Aflatoxin B1 in maize harvested over 3 years in Iran

The potential risk of exposure to Aflatoxin B1 (AFB1) is well known. AFB1 contaminations investigated in 373 samples collected during 2006-2008 at harvest stage, from different agro climatic regions of the major maize production area of Iran, including Ardabil (North West), Khuzestan (South West) and Fars at the South of Iran. AFB1 was determined by CD-ELISA and was detected in 146 samples (43.6%), in which only 22.5% were contaminated to higher than MRL level. The amount of aflatoxin in maize samples varied across the years, the percentage of contamination in 2006, 2007 and 2008 were 86.7%, 71.4% and 100% respectively for Ardabil, 63.4%, 41.3% and 24.5% for Khuzestan, 17%, 14.8% and 27.6% for Fars province. The mean of contamination was 15.63, 57.67 and 154.13 μg/kg for Ardabil; 14.41, 35.93 and 1.61 μg/kg for Khuzestan; 0.9, 2.12 and 36.39 μg/kg for Fars province. This is the first report of AFB1 maize contamination to AFB1 in the major maize producing areas of Iran.     

An initial characterization of aflatoxin B1 contamination of maize sold in the principal retail markets of Kigali,Rwanda

Food security considerations have shifted in recent years, with the recognition that available food should also be nutritious and safe. There is a growing evidence base for contamination of maize and other crops by fungal toxins in the tropics and sub-tropics. As an initial snapshot of contamination by one of these toxins in Rwanda, Aflatoxin B1 (AFB1) was analyzed in 684 samples of maize flour collected in seven principal retail markets of Kigali and in 21 samples of animal feed from seven feed vendors. Two rounds of sample collections were carried out, the first in September 2014 and the second in January 2015. A questionnaire given to vendors was used to determine if gender and education level of vendors, origin of maize and awareness of aflatoxins had any significant effect on AFB1 level in collected samples. Enzyme-Linked Immunosorbent Assay (ELISA) and Immuno-affinity fluorimetery were used to analyze samples. Only markets had a significant effect on AFB1 level; for the two collections, differences were inconsistent among markets. In the first round, market means of AFB1 varied between 8.0 ± 5.57 μg/kg and 24.7 ± 23.74 μg/kg and for the second round, between 10.4 ± 8.4 μg/kg and 25.7 ± 25.85 μg/kg. In most animal feed samples AFB1 was >100 μg/kg. None of the vendors interviewed was aware of the risk of mycotoxin contamination in their maize-based flours and feed. Limits set by the United States Food and Drug Administration (20 μg/kg) for total aflatoxins and European Commission (2 μg/kg) for AFB1 for maize flour imports, were varied between 2–35% and 66–100% of samples, respectively. The implications of this study for human and animal health in Rwanda suggest that expanded surveys are needed to understand the scope of contamination, given the influence of environment and other factors on aflatoxin accumulation. Available options to mitigate and monitor aflatoxin contamination can be further deployed to reduce contamination.     

Aflatoxin B1 occurrence in maize sampled from Croatian farms and feed factories during 2013

The aim of the study was to determine the level of aflatoxin B₁ (AFB₁) in maize sampled from farms and feed factories situated in Northern, Central and Eastern Croatia during 2013, following the occurrence of cow milk AFM₁ contamination. Maize samples (n = 633) were analysed using Enzyme-Linked Immunosorbent Assay (ELISA) as a screening method and High Performance Liquid Chromatography Tandem Mass Spectrometry (LC–MS/MS) as a confirmatory method. Mean AFB₁ value found in maize coming from all investigated regions equalled to 81 μg/kg, with the maximal value of 2072 μg/kg found in maize obtained from Eastern Croatia. The observed contamination might have arisen on the grounds of extremely hot (>98%) and dry (<2%) weather witnessed from May to September 2012 during the maize growth and harvesting period, which might have favoured AFB₁ production and consequently the contamination of dairy cattle feeds. In order to prevent the adverse effects of AFB₁ on humans and animals, and also to reduce losses in agricultural production, systematic monitoring and further investigations of AFB₁ contamination are necessary.     

Development of novel monoclonal antibodies-based ultrasensitive enzyme-linked immunosorbent assay and rapid immunochromatographic strip for aflatoxin B1 detection

Monoclonal antibodies (mAbs) that are specific to aflatoxin B1 (AFB1) were produced from hybridoma cell lines 3F6G11 and 9C7C11 by the fusion of P3/NS1/1-AG4-1 myeloma cells with spleen cells that were isolated from a BALB/c mouse that was immunized with AFB1-bovine serum albumin (BSA). Both 3F6G11 and 9C7C11 mAbs are the immunoglobulin G1 isotypes. Competitive direct enzyme-linked immunosorbent assays (cdELISA) were established to characterize these antibodies. In the 3F6G11 mAb based cdELISA, the concentrations causing 50% inhibition of binding of AFB1-horseradish peroxidase to the antibody by AFB1, AFB2, AFG1, and AFG2 were found to be 0.051, 0.050, 1.820, and 1.270 ng/ml, respectively. Using 9C7C11 mAbs, similar IC₅₀ values for AFB1, AFB2, AFG1 and AFG2 were obtained as 0.045, 0.057, 2.530 and 2.120 ng/ml, respectively. A rapid and sensitive gold nanoparticle immunochromatographic strip (immunostrip) was also established for these antibodies. This strip has a detection limit of 1.0 ng/ml for AFB1 and the whole assay can be completed within 10 min. Extensive analysis of 20 samples by 3F6G11 mAb and 9C7C11 mAbs cdELISAs revealed that six samples were slightly contaminated by AFB1 at concentrations from 0.160 to 16.10 ng/g. Results of analyses of 20 samples with an immunostrip assay correlate well with those obtained using cdELISA. The proposed cdELISA and immunostrip methods are highly sensitive for the rapid screening of AFB1 in food samples.     

Assessment of aflatoxin M1 levels in pasteurized and UHT milk consumed in Prishtina,Kosovo

To assess public health hazards associated with the occurrence of AFM1 residues in pasteurized milk and UHT milk a survey was carried out, in Prishtina, capital city of Kosovo. In the present study, a total of 178 samples, 84 pasteurized milk and 94 UHT milk were collected during 6 months (July to December 2013). They were obtained from retail outlets in Prishtina city (Kosovo). The occurrence and concentration range of AFM1 in the samples were investigated by competitive enzyme-linked immunosorbent assay (ELISA) method. There was a high incidence of AFM1 (81.0%) in both pasteurized and UHT milk samples. Eighty three percent (83.3%) of the pasteurized milk samples and seventy eight percent (78.7%) of the UHT milk samples contained AFM1. The positive incidence of AFM1 in the pasteurized milk and the UHT milk samples ranged from 5.16 to 110 ng/L and from 5.02 to 62 ng/L, respectively. AFM1 levels in 18 (21.4%) pasteurized milk samples and 4 (4.2%) UHT milk samples exceeded the maximum tolerable limit of the EC according to the European Union regulation limits of 50 ng/L. AFM1 levels in the samples show that there is a presence of high AFM1 level that constitutes a human health risk in Kosovo. The results of this study imply that more emphasis should be given to the routine AFM1 inspection of milk and dairy products in the Prishtina region.     

A novel electrochemical piezoelectric label free immunosensor for aflatoxin B1 detection in groundnut

An electrochemical quartz crystal microbalance (EQCM) based label-free immunosensor has been developed for the quantitative detection of aflatoxin B1 (AFB1) in groundnut. The gold (Au) coated quartz crystal (6 MHz) functionalized with self-assembled monolayer (SAM) of 4-aminothiophenol (4-ATP) has been utilized to immobilize anti-aflatoxin antibodies (aAFB1). The quartz crystal microbalance QCM frequency and EQCM cyclic voltammetry measurements have been used to optimize the deposition of SAM layer on Au electrode (4-ATP/Au), antibody immobilization (aAFB1/4-ATP/Au), bovin serum albumin (BSA) adsorption (BSA/aAFB1/4-ATP/Au) and immuno interaction (AFB1/BSA/aAFB1/4-ATP/Au). Interestingly, the EQCM studies conducted on this immunoelectrode provide wider linear range of 0.1–4.0 ng mL⁻¹ and higher sensitivity than those obtained using under identical condition. The high association constant of 9.4 × 10⁻² ng mL⁻¹ of the EQCM immunosensor can be attributed to molecularly oriented self assembled monolayer of 4-ATP on QCM gold electrode that acts as a nanowire between aAFB1 and electrode through amide linkage formed by the NH₂ group of 4-ATP and COOH group of Fc part of aAFB1. This linkage also helps to project paratope part of aAFB1 to interact with AFB1. The developed label free EQCM based immunosensor was tested for the AFB1 detection in the extract of contaminated groundnut and the results were compared with Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The comparative results demonstrate the suitability of this sensor for routine screening of groundnut and the percent error is found to be ±12%.     

Incidence of aflatoxin M1 in human breast milk in Tehran, Iran

This study examined the exposure of infants to aflatoxin M1 (AFM1) and of lactating mothers to aflatoxin B1 (AFB1), using AFM1 in breast milk as a biomarker for exposure to AFB1. An enzyme-linked immunosorbent assay (ELISA) was modified for the analysis of AFM1 in breast milk samples from 160 women in Tehran, Iran. AFM1 was detected in 157 samples by average concentration of 8.2 ± 5.1 ng/kg (range 0.3–26.7 ng/kg).The concentration of AFM1 in one sample was higher than the maximum tolerance limit accepted by European Union and USA (25 ng/kg), but in 55 samples was higher than the maximum concentration recommended by Australia and Switzerland (10 ng/kg).Logistic regression Analysis failed to show significant correlation between AFM1 and gestational age, education, postnatal age, gender, nationality, clinical condition, the number of family member, the number of children, type and amount of dairy consumption, vegetable, fruits, oil and meat. But it was significant relation to the cereal consumption, also to the height at birth.     

The occurrence and effect of unit operations for dairy products processing on the fate of aflatoxin M1: A review

Mold contamination has challenged the safety of feed production and processing because of its undeniable role in the spoilage and the possible consequent toxicity impact on human health and the economy. Aflatoxin M₁ (AFM₁) is a hepatocarcinogenic derivative of aflatoxin B₁ excreted into the milk after ingestion of feed contaminated by certain molds. Because of the important role of dairy products, especially milk in the human diet, there is a huge concern about the presence of AFM₁ in milk and dairy products. In this article, the occurrence of AFM₁ and the fate of AFM₁ during processing of milk and dairy products, such as yoghurt and cheeses, since 1996 until today, was reviewed. The evaluation of mechanisms by which AFM₁ is affected by each processing step is of major importance to provide useful and accurate information to develop risk assessment studies and risk management strategies.     

Diminution of aflatoxin B1 production caused by an active packaging containing cinnamon essential oil

The antifungal and antimycotoxigenic action of an active package containing cinnamon essential oil have been evaluated against the mold Aspergillus flavus on the aflatoxin B1 production. Two independent experiments were carried out, the first one with cinnamon on a paper diffusion disc placed in vapor phase and the second one with an active PP (Polypropylene) films containing the essential oil. The culture media, exposure time, closure of the Petri dish and cinnamon concentration were evaluated. The first experiment revealed an important reduction on mycotoxin, even when the mold grew, and the action remained for 15 days. The second experiment highlighted the importance of cinnamon concentration on the antimycotoxigenic action, achieving a strong reduction with the sub-inhibitory concentration (2% of cinnamon) and a complete reduction with fungicidal concentration (4% and 6% cinnamon). The UPLC system coupled to a fluorescence detector was optimized for analysis of aflatoxin B1.     

Storage stability of maize-groundnut composite flours and an assessment of aflatoxin B1 and ochratoxin A contamination in flours and porridges

Defatting of groundnut flour used for composite development can not only improve nutritional quality of its products but also the storage stability. Maize, groundnut and their composite (full fat and defatted) flours were prepared and stored at room temperature over a period of 3 months. Storage stability of these products was assessed based on changes in water activity, peroxide value (PV), free fatty acids (FFA), thiobarbituric acid (TBA), microbiological profiling and levels of mycotoxins that included aflatoxin B₁ (AFB₁) and ochratoxin A (OTA). Overall results revealed that the rate of change of PV, FFA and TBA significantly (p ≤ 0.05) increased with increasing storage time, which was highest for full fat flours than in the defatted flours. For example, PV of the FFG and DFG were respectively, 0.88 and 0.40 mEq/kg, meanwhile TBA was 4.53 and 2.71 mg malonaldehyde/kg. There was a much higher rate of increase in FFA (%) with increasing storage time in full fat and composite flours when compared to that of their defatted counterparts. Generally, microbiological data demonstrated an increase in total microbial counts during storage in these foods possibly resulting in mycotoxins, AFB₁ (range: 9.08–38.48 μg/kg) and OTA (range: 0.33–19.50 μg/kg) in all samples with groundnut and maize having the highest contamination levels. A 127.8% increase in OTA level was noted when maize flour inclusion level in the full fat composite increased from 55 to 85%, but only a 24.7% increase in OTA level was noted in defatted composites during storage. Reducing the inclusion level of groundnut flour, the main source of AFB₁ as found, resulted in a drastic reduction in AFB₁ level in full fat and defatted composite flours by 54.1 and 76.4%, respectively, during storage. The findings highlight that shelf life stability of composites can be maintained upon defatting during the fortification process. It can therefore, be inferred that monitoring quality and safety of the raw materials as well as that of the final products during storage is crucial.     

Seasonal prevalence level of aflatoxin M1 and its estimated daily intake in Pakistan

Aflatoxin M₁ level was measured in 520 milk samples during autumn, winter, spring and summer seasons of 2013–14 in five districts of Southern Punjab-Pakistan. Analyses were performed by using enzyme linked immuno sorbent assay (ELISA) method. Aflatoxin M₁ was found positive in 93% milk samples in the range of 0.001–0.26 μg/l while 53% samples were found to exceed the European Union maximum Limit for aflatoxins M₁ i.e. 0.05 μg/l. The seasonal prevalence level of AFM₁ was found in the order of winter > spring > autumn > summer. Comparing the aflatoxin M₁ level during different day times, morning milk was found 37–50% more contaminated than evening milk. The estimated daily intake (EDI) of aflatoxins M₁ during different seasons of year for various age groups was found in the range of 0.22–5.45 ng/kg/day. Infants were found in the highest risk group while adults were in the lowest. The results of the study indicate that people of Pakistan are at high risk of health issues related with aflatoxins M₁.     

Novel monoclonal antibody-based sensitive enzyme-linked immunosorbent assay and rapid immunochromatographic strip for detecting aflatoxin M1 in milk

Monoclonal antibody (mAb) that is specific to AFM1 was generated from the hybridoma cell line, 10F3C10, which was obtained by the fusion of mouse NS1 myeloma cells with the spleen cells of mouse that had been immunized with AFM1-bovine serum albumin (BSA). The 10F3C10 mAb is belong to the immunoglobulin G1 isotype. Both competitive direct and indirect enzyme-linked immunosorbent assay (ELISA) was utilized to characterize the mAb for AFM1. The concentrations of AFM1, AFB1 and AFG1 that caused 50% inhibition (IC₅₀) of the binding of AFM1-horseradish peroxidase (AFM1-HRP) to the antibody were found to be 0.022, 0.310 and 2.12 ng/mL, respectively. The immunochromatographic strip (immunostrip) assay with mAb-gold nanoparticle conjugates as a detection marker exhibited a visual limit of detection of 0.1 ng/mL for AFM1 and the analysis took a total of 10 min. Closely examining 17 milk-based samples using cdELISA revealed that four were slightly contaminated with AFM1 at concentrations from 0.002 to 0.054 ng/mL. All milk samples were negative in the immunostrip test because the levels of contaminant were below the detection limit of the strip. Notably, the presented cdELISA and immunostrip methods are highly sensitive methods for detecting AFM1 in milk.     

Occurrence of aflatoxin M1 in white cheese samples from Tehran, Iran

This study was undertaken to determine the occurrence of aflatoxin M₁ (AFM₁) in 50 white cheese samples from 2 dairy factories in summer 2008 and winter 2009. Enzyme-linked immunosorbent assay (ELISA) method was used for analysis of the samples. Aflatoxin M₁ was found in 60% of the cheese samples, ranging from 40.9 to 374 ng/kg. Toxin levels in 6% of the samples exceeded the Iranian national standard limit i.e. 200 ng/kg. Considering seasonal variability, mean concentration of AFM₁ in the samples collected in winter was significantly (P < 0.03) higher than those collected in summer. Therefore, high occurrence of AFM₁ in cheese samples could be a potential hazard for public health.     

Occurrence of aflatoxin M1 in Italian cheese: Results of a survey conducted in 2010 and correlation with manufacturing, production season, milking animals, and maturation of cheese

Aflatoxin M₁ (AFM₁), a carcinogenic metabolite secreted into milk by animals fed with crops contaminated by aflatoxin B₁, can be found in dairy products because of its relative stability to treatments used to produce foodstuffs, and also to long-term storage. Maximum admissible limits of AFM₁ in milk have been set up worldwides; specific regulations regarding dairy products have also been established in some countries. Nevertheless, little and rather discordant data on the occurrence of such a contaminant in cheese and other dairy products is available, and mainly in those countries which are important producers and consumers of cheese, such as, for example, Italy. Therefore, a one-year survey was conducted by measuring AFM₁ contamination in cheese purchased on the Italian market. More than a hundred samples representing the highest variability in terms of type of cheese, origin, cheese-making process, and maturation were collected and analysed through a previously described ELISA method coupled to a very rapid, simple and solvent-free extraction. More than 83% of samples showed detectable levels of AFM₁ (>25 ng kg⁻¹); most of them were found to be contaminated at a level between 50 and 150 ng kg⁻¹. The measured AFM₁ concentration was correlated to four factors which were presumed to influence the contamination level: manufacturing, production season, milking animal, and maturation. Statistical analyses demonstrated that milking animals and manufacturing affect AFM₁ concentrations, as cheeses obtained from cows’ milk and from artisanal production are more contaminated than cheeses produced with milk belonging to other animals and in industrial contexts. The others two factors showed statistically non-significant differences between groups.     

Two year survey on the occurrence and seasonal variation of aflatoxin M1 in milk and milk products in Serbia

The incidence of contamination of aflatoxin M1 (AFM1) in milk and milk products samples collected in Serbia was investigated by using the competitive enzyme linked immunosorbent assay (ELISA) technique. A total of 1438 samples composed of 678 raw milk, 438 heat treated milk and 322 milk product samples that were analyzed during the period of 2013–2014, including all seasons. The AFM1 levels exceeded the European Union maximum residue permitted amount (EU MRL) in 56.3% raw milk, 32.6% heat treated milk and 37.8% of milk product samples. Milk powders had the highest mean AFM1 concentration (0.847 μg/kg) of all types of milk products examined. Mean concentration of AFM1 in raw milk samples during the period of winter in Serbia was 0.358 μg/kg and did not significantly differ from the mean concentrations of 0.375 μg/kg during the spring. However, the AFM1 raw milk concentration in the summer (0.039 μg/kg) and autumn season (0.103 μg/kg) was significantly lower. Seasonal variation of AFM1 concentrations in heat treated milk samples followed the trend observed in raw milk. Mean raw milk AFM1 concentration has dropped down by 10 fold from 0.314 μg/kg in 2013 to 0.035 μg/kg in 2014. The fraction of raw milk samples exceeding the EU MRL has decreased from 62.3% to 11.5% by the end of 2014.     

A practical test system for sensitive, rapid screening and authentication of peanut allergens in imported and exported food products in Chinese Customs

Proper food allergen labeling protects consumers with serious food allergies, such as peanut (Arachis hypogaea) allergies. Currently, there is no widely accepted standard peanut allergen detection protocol for use by Customs agencies, which could avoid trade disputes caused by improper labeling. Herein we developed a peanut allergen screening and confirmation system for sensitive, rapid identification of peanut allergen ingredients which used gold immunochromatography assay strips followed by confirmatory western blotting. Gold immunochromatography assay strips were prepared with polyclonal antibodies against total peanut proteins for preliminary peanut allergen screening in foods labeled peanut-free. Western blotting with Ara h1-specific monoclonal antibodies was performed to confirm the results to exclude false positive results. Of 285 food samples tested, 164 were labeled as containing peanut allergens. The gold immunochromatography assay determined that 116 were negative, in accordance with their original labels. Five samples were positive, which was not consistent with their labels. These 5 positive samples were subjected to western blotting confirmatory tests. Only one was confirmed to be positive. We reported this result to the manufacturer and suggested they change the product label. This system, which includes sequential classification, screening, confirmation and reporting steps, was useful for monitoring peanut contamination in imported and exported foods by Chinese Customs.     

Inhibition of aflatoxin B1, B2, G1 and G2 production by Aspergillus parasiticus in nuts using yellow and oriental mustard flours

Aflatoxins (AFs) are naturally occurring mycotoxin compounds produced by several species of Aspergillus, as Aspergillus flavus and Aspergillus parasiticus and are mutagenic, teratogenic, and carcinogenic compounds that have been implicated as causative agents in human hepatic and extra hepatic carcinogenesis. In this study, the reduction of the AFs present in dried fruits (peanut, cashew, walnut, almond, hazelnut and pistachio), produced by A. parasiticus CECT 2681, by isothiocyanates (ITCs) generated by the enzymatic hydrolysis of the glucosinolates (GLCs) present in oriental and yellow mustard flours was evaluated. The AFs reduction activity through ITCs application in dried fruits was carried out using a model and food system experiments. The quantification of the AFs in the food products analyzed was carried out employing the technique of the liquid chromatography (LC) coupled to the mass spectrometry detection in tandem (MS/MS). The ITCs produced through GLCs hydrolysis reduced the A. parasiticus growth in the food products tested and in particular in the model system experiments the AFs B₁, B₂, G₁ and G₂ reduction ranged meanly from 83.1 to 87.2% using the oriental mustard flour, whereas employing the yellow flour the mean reduction observed ranged from 27.0 to 32.5%. In the food system experiments carried out employing only the oriental mustard flour the mean AFs reduction observed ranged from 88 to 89%.     

Effectiveness of pulsed light treatment for degradation and detoxification of aflatoxin B1 and B2 in rough rice and rice bran

Aflatoxins primarily accumulate in the hull and bran layers of rough rice making these by-products of rice milling unsuitable for animal feed or human consumption. Contaminated rough rice is also a potential source of aflatoxin exposure to workers handling the grain during post-harvest storage and processing. Currently, no technologies are available to remove or detoxify these toxic and mutagenic fungal metabolites from contaminated rough rice. Pulsed light (PL) is a novel technology with the potential to degrade and detoxify aflatoxins in foods and their processing by-products. Rough rice was inoculated with Aspergillus flavus to produce aflatoxin B₁ (AFB₁) and B₂ (AFB₂) contamination, followed by PL treatments of 0.52 J/cm²/pulse for various durations. A PL treatment time of 80 s reduced AFB₁ and AFB₂ in rough rice by 75.0% and 39.2%, respectively; while a treatment time of 15 s reduced AFB₁ and AFB₂ in rice bran by 90.3% and 86.7%, respectively. Since PL treatments result in the degradation of aflatoxins in situ, the toxicity and mutagenic activity of the residual by-products of AFB₁ and AFB₂ after PL treatment were evaluated. Toxicity was estimated using the brine shrimp (Artemia salina) lethality assay and mutagenicity measured by the fluctuation test with Salmonella typhimurum tester strains TA98 and TA100. The mutagenic activity of AFB₁ and AFB₂ was completely eliminated by PL treatment, while the toxicity of these two aflatoxins was significantly decreased. The obtained results suggest that PL technology has a promising potential to degrade, detoxify, and inactivate the mutagenic activity of aflatoxins in rough rice and rice bran.     

An immunomagnetic-bead-based enzyme-linked immunosorbent assay for sensitive quantification of fumonisin B1

A sensitive enzyme-linked immunosorbent assay (ELISA) based on immunomagnetic beads (IMB-ELISA) was established using a magnetic-bead signal-enrichment system. The immunomagnetic beads were coated with polyclonal antibody directed against keyhole limpet hemocyanin (KLH), which were then coupled with a KLH–fumonisin B1 (FB1) conjugate. Anti-FB1 monoclonal antibody and sample extract were mixed and added to the immunomagnetic-bead solution. After the addition of horseradish peroxidase (HRP)-labeled goat anti-mouse antibody and the substrate solution, stop solution was added and the optical density of the reaction mixture was determined. To improve the performance of this method, the dilution of the immunomagnetic beads, the concentrations of the monoclonal antibody and HRP-labeled goat anti-mouse antibody, and the incubation time for the competition reaction were optimized. Based on the optimum conditions, the regression equation for this IMB-ELISA in quantifying FB1 was y = −0.3538x + 0.703 (R² = 0.9988). The detection limit and IC₅₀ were 0.24 ng/mL and 3.17 ng/mL, respectively. The working range was 0.54–26.3 ng/mL. The recovery rates were 80.4–114.7%, when the spiked concentrations ranged from 19.5 to 156.3 μg/kg. This IMB-ELISA is accurate and more sensitive and less time-consuming than the conventional ELISA.     

Review on the natural co-occurrence of AFB1 and FB1 in maize and the combined toxicity of AFB1 and FB1

Mycotoxins rarely occur individually in foodstuffs and are considered a food safety risk, particularly for highly consumed foods like maize. Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are two of the toxicologically most relevant mycotoxins occurring in maize. Their co-occurrence in field and stored maize is described in this review, and the highest co-occurrence rate is observed in stored maize. In all reviewed studies, fumonisin B1 levels exceed aflatoxin B1 levels and in some cases even by up to a thousand fold. Co-occurrence and subsequently combined exposure of AFB1 and FB1 is of public health concern given that both in-vivo and in-vitro scientific evidence exists that various toxicological effects caused by combined exposure occur. In the majority of the studies reviewed in this paper the data suggest a modulation of the toxic effects of aflatoxin B1 and fumonisin B1 ranging from increased carcinogenicity, immunotoxicity and decreased growth in various animal species and cell lines. The emerging scientific data indicating the modulatory effects of combined exposure to aflatoxin B1 and fumonisin B1 is a sound basis for further investigation of the effects of combined exposure and the subsequent human health risk.