Deoxynivalenol In Wheat Research Articles

Cu2O nanoparticles with morphology-dependent peroxidase mimic activity: a novel colorimetric biosensor for deoxynivalenol detection.

Different morphological Cu2O nanoparticles including cube, truncated cube, and octahedron were successfully prepared by a selective surface stabilization strategy. The prepared cube Cu2O exhibited superior peroxidase-like activity over the other two morphological Cu2O nanoparticles, which can readily oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to form visually recognizable color signals. Consequently, a sensitive and simple colorimetric biosensor was proposed for deoxynivalenol (DON) detection. In this biosensor, the uniform cube Cu2O was employed as the vehicle to label the antibody for the recognition of immunoreaction. The sensing strategy showed a detection limit as low as 0.01ng/mL, and a wide linear range from 2 to 100ng/mL. Concurrently, the approximate DON concentration can be immediately and conveniently observed by the vivid color changes. Benefiting from the high sensitivity and selectivity of the designed biosensor, the detection of DON in wheat, corn, and tap water samples was achieved, suggesting the bright prospect of the biosensor for the convenient and intuitive detection of DON in actual samples.

Organic acid preservation of cereal grains improves grain quality, growth performance, and intestinal health of post-weaned pigs

This study investigated the effect of preserving wheat and barley grains with an organic acid liquid surfactant mould inhibitor compared to conventional artificial drying and assessed its effects on the health and performance of pigs post-weaning (PW). A 2 × 2 factorial arrangement was conducted to investigate the interaction between grain preservation method (dried vs. preserved) and zinc oxide (ZnO) inclusion (yes vs. no) on growth performance, diarrhoea scores and incidence, and total tract nutrient digestibility. One hundred and ninety-two pigs (3 pigs/pen; 16 replicates/treatment) were assigned to one of four experimental diets for 35 days: (1) dried grain diet, (2) preserved grain diet, (3) dried grain diet with ZnO and (4) preserved grain diet with ZnO. Diets were formulated to contain similar levels of net energy and standardised ileal digestible lysine. On day 35 PW, 24 pigs (12 replicates/treatment) from the non-ZnO supplemented groups were euthanised and digesta was collected for coefficient of apparent ileal digestibility (CAID), gut microbial population and volatile fatty acid analysis. Stomach tissue was also collected for gene expression analysis, as well as small intestine samples for gut morphology. Notable improvements in grain quality were observed in the preserved grain, including a reduction in grain pH, mould presence, and contamination by mycotoxins, specifically deoxynivalenol in wheat and barley, and ochratoxin A and HT-2 toxin in barley. The preserved grain diet improved average daily gain (ADG; P < 0.01) and body weight (BW; P < 0.01) compared to the dried grain diet. The incorporation of ZnO increased average daily feed intake (ADFI; P < 0.01) and BW (P < 0.05) in the dried grain diet, however, ZnO did not affect ADFI (P > 0.05), and reduced ADG and BW in the preserved grain diet (P < 0.05). Pigs offered the preserved grain diet had reduced faecal scores and diarrhoea incidence compared to those offered the dried grain diet (P < 0.05). Supplementation of ZnO reduced faecal scores and diarrhoea incidence compared to non-supplemented pigs (P < 0.001). On day 35 PW, the preserved grain diet had improved CAID of nitrogen and gross energy (P < 0.05), lower levels of colonic branched-chain volatile fatty acids (P < 0.05), and beneficial shifts in gut microbial populations. Specifically, there was a reduction in ileal Streptococcus (P < 0.001) and an increased abundance of colonic Faecalibacterium (P < 0.05). In conclusion, organic acid preservation improved grain quality, benefiting post-weaned pigs through improved nutrient digestibility and gut health, thus enhancing overall growth performance PW.

Iron-copper nanozyme mimicking laccase for colorimetric determination of deoxynivalenol in feed

Due to the simplicity of their synthesis, robust stability, and adjustable enzymatic activities, nanozymes are particularly effective in inducing changes in substrate coloration, thus proving to be invaluable tools in colorimetric analysis. In this study, terephthalic acid was employed as an organic ligand to synthesize an iron-copper nanozyme with laccase activity using a one-pot hydrothermal method. Remarkably, the introduction of deoxynivalenol (DON) enhanced the laccase activity, significantly deepening the substrate’s color. The absorbance displayed a strong correlation with DON concentrations ranging from 5 μM to 35 μM, following the linear equation Y = 0.03097x + 0.00883 with a correlation coefficient (R2) of 0.994, and the limit of detection (LOD) was found to be 0.59 μM. This developed colorimetric method was then applied to determination DON in wheat, wheat bran, and corn samples, exhibiting relative standard deviations (RSD) between 1.5 % and 2.8 %. The analytical results were consistent with those obtained using the standard high performance liquid chromatography (HPLC) method. Therefore, this rapid, sensitive, and cost-effective technique promises efficient determination of DON in feed samples.

Novel Label-Free GelRed-Aptamer Sensor for the Rapid Determination of Deoxynivalenol in Wheat Caused by Fusarium graminearum

Deoxynivalenol (DON) is the key virulence factor in Fusarium head blight. However, rapid and low-cost methods for DON are limited. Herein, a novel label-free GelRed-aptamer sensor was developed for the detection of DON. GelRed was embedded in double strain DNA (dsDNA) consisting of a single chain aptamer and its complementary DNA (cDNA), resulting in the increase of fluorescence intensity. However, DON preferentially combined with the aptamer and did not combine with its cDNA, which would result in the decrease in the formation of the GelRed/aptamer/cDNA complex, greatly reducing the fluorescence intensity. The samples were extracted from wheat, centrifuged, and filtered through a 0.22 μm membrane. Good linearity was obtained for DON from 3.13 to 313 mg L−1. The limit of quantitation (LOQ) for wheat samples was 6.07 mg L−1, providing a low cost method for DON compared with enzyme-linked immunosorbent assays. Experiments with spiked samples showed good recoveries from 92% to 105% with relative standard deviations less than 5.33% with analysis within 20 min. This method is simple and low cost with potential applications in agriculture and food.

Novel Endophytic Pseudescherichia sp. GSE25 Strain Significantly Controls Fusarium graminearum and Reduces Deoxynivalenol in Wheat.

Fusarium heading blight (FHB) is a devastating disease in wheat, primarily caused by field invasion of Fusarium graminearum. Due to the scarcity of resistant wheat varieties, the agricultural sector resorts to chemical fungicides to control FHB incidence. On the other hand, biocontrol represents a promising, eco-friendly approach aligned with sustainable and green agriculture concepts. In the present study, a bacterial endophyte, Pseudescherichia sp. (GSE25), was isolated from wheat seeds and identified through complete genome sequencing and phylogenetic analysis. In vitro testing of this endophytic strain demonstrated strong antifungal activity against F. graminearum PH-1 by inhibiting spore germination, suppressing germ tube growth, and causing cell membrane damage. Under field conditions, the strain GSE25 significantly reduced the FHB incidence and the associated deoxynivalenol mycotoxin accumulation by over 60% and 80%, respectively. These findings highlight the potential of the isolated bacterial endophyte Pseudescherichia sp. GSE25 strain as a biocontrol agent in protecting wheat from FHB-caused F. graminearum. This is the first report showing a biocontrol effect of Pseudescherichia sp. a strain against phytopathogens.

Interconnectable 3D-printed sample processing modules for portable mycotoxin screening of intact wheat

BackgroundThe increasing demand for food and feed products is stretching the capacity of the food value chain to its limits. A key step for ensuring food safety is checking for mycotoxin contamination of wheat. However, this analysis is typically performed by rather complex and expensive chromatographic methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS). These costly methods require extensive sample preparation that is not easily carried out at different points along the food supply chain. To overcome such challenges in sample processing, an inexpensive and portable sample preparation device was needed, that required low skill, for rapid sample-to-result mycotoxin screening. ResultsWe describe 3D-printed and interconnectable modules for simple, integrated and on-site sample preparation, including grinding of wheat kernels, and solvent-based extraction. We characterized these 3D-printed modules for mycotoxin screening and benchmarked them against a laboratory mill using commercial lateral flow device(s) (LFD) and in-house validated LC-MS/MS analysis. Different integrated sieve configurations were compared based on grinding efficiency, and we selected a sieve size of 2 mm allowing grinding of 10 g of wheat within 5 min. Moreover, 10 first time-users were able to operate the grinder module with minimal instructions. Screening for deoxynivalenol (DON) in naturally contaminated samples at the regulatory/legal limit (1.25 mg kg−1) was demonstrated using the developed 3D-printed prototype. The whole process only takes 15 min, from sample preparation to screening result. The results showed a clear correlation (R2 = 0.96) between the LFD and LC-MS/MS. SignificanceOur findings demonstrate the potential of 3D-printed sample handling equipment as a valuable extension of existing analytical procedures, facilitating the on-site implementation of rapid methods for the determination of mycotoxins in grains. The presented prototype is inexpensive with material costs of 2.5€, relies on biodegradable 3D printing filament and can be produced with consumer-grade printers, making the prototype readily available. As a future perspective, the modular character of our developed tool kit will allow for adaptation to other hard food commodities beyond the determination of DON in wheat.

Development and application of lateral flow strip with three test lines for detection of deoxynivalenol in wheat.

Lateral flow strip was widely used and their qualitative and quantitative performance was in continuous improvement. However, the traditional strip was in a single-test-line format, which restricted operators to making a semi-quantitative judgment around a desired threshold concentration. Herein, a single strip with three test lines (TTLS) was developed for the semi-quantitative and quantitative determination of deoxynivalenol (DON). Four visual detection thresholds were obtained under optimized conditions and 35 wheat samples with DON content from 45µg/kg to 2841µg/kg were used to verify the method. The detection results were compared with that of the traditional strip and UPLC-MS/MS. In a three-test-line format, TTLS could reveal at least 200, 500, 1000, and 2000µg/kg DON existed in different samples by the naked eye. The agreement analysis and statistical results indicated the new TTLS can be used as a useful tool for quantitative detection of DON with wide dynamic range.

Screening-Capture-Integrated Electrochemiluminescent Aptasensor Based on Mesoporous Silica Nanochannels for the Ultrasensitive Detection of Deoxynivalenol in Wheat.

To prevent the contamination of cereals by mycotoxins, establishing a sensitive and rapid method for the detection of mycotoxins is essential. In this study, a screening-capture-integrated electrochemiluminescence (ECL) aptasensor based on mesoporous silica films (MSFs) was successfully prepared for the ultrasensitive and highly selective detection of deoxynivalenol (DON) in wheat. The narrow nanochannels of MSFs can realize size screening, thereby eliminating the influence of macromolecular substances and providing a pure environment for the signal probe (tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)32+)) to reach the indium tin oxide (ITO) conductive substrate, which significantly improves the anti-interference ability of the screening-capture-integrated ECL sensor. The aptamer (Apt) attached to the surface of the MSFs can specifically capture DON, and the resulting DON-Apt complex has a gated effect on the MSFs, triggering the inhibition of Ru(bpy)32+ in the electrolyte from reaching the ITO surface. Therefore, the ECL intensity of the sensor decreased with increasing DON concentration to achieve a quantitative detection of DON. Under optimized conditions, the linear range of the screening-capture-integrated ECL aptasensor was 0.001-200 μg/kg, and the detection limit was as low as 5.27 × 10-5 μg/kg (S/N = 3). In conclusion, this study developed a screening-capture-integrated ECL aptasensor that combines size screening and specific capture for the detection of DON in wheat, providing a new approach for the early detection of wheat mildew.

Degradation of deoxynivalenol in wheat by double dielectric barrier discharge cold plasma: identification and pathway of degradation products.

Deoxynivalenol (DON) produced during the onset of fusarium head blight not only affects the quality and safety of wheat but also causes serious harm to human and livestock health. However, due to the high stability of DON, it is difficult to eliminate it or reduce it naturally after it has been produced. Cold plasma technology is a non-thermophysical processing technology that has been widely used for microbial inactivation and mycotoxin degradation. In this study, the degradation efficiency of double dielectric barrier discharge (DDBD) cold plasma on DON in aqueous solution and wheat was studied; the structures of degradation products of DON and its pathway were clarified, and the effect of DDBD plasma on wheat quality was evaluated. Double dielectric barrier discharge cold plasma was used for efficient degradation of DON (0.5 ~ 5μgmL^-1) solution and achieved a degradation rate of 98.94% within 25 min under the optimal conditions (voltage 100 V, frequency 200 Hz, duty cycle 80%). Furthermore, 10 degradation products (C15 H24 O5 , C15 H22 O6 , C15 H22 O9 , C16 H22 O7 , C15 H20 O7 , C15 H20 O9 , C15 H18 O8 , C15 H22 O5 , C16 H24 O5 , and C15 H18 O9 ) were identified by ultra-performance liquid chromatography-time of flight-mass spectrometry (UPLC-TOF-MS/MS) combined with Metabolitepilot and Peakview software. The degradation pathway of DON was obtained based on the chemical structures and accurate mass of these products. The DON degradation rate of 61% in wheat was achieved after treatment for 15 min, which slightly affects the moisture content, proteins, and wheat starch. Applying DDBD to wheat could effectively reduce the level of DON contamination, which provides a theoretical basis for applying cold plasma to the degradation of DON in wheat. © 2022 Society of Chemical Industry.

Effects of tempering with plasma activated water on the degradation of deoxynivalenol and quality properties of wheat

Deoxynivalenol (DON) is prevalent in wheat and threatens the health of humans and animals. It has been certificated that plasma activated water (PAW) can effectively degrade DON in wheat. However, the application of PAW used in the production of wheat flours was not reported nowadays. Thus, PAW was used to replace pure water in the traditional tempering process to eliminate DON in wheat, and DON degradation effect of PAW was compared with H2O2 and O3. The DON degradation rate was 58.78 % by tempering for 24 h with PAW prepared at 50 kV for 10 min. The H2O2 and O3 were found to be critical contributors in PAW for DON degradation. Afterwards, effects of PAW on microorganism inactivation and wheat qualities were studied. After tempering with PAW, the bacterial and fungal counts, the number of surviving Fusarium graminearum in wheat were decreased significantly. Moreover, no negative effects were observed except a slight decrease in vitamin E content. Therefore, tempering with PAW can be a promising strategy to control DON pollutant in wheat.

Electronic Nose for the Rapid Detection of Deoxynivalenol in Wheat Using Classification and Regression Trees.

Mycotoxin represents a significant concern for the safety of food and feed products, and wheat represents one of the most susceptible crops. To manage this issue, fast, reliable, and low-cost test methods are needed for regulated mycotoxins. This study aimed to assess the potential use of the electronic nose for the early identification of wheat samples contaminated with deoxynivalenol (DON) above a fixed threshold. A total of 214 wheat samples were collected from commercial fields in northern Italy during the periods 2014–2015 and 2017–2018 and analyzed for DON contamination with a conventional method (GC-MS) and using a portable e-nose “AIR PEN 3” (Airsense Analytics GmbH, Schwerin, Germany), equipped with 10 metal oxide sensors for different categories of volatile substances. The Machine Learning approach “Classification and regression trees” (CART) was used to categorize samples according to four DON contamination thresholds (1750, 1250, 750, and 500 μg/kg). Overall, this process yielded an accuracy of >83% (correct prediction of DON levels in wheat samples). These findings suggest that the e-nose combined with CART can be an effective quick method to distinguish between compliant and DON-contaminated wheat lots. Further validation including more samples above the legal limits is desirable before concluding the validity of the method.

Exposure assessment of deoxynivalenol in wheat and its products among residents in different regions of China

To assess the exposure and health risks of deoxynivalenol(DON) ingested by wheat and its products by residents in China&apos;s northern and southern regions. We collected DON content data in wheat and its products from various provinces and cities in China by searching the literature. The food consumption data came from the food consumption survey of Chinese residents in 2015. The point assessment method and the probability assessment method were used to evaluate the exposure of residents of various age groups in the southern and northern regions through wheat and its products. Then the acute reference dose(ARfD) 8 μg/(kg·BW) and provisional maximum tolerated daily intake(PMTDI) 1 μg/(kg·BW·d) of DON were used as a reference value to assess the acute and chronic health risks of DON exposure in each population. The mean content of DON in wheat and its products in the south was 578.51 μg/kg, and in the north was 214.98 μg/kg, both of which were lower than the limit value(1000 μg/kg). The result of point assessment showed that 99% of residents do not have acute poisoning risk when ingesting DON through wheat and its products. In the south, the DON exposure in all age groups was higher than PMTDI at the 90 th percentile consumption level of wheat and its products. In the north, the DON exposure in all age groups was higher than PMTDI at the 75 th percentile consumption level. The result of the probability assessment showed that in the south, the proportion of people with DON exposure exceeding PMTDI in the age groups ≤6 years old, 7-12 years old, 13-17 years old, and ≥18 years old was 13.57%, 10.75%, 9.68% and 9.48%, respectively. In the north, the proportion was 22.05%, 21.67%, 17.69% and 14.41%, respectively. The exposure of DON to wheat and its products and the proportion of people exceeding PMTDI in the northern area was significantly higher than that in the southern area(P&lt;0.001). The exposure to DON and the proportion of people exceeding PMTDI of the low-age group(≤6 years old) was higher than that of the high-age group(P&lt;0.001). Exposure to DON from wheat and its products among the high consumers in China was considerably high, with a certain chronic health risk, especially the low-age residents in northern areas, which should be paid attention to.

Degradation efficiency and products of deoxynivalenol treated by cold plasma and its application in wheat

Deoxynivalenol (DON) is one of the mycotoxins that occur frequently in wheat and considered a serious threaten to health. Cold plasma was used as an efficient approach for DON degradation in this study. The influences of working gas type, voltage and processing time of cold plasma system on DON degradation were investigated. It was found that 83.99% of DON solid standard could be degraded after 8 min treatment at 50 kV in air atmosphere. LC/TOF-MS was used to analyze the degradation products of DON after cold plasma treatment. It showed that the epoxy group, double bond and hydroxyl groups which responsible for the toxicity of DON might be destroyed by plasma, and total 4 molecular formulas and 7 possible degradation products were deduced. The cold plasma system was further applicated in the degradation of DON in wheat samples. Negligible effects on wheat quality were observed after degradation except for a slight decrease in whiteness of wheat powder. Therefore, cold plasma may be a promising strategy for DON contaminant in wheat. • Seven degradation products of DON were speculated. • The possible degradation pathway was inferred according to the product structures. • DBD cold plasma can be used to degrade DON in wheat. • Negligible effects on wheat quality were observed after DBD cold plasma treatment.

Determination of Deoxynivalenol in Wheat, Barley, Corn Meal, and Wheat-Based Products by Simultaneous Multisample Fluorescence Polarization Immunoassay Using a Portable Analyzer

Determination of Deoxynivalenol in Wheat, Barley, Corn Meal, and Wheat-Based Products by Simultaneous Multisample Fluorescence Polarization Immunoassay Using a Portable Analyzer

Global wheat trade and Codex Alimentarius guidelines for deoxynivalenol: A mycotoxin common in wheat

Deoxynivalenol (DON), a mycotoxin produced by Fusarium species that infect cereal grains, including wheat, is a significant food safety concern because of its adverse gastrointestinal effects and potential immunotoxicity. In 2015, the Codex Alimentarius Commission of the United Nations set guidelines for maximum allowable DON in wheat and other cereal grains. In this analysis, we employ social network models to analyze global wheat trade patterns in the years before and after the Codex DON guidelines were enacted in 2015: each year from 2012 to 2018 inclusive. Global wheat trading patterns in these seven years all presented hybrid structures: clusters of countries by continent, but a core-periphery structure within each continental cluster. This means that wheat trade, unlike maize and pistachio trade as determined from previous studies, appears to be driven by geographic proximity rather than similarity in food safety regulations. We found no evidence that global wheat trading patterns between nations changed as a result of the Codex DON guidelines, which stands in contrast to our earlier analyses of how aflatoxin regulations affected both maize and pistachio trade worldwide. This may be because insufficient time has passed, or because a single unified DON guideline does not have the same effect as multiple different national-level aflatoxin regulations in changing world food trade. If the central nations in such a global trade structure do not move upon a new policy, it is unlikely that the policy will affect the overall structure of global wheat trade. Without a core-periphery structure and engaged nations in the center of world wheat trade adopting these guidelines, it may take more years yet for these guidelines to be widely adopted, and for populations worldwide to benefit from lower DON exposure in their diets.

Fast Deoxynivalenol Determination in Cereals Using a White Light Reflectance Spectroscopy Immunosensor.

Deoxynivalenol (DON) is a mycotoxin produced by certain Fusarium species and found in a high percentage of wheat and maize grains cultured worldwide. Although not so toxic as other mycotoxins, it exhibits both chronic and acute toxicity, and therefore methods for its fast and accurate on-site determination are highly desirable. In the current work, we employ an optical immunosensor based on White Light Reflectance Spectroscopy (WLRS) for the fast and sensitive immunochemical label-free determination of DON in wheat and maize samples. The assay is completed in 12 min and has a quantification limit of 2.5 ng/mL in buffer corresponding to 125 μg/kg in whole grain which is lower than the maximum allowable concentrations set by the regulatory authorities for grains intended for human consumption. Several extraction protocols have been compared, and the highest recovery (>90%) was achieved employing distilled water. In addition, identical calibration curves were received in buffer and wheat/maize extraction matrix providing the ability to analyze the grain samples using calibrators in buffer. Recoveries of DON from spiked wheat and maize grain samples ranged from 92.0(±4.0) to 105(±4.0)%. The analytical performance of the WLRS immunosensor, combined with the short analysis time and instrument portability, supports its potential for on-site determinations.

Prevalence of Mycoflora and Fusarium graminearum Chemotype DON in Wheat in Bechar Province of South-Western Algeria

Wheat and its derivatives are a main staple food for the Algerian populations. The objective of this study aims to analyze local and imported wheat grains for fungi particularly Fusarium graminearum chemotype DON and evaluate deoxynivalenol (DON) contaminated wheat collected from Bechar region, in south-western Algeria. A total of 64 of wheat samples were examined for fungal contamination and fungal load was determined by means of standard microbiological method. DON was detected using the ELISA technique. The results revealed that 98.44% of analyzed samples showed positive results regarding fungal contamination. More precisely, local wheat was dominated by Aspergillus and Penicillium and imported wheat was dominated by Fusarium, Penicillium and Aspergillus species. Results showed that 62.5% of F. graminearum strains produced DON. Contamination levels of wheat with DON ranging from &lt;0.04 ppm to &gt;5ppm for soft wheat and from &lt;0.12ppm to &gt;15ppm for durum wheat. So, 62.96% of soft wheat grains and 55.56% of durum wheat imported from France, and also 18.18% of local durum wheat exceed the permissible limit by far. This study provides basic grounds in assessing the degree of fungal and potential DON contamination in Algerian wheat.

Assessment of Deoxynivalenol in Wheat, Corn and Its Products and Estimation of Dietary Intake.

The main goal of the present research was to explore the seasonal variation of deoxynivalenol (DON) in wheat, corn, and their products, collected during 2018–2019. Samples of 449 of wheat and products and 270 samples of corn and their products were examined using reverse-phase liquid chromatography with a UV detector. The findings of the present work showed that 104 (44.8%) samples of wheat and products from the summer season, and 91 (41.9%) samples from winter season were contaminated with DON (concentration limit of detections (LOD) to 2145 µg/kg and LOD to 2050 µg/kg), from summer and winter seasons, respectively. In corn and products, 87 (61.2%) samples from summer and 57 (44.5%) samples from winter season were polluted with DON with levels ranging from LOD to 2967 µg/kg and LOD to 2490 µg/kg, from the summer and winter season, respectively. The highest dietary intake of DON was determined in wheat flour 8.84 µg/kg body weight/day from the summer season, and 7.21 µg/kg body weight/day from the winter season. The findings of the work argued the need to implement stringent guidelines and create awareness among farmers, stakeholders, and traders of the harmful effect of DON. It is mostly observed that cereal crops are transported and stockpiled in jute bags, which may absorb moisture from the environment and produce favorable conditions for fungal growth. Therefore, these crops must store in polyethylene bags during transportation and storage, and moisture should be controlled. It is highly desirable to use those varieties that are more resistant to fungi attack. Humidity and moisture levels need to be controlled during storage and transportation.

Fusarium head blight in Argentina: Pathogen aggressiveness, triazole tolerance and biocontrol-cultivar combined strategy to reduce disease and deoxynivalenol in wheat

Fusarium head blight (FHB) management includes genetic and biological techniques, together with good agronomic practices. The combined use of chemical and biocontrol strategies along with moderately resistant wheat cultivars is a promising approach to manage the disease. The application of fungicide has shown a reduction in disease severity and mycotoxins accumulation in grains, during natural or artificial infections. Previously, we have demonstrated that Bacillus velezensis RC218 was able to diminish FHB severity and deoxynivalenol (DON) accumulation on harvested grains in bread and durum wheat under field conditions in two locations. The aims of the present study were to evaluate both triazole-based fungicides tolerance of Fusarium graminearum ss populations isolated from wheat in Argentina and the aggressiveness of F. graminearum ss strains with different trichothecene profiles on wheat cultivars, and to determine the efficiency of a biocontrol agent on disease severity, DON accumulation on moderately resistant wheat cultivars tested under greenhouse conditions. The strains evaluated against tebuconazole, prothioconazole and the mixture of both showed an intermediate susceptibility growing under in vitro assays, and few of them showed high tolerance to the evaluated fungicides. Regarding strains aggressivity, 8 Fusarium graminearum ss and 1 Fusarium meridionale strains were able to produce disease severity from 10 to 35% and deoxynivalenol from 0.2 to 10 ppm during field trials. The interaction of a biocontrol agent and moderately resistant wheat cultivars, tested under greenhouse trials, showed a better performance of moderately resistant wheat cultivar MS INTA 415 when Bacillus velezensis RC218 was applied. Significant reduction on disease severity (43%) and deoxynivalenol accumulation (60%) were also observed when the biocontrol agent was applied to moderately susceptible wheat cultivar K. Liebre. Taking into account the climate change, further research will be needed to study combined strategies with fungicides, biocontrol and less susceptible wheat cultivars to manage FHB severity and mycotoxin accumulation.

Photocatalysis and degradation products identification of deoxynivalenol in wheat using upconversion nanoparticles@TiO2 composite

Deoxynivalenol (DON) is one of the most common contaminants of cereal grains. Efficient and environmental-friendly technology to eliminate DON is important for food safety and environmental protection. In this work, upconversion nanoparticles (UCNP) coated with titanium dioxide (TiO2) photocatalysts were synthesized. Then, a photocatalytic experiment was performed to test the impact of NaYF4:Yb,Tm@TiO2 of DON degradation. Our results showed the DON degradation rate at 10 μg/mL under simulated sunlight using NaYF4:Yb,Tm@TiO2 (6 mg/mL) approached 100% within 60 min at pH 8.0. UPLC-Q-TOF MS was used to monitor the degradation process and three degradation products were identified, namely C15H20O8, C15H20O7 and C15H20O5. Subsequently, we studied the photocatalytic degradation of DON in wheat, providing a theoretical basis for photocatalytic degradation of contaminated grain samples. This study demonstrated that UCNP@TiO2 photocatalysis has the potential for detoxification in food security applications.