A survey on the occurrence of aflatoxin M1 in milk samples in Ardabil, Iran

Occurrence and risk characterization of aflatoxin M1 in milk samples from southeastern Iran using the margin of exposure approach

This study aimed to investigate Aflatoxin-M1 (AFM1) contamination in pasteurized and raw milk samples consumed in Kerman and Rafsanjan in southeastern Iran. In this cross-sectional study, a total of 100 samples of raw (n = 67) and pasteurized (n = 33) milk were randomly collected from retail stores, supermarkets, and milk transport tankers in the winter of 2020 and the summer of 2021. The level of AFM1 contamination in the collected samples was evaluated by high-performance liquid chromatography with fluorescence detection (HPLC-FD). AFM1 was detected in 95% of samples and its median concentration was 17.38 ng/L. The median concentration of AFM1 in the pasteurized milk samples (24.89 ng/L) was significantly higher than in the raw milk samples (13.54 ng/L). The AFM1 contamination level in 20% (raw = 13% and pasteurized = 7%) of the samples was higher than the maximum permitted level (MPL) recommended by the European Union (i.e., 50 ng/L), whilst 4% (raw = 3% and pasteurized = 1%) of the samples was higher than the Iranian maximum standard limit (i.e., 100 ng/L). The hazard index (HI) was higher than 1 in 16%, 18%, and 35% of total milk samples for men, women, and children, respectively. The AFM1 contamination level in the milk samples collected in southeastern Iran was worrying. The margin of exposure (MoE) values were lower than 10,000 for children. Because aflatoxins are among the most potent carcinogens known, prevention of milk contamination in all stages from the farm to the table can considerably reduce the community's exposure to AFM1 and its consequent health risks.

A national systematic literature review for aflatoxin M1 in commonly consumed cheese brands in Iran: Human health risk assessment by Monte Carlo simulation

Cheese is popular in Iran because of its high nutritional value; therefore, it is necessary to control this product regarding health risk factors, particularly aflatoxin M1 (AFM1). This research reviewed AFM1 in various varieties of cheese in Iran to assess the potential health risks associated with consuming these products for different age groups. In this regard, all accessible papers from different databases were screened between June 27, 2000 and October 10, 2022 b y systematic research and then considering the selection criteria of the studies; finally, 22 articles were selected for the current review. The amount and prevalence of AFM1 were calculated and separated based on the cheese variety, and the sampling location; health risk assessment (HRA), statistical, uncertainty, and sensitivity analysis for AFM1 of cheese for different age groups were performed. The study results for 2143 samples showed that the overall average AFM1 for cheese is 160 ± 175 ng/kg, below the European Commission (EC) regulation (250 ng/kg). AFM1 contaminated 72.42% of all cheese samples, and 13% of these contaminated samples had a higher AFM1 than the EC regulation. Cheese varieties were ranked based on average levels of AFM1 as white pasteurized > traditional > creamy > probiotic > Lighvan, and this ranking was obtained based on sampling locations as market > dairy factories > livestock farms. Based on the HRAs, from the perspective of the liver cancer risk (LCR), the margin of exposure (MOE), and the hazard index (HI) approach, it can be concluded that cheese produced in Iran, in terms of AFM1, particularly for children, poses serious health risks. Accordingly, it is imperative to carefully consider implementing suitable management methods to inhibit the growth of aflatoxin B1 (AFB1) in livestock fodder, and training in sanitary production and processing of dairy products according to world standards is suggested for industrial and traditional cheese producers across Iran.

The occurrence of aflatoxin M1 in milk samples of Iran: a systematic review and meta-analysis

In this study, the average level of aflatoxin M1 in various types of milk from 107 articles (297 studies with 16,274 milk samples) were meta-analyzed using random-effect model based on the milk varieties (animal species and heating processes), geographical regions, seasons, detection techniques and dairy farming subgroups. Studies on milk contamination with aflatoxin M1 in Iran were collected using universal and Persian databanks from January 1974 to the end of November 2021. The overall aflatoxin M1 mean concentration and prevalence in milk samples of Iran were 39.65 ng/l (95% CI: 36.00-43.30) and 80% (95% CI: 76-85%), respectively. The rank order of importance of various variables in mean levels of aflatoxin M1 in milk samples included milk type (animal species) > geographical regions > detection techniques > dairy farming types > milk types (heating processes) > seasons. Findings revealed that the overall content of aflatoxin M1 in milk samples of Iran was lower than that allowed by the European Union, Institute of Standards and Industrial Research of Iran, and the USA, possibly due to the milk monitoring by the Iranian regulatory systems.

Multi-mycotoxin occurrence in feed, metabolism and carry-over to animal-derived food products: A review

The world requests for raw materials used in animal feed has been steadily rising in the last years driven by higher demands for livestock production. Mycotoxins are frequent toxic metabolites present in these raw materials. The exposure of farm animals to mycotoxins could result in undesirable residues in animal-derived food products. Thus, the potential ingestion of edible animal products (milk, meat and fish) contaminated with mycotoxins constitutes a public health concern, since they enter the food chain and may cause adverse effects upon human health. The present review summarizes the state-of-the-art on the occurrence of mycotoxins in feed, their metabolism and carry-over into animal source foodstuffs, focusing particularly on the last decade. Maximum levels (MLs) for various mycotoxins have been established for a number of raw feed materials and animal food products. Such values are sometimes exceeded, however. Aflatoxins (AFs), fumonisins (FBs), ochratoxin A (OTA), trichothecenes (TCs) and zearalenone (ZEN) are the most prevalent mycotoxins in animal feed, with aflatoxin M₁ (AFM1) predominating in milk and dairy products, and OTA in meat by-products. The co-occurrence of mycotoxins in feed raw materials tends to be the rule rather than the exception, and the carry-over of mycotoxins from feed to animal source foods is more than proven.

An overview of aflatoxin B1 biotransformation and aflatoxin M1 secretion in lactating dairy cows

Milk is considered a perfect natural food for humans and animals. However, aflatoxin B1 (AFB1) contaminating the feeds fed to lactating dairy cows can introduce aflatoxin M1 (AFM1), the main toxic metabolite of aflatoxins into the milk, consequently posing a risk to human health. As a result of AFM1 monitoring in raw milk worldwide, it is evident that high AFM1 concentrations exist in raw milk in many countries. Thus, the incidence of AFM1 in milk from dairy cows should not be underestimated. To further optimize the intervention strategies, it is necessary to better understand the metabolism of AFB1 and its biotransformation into AFM1 and the specific secretion pathways in lactating dairy cows. The metabolism of AFB1 and its biotransformation into AFM1 in lactating dairy cows are drawn in this review. Furthermore, recent data provide evidence that in the mammary tissue of lactating dairy cows, aflatoxins significantly increase the activity of a protein, ATP-binding cassette super-family G member 2 (ABCG2), an efflux transporter known to facilitate the excretion of various xenobiotics and veterinary drugs into milk. Further research should focus on identifying and understanding the factors that affect the expression of ABCG2 in the mammary gland of cows.

Aflatoxin M1 in Milk Worldwide from 1988 to 2020: A Systematic Review and Meta-Analysis

Background. Aflatoxins are found in various types of food and animal feed. Food contamination with aflatoxin toxin is of particular importance today. Various studies have reported different prevalence of aflatoxin M1 in animal milk. Therefore, due to the importance of this toxin, its role in health, and lack of general statistics about it worldwide, the present study aimed to determine the prevalence of aflatoxin M1 in milk worldwide with a systematic review and meta-analysis study. Methods. In this review study, national and international databases were extracted from SID, MagIran, IranMedex, IranDoc, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (ISI) between January 1988 and February 2020. A random effects model was used for analysis, and heterogeneity of studies with an I2 index was investigated. Data were analyzed using Comprehensive Meta-Analysis (version 2). Results. The prevalence of aflatoxin M1 in milk worldwide from January 1988 to February 2020 in 122 articles with a sample size of 18921 was 79.1% (95% CI: 75.5–82.3%). Regarding the heterogeneity based on metaregression, there was a significant difference between the effect of the year of study (p≤0.001) and sample size (p≤0.001) with the prevalence of aflatoxin M1 in animal milk. Conclusion. The results of this study show that the prevalence of aflatoxin M1 in milk is high worldwide. Therefore, considering the importance of the milk group and its products, special measures should be taken to protect the ration from aflatoxin molds and milk quality.

Assessment of aflatoxin in milk and feed samples and impact of seasonal variations in the Punjab, Pakistan

The present study was designed to assess the incidence of aflatoxin contamination in animal feed and raw milk samples (total 240 each) collected from dairy farms during the complete year of 2015. These samples were collected through a cluster random sampling technique by dividing the province of Punjab, Pakistan into five clusters (north, south, east, west and central). Factors (environmental & physical) affecting aflatoxin contamination in milk and animal feed at farms were also studied. The AFM1 levels in raw milk & AFB1 levels in feed samples were analyzed by using the ELISA technique. Results demonstrated that overall about 53% raw milk samples from dairy farms were contaminated beyond the US MRL (0.50 µg/L) for AFM1 with than average level of 0.59 µg/L, while the 95% farm feed samples were exceeding the FDA MRL (20 µg/kg) of AFB1 with average level of 43 µg/kg. During winter season, the concentration of AFM1 was higher in all clusters with avg 0.68 µg/L, while the AFB1 contamination was highest in the spring season with avg 54 µg/kg. Market feed prices had negative correlation with AFB1 contamilevels, which were further supported by the positive correlation between quantity of feed at farms with AFM1 and AFB1 contamination. Results exhibited significantly positive impact of environmental factors on milk and feed aflatoxin contamination levels, whereas temperature showed an inverse relationship with AFM1 and AFB1 levels. The study recommends need of synergistic extension work to support dairy farms and highlight the contamination levels for regulatory bodies to introduce strategic policies for control measures.

The overall and variations of Aflatoxin M1 contamination of milk in Iran: A systematic review and meta-analysis study

Major databases were searched until January 2019 and 77 eligible studies were included in the meta-analysis to estimate the overall mean of AFM1 in milk in Iran. The mean of AFM1 levels was obtained 55.97 ng/kg (95% CI: 50.09-61.84). However, the pooled estimated mean of AFM1 levels in milk were 94.58 (95% CI: 70.24-118.92), 59.19 (95% CI: 51.84-66.54) and 35.23 ng/kg (95% CI: 31.53-38.92), considering 4, 55 and 18 TLC, ELISA and HPLC-based studies (including 354, 9224 and 2606 samples), respectively. Also, there is a wide variation of AFM1 levels among different geographical regions which were the highest in northern (88.77 ng/kg). The AFM1 contamination of milk taken from the areas with humid climate was higher than the arid climate. AFM1 Levels were the highest in winter (48.70 ng/Kg). The level of AFM1 in pasteurized, raw, and UHT milk were 49.76, 55.08 and 94.81 ng/kg, respectively.

Occurrence of Aflatoxin M1 in Raw Milk from Manufacturers of Infant Milk Powder in China

This survey was performed to investigate the occurrence of aflatoxin M1 (AFM1) contamination of raw milk from manufacturers of infant milk powder in China. A total of 1207 raw milk samples were collected overall from four seasons of 2016 in Northeast China, Northwest China, Northern China, and Central China (11 provinces and one municipality). Results showed that 56 of the 1207 raw milk samples (4.64%) were positive for AFM1, which were obtained from Heilongjiang (two samples), Gansu (one sample), Shaanxi (46 samples), Beijing (one sample), and Hunan (six samples) provinces. None of the raw milk samples from manufacturers of infant milk powder exceeded the Chinese limit (62.5 ng/L) in 2016. Only a few raw milk samples were not suitable for use in infant milk according to EU (European Union) or U.S. infant milk limits. Furthermore, based on this survey and previous studies, it is particularly important to avoid AFM1 contamination in raw milk during the winter.

A survey of aflatoxin M1 in cow milk in Southern Iran

The competitive enzyme-linked immunosorbent assay technique was used to evaluate aflatoxin M1 (AFM1) levels in 168 samples of raw milk (135 samples and 33 samples from bulk tanks of farms and milk collection centers, respectively) and 12 samples of pasteurized milk in Fars province, Southern Iran. AFM1 was found in 55.56% of the samples with a mean concentration of 21.31 ng/L. The concentration of AFM1 in raw milk samples from farms was significantly (p < 0.05) lower than that in samples from collection centers and pasteurized milk. The concentration of AFM1 was not influenced by season, location, or type of farm. The concentrations of AFM1 in all samples were lower than the Iranian national standard limit (100 ng/L), but in 30% of raw cow milk samples they were higher than the maximum tolerance limit accepted by the European Union (50 ng/L); therefore, more effort is needed to control AFM1 levels in milk produced in Southern Iran.

Aflatoxin M1 in milk and milk products: a short review

Aflatoxin M1 (AFM1) is associated with carcinogenicity, genotoxicity, mutagenicity, and teratogenicity and as a result, represents a human health problem worldwide. This review will detail the toxicity, analytical methodology, occurrence, and prevention and control of AFM1 in milk and milk products. The probable daily intakes (PDI) per bodyweight (bw) worldwide ranged from 0.002 to 0.26 ng/kg bw/day for AFM1. Nevertheless, the high occurrence of AFM1 demonstrated in this review establishes the need for monitoring to reduce the risk of toxicity to humans. The recommended extraction method of AFM1 from milk is liquid-liquid with acetonitrile because of the acceptable recoveries (85-97%), compatibility with the environment, and cleanest extracts. The recommended analytical technique for the determination of AFM1 in milk is the high performance-liquid chromatography-fluorescence detector (HPLC-FLD), achieving a 0.001 µg/kg detection limit. The HPLC-FLD is the most common internationally recognised official method for the analysis of AFM1 in milk. The suggested extraction and analytical method for cheese is dichloromethane (81-108% recoveries) and ELISA, respectively. This review reports the projected worldwide occurrence of AFM1 in milk of 2010-2015. Of the 7,841 samples, 5,873 (75%) were positive for AFM1, 26% (2,042) exceeded the maximum residue levels (MRL) of 0.05 µg/kg defined by the European Union and 1.53% (120) exceeded the MRL of 0.5 µg/kg defined by the US Food and Drug Administration. The most effective way of preventing AFM1 occurrences is to reduce contamination of AFB1 in animal feed using biological control with atoxigenic strains of Aspergillus flavus, proper storage of crops, and the addition of binders to AFB1-contaminated feed. Controllable measures include the addition of binders and use of biological transforming agents such as lactic acid bacteria applied directly to milk. Though the one accepted method for the control of AFM1 in milk and milk products is the enforcement of governmental MRL.

Aflatoxin B1 in eggs and chicken livers by dispersive liquid-liquid microextraction and HPLC

A rapid, low-cost and simple technique has been developed for the determination of aflatoxin B1 (AFB1) in eggs and livers using high-performance liquid chromatography (HPLC) with UV detection. In this study, the presence of AFB1 was investigated in 150 eggs and 50 chicken livers from the local market of Tabriz, Iran. AFB1 was extracted with a mixture of acetonitrile:water (80:20) and cleaned up by dispersive liquid-liquid microextraction which is a very economical, fast and sensitive method. AFB1 was quantified by HPLC-UV without need for any complex derivatisation in samples to enhance the detection. The results showed that 72% of the liver and 58% of the egg samples were contaminated with AFB1 ranging from 0.30 to 16.36 µg kg (̶1). limit of detection and limit of quantification for AFB1 were 0.08 and 0.28 µg kg (̶ 1), respectively. The proposed method is suitable for fast analysing of AFB1 in egg and liver samples.

Aflatoxin M1 contamination in cow and buffalo milk samples from the North West Frontier Province (NWFP) and Punjab provinces of Pakistan

A total of 178 milk samples (94 of buffalo and 84 of cow) were randomly taken from Punjab and the North West Frontier Province (NWFP) of Pakistan (n = 89 in each province) and analysed for the presence of aflatoxin M1 (AFM1) by HPLC-FLD. From Punjab about 46% of buffalo's and 49% of cow's milks were contaminated with AFM1 as compared with 52% and 51% for milk samples from NWFP, respectively. Overall, the mean AFM1 concentration was 0.046 µg kg(-1) with a maximum of 0.350 µg kg(-1). All samples complied with the Codex Alimentarius limit of 0.50 µg kg(-1) for AFM1 in milk, but 16.3% of samples exceeded the European Union maximum level of 0.05 µg kg(-1). Another set of 415 buffalo's and cow's milk samples (213 morning milks and 202 evening milks) were analysed. Statistical analysis revealed significant differences (p < 0.05) between mean AFM1 concentrations in milk during the morning (0.043 µg kg(-1)) and the evening (0.028 µg kg(-1)) lactation times.

Determination of aflatoxin M1 in milk by high-performance liquid chromatography in Mashhad (north east of Iran)

The aim of this study was to evaluate aflatoxin M1 (AFM1) contamination in milk samples in Mashhad in Iran. A total of 60 milk samples were collected from retail stores of five regions in June 2011. The occurrence and concentration range of AFM1 in the samples were investigated by high-performance liquid chromatography method. AFM1 was found in 100% of the examined milk samples by average concentration of 16.16 ng/L and the contamination level ranging between 2 and 64 ng/L. The concentration of AFM1 in all the samples was lower than the Iranian national standard and Food and Drug Administration limit (500 ng/L), and only in one (1.6%) of the samples, the concentration of AFM1 was greater than the maximum tolerance limit (50 ng/L) accepted by European Union and Codex Alimentarius Commission. Statistical evaluation showed no significant difference between the mean concentrations of AFM1 in milk samples taken from different regions ( p > 0.05).

Determination of aflatoxin m1 in milk by ELISA technique in mashad (northeast of iran)

The aim of this study was to detect the amount of aflatoxin M₁ (AFM₁) in pasteurized milk samples in Mashad in northeast of Iran. For this purpose, 42 milk samples were collected from retail stores during fall 2011 and analyzed for AFM₁ by enzyme-linked immunosorbent assay (ELISA) technique. All the analyses were done twice. Results showed presence of AFM₁ in 97.6% of the examined milk samples by average concentration of 23 ± 16 ppt and contamination level ranging between 6 and 71 ppt. The concentration of AFM₁ in all the samples was lower than the Iranian national standard and Food and Drug Administration limits (500 ppt), and, only in 3 (1.6%) samples, AFM₁ concentration was more than the maximum tolerance limit (50 ppt) accepted by European Union and Codex Alimentarius Commission. According to our findings and previous studies, AFM₁ contamination of milk is not a concern in this region, and the regional standard of AFM₁ contamination in milk might be changed to lower than 100 ppt.

Developments in mycotoxin analysis: an update for 2009-2010

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2009 and mid-2010. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. New and improved methods for mycotoxins continue to be published. Immunological-based method developments continue to be of wide interest in a broad range of formats. Multimycotoxin determination by LC-MS/MS is now being targeted at the specific ranges of mycotoxins and matrices of interest or concern to the individual laboratory. Although falling outside the main emphasis of the review, some aspects of natural occurrence have been mentioned, especially if linked to novel method developments.