Occurrence of aflatoxin M1 in Korean dairy products determined by ELISA and HPLC

Simultaneous Dual-Sensing Platform Based on Aptamer-Functionalized DNA Hydrogels for Visual and Fluorescence Detection of Chloramphenicol and Aflatoxin M1

In this study, a chloramphenicol and aflatoxin M1 aptamer-functionalized DNA hydrogel was designed for the simultaneous detection of chloramphenicol and aflatoxin M1 for the first time. The acrydite-modified chloramphenicol aptamer sequence was used to synthesize the DNA hydrogel and for visual detection of chloramphenicol depending on the gel-to-sol transition of the target-responsive DNA hydrogel. The DNA hydrogel formulation was set as follows: 60% of each linear polyacrylamide-DNA conjugate and 40% of acrylamide and chloramphenicol aptamer/DNA strand-1 at a molar ratio of 1:1, and the lowest concentration of chloramphenicol leading to gel dissociation was 1.0 nM at 25 °C. Furthermore, the formalized aptamer-functionalized DNA hydrogel was used to detect aflatoxin M1 by measuring the recovery of the fluorescence signal that was quenched when the FAM-labeled aflatoxin M1 aptamer and BHQ1-labeled DNA strand-2 were hybridized to form a double-stranded DNA in the network of hydrogel. The detection platform was successfully applied to the detection of chloramphenicol and aflatoxin M1, both in aqueous solution and in milk. The aptamer-functionalized DNA hydrogel had detection (LOD) and quantification limits (LOQ) for aflatoxin M1 as 1.7 and 5.2 nM, respectively. Using two aptamer sequences with high affinity and specificity, the dual-sensing platform based on the DNA hydrogel achieved higher selectivity for chloramphenicol and aflatoxin M1, which demonstrated its potential as a reliable simultaneous detection platform against two different targets for monitoring food safety.

Detection of Potential Microbial Contaminants and Their Toxins in Fermented Dairy Products: a Comprehensive Review

Fermented dairy products are dominant constituents of daily diets around the world due to their desired organoleptic properties, long shelf life, and high nutritional value. Probiotics are often incorporated into these products for their health and technological benefits. However, the safety and possible contamination of fermented dairy products during the manufacturing process could have significant deleterious health and economic impacts. Pathogenic microorganisms and toxins from different sources in fermented dairy products contribute to outbreaks and toxicity cases. Although the health and nutritional benefits of fermented dairy products have been extensively investigated, safety hazards due to contamination are relatively less explored. As a preventive measure, it is crucial to accurately identify and determine the associated microbiota or their toxins. It is noteworthy to highlight the importance of detecting not only the pathogenic microbiota but also their toxic metabolites so that putative outbreaks can thereby be prevented or detected even before they cause harmful effects to human health. In this context, this review focuses on describing techniques designed to detect potential contaminants; also, the advantages and disadvantages of these techniques were summarized. Moreover, this review compiles the most recent and efficient analytical methods for detecting microbial hazards and toxins in different fermented dairy products of different origins. Causative agents behind contamination incidences are also discussed briefly to aid in future prevention measures, as well as detection approaches and technologies employed. Such approach enables the elucidation of the best strategies to control contamination in fermented dairy product manufacturing processes.

A bivalent binding aptamer-cDNA on MoS2 nanosheets based fluorescent aptasensor for detection of aflatoxin M1

To ensure the safety of dairy products, especially milk, and consequently protect human health, accurate and simple analytical techniques are highly necessary to determine the low concentration of aflatoxin M₁ (AFM₁) as an important carcinogen. Herein, a novel, accurate and simple fluorescent aptasensor was designed for selective detection of AFM₁ based on bivalent binding aptamer-cDNA (BBA-cDNA) structure. Moreover, MoS₂ nanosheets (MoS₂ NSs) were used as the fluorescent quencher and FAM-labeled complementary strand of aptamer (FAM-CS) was applied as a fluorescent probe. In this study, we achieved a new result. Unlike previous studies, in this work, the BBA-cDNA structure was not disassembled in the presence of the target. Therefore, as the AFM1 concentration increased, more targets were attached to the BBA-cDNA structure and as a result, the BBA-cDNA structure/AFM1 could not be placed on the surface of MoS2 NSs, leading to the more fluorescent intensity detection. Under optimized conditions, the developed fluorescent analytical method revealed great selectivity toward AFM₁ with a limit of detection (LOD) of 0.5 nM and a linear range from 0.7 to 10 nM. This fabricated aptasensor indicated excellent analytical performance for AFM₁ detection in milk samples with LOD of 0.1 nM. Overall, the proposed approach could provide an effective basis for small molecule analysis to guarantee food and human safety using appropriate aptamer sequences.

An assessment of the occurrence and nutritional factors associated with aflatoxin M1, ochratoxin A, and zearalenone in the breast milk of nursing mothers in Hamadan, Iran

This research investigated the occurrence of aflatoxin M1 (AFM1), ochratoxin A (OTA), and zearalenone (ZEN) in human milk samples in the Hamadan city, Iran. The study was carried out using the milk of nursing mothers from ten governmental health care centers. Mycotoxin content of ninety milk samples measured using enzyme-linked immunosorbent assay (ELISA). All samples that tested positive for AFM1 with the ELISA test were subsequently analyzed by high-performance liquid chromatography (HPLC). The mean ± SD concentrations of AFM1, determined by ELISA and HPLC were 5.98 ± 1.47 and 4.36 ± 1.23 ng/L, respectively. OTA and ZEN levels were below the detection limit (<5 ng/L) in all samples. None of the contaminated samples exceeded the regulation limit set by the European Commission (25 ng/L) for AFM1 in infant formula. We found a significant correlation between the AFM1 concentration in breast milk and infant age and milk consumption by the nursing mother (p < 0.05). These findings revealed that infants are susceptible to AFM1 exposure from their mother's milk. The authors recommend that additional research be conducted on the analysis of foodstuff and biological fluids for various mycotoxins.

Health risk assessment of aflatoxin M1 in infant formula milk in IR Iran

In this study, two accurate, precise, selective and sensitive methods were developed for determining aflatoxin M1 (AFM1) in infant formula milk using immunoaffinity column clean-up followed by high performance liquid chromatography (HPLC) with fluorescence detection. The validated methods were used for determination of AFM1 in 29 samples of 6 different infant formula milk brands and the risk of AFM1 in infants aged zero to 6 months old was assessed using cancer risk, Margin of Exposure (MOE) and Hazard Index (HI). Only one sample (3.4%) was contaminated with AFM1. Although the results showed that MOE values for the mean and median exposure to AFM1 was <10,000 in infants, the additional cancer risk due to mean and median exposure to AFM1 in infant <6 months were 0.00010 and 0.00012 additional cases per year per 10⁵ individuals, respectively, which indicates no health concern. In addition, HI values for the mean and median exposure to AFM1 for infants were quite below one which indicates no health concern. To the best of our knowledge, this is the first report on risk assessment of AFM1 in infant formula milk consumed by Iranian infants <6 months old, presenting a low risk for the evaluated groups.

Specific monitoring of aflatoxin M1 in real samples using aptamer binding to DNFS based on turn-on method: A novel biosensor

In the present work, a novel biocompatible scaffold was fabricated for the DNA aptamer immobilization. For the first time, amino-functionalized dendritic fibrous nanosilica (KCC-1-nPr-NH₂ ) and gold nanoparticle supported by chitosan (AuNPs-CS) were synthesized and electrodeposited successfully on the surface of the glassy carbon electrode by chronoamperometry technique. Unique oligonucleotide of aflatoxin M1 (5'-ATC CGT CAC ACC TGC TCT GAC GCT GGG GTC GAC CCG GAG AAA TGC ATT CCC CTG TGG TGT TGG CTC CCG TAT) labeled by toluidine blue was immobilization on the prepared interface. Hence, a novel aptamer-based bioassay was formed for highly sensitive quantitation of AFM1 using cyclic voltammetry and differential plus voltammetry. The structure and morphology of GQDs-CS/KCC-1-nPr-NH₂ were investigated by Fourier-transform infrared spectroscopy, X-ray diffraction, atomic force, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The achieved low limit of quantification of apta-assay for detection of AFM1 was 10fM. Also, calibration curve was linear from 0.1μM to 10fM in real samples. The proposed apta-assay has acceptable long-term stability. Designed aptasensor has a lot of remarkable advantages including excellent selectivity, sensitivity, and stability that could be used as facile bio-device for the determination of AFM1 in milk samples.

Aflatoxin M1 contamination level in Iranian milk and dairy products: a systematic review and meta-analysis

Aflatoxin M1 is a derivate of aflatoxin B1 and an important contaminant of milk and dairy products. This systematic review and meta-analysis was conducted on relevant Persian and English original articles in national and international databases with no time limits until 1 January 2018. In total 605 articles were found among which 70 articles met the inclusion criteria for meta-analysis. The prevalence (95% confidence interval (CI)) and mean concentration (95% CI) of aflatoxin M1 was found to be 64% (53-75%) and 39.7 ng/l (31.9-47.4 ng/l) in raw milk, 95% (89-98%) and 62.3 ng/l (40.6-84 ng/l) in pasteurised milk, 71% (56-84%) and 60.1 ng/l (30.9-89.3 ng/l) in sterilised milk, 59% (20-93%) and 5.5 ng/l (3.3-7.7 ng/l) in breast milk and 72% (61-81%) and 82.3 ng/kg (63.7-100.9 ng/kg) in dairy products. In general, 9% (4-16%) of milks and 10% (4-17%) of dairy products had aflatoxin M1 in concentrations exceeding the permitted level of Iranian standards (500 ng/l). Based on the maximum permitted aflatoxin M1 concentration in standards of Europe (50 ng/l), these percentages increase to 25% (18-32%) for milks and 18% (9-29%) for dairy products. According to the results, further control and preventive measures should be applied on livestock feeds because decreased aflatoxin B1 contamination at this level results in decreased aflatoxin M1 in milk and dairy products.

Aflatoxin M1 in milk in Hisar city, Haryana, India and risk assessment

Aflatoxin M1 (AFM1) contamination in 150 samples of milk, sold in market of Hisar city of Haryana, India, was investigated by using High Pressure Liquid Chromatography (HPLC). Out of these, 40 samples contained AFM1 at a concentration below the limit of detection (LOD) of 0.052 μg/kg. Among the AFM1 contaminated samples, 46 raw milk samples contained a concentration above the LOD but less than the limit of quantitation (LOQ), whereas 64 samples were above the LOQ. Of these samples, 31 exceeded the maximum limit of 0.5 μg/kg prescribed by FSSAI, India. Based on this study, the dietary intake of AFM1 for adults through consumption of milk was estimated. The results indicated that AFM1 contamination can be a food safety issue for raw and pasteurised milk consumed in India. Therefore, there is a need for a national monitoring programme to control the level of mycotoxins in milk.

Occurrence and Seasonal Variations of Aflatoxin M1 in Milk from Punjab, Pakistan

The manifestation of aflatoxins in feed and food is a major issue in the world as its presence leads to some health problems. This study investigates the incidence of aflatoxin M₁ (AFM₁) contamination in raw milk samples which were collected from Punjab, Pakistan. The Cluster Random Sampling technique was used to collect 960 milk samples from five different regions, and samples were collected every month. The AFM₁ level in raw milk was analyzed by the ELISA technique. The findings demonstrate that 70% of samples exceeded the United States permissible maximum residue limits (MRL 0.50 µg/L), with an overall AFM₁ level that ranged from 0.3 to 1.0 µg/L. AFM₁ contamination varied with the season: The highest average contamination was detected in winter (0.875 µg/L), followed by autumn (0.751 µg/L), spring (0.654 µg/L), and summer (0.455 µg/L). The Eastern region exhibited the highest average AFM₁ contamination (0.705 µg/L). Milk samples from the Northern region were found to be widely contaminated, as 86.9% samples exceeded the US MRL, followed by the Eastern region, with 72.3% samples being contaminated with >0.5 µg/L AFM₁. The study indicated that the raw milk supply chain was heavily contaminated. Recommendations and remedial measures need to be developed by regulatory authorities to improve the raw milk quality.

Contamination level and exposure assessment to Aflatoxin M1 in Jordanian infant milk formulas

Aflatoxin M1 (AFM1) is a principal hydroxylated-aflatoxin B1 (AFB1) metabolite, and has been classified as possible human carcinogen (group 2B). The aim of this study was to survey the contamination level, estimated daily intake (EDI) and tolerable daily intake % (TDI%) of AFM1 in Jordanian infant milk formulas. A total of 120 samples, 48 starter and 72 follow-on formula samples were collected and analyzed using ELISA technique. Of the 120 surveyed samples, 58 (48.33%) were AFM1-positive and exceeded the EU maximum limit for AFM1 in IMF (25 ng/kg). The average AFM1 concentration was 69.93 and 84.78 ng AFM1/kg, with range of <5 - 89.25 and <5 - 213.84 ng AFM1/kg in starter and follow-on formula, respectively. It is also noteworthy the high EDI of AFM1 by infants (1.557 and 1.551 ng AFM1/kg b.w./day), and the high TDI% values (786.9 and 775.9%). In addition, current study indicated high-extrapolated AFB1 content in the feed; accordingly, raised the need to implement good agricultural and hygienic practices as preventive and controlling measures to decrease AFM1 in milk and IMF through controlling AFB1 in feed at the farm level. Finally, it is obvious that the contamination of IMF by AFM1 is an international problem, and the protection of infants and young children against AFM1 in Jordan requires a fundamental setup of clear legal limits of AFM1 in Jordanian standards and strict monitoring and continual analysis of IMF traded and consumed in Jordan.

Determination of aflatoxin M1 using an aptamer-based biosensor immobilized on the surface of dendritic fibrous nano-silica functionalized by amine groups

Aflatoxins are potential food pollutants produced by fungi. Among them, aflatoxin M1 (AF M1) is the most toxic. A great deal of concern is associated with AF M1 toxicity. Aflatoxins are potential food pollutants produced by fungi. Among them, aflatoxin M1 (AF M1) is the most toxic. A great deal of concern is associated with AF M1 toxicity. In the present work, a novel aptamer-based bioassay was developed for monitoring aflatoxin M1 (AF M1) in real samples. A chitosan-modified graphene quantum dot (GQD-CS) nanocomposite was used as a biocompatible substrate coated with dendritic fibrous nanosilica functionalized by amine groups (KCC-1-NH₂-Tb). Accordingly, an innovative biocompatible polymeric matrix was prepared for aptamer immobilization. The unique oligonucleotide of AF M1 (5'-ATC CGT CAC ACC TGC TCT GAC GCT GGG GTC GAC CCG GAG AAA TGC ATT CCC CTG TGG TGT TGG CTC CCG TAT) labelled by toluidine blue was immobilized on the engineered interface. Hence, a novel aptamer-based bioassay was formed for the highly sensitive quantitation of AF M1 using cyclic voltammetry and differential pulse voltammetry techniques. The structure and morphology of GQDs-CS/KCC-1-NH₂-Tb was investigated by Fourier transform infrared spectroscopy, X-ray diffraction, atomic force and scanning electron microscopy and energy-dispersive X-ray spectroscopy. The toxicity tests, which were performed by MTT assays, revealed the biocompatible nature of KCC-1-NH₂-Tb. The engineered aptasensor demonstrated excellent behaviour toward the determination of AF M1, where the low limit of quantification was 10 fM. The proposed aptamer-based bioassay was successfully used for the monitoring of AF M1 in milk samples. This work provides a beneficial reference for the sensing of other toxins in food/pharmaceutical assays and veterinary medicine.

Quantification of aflatoxin M1 carry-over rate from feed to soft cheese

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The levels of AFM₁ in milk produced in Argentina are relatively low.

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Milk production, fiber particle size and AFB₁ level affected the carry-over rate.

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The greatest proportion of AFM₁ in milk is detected in whey during cheese. production.

From January to December 2016, samples of milk and feeds of dairy cattle were monthly collected. The concentration of mycotoxins in all matrices was determined using the enzymatic immunoassay technique. The average concentration of aflatoxin B₁ (AFB₁), deoxynivalenol (DON) and zearalenone (ZEA) in feed was 3.01, 218.5 and 467 ug/kg, respectively. The average AFB₁ carry-over rate was 0.84% with a variation between 0.05 to 5.93%. Particle size of the feed (P = 0.030) and individual milk production (P = 0.001) affected this rate. Mini-soft cheeses were produced using milk naturally contaminated with aflatoxin M₁ (AFM₁) as raw material to study its distribution both in whey and in cheese. The average level of AFM₁ in milk was 0.014 μg/l. None of milk samples exceeded the maximum level accepted for AFB₁ by the Southern Common Market (MERCOSUR) legislation (0.5 μg/l) and only 5.5% of samples exceeded the European Union (UE) regulations (0.05 μg/l). After the cheese elaboration, the concentration of AFM₁ was determined in whey and in cheese. The greatest proportion (60%) was detected in whey while 40% AFM₁ remained in the cheese. However, the concentration of AFM₁ was higher in the cheese compared to the original milk.

Aflatoxin M1 levels in different marketed milk products in Nairobi, Kenya

Milk is an important source of energy and nutrients, especially for children, and in Kenya, milk consumption is higher than other countries in the region. One major concern with milk is the risks of chemical contaminants, and reports of high levels of aflatoxin M1 (AFM1) in milk in Kenya has been causing public health concerns. This study collected marketed milk products every month during 1 year, just as a consumer would purchase them from retailers and traders in a low-income area, and a major supermarket in a middle/high-income area. In total, 291 sampled milk products (raw, pasteurised, UHT milk, yoghurt and lala) were collected and analysed for AFM1 using a commercial ELISA kit. More than 50% of the samples exceeded 50 ng/kg (the level allowed in the EU), but only three samples exceeded 500 ng/kg (the level allowed in the USA). Geometric mean AFM1 level was 61.9 ng/kg in the 135 samples from the low-income area while it was 36.1 ng/kg in the 156 from the higher income area (p < 0.001). The levels varied significantly depending on the time of year, with lowest levels of milk in January. There were also differences between manufacturers and products, with UHT milk having lower levels. There was no difference depending on the price for all dairy products, but when only including milk, higher price was associated with lower levels of AFM1. In conclusion, this study shows that milk purchased by a consumer is likely to contain AFM1 above 50 ng/kg, and that further research is needed to find ways to mitigate AFM1 contamination through working with farmers and milk processors both in the formal and informal sectors.

Aflatoxin M1 in cow, sheep, and donkey milk produced in Sicily, Southern Italy

Samples (n = 485) of raw (n = 394) or heat-treated (n = 91) milk of three different species (cow, n = 170; sheep, n = 133; donkey, n = 84), collected 2013-2016 in Western Sicily (Southern Italy), were analyzed for aflatoxin M₁ (AFM₁) by enzyme-linked immunosorbent assay (ELISA). Positive ELISA results were further analyzed by HPLC with fluorescence detection. Both methods had a detection limit for AFM₁ in milk of 7 ng kg^-1. ELISA yielded 12.9 and 5% positives in cows and sheep milk, respectively, all samples of donkey milk were negative. Levels of AFM₁ were in most cases at 0.007-< 0.05 μg kg^-1, only two samples (sheep milk) slightly exceeded the European Union maximum level of 0.05 μg kg^-1. Only 6% of the samples were positive for AFM₁ in a concentration range of 0.008-0.15 μg kg^-1. Only milk samples collected directly from farms were positive. Overall, the levels were much lower than previously reported for Southern Italy cow and sheep milk samples purchased in retail stores. The results of this work indicate a continuous improvement of the feeding techniques on dairy farms of Southern Italy, which is essential to ensure consumers' protection.

Achievements and Prospects in Electrochemical-Based Biosensing Platforms for Aflatoxin M₁ Detection in Milk and Dairy Products

Aflatoxins, which are mainly produced by Aspergillus flavus and parasiticus growing on plants and products stored under inappropriate conditions, represent the most studied group of mycotoxins. Contamination of human and animal milk with aflatoxin M₁, the hydroxylated metabolite of aflatoxin B₁, is an important health risk factor due to its carcinogenicity and mutagenicity. Due to the low concentration of this aflatoxin in milk and milk products, the analytical methods used for its quantification have to be highly sensitive, specific and simple. This paper presents an overview of the analytical methods, especially of the electrochemical immunosensors and aptasensors, used for determination of aflatoxin M₁.

Detection of Adulterants and Contaminants in Liquid Foods-A Review

Milk and fruit juices have paramount importance in human diet. Increasing demand of these liquid foods has made them vulnerable to economic adulteration during processing and in supply chain. Adulterants are difficult to detect by consumers and thus necessitating the requirement of rapid, accurate and sensitive detection. The potential adulterants in milk and fruit juices and their limits set by different regulatory bodies have been briefly described in this review. Potential advantages and limitations of various techniques such as physicochemical methods, chromatography, immunoassays, molecular, electrical, spectroscopy with chemometrics, electronic nose, and biosensors have been described. Spectroscopy in combination with chemometrics has shown potential for rapid, precise, and sensitive detection of potential adulterants in these liquid foods.

Assessment of Aflatoxin M1 and Heavy Metal Levels in Mothers Breast Milk in Famagusta, Cyprus

Breast milk contributes towards optimal nutrition for infants. However, studies showed that it can also contain different toxins and heavy metals, which reduce its health benefits. The aim of this study is to determine the level of contaminants such as aflatoxin M1 (AFM1), Pb, Cd, As, and Hg in breast milk samples from Famagusta, Cyprus. Correlations between moldy food consumption, smoking habits of the mothers, and contaminant levels in breast milk were also investigated. Breast milk samples from 50 lactating mothers in rural and urban areas of Famagusta District were analyzed for AFM1 by ELISA. Eighty percent of them were found to be contaminated with AFM1 with the mean measurement of 7.84 ± 1.72 ng/l. Socio-demographic status, moldy food consumption habits, and smoking status do not have any effect on the AFM1 levels observed in breast milk. Heavy metal levels in breast milk were examined by inductively coupled plasma mass spectrometry, and the mean measurements were1.19 ± 1.53 ppm for Pb, 0.73 ± 0.58 ppm for As, 0 ± 0.20 ppm for Hg, and 0.45 ± 0.23 ppm for Cd. This study indicates that the levels of these contaminants in breast milk samples obtained in Famagusta District are well within the acceptable levels. However, the presence of AFM1 and heavy metals still may pose risks for infant health.

Production of a monoclonal antibody against aflatoxin M1 and its application for detection of aflatoxin M1 in fortified milk

Aflatoxin M1 (AFM1) is a toxic metabolite of the fungal product aflatoxin found in milk. For food safety concern, maximum residual limits of AFM1 in milk and dairy products have been differently enforced in many countries. A suitable detection method is required to screen a large number of product samples for the AFM1 contamination. In this study, monoclonal antibodies (MAbs) against AFM1 were generated using a conventional somatic cell fusion technique. After screening, five MAbs (AFM1–1, AFM1–3, AFM1–9, AFM1–11, and AFM1–17) were obtained that showed cross-reactivity with aflatoxin B1 (AFB1) and aflatoxin G1 (AFG1) but with no other tested compounds. An indirect competitive enzyme-linked immunosorbent assay (ELISA) using a partially purified MAb and antigen-coated plates yielded the best sensitivity with the 50% inhibition concentration (IC₅₀) and the limit of detection (LOD) values of 0.13 ng/mL and 0.04 ng/mL, respectively. This indirect competitive ELISA was used to quantify the amount of fortified AFM1 in raw milk. The precision and accuracy in terms of % coefficient of variation (CV) and % recovery of the detection was investigated for both intra- (n = 6) and inter- (n = 12) variation assays. The % CV was found in the range of 3.50–15.8% and 1.32–7.98%, respectively, while the % recovery was in the range of 92–104% and 100–103%, respectively. In addition, the indirect ELISA was also used to detect AFM1 fortified in processed milk samples. The % CV and % recovery values were in the ranges of 0.1–33.0% and 91–109%, respectively. Comparison analysis between the indirect ELISA and high performance liquid chromatography was also performed and showed a good correlation with the R² of 0.992 for the concentration of 0.2–5.0 ng/mL. These results indicated that the developed MAb and ELISA could be used for detection of AFM1 in milk samples.

Exposure of Infants to Aflatoxin M1 from Mother's Breast Milk in Ilam, Western Iran

Objectives

Aflatoxins as a highly toxic group of mycotoxins are present in the environment and foodstuff. These have been reported to cause serious health problems in humans. Since aflatoxin M1 (AFM1) is excreted into breast milk, investigating the exposure of infants to AFM1 is of special concern.

Methods

In the present study, breast milk samples were collected from 85 lactating mothers in Ilam province, Iran, and the levels of AFM1 were analyzed using the enzyme-linked immunosorbent assay-based technique. AFM1 was detected in breast milk of all lactating women. The mean contamination level was 5.91 ± 2.031 ng/L, ranging from 2 ng/L to 10 ng/L.

Results

Multiple regression analysis indicated no significant associations of consumption of milk and dairy products, meat, fish, legumes, grain products, fruits, and nuts with the concentration of AFM1 in breast milk. Furthermore, no significant association was observed between AFM1 concentration and anthropometric data of infants.

Conclusion

In western parts of Iran, lactating mothers and their infants could be at risk of aflatoxin B1 and AFM1 exposure, respectively. Therefore, in Iran, the evaluation of AFM1 in human breast milk as a biomarker for postnatal exposure of infants to this carcinogen requires more attention in different regions and various seasons.

Aflatoxin M1 in raw and imported powdered milk sold in Khartoum state, Sudan

The aim of this study is to determine the level of contamination of aflatoxin M1 (AFM1) in raw and imported powdered milk in Khartoum state, Sudan. Thirty-five samples of fresh cow milk were collected from different farms, based on the source of concentrated feed introduced to the dairy cows (locally vs. commercially produced) and the size of the farm (≤ 50 vs. >50 cows/farm). Also 12 samples of powdered milk were obtained from repacking companies in Khartoum state. The samples were analysed by a fluorometer, using the Vicam method. AFM1 was detected in all raw and powdered milk samples. Almost 50% of the contaminated powdered milk samples and all the raw milk samples exceeded the European Union limit of 0.05 µg/kg whereas 33% of the contaminated powdered milk samples and 77% of the raw milk samples exceeded the limit of Codex regulations (0.5 µg/kg). The results revealed that the concentration of AFM1 is affected significantly (P < 0.05) by the source of concentrated feed (locally produced or purchased) but not by the farm size. It was concluded that the levels of AFM1 in the milk samples indicated that the feeds offered to the cows were contaminated with aflatoxin B1 to such a level that it might cause a serious health problem to the public. Therefore, there is a need to limit the exposure to aflatoxin by imposing regulatory limits, as well as further studies on large scale bases are needed to investigate the amount of AFM1 in milk and dairy products.

Aflatoxin M1 in milk from urban and rural farmhouses of Punjab, Pakistan

Aflatoxin M1 (AFM1) was determined in 107 milk samples collected from urban and rural farmhouses from Punjab, Pakistan, by HPLC with fluorescence detection. An incidence rate of 64% (38/59) in milk samples from urban farmhouses was found, with a mean concentration of 0.064 ± 0.023 μg L(-1). In rural samples about 52% (25/48) of milk samples were contaminated with AFM1, with a mean of 0.04 ± 0.034 μg L(-1). About 42% of milk samples from urban and 27% from rural farmhouses were well above the limit permitted by the European Union (EU). However, only 15% and 8% of milk samples from urban and rural farmhouses, respectively, exceeded the limit of USDA/Codex regulations. The results showed that the contamination of milk with AFM1 from Punjab, Pakistan, when compared with Codex limit is present and needs continuous monitoring. The awareness and education among dairy farmers on the potential health risks associated with aflatoxins should be communicated.

A review on aflatoxin contamination and its implications in the developing world: a sub-Saharan African perspective

Mycotoxins contamination in some agricultural food commodities seriously impact human and animal health and reduce the commercial value of crops. Mycotoxins are toxic secondary metabolites produced by fungi that contaminate agricultural commodities pre- or postharvest. Africa is one of the continents where environmental, agricultural and storage conditions of food commodities are conducive of Aspergillus fungi infection and aflatoxin biosynthesis. This paper reviews the commodity-wise aetiology and contamination process of aflatoxins and evaluates the potential risk of exposure from common African foods. Possible ways of reducing risk for fungal infection and aflatoxin development that are relevant to the African context. The presented database would be useful as benchmark information for development and prioritization of future research. There is need for more investigations on food quality and safety by making available advanced advanced equipments and analytical methods as well as surveillance and awareness creation in the region.

Label-free detection of aflatoxin M1 with electrochemical Fe3O4/polyaniline-based aptasensor

The selective detection of ultratrace amounts of aflatoxin M1 (AFM1) is extremely important for food safety since it is the most toxic mycotoxin class that is allowed to be present on cow milk with strictly low regulatory levels. In this work, Fe3O4 incorporated polyaniline (Fe3O4/PANi) film has been polymerized on interdigitated electrode (IDE) as sensitive film for AFM1 electrochemical biosensor. The immobilized aptamers as an affinity capture reagent and magnetic nanoparticles for signal amplification element have been employed in the sensing platform. Label-free and direct detection of the aptamer-AFM1 on Fe3O4/PANi interface were performed via electrochemical signal change, acquired by cyclic and square wave voltammetries. With a simplified strategy, this electrochemical aptasensor shows a good sensitivity to AFM1 in the range of 6-60 ng·L(-1), with the detection limit of 1.98 ng·L(-1). The results open up the path for designing cost effective aptasensors for other biomedical applications.

Association between aflatoxin M1 excreted in human urine samples with the consumption of milk and dairy products

This study aimed to find the association between urinary aflatoxin M(1) level and milk and dairy products consumption. Of 160 morning urine samples collected, aflatoxin M(1) was detected in 61.3 % samples (n = 98) [mean ± SD = 0.0234 ± 0.0177 ng/mL; range = 0-0.0747 ng/mL]. Of these positive samples, 67.3 % (n = 66) had levels above the limit of detection. Respondents with intake of milk and dairy products above median (67.79 g/day) had significantly high level of AFM(1) compared to those with low intake. A significant and positive association (φ = 0.286) was found between milk and dairy products consumption and urinary aflatoxin M(1) level.

Aflatoxin M1 determination in yoghurt produced in Guilan province of Iran using immunoaffinity column and high-performance liquid chromatography

The present study was aimed to determine the presence and levels of aflatoxin M(1) (AFM(1)) in 120 natural yoghurt samples consisting of 80 samples of commercial and 40 samples of traditional yoghurt in Guilan province in the north of Iran. The occurrence and concentration range of AFM(1) in samples were determined by immunoaffinity column extraction and high-performance liquid chromatography. Analysis of yoghurts showed that all the samples were contaminated with AFM(1) in concentration levels ranging from 4.2 to 78.9 ng/kg. In general, 16 samples (13.33%) had higher AFM(1) level than the maximum tolerance limit (50 ng/kg) accepted by European Union, but the contamination level was lower than 500 ng/kg in all the samples, which is accepted by Codex Alimentarius and National Standard. The concentration of AFM(1) in 26 samples (21.66) was lower than 10 ng/kg. The range of contamination of AFM(1) was comparatively higher in traditional yoghurt (average concentration of 32.9 ng/kg) than that in commercial yoghurt (average concentration of 21.6 ng/kg; p < 0.01). Because yoghurt is the most popular dairy product consumed in Iran, the AFM(1) contamination is a serious problem for public health. This study reports the data of a first survey on the presence of AFM1 in yoghurt in Guilan, Iran.