Aflatoxin B1 Concentration Research Articles

High Precisive Prediction of Aflatoxin B1 in Pressing Peanut Oil Using Raman Spectra Combined with Multivariate Data Analysis.

This study proposes a label-free rapid detection method for aflatoxin B1 (AFB1) in pressing peanut oil based on Raman spectroscopy technology combined with appropriate chemometric methods. A DXR laser Raman spectrometer was used to acquire the Raman spectra of the pressed peanut oil samples, and the obtained spectra were preprocessed by wavelet transform (WT) combined with adaptive iteratively reweighted penalized least squares (airPLS). The competitive adaptive reweighted sampling (CARS) method was used to optimize the characteristic bands of the Raman spectra pretreated by the WT + airPLS, and a partial least squares (PLS) detection model for the AFB1 content was established based on the features optimized. The results obtained showed that the root mean square error of prediction (RMSEP) and determination coefficient of prediction () of the optimal CARS-PLS model in the prediction set were 22.6 µg/kg and 0.99, respectively. The results demonstrate that the Raman spectroscopy combined with appropriate chemometrics can be used to quickly detect the safety of edible oil with high precision. The overall results can provide a technical basis and method reference for the design and development of the portable Raman spectroscopy system for the quality and safety detection of edible oil storage, and also provide a green tool for fast on-site analysis for regulatory authorities of edible oil and production enterprises of edible oil.

Evaluation of Growth Performance, Nitrogen Balance and Blood Metabolites of Mutton Sheep Fed an Ammonia-Treated Aflatoxin B1-Contaminated Diet.

Experiments were conducted to evaluate the effects of an aflatoxin B1 (AFB1)-contaminated diet treated with ammonia on the diet detoxification and growth performance, nutrient digestibility, nitrogen utilization, and blood metabolites in sheep. Twenty-four female mutton sheep with an initial body weight of 50 ± 2.5 kg were randomly assigned to one of three groups: (1) control diet (C); (2) aflatoxin diet (T; control diet supplemented with 75 μg of AFB1/kg of dry matter); and (3) ammoniated diet (AT; ammoniated aflatoxin diet). The results showed decreases (p < 0.05) in average daily feed intake, nutrient digestibility of dry matter, crude protein and ether extract, and retained nitrogen, and an increase (p < 0.05) in urine nitrogen excretion in sheep fed diet T compared with those fed the other diets. In comparison to C and AT, feeding T decreased (p < 0.05) the concentrations of total protein, immunoglobulin A, immunoglobulin G, immunoglobulin M, superoxide dismutase, and total antioxidants and increased (p < 0.05) the concentrations of alanine amino transferase, malondialdehyde, and interleukin-6. In summary, ammonia treatment has the potential to decrease the concentration of AFB1 and alleviate the adverse effects of AFB1.

Functional Characterization and Whole-Genome Analysis of an Aflatoxin-Degrading Rhodococcus pyridinivorans Strain.

Simple SummaryThe microbiological degradation of AFB1 has been a promising approach to control AFB1 contamination. Here, we characterize a Rhodococcus pyridinivorans strain that can efficiently degrade AFB1. The AFB1-degrading capacity of this bacterial strain was characterized, and the completed genome was sequenced and analyzed. Further proteomic analyses of this strain identified a total of 723 proteins in an extracellular component that showed the strongest capacity to degrade AFB1 (degradation rate 83.7%). Multiple potential AFB1-degrading enzymes, and enzymes that are reported to respond to AFB1 treatment, have been identified accordingly. These findings provide a genomic, proteomic, and experimental approach for characterizing an efficient AFB1-degrading bacterial strain with great potential for use in the remediation of AFB1 contamination.Aflatoxin B1 (AFB1) is one of the most toxic, naturally occurring carcinogen compounds and is produced by specific strains of fungi. Crop contamination with AFB1 can cause huge economic losses and serious health problems. Many studies have examined the microbiological degradation of AFB1, especially the use of efficient AFB1-degrading microorganisms, to control AFB1 contamination. Here, we reported the identification of a new Rhodococcus pyridinivorans strain (4-4) that can efficiently degrade AFB1 (degradation rate 84.9%). The extracellular component of this strain showed the strongest capacity to degrade AFB1 (degradation rate 83.7%). The effects of proteinase K, SDS, temperature, pH, incubation time, and AFB1 concentration on the AFB1 degradation ability of the extracellular component were investigated. We sequenced the complete genome of this strain, encoding 5246 protein-coding genes and 169 RNA genes on a circular chromosome and two plasmids. Comparative genomic analysis revealed high homology with other Rhodococcus strains with high AFB1-degradation ability. Further proteomic analyses of this strain identified a total of 723 proteins in the extracellular component, including multiple potential AFB1-degrading enzymes, along with enzymes that are reported to response to AFB1 treatment. Overall, the results demonstrate that R. pyridinivorans 4-4 would be an excellent candidate for the biodegradation and detoxification of AFB1 contamination.

Proximate composition, microbiological quality and presence of total aflatoxins and aflatoxin B1 in the flesh of three snails’ species (Achatina achatina, Achatina fulica and Archachatina marginata) from a selected locality of Yaoundé, Cameroon

The increasing need for animal proteins has led to an interest in non-conventional protein sources such as snails. Although several species of snails are locally reared and highly prized by Cameroonians, there is a lack of information regarding their composition and safety. This work aimed at assessing the chemical composition, the microbiological quality and the total aflatoxins (AFs) and aflatoxin B1 (AFB1) contents of the fleshes from three snails’ species traditionally reared in the city of Yaoundé, Cameroon. Samples of Achatina achatina (10), Achatina fulica (10) and Archachatina marginata (10) were randomly collected from a selected farm in Mimboman quarter of Yaoundé and their chemical composition and microbiological quality were evaluated through AOAC and ISO methods, respectively. Their levels of AFs and AFB1 were assessed using competitive ELISA. The results showed that snail fleshes were a good source of proteins and iron with the one from A. achatina containing the highest protein (15.26%) and iron (7.80 mg/100g) contents. Microbiological analyses revealed that the total aerobic counts of the different samples of snail fleshes were all higher than 6 Log CFU/g thus suggesting a reduced shelf life of the raw product. The safety issue of the snail fleshes is questionable as they contained pathogens such as coliforms and Staphylococcus spp. at levels higher than the norms. Although yeasts and moulds were found in snail fleshes at loads ranging from 3.5 to 4.17 Log CFU/g, their AFs and AFB1 contents were respectively below 0.22 and 0.44 ppb, values that are lower than that of raw food intended for human consumption. This study demonstrated the potential of snails as an alternative protein source from animal origin and suggests that particular attention should be paid by the government to sensitize the farmers on good hygiene and farming practices and the consumers on good cooking practices.

Determination of aflatoxin B1 in rice flour based on an enzyme-catalyzed Prussian blue probe

Aflatoxin B1 (AFB1) is a toxin that is widely present in food and feed and poses a serious threat to the health of humans and livestock. In this work, we proposed the quantitative detection method of AFB1 contamination using a simple, sensitive, and specific colorimetric immunoassay based on gold nanoparticles labeled with glucose oxidase (GOx)/rabbit anti-mouse immunoglobulin G. In our strategy, Prussian blue was produced by a GOx catalyst-assisted Fe3+ and Fe(CN)63− system, which was designed and employed as a probe. Without GOx, the Fe3+ and Fe(CN)63− system containing glucose did not produce Prussian blue, while under the catalyzation of GOx, the H2O2 generated from glucose oxidation reduced Fe3+ to Fe2+, resulting in a visible color change from yellow to blue. With an increase in AFB1 concentration, the absorbance at 706 nm gradually decreased linearly from 0.5 ng/mL to 5 ng/mL, with a detection limit of 0.35 ng/mL. Thus, acceptable recovery(g/100 g) (87.6–106.0) were achieved in the spiked rice flour samples. As a result, this simple, sensitive, and specific colorimetric method may be used for AFB1 evaluation in the food industry, and our work paves the way for the evaluation of other analytes using the respective antibodies.

Effects of Dietary Aflatoxin B1 on Hybrid Striped Bass (Morone chrysops × M. saxatilis) and Assessment of Supplemental Arginine as a Potential Aflatoxicosis Alleviator

Aflatoxin contamination of feeds poses a significant threat to aquaculture. This six-week study was conducted to evaluate the impact of aflatoxin B1 (AFB1) in diets with and without supplemental arginine (Arg) on the production performance, somatic indices, body composition, and immune responses of hybrid striped bass (HSB). Six experimental diets were formulated to contain different levels of AFB1 (0, 1, or 2 mg/kg) and supplemental Arg (0 or 2%) following a 3 × 2 factorial arrangement. Triplicate groups of HSB (~5.44 g/fish) stocked in 18 glass aquaria were randomly assigned each diet and fed at a rate approaching apparent satiation twice daily. At the conclusion of the feeding trial, no interactions among dietary AFB1 and Arg were found. However, both medium (~1 mg/kg) and high (~2 mg/kg) levels of dietary AFB1 caused severe toxic effects on HSB directly affecting performance. Relative to control groups without AFB1 supplementation, steep reductions in weight gain (from 553% to 120% of initial weight), feed efficiency ratio (from 0.96 to 0.36), and protein retention (from 43% to 12%) were found in fish fed diets containing medium AFB1, and further reductions were observed in groups exposed to high AFB1. Dietary AFB1 also negatively affected condition factor and somatic indices and reduced whole-body protein and lipid contents relative to control groups. Significantly lower plasma hemolytic and lysozyme activities were found in fish exposed to dietary AFB1. Despite no significant protective effect of supplemental Arg being observed for most response parameters, reduced levels of Arg in plasma and muscle of AFB1-fed HSB indicated increased catabolism under nutritional stress. In conclusion, this study demonstrated that exposure to dietary AFB1 concentrations of ~1 and 2 mg/kg severely affected HSB and that supplemental Arg above requirement levels may be ineffective in alleviating aflatoxicosis.

Aflatoxin contamination in dairy feed during wet and dry seasons in selected rural areas of Sidama zone in Southern Ethiopia

This study was conducted in the southern region of Ethiopia. The objectives were to assess the occurrence and level of aflatoxin B1 contamination in dairy cow feeds. The analytical technique used was Enzyme-linked immunosorbent assay(ELISA). Two-way ANOVA was used to analyze +the season and location interaction effect. Laboratory analysis showed that 81.2% of the feed samples had a detectable level of AFB1 within the range of 0.067-29.69 µg/kg and with an average of 7.91±5.83 µg/kg. From the positive samples, 52.5 and 4.58% of the feed sample were above EU (5 µg/kg) and USA (20 µg/kg) limits for dairy cattle feed respectively. Average AFB1 concentration during the dry season (8.74± 5.6 µg/kg) is significantly higher (P&lt;0.05) than wet season (7.02± 5.86 µg/kg). This result implies that sustainable good practices should be maintained for all feed harvesting, storage, and feeding practices by feed producers and dairy farmers regarding aflatoxin contamination.

Aflatoxin B1 Metabolism of Reared Alphitobius diaperinus in Different Life-Stages.

Simple SummaryThe contamination of food and feed by aflatoxins causes major health and economic consequences, especially in sub-Saharan Africa. Aflatoxins can cause liver cancer and other health issues. Certain reared insect species that are being considered as an alternative protein source have been found to metabolically convert aflatoxins in their diet. The aim of this study was to investigate the metabolism of aflatoxin B1 by Lesser Mealworm to determine if this chemical is present in the substrate on which this species is reared. Possible differences in metabolic rate and/or metabolic compounds in three different life-stages of this species were investigated. We observed no negative effects on growth and survival, suggesting that the Lesser Mealworm is very resistant to aflatoxin B1. Analyses of the larvae and the excreta after the experiment showed that aflatoxin B1 and known aflatoxin derivatives (metabolites) were not present in the insects, and concentrations in the excreta were up to 40% of the spiked concentrations in the feed. It was not clear whether the other proportion that could not be quantified was completely detoxified or converted into unidentified (toxic) metabolites. If detoxification can be verified, then the Lesser Mealworm is a very suitable candidate for the rearing on aflatoxin-contaminated feed materials.The presence of carcinogenic aflatoxins in food and feed is a major issue. In prior studies, aflatoxin B1 (AfB1) and known primary metabolites were absent from Lesser Mealworm (LMW, Alphitobius diaperinus) reared on contaminated diets. LMW is a promising alternative protein source. The objectives of this stu\\dy were to determine whether LMW can be reared on AfB1-contaminated feed in each life-stage, and to gather more insight into potential metabolites formed. Results suggested no adverse effects in terms of survival/growth when three stages of LMW (larvae, pre-pupae, beetles) were exposed to feed containing AfB1 concentrations of 200 and 600 µg/kg for 48 h. Insect and frass samples were analyzed by LC-MS/MS and high-resolution MS to, respectively, quantify concentrations of AfB1 and its major metabolites, and determine secondary metabolites. No AfB1 or major metabolites were quantified in the insect samples. Mass balance calculations showed that up to 40% of spiked AfB1 could be recovered in the frass, in the form of AfB1, aflatoxicol and AfM1. HRMS results suggested the presence of additional metabolites in the frass, but, due to lack of commercially available reference standards for these compounds, exact identification and quantification was not possible. More research is needed to verify the absence of toxicity.

Human health risk assessment of aflatoxin M1 in raw and pasteurized milk from the Kermanshah province, Iran

The principal purpose of this study was to investigate the amount and human health risk assessment by Monte Carlo simulation for aflatoxin M1 (AFM1) in milk in Kermanshah province, Iran. For this purpose, a total of 108 composite samples were analyzed for AFM1 levels using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Based on AFM1 in milk, aflatoxin B1 (AFB1) in animal feed, exposure, and human health risk were evaluated. The results showed that the total mean of AFM1 in raw milk in summer and winter was 49 ± 2 and 14 ± 1 ng/L, respectively, while in pasteurized milk was 6 ± 1 and 10 ± 1 ng/L, respectively, and in general, the mean amount of AFM1 in both raw and pasteurized milk is significantly different between summer and winter. Based on the results, it was found that 16.7% of all samples had AFM1 higher than the European Union (EU) limit (50 ng/L). Accordingly, the AFM1 level of raw milk in summer had health risks for all age groups of men and women. In conclusion, in Kermanshah province, AFM1 concentrations in milk produced by livestock should be reduced, especially during the summer seasons; basic procedures should be implemented to reduce AFB1 concentrations in lactating animals' foods.

Detection of biological and aflatoxin B1 contaminants in broiler feed at the poultry shop Sumbersari District, Jember

Abstract Food from an animal is one source of animal protein that needs to be guaranteed food safety to avoid negative impacts on human health. Improper storage can trigger contamination from toxic bacteria and molds that can leave residues in the food commodities. Molds proliferate in environments that contain excessive moisture. environmental conditions in Indonesia which are tropical climate with high temperature, rainfall, and high humidity which is very suitable for growing toxigenic molds. This study aimed to detect bacterial contamination of salmonella, molds, and aflatoxin B1 content in broiler chicken feed in several poultry shops in the Sumbersari sub-district, Jember. Samples of crumble broiler feed were taken from 10 different poultry shops with different distributors. The parameters tested were the content of salmonella, fungi, and aflatoxin B1. The results were analyzed descriptively showed that all samples tested did not contain salmonella bacteria, the content of aflatoxin B1 was below the standards set by FAO and SNI although there were some samples containing several fungi between 0.7 x 103 to 4.2 x 103 μg/kg. The conclusion of this study was feed circulating in the Sumbersari sub-district, Jember does still safe for livestock consumption so that it does not hurt livestock and human health who consume food products produced by livestock.

A point-of-use lateral flow aptasensor for naked-eye detection of aflatoxin B1

Aflatoxin B1 (AFB1) contamination in food is not only a serious health threat to humans, but also a considerable economic burden worldwide. Rapid and accurate detection of AFB1 during production, processing, transportation and storage is therefore a prerequisite to prevent spreading of AFB1. Here, we developed a simple and easy-to-use lateral flow aptasensor (LFA) to visually detect AFB1 using AFB1 aptamer. Polystyrene dyed particles were used as a signal reporter to enable colorimetric readout by naked eyes, in which the signal is directly proportional to the concentration of AFB1. Both aptamer specificity and target induced strand release approach enable a single-step AFB1 detection. The whole assay took 35 min to complete, starting from sample/dye complex incubation to color acquisition. Under the optimized condition, this sensing platform could detect AFB1 as low as 4.56 ng mL−1 with two distinct linear ranges of 0–0.05 μg mL−1 and 0.05–1 μg mL−1. LFA validation with 4 spiked samples (peanut, corn, rice and chili powder) showed satisfying AFB1 recovery within the range of 90.83–110.21%. Our LFA platform could potentially be applied to the on-site, naked-eye, and instrument-free detection of AFB1 or other substances with available aptamers.

A surface-enhanced Raman scattering aptasensor for ratiometric detection of aflatoxin B1 based on graphene oxide-Au@Ag core-shell nanoparticles complex

Aflatoxin B1 (AFB1) has the strongest carcinogenesis and mutagenesis effects. Herein, a novel ratiometric surface-enhanced Raman scattering (SERS) aptasensor based on graphene oxide (GO) as a corrective internal standard (IS) and signal amplifier was constructed for reliable detection of AFB1. 4-Mercaptobenzoic acid as Raman reporter embedded in [email protected] core-shell nanoparticles and AFB1aptamer conjugated to the Ag shell acted as the signal probes ([email protected] NPs-AFB1apt). AFB1apt was attached to the surface of GO with Raman signals modified Au NPs/Indium tin oxide glass (GO/Au NPs/ITO) via π–π stacking interaction, facilitating further amplification of the signal. With an increase of AFB1 concentration (0.0001 ng/mL–100 ng/mL), the probes were released owing to the affinity of aptamers, causing the decreased 4-MBA intensity (I4-MBA) and unchanged GO intensity (IGO). Therefore, the quantitative test was achieved based on the ratiometric value (I4-MBA/IGO). A good negative correlation (R2 = 0.992) was achieved and the limit of detection (LOD) was as low as 0.1 pg/mL, proving the proposed sensor can become an efficient analytical tool and shows a bright application prospect in the food detection field.

Determination of aflatoxin B1 (AFB1) in maize based on a portable Raman spectroscopy system and multivariate analysis

Aflatoxin B1 (AFB1) is the most widely distributed, most toxic, and most harmful, and it is widely present in moldy grains. This study proposes a new method for quantitative and rapid determination of the AFB1 content in maize based on Raman spectroscopy. The Raman spectra of maize samples with different mildew degrees were collected by a portable laser Raman spectroscopy system. Three different spectral selection methods, which were bootstrapping soft shrinkage (BOSS), variable combination population analysis (VCPA) and competitive adaptive reweighted sampling (CARS), were applied to optimize the characteristic wavelength variables of the pretreated Raman spectra. The support vector machine (SVM) detection models based on different optimized characteristic wavelength variables were established, and the results of each detection model were compared. The results obtained showed that the performance of the SVM models established by optimized features was significantly better than the performance of the SVM model built by full-spectrum data. Among them, the SVM model based on the characteristic wavelength variables optimized by the CARS method had the best performance, and its root mean square error of prediction (RMSEP) was 3.5377 μg∙kg−1, the determination coefficient of prediction (RP2) was 0.9715, and the relative prediction deviation (RPD) was 5.8258. The overall results reveal that the rapid quantitative detection of the AFB1 in maize by Raman spectroscopy has a promising application prospect. In addition, the implementation of the characteristic wavelength optimization of Raman spectra in the model calibration process can effectively improve the detection accuracy of chemometric models.

Prevalence of Aflatoxins in Selected Dry Fruits, Impact of Storage Conditions on Contamination Levels and Associated Health Risks on Pakistani Consumers.

Dry fruits and nuts are nutritious foods with several health-promoting properties. However, they are prone to contamination with aflatoxins at all stages of production and storage. The present study aimed to determine the natural occurrence of aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), and total aflatoxins (AFT) in dates, pistachios, and walnuts collected from four districts of South Punjab (Pakistan), and to assess the associated health risks as estimated by dietary exposure and the Margin of Exposure (MoE) determinations. The contents of AFB1 and AFT in these food products were monitored during storage under three different conditions (open-air, hermetically closed jars, and refrigeration at 4 °C) to determine the most efficient conditions in preventing aflatoxin accumulation. HPLC-fluorescence analysis of 60 samples of these products for aflatoxin contamination showed that 52 (86.7%) samples were contaminated at different levels, with a maximum of 24.2 ng/g. The overall (all samples) mean concentrations of AFB1, AFB2, AFG1, AFG2, and AFT were 3.39 ± 2.96, 1.39 ± 1.68, 1.63 ± 1.48. 1.12 ± 1.23, and 7.54 ± 6.68, respectively. The Estimated Daily Intake (EDI) and MoE of aflatoxins through the consumption of the products ranged from 0.06 ng/kg bw/day to 2.0 ng/kg bw/day and from 84.84 to 2857.13, respectively, indicating that consumers are at high health risk. Significant differences were recorded between aflatoxin levels in the samples stored under different storage conditions, with storage under refrigeration (4 °C) being the most effective in controlling aflatoxin accumulation, although storage in closed jars was also efficient and offers a more flexible alternative to retailers. The findings of the study urge official authorities of Pakistan to implement appropriate regulatory and control measures and surveillance program to alleviate the potential public health risks associated with the consumption of dry fruits and nuts in the scope of their increased consumption.

Feature Wavelength Selection Based on the Combination of Image and Spectrum for Aflatoxin B1 Concentration Classification in Single Maize Kernels

Aflatoxin B1 (AFB1) is a very strong carcinogen, maize kernels are easily infected by this toxin during storage. Rapid and accurate identification of AFB1 is of great significance to ensure food safety. In this study, a novel method for classification of AFB1 in single maize kernels was developed. Four groups of maize kernel samples with different AFB1 concentrations (10, 20, 50, and 100 ppb) were prepared by artificial inoculation of toxin. In addition, one group of maize kernel samples without AFB1 were prepared as control, each group with 70 samples. The visible and short wave near-infrared (Vis-SWNIR) region (500–1000 nm) and long wave near-infrared (LWNIR) region (1000–2000 nm) hyperspectral images of all samples were obtained respectively, and the hyperspectral images in 500–2000 nm range was obtained after spectral pretreatment and fusion. Kennard-Stone algorithm was used to divide the samples into calibration set or prediction set. Competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to roughly select the characteristic wavelengths of the calibration set samples, and 25 and 26 effective wavelengths were obtained respectively. Based on the roughly selected wavelengths, a method of fine selection of the characteristic wavelengths was proposed by using the gray-value difference of image (GDI), and a few number of characteristic wavelengths were further selected. Under the LDA classification model, 10 characteristic wavelengths were selected to test the prediction set and the independent verification samples, and the ideal result were obtained with an accuracy of 94.46% and 91.11%, respectively. This study provides a new approach for AFB1 concentration classification of single maize kernels.

A HepG2 Cell-Based Biosensor That Uses Stainless Steel Electrodes for Hepatotoxin Detection.

Humans are frequently exposed to environmental hepatotoxins, which can lead to liver failure. Biosensors may be the best candidate for the detection of hepatotoxins because of their high sensitivity and specificity, convenience, time-saving, low cost, and extremely low detection limit. To investigate suitability of HepG2 cells for biosensor use, different methods of adhesion on stainless steel surfaces were investigated, with three groups of experiments performed in vitro. Cytotoxicity assays, which include the resazurin assay, the neutral red assay (NR), and the Coomassie Brilliant Blue (CBB) assay, were used to determine the viability of HepG2 cells exposed to various concentrations of aflatoxin B1 (AFB1) and isoniazid (INH) in parallel. The viability of the HepG2 cells on the stainless steel surface was quantitatively and qualitatively examined with different microscopy techniques. A simple cell-based electrochemical biosensor was developed by evaluating the viability of the HepG2 cells on the stainless steel surface when exposed to various concentrations of AFB1 and INH by using electrochemical impedance spectroscopy (EIS). The results showed that HepG2 cells can adhere to the metal surface and could be used as part of the biosensor to determine simple hepatotoxic samples.

Aflatoxin B1 variations in animal feeds along the supply chain in Tanzania and its possible reduction by heat treatment

ABSTRACT This study evaluated the presence of aflatoxin B1 in five different animal feeds collected from manufacturers, suppliers and consumers and its possible reduction by heating at 100°C for 180 min. A total of 160 animal feed samples were collected and analyzed by using lateral flow immunoassay method. The results revealed that all animal feeds analyzed were positive for aflatoxin B1 with 91% samples containing high concentrations ranging from 24.00 to 76.23 ng/g above the international allowable standard for animal feeds (20 ng/g). Maize bran (76 ng/g) and sunflower cake (63 ng/g) had higher aflatoxin B1 concentrations, correlating with higher moisture content. Upon heating the feeds, aflatoxin B1 was reduced to a concentration ranging from 2.24 to 9.78 ng/g (<20 ng/g). Our study suggests high potential health problems to animals and humans from aflatoxins requiring proper heating and frequent monitoring of the animal feeds for aflatoxin B1.

The effects of natamycin and hexanoic acid on the bacterial community, mycotoxins concentrations, fermentation profiles, and aerobic stability of high moisture whole-crop corn silage

The objective of the study was to evaluate the effects of natamycin, hexanoic acid, and Lactobacillus plantarum on fermentation characteristics, aerobic stability, mycotoxins concentrations, and bacterial community in high moisture whole-crop corn silage. Whole-crop corn was harvested at 1/2 milk lines stage and ensiled without additive (CON), with L. plantarum (LP, 1 ×106 cfu/g FW), natamycin (NAT, 0.2 mg/kg FW), or hexanoic acid (HEX, 0.4 mg/kg FW). The addition of NAT and LP enhanced (P < 0.05) lactic acid (LA) production as compared to CON and HEX silage. HEX depressed LA accumulation leading to higher (P < 0.05) pH and water-soluble carbohydrates (WSC). The HEX and NAT silages had lower (P < 0.05) yeast count and ethanol concentration than CON and LP silages. NAT and LP decreased the concentration of ammonia N as compared to CON silage with the lowest value in LP silage. After 60 d of ensiling, LP silage spoiled within 22 h, NAT silage was stable for 41 h, which was slightly (P > 0.05) longer than CON silage (34 h). The HEX silage showed the longest aerobic stability (>144 h) among all silages. Ensiling decreased zearalenone (ZEN) and deoxynivalenol (DON) concentrations (P < 0.05). The LP and NAT silages had significantly (P < 0.05) lower aflatoxin B1(AFB1), ZEN, and DON concentrations than fresh corn, CON, and HEX silages. All additives depressed the growth of Lactococcus, but increased the relative abundance (RA) of Lactobacillus compared to CON. LP reduced the RA of Leuconostocs, while HEX showed stronger antibacterial abilities to Klebsiella than LP and NAT. In conclusion, HEX improved the aerobic stability, whereas NAT and LP improved fermentation quality by enhancing the proliferation of Lactobacillus during ensiling of high moisture whole-crop corn.

Aflatoxin B1 impairs in vitro early developmental competence of ovine oocytes

Aflatoxin is considered as one of the most harmful mycotoxins in the world to be found in human food and animal feed. Previous reports have revealed that Aflatoxin B1 (AFB1) may disrupt gamete development through epigenetic modifications as well as promotion of oxidative stress, excessive autophagy, and apoptosis. Therefore, in this study we aimed to address the effects of AFB1 on the meiotic and cytoplasmic maturation, internal reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨm), blastocyst formation as well as mRNA alterations for the apoptotic (BAX and Caspase3), anti-apoptotic (BCL2), and DNA methyltransferase (DNMTs) genes in ovine oocytes. To accomplish this, maturation of oocytes was performed in presence of increasing AFB1 concentrations (0, 10, 50, and 100 μM). Meiotic and cytoplasmic maturation, intracellular ROS level, and ΔΨm were evaluated following 24 h of IVM. Embryonic cleavage and blastocyst formation following fertilization were also assessed. We also investigated alterations of BAX, BCL2,Caspase3, DNMT1, DNMT3a, and DMT3b mRNA levels in mature oocytes. In the presence of 50 and 100 μM AFB1, the number of oocytes reaching the metaphase II stage decreased and the oocytes presented with lower intracellular levels of GSH (P < 0.05). Furthermore, intracellular ROS production in matured oocytes reached the highest-level following exposure to 50 and 100 μM of AFB1 (P < 0.05). Reduction of ΔΨm was clearly evident in the AFB1-treated groups (P < 0.05). Rates of cleavage and blastocyst formation decreased in the presence of AFB1 as compared with those recorded in the Control group (P < 0.05). Apoptosis-related gene analysis in AFB1 treated groups (10 and 50 μM) revealed a higher abundance of the BAX and Caspase3 genes, and a lower abundance of the BCL2 gene as compared with the Control group (P < 0.05). Additionally, our data showed that relative abundances of DNMT3b gene decreased in the 10 μM group when compared to the Control group (P < 0.05). We showed that exposure of oocytes to AFB1 leads to a reduced nuclear and cytoplasmic maturation that may ultimately impair the embryonic development in the sheep oocyte. Furthermore, alterations in DNA methylation and initiation of apoptosis through excessive ROS generation could be a prime molecular mechanism responsible for the disruption of oocyte developmental competence in the presence of AFB1 in the ovine model.

Detection of aflatoxin B1 with a new label-free fluorescence aptasensor based on PVP-coated single-walled carbon nanohorns and SYBR Gold.

This paper describes a novel fluorescence label-free aptasensor to detect aflatoxin B1 (AFB1) by utilizing SYBR Gold, aptamer, and single-walled carbon nanohorns (SWCNHs). In the presence of AFB1, the conformation of AFB1-specific aptamer went through and the spatialstructure of this specific aptamer was transformed accordingly. Due to the resistance of the transformed aptamer when adsorbed on the surface of SWCNHs, the protection of the fluorescence of SYBR Gold was accomplished. Consequently, concentrations of AFB1 showed a strong association with fluorescence intensity. The detection limit (LOD) of AFB1 was 1.89ng/mL, while the linear range was 5-200ng/mL and fluorescence intensity satisfactorily correlated (R2 = 0.9919) with the logarithm of AFB1 concentration.