures (pH 7.0-10.0 and 35-50 °C). In addition, the specific activities of purified ZHDR52 and ZHDP83 against ZEA were 196.11 and 229.64 U/mg, respectively. The results of these two novel lactonases suggested that, compared with ZHD101, these two novel lactonases transformed ZEA into different products. The slight position variations in E126 and H242 in ZDHR52/ZEA and ZHDP83/ZEA obtained via structural modelling may explain the difference in degradation products. Moreover, the MCF-7 cell proliferation assay indicated that the products of ZEA degradation using ZHDR52 and ZHDP83 did not exhibit estrogenic activity. CONCLUSIONS: ZHDR52 and ZHDP83 are alkali ZEA-degrading enzymes that can efficiently and irreversibly degrade ZEA into non-estrogenic products, indicating that they are potential candidates for commercial application. This study identified two excellent lactonases for industrial ZEA detoxification.

Enhancing the activity of zearalenone lactone hydrolase toward the more toxic α-zearalanol via a single-point mutation.

Zearalenone (ZEN) and its derivatives are estrogenic mycotoxins known to pose significant health threats to humans and animals. Especially, the derivative α-zearalanol (α-ZAL) is over 10 times more toxic than ZEN. Simultaneous degradation of ZEN and its derivatives, especially α-ZAL, using ZEN lactone hydrolases (ZHDs) is a promising solution to eliminate their potential hazards to food safety. However, most available ZHDs exhibit limited activity toward the more toxic α-ZAL compared to ZEN. Here, we identified a broad-substrate spectrum ZHD, named ZHDAY3, from Exophiala aquamarina CBS 119918, which could not only efficiently degrade ZEN but also exhibited 73% relative activity toward α-ZAL. Through rational design, we obtained the ZHDAY3(N153H) mutant, which exhibited the highest specific activity (253.3 ± 4.3 U/mg) reported so far for degrading α-ZAL. Molecular docking, structural comparative analysis, and kinetic analysis collectively suggested that the shorter distance between the side chain of the catalytic residue His242 and the lactone bond of α-ZAL and the increased binding affinity to the substrate were mainly responsible for the improved catalytic activity of ZHDAY3(N153H) mutant. This mechanism was further validated through additional molecular docking of 18 mutants and experimental verification of six mutants.IMPORTANCEThe mycotoxins zearalenone (ZEN) and its derivatives pose a significant threat to food safety. Here, we present a highly promising ZEN lactone hydrolase (ZHD), ZHDAY3, which is capable of efficiently degrading both ZEN and the more toxic derivative α-ZAL. Next, the ZHDAY3(N153H) mutant obtained by single-point mutation exhibited the highest specific activity for degrading α-ZAL reported thus far. We further elucidated the molecular mechanisms underlying the enhanced hydrolytic activity of ZHDAY3(N153H) toward α-ZAL. These findings represent the first investigation on the molecular mechanism of ZHDs against α-ZAL and are expected to provide a significant reference for further rational engineering of ZHDs, which will ultimately contribute to addressing the health risks and food safety issues posed by ZEN-like mycotoxins.

Site-directed display of zearalenone lactonase on spilt-intein functionalized nanocarrier for green and efficient detoxification of zearalenone.

In this study, we prepared a functional organic-inorganic hybrid nanoflower (InHNF) via split intein moiety in a biomineralization process without using organic solvents. InHNF could specifically bind the target enzymes from crude cell lysates within seconds and site-directedly display them on the surface by forming a peptide bond with enzyme's terminal amino acid residue. This unique feature enabled InHNF to increase the specific activity of zearalenone detoxifying enzyme ZHD518 by 40 âˆ¼ 60% at all tested temperatures and prevented enzyme denaturation even under extreme pH conditions (pH 3-11). Furthermore, it exhibited excellent operational stability, with a residual activity of over 70% after eight reaction cycles. Strikingly, InHNF-ZHD518 achieved above 50% ZEN degradation despite the near inactivation of free ZHD518 in beer sample. Overall, InHNF nanocarriers can achieve environmentally friendly, purification-free, and site-directed immobilization of food enzymes and enhance their catalytic properties, making them suitable for a wide range of industrial applications.

pH-induced interaction mechanism of zearalenone with zein: Binding characteristics, conformational structure and intermolecular forces.

Zein-bound zearalenone (ZEN) complexes are naturally existed in maize by their spontaneous interaction, which significantly impacts the risk assessment of ZEN. Additionally, the pH levels in processing could affect the binding or release of zein-bound ZEN. In this study, pH-induced interaction mechanism of ZEN with zein were studied. Results showed that the acid conditions increased the binding constant (Ka) from 3.46 to 10.0 × 104 L/mol, binding energy from -17.38 to -43.49 kJ mol-1. By increasing hydrophobic interaction and hydrogen bond of ZEN with zein, the binding of ZEN with zein was promoted, forming zein-bound ZEN. Whereas, alkaline conditions decreased the Ka to 1.45 × 104 L/mol and binding energy to 148.48 kJ mol-1, weakened ZEN-zein interaction and stretched zein molecules, resulting the release of ZEN from zein. This study could provide important theoretical basis for perfecting risk assessment and controlling zein-bound ZEN during processing.

Adsorption of Zearalenone by Aureobasidium pullulans Autolyzed Biomass Preparation and Its Detoxification Properties in Cultures of Saccharomyces cerevisiae Yeast.

Different preventive strategies are needed to minimize the intake risks of mycotoxins, including zearalenone (ZEN). The aim of this study was to determine the ZEN adsorption ability of an autolyzed biomass preparation of polymorphic yeast Aureobasidium pullulans A.p.-3. The evaluation of the antitoxic properties of the preparation was also performed in relation to Saccharomyces cerevisiae yeast (ATCC 2366, ATCC 7090 and ATCC 9763) used as a model cell exposed to a toxic ZEN dose. The preparation at a dose of 5 mg/mL showed the adsorption of ZEN present in model systems at concentrations between 1 µg/mL to 100 µg/mL. The highest degree of adsorption was established for ZEN concentrations of 1 µg/mL and 5 µg/mL, becoming limited at higher doses of the toxin. Based on the Langmuir model of adsorption isotherms, the predicted maximum ZEN adsorption was approx. 190 µg/mL, regardless of pH. The growth of three strains of S. cerevisiae yeast cells in the medium with ZEN at concentrations within the range of 1.56 µg/mL-100 µg/mL was analyzed to determine the minimum inhibitory concentration. The growth of all tested strains was especially limited by high doses of ZEN, i.e., 50 and 100 µg/mL. The protective effect of the tested preparation was noted in relation to yeast cells exposed to toxic 100 µg/mL ZEN doses. The highest yeast cell growth (app. 36% percentage) was noted for a S. cerevisiae ATCC 9763 strain compared to the medium with ZEN but without preparation. More detailed tests determining the antitoxic mechanisms of the A. pullulans preparation are planned in the future, including cell culture bioassays and animal digestive tract models.

Simultaneous removal of aflatoxin B1 and zearalenone in vegetable oils by hierarchical fungal mycelia@graphene oxide@Fe3O4 adsorbent.

Physical adsorbents for detoxification are widely used in vegetable oil industry. So far, the high-efficiency and low-cost adsorbents have not been well explored. Here, a hierarchical fungal mycelia@graphene oxide@Fe3O4 (FM@GO@Fe3O4) was fabricated as an efficient adsorbent for simultaneous removal of aflatoxin B1 (AFB1) and zearalenone (ZEN). The morphological, functional and structural characteristics of the prepared adsorbents were systematic investigated. Batch adsorption experiments in both single and binary systems were conducted, and the adsorption behaviours and mechanism were explored. The results indicated that the adsorption process occurred spontaneously and the mycotoxin adsorption could be described as physisorption through hydrogen bonding, π-π stacking, electrostatic and hydrophobic interactions. Due to good biological safety, magnetic manipulability, scalability, recyclability and easy regeneration, FM@GO@Fe3O4 performance is suitable for application as a detoxification adsorbent in vegetable oil industry. Our study addresses a novel green strategy for removing multiple mycotoxins by integrating the toxigenic isolates with advanced nanomaterials.

Biochemical characterization and molecular modification of a zearalenone hydrolyzing enzyme Zhd11D from Phialophora attinorum.

ZEN lactone hydrolase (ZHD) can hydrolyze zearalenone (ZEN) to less or non-toxic product, providing an environment-friendly way for food or feeds-containing ZENs detoxification. Here, a newly identified ZHD from Phialophora attinorum, annotated as Zhd11D, was characterized to exhibit highest activity against ZEN at pH 8.0 and 35 â„ƒ with a specific activity of 304.7 U/mg, which was far higher than most of the reported ZHDs. A nonspecific protein engineering method was introduced through fusing a segment of amphiphilic short peptide S1 at the N-terminus of Zhd11D, resulting in both improved activity (1.5-fold) and thermostability (2-fold at 40 â„ƒ). Biochemical analysis demonstrated that self-aggregation caused by intermolecular interactions between S1 contributed to the improvement of the enzymatic properties of Zhd11D. Additionally, S1-Zhd11D showed a higher hydrolysis rate of ZEN than Zhd11D in peanut oil.

The Motion Paradigm of Pre-Dock Zearalenone Hydrolase Predictions with Molecular Dynamics and the Docking Phase with Umbrella Sampling.

Zearalenone (ZEN) is one of the most prevalent estrogenic mycotoxins, is produced mainly by the Fusarium family of fungi, and poses a risk to the health of animals. Zearalenone hydrolase (ZHD) is an important enzyme capable of degrading ZEN into a non-toxic compound. Although previous research has investigated the catalytic mechanism of ZHD, information on its dynamic interaction with ZEN remains unknown. This study aimed to develop a pipeline for identifying the allosteric pathway of ZHD. Using an identity analysis, we identified hub genes whose sequences can generalize a set of sequences in a protein family. We then utilized a neural relational inference (NRI) model to identify the allosteric pathway of the protein throughout the entire molecular dynamics simulation. The production run lasted 1 microsecond, and we analyzed residues 139-222 for the allosteric pathway using the NRI model. We found that the cap domain of the protein opened up during catalysis, resembling a hemostatic tape. We used umbrella sampling to simulate the dynamic docking phase of the ligand-protein complex and found that the protein took on a square sandwich shape. Our energy analysis, using both molecular mechanics/Poisson-Boltzmann (Generalized-Born) surface area (MMPBSA) and Potential Mean Force (PMF) analysis, showed discrepancies, with scores of -8.45 kcal/mol and -1.95 kcal/mol, respectively. MMPBSA, however, obtained a similar score to that of a previous report.

Characterization of modified rice straw biochar in immobilizing Bacillus subtilis 168 and evaluation on its role as a novel agent for zearalenone-removal delivery.

Microbial remediation of environmental pollutants can be advanced by carrier based cells immobilization. Whereas the effects of microorganisms immobilized on biochar for removal of zearalenone (ZEN) still remain unknown. Herein, this work presented the characterization of rice straw biochar (RSB) around modification in immobilizing Bacillus subtilis 168 and the role in fighting ZEN in vitro. Specifically, 10% of RSB with pH 5 condition were optimal for bearing cells, where majority of cells loaded inside the pore and minority on surface with agglomeration or scattering status. Octadecyl trimethyl ammonium chloride-inclusion RSB showed better performances including over 93% of ZEN detoxification rate (32.48% in free cells), cells preservation, and stability of detoxification in simulated gastrointestinal environment. RSB treated with sulphuric acid made nutrients adsorption generally less than 6.5%. No residues of α-ZEL and α-ZAL were found in ZEN biotransformation process whether by free cells or composites. Mechanism discussion implied that predominant monolayer chemisorption by RSB and subsequent biodegradation by extracellular enzymes from microorganism involved in ZEN-removal process. Collectively, these findings contribute to provide an applying strategy for coordination of biochar and microorganisms as potentially mycotoxin detoxifying agent in agricultural feed bioremediation and environmental decontamination processes.

Removal of Aflatoxin B1 and Zearalenone in Mixed Aqueous Solution by Palygorskite-Montmorillonite Materials In Situ Prepared from Palygorskite Mineral.

In view of the animal feeds inevitably contaminated by multiple mycotoxins, eco-friendly and efficient palygorskite-montmorillonite (Pal-Mt) materials were prepared to remove polar aflatoxin B1 (AFB1) and weak polar zearalenone (ZEN) from mixed mycotoxins aqueous solution. The adsorption properties and bonding mechanisms between Pal-Mt materials and mycotoxins (AFB1 and ZEN) were investigated systematically. The as-prepared Pal-Mt showed excellent adsorption capacity for AFB1 and ZEN in single- and binary-mycotoxin systems, indicating the effectiveness of Pal-Mt acting as multiple mycotoxin adsorbents. The kinetics of adsorption for ZEN was fast due to the adsorption on the external surface (film and intraparticle diffusion), while AFB1 molecules permeated into mesopores after the external adsorption for the more planar structure. Adsorption isotherms demonstrated that heterogeneous surface adsorption appeared between Pal-Mt and AFB1, and monolayer adsorption occurred on Pal-Mt and ZEN for different polarities of mycotoxins. Thermodynamic parameters illustrated that the adsorption process of both AFB1 and ZEN onto Pal-Mt was spontaneous and endothermic. The adsorption mechanism studies suggested that hydrogen bonding, electrostatic attraction, calcium bridging linkage, and ion-dipole played fundamental roles in the interaction between Pal-Mt and these two mycotoxins.

The N-terminal hydrophobicity modulates a distal structural domain conformation of zearalenone lacton hydrolase and its application in protein engineering.

Zearalenone (ZEN) is one of the most common mycotoxins in maize, wheat, barley, sorghum, rye and other grains. ZEN contamination in feed is an international health issue due to its estrogenicity by competitively binding to estrogen receptors. Enzymatic detoxification of ZEN is superior to physical and chemical methods in terms of safety, environmental impact and preserving nutritional value and palatability, but is hampered by both the currently limited repertoire of detoxifying enzymes and the lack of knowledge about their structure-function relationships. In this study, a ZEN lacton hydrolase candidate (ZHD11C) was identified from thermo-tolerant Fonsecaea multimorphosa CBS 102226, and characterized to be more thermostable than these reported homologues. An intriguing feature of ZHD11C is that the N-terminal hydrophobicity affects its thermal stability and causes conformational change of a domain far from the N-terminal. This finding was successfully applied to enhance the thermostability of the most active ZEN lacton hydrolase ZHD518 through rationally tailoring its N-terminal hydrophobicity. Our results not only provide more insights into the structure-function relationships of ZEN lacton hydrolases, but generate better candidate for bio-decontamination of zearalenone in feed industries.

Hydrophilic Covalent Organic Frameworks Coated Steel Sheet As a Mass Spectrometric Ionization Source for the Direct Determination of Zearalenone and Its Derivatives.

Zearalenone has attracted worldwide attention due to its toxic properties and threat to public health. A rapid determination method for zearalenone and its derivatives by hydrophilic covalent organic frameworks coated steel sheet (HCOFCS) combined with ambient mass spectrometry (AMS) was developed. The HCOFCS behaved as both a tip for solid-phase microextraction and a solid substrate for electrospray ionization mass spectrometry (ESI-MS). To evaluate the HCOFCS-ESI-MS method, five zearalenone and its derivatives in milk samples were determined, including zearalenone (ZEA), α-zearalenol (α-ZEL), ß-zearalenol (ß-ZEL), α-zearalanol (α-ZAL), and ß-zearalanol (ß-ZAL). After the extraction procedure, the HCOFCS was directly added with a high voltage for ESI-MS, and the analysis could be completed within 1 min. The developed method showed good linearity in the range 0.1-100 µg/L with a coefficient of determination (R2) > 0.9991. The limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.05 to 0.1 and 0.2 to 0.3 µg/L, respectively. The results demonstrated that the HCOFCS combined with ESI-MS can be used for the rapid and sensitive determination of trace ZEA and its derivatives in milk samples with satisfactory recoveries from 80.58% to 109.98% and reproducibility with relative standard deviations (RSDs) no more than 11.18%. Furthermore, HCOFCS showed good reusability, which could reuse at least 10 extraction cycles with satisfactory adsorption performance.

Excavation, expression, and functional analysis of a novel zearalenone-degrading enzyme.

Zearalenone (ZEN) is a toxic secondary metabolite of Fusarium sp. commonly found in wheat, corn, and other crops. In addition to economic losses, ZEN can seriously endanger the health of both humans and livestock, thus presenting an urgent need for ZEN-detoxifying enzymes that function in the extreme heat or pH conditions of industrial fermenters. Here, we identify and characterize the activity of the ZEN-degrading enzyme from Exophiala spinifera, ZHD_LD, which shares 60.15% amino acid identity and a conserved catalytic triad with the well-characterized ZEN-detoxifying protein ZHD101 from Clonostachys rosea. Biochemical activity and stability assays indicated that purified recombinant ZHD_LD exhibited high activity against ZEN with optimal reaction conditions of 50 ℃ and pH 7.0-10.0. Structural modeling of the ZHD_LD active site and comparison with ZHD101 revealed its likely mechanism of ZEN degradation. This research provides an industrially valuable candidate enzyme for ZEN detoxification in food and livestock feed.

Simultaneous Detoxification of Aflatoxin B1, Zearalenone and Deoxynivalenol by Modified Montmorillonites.

Raw Ca-based montmorillonite (MMT) was treated by H2SO4, calcination and organic compounds (hexadecyltrimethyl ammonium bromide (HTAB), cetylpyridinium chloride (CPC) and chitosan (CTS)), respectively. The modified montmorillonites were characterized by different methods and their adsorption performances for three mycotoxins (Aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON)) were evaluated at pH = 2.8 and 8.0, respectively. The results indicate that surfactants (CPC and HTAB) intercalation is the most efficient modification, which obviously improves the adsorption performance of montmorillonite for mycotoxins, with adsorption efficiency of above 90% for AFB1 and ZEA whether under acid or alkaline conditions, due to the increase in basal spacing and the improvement of hydrophobicity. Moreover, the adsorption efficiencies of AFB1 and ZEA over CPC-modified montmorillonite (CPC-AMMT-3) coexisting with vitamin B6 or lysine are still at a high level (all above 94%). All modified montmorillonites, however, have low adsorption efficiency for DON, with somewhat spherical molecular geometry.

Detection Strategies of Zearalenone for Food Safety: A Review.

Zearalenone (ZEN) is a toxic compound produced by the metabolism of fungi (genus Fusarium) that threaten the food and agricultural industry belonging to the in foods and feeds. ZEN has toxic effects on human and animal health due to its mutagenicity, teratogenicity, carcinogenicity, nephrotoxicity, immunotoxicity, and genotoxicity. To ensure food safety, rapid, precise, and reliable analytical methods can be developed for the detection of toxins such as ZEN. Different selective molecular diagnostic elements are used in conjunction with different detection strategies to achieve this goal. In this review, the use of electrochemical, colorimetric, fluorometric, refractometric as well as other strategies were discussed for ZEN detection. The success of the sensors in analytical performance depends on the development of receptors with increased affinity to the target. This requirement has been met with different immunoassays, aptamer-assays, and molecular imprinting techniques. The immobilization techniques and analysis strategies developed with the combination of nanomaterials provided high precision, reliability, and convenience in ZEN detection, in which electrochemical strategies perform the best.

Anti-mycotoxigenic and antifungal activity of ginger, turmeric, thyme and rosemary essential oils in deoxynivalenol (DON) and zearalenone (ZEA) producing Fusarium graminearum.

This study aimed to evaluate the antimycotoxigenic effect of essential oils (EOs) obtained from four different aromatic plants on the production of deoxynivalenol (DON) and zearalenone (ZEA) by Fusarium graminearum. The EOs from ginger (GEO), turmeric (TEO), thyme (ThEO) and rosemary (REO) were obtained by hydrodistillation and identified by gas chromatography/mass spectrometry (GC/MS). The major compounds found were mostly monoterpenes and sesquiterpenes. The minimum inhibitory concentration (MIC) and minimum fungicide concentration (MFC) were 11.25, 364, 366 and 11,580 µg mL-1 for ThEO, GEO, REO and TEO, respectively. The results evidenced that the assessed EOs inhibited DON and partially ZEA production by F. graminearum. ThEO and GEO were the EOs with most potent antimycotoxigenic action for DON and ZEA, respectively. These EOs have shown promising results in vitro regarding inhibition of mycotoxin production and might be used in the future as substitutes for synthetic fungicides.

Single-crystal ordered macroporous metal-organic framework as support for molecularly imprinted polymers and their integration in membrane formant for the specific recognition of zearalenone.

Zearalenone is a fungal contaminant that is widely present in grains. Here, a novel molecularly imprinted membrane based on SOM-ZIF-8 was developed for the rapid and highly selective identification of zearalenone in grain samples. The molecularly imprinted membrane was prepared using polyvinylidene fluoride, cyclododecyl 2,4-dihydroxybenzoate as a template and SOM-ZIF-8 as a carrier. The factors influencing the extraction of zearalenone using this membrane, including the solution pH, extraction time, elution solvent, elution time, and elution volume, were studied in detail. The optimized conditions were 5 mL of sample solution at pH 6, extraction time of 45 min, 4 mL of acetonitrile:methanol = 9:1 as elution solvent, and elution time of 20 min. This method displayed a good linear range of 12-120 ng/g (R2  = 0.998) with the limits of detection and quantification of this method are 1.7 and 5.5 ng/g, respectively. In addition, the membrane was used to selectively identify zearalenone in grain samples with percent recoveries ranging from 87.9 to 101.0% and relative standard deviation of less than 6.6%. Overall, this study presents a simple and effective chromatographic pretreatment method for detecting zearalenone in food samples.