Assessment of aflatoxin M1 contamination in pasteurized and UHT milk marketed in central part of 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.

Incidence of Aflatoxin M1 in Milk and Milk Products from Punjab, Pakistan, and Estimation of Dietary Intake

In the present study, 124 samples of milk and milk products were analyzed for the presence of aflatoxin M1 (AFM1), which were purchased from the central cities of Punjab, Pakistan. The analysis was carried out using reverse-phase liquid chromatography, which was equipped with a fluorescence detector. The results showed that 66 samples (53.8%) of raw milk and milk products were found to be contaminated with detectable levels of AFM1 above ≤50 ng/L, and 24.2% of the samples had levels of AFM1 higher than the permissible limit of the European Union (EU; 50 ng/kg). In total, 53.6% of the raw milk, 57.8% of the UHT (ultra-heat-temperature) milk, 45% of the powdered milk, 57.1% of the yogurt, 55.5% of the cheese, and 50% of the buttermilk samples had levels higher than the LOD, i.e., 4 ng/L. The highest mean of 82.4 ± 7.8 ng/kg of AFM1 was present in the positive samples of raw milk. The highest dietary intake of AFM1 was found in infants’ milk (5.35 ng/kg/day), UHT milk (1.80 ng/kg/day), powdered milk (5.25 ng/kg/day), and yogurt (1.11 ng/kg/day). However, no dietary intake was detected in the cheese and butter milk samples used for infants. The results from the undertaken work are beneficial for establishing rigorous limits for AFB1 in animal feed, especially considering the high prevalence rate of hepatitis cases in the central cities of Punjab, Pakistan.

Aflatoxin M1 Contamination of Ghanaian Traditional Soft Cottage Cheese (Wagashie) and Health Risks Associated with Its Consumption

Wagashie is an unripened traditional cheese consumed in West Africa including Ghana. Being a milk product, it is unfortunately susceptible to aflatoxin M1 (AFM1) contamination, which is indeed a grave health challenge globally. This study evaluated AFM1 levels and health risk characterization associated with wagashie (n = 182) sampled from different locations in Ghana. AFM1 was measured with high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). Risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Out of the 182 samples analyzed for AFM1, 93/182 (51.1%) tested positive between the range 0.00 ± 0.00–3.60 ± 0.99 µg/kg. Risk assessments of AFM1 using deterministic models produced outcomes that ranged between 0.11 and 3.60 ng/kg bw/day, 0.09–1.54, 0–0.0323 ng aflatoxins/kg bw/day, and 3.5 x 10−3 −0.06 cases/100,000 person/yr for estimated daily intake (EDI), margin of exposure (MOE), average potency, and cancer risks, respectively, for the age categories investigated. It was established that the consumption of wagashie posed adverse health effects on all age categories in the selected regions of the study because all calculated MOE values were less than 100,000. Therefore, contamination of wagashie with AFM1 should be a serious public health concern and as such considered a high precedence for Ghana’s risk management actions.

Aflatoxin M1 in Raw Milk, Pasteurized Milk and Cottage Cheese Collected along Value Chain Actors from Three Regions of Ethiopia

Milk is a highly nutritious and perfect natural food for humans. However, when lactating animals feed on Aflatoxin B1 (AFB1)-containing feed, the hydroxyl metabolite aflatoxin M1 (AFM1) contaminates the milk and dairy products. The objective of the current study was to assess the level of AFM1 in raw milk, normally pasteurized milk and Ethiopian cottage cheese collected from value chain actors (producers, collectors, processors and retailers). Cross-sectional study and simple random techniques were used to collect primary samples. A total of 160 composite samples was collected; raw milk (n = 64), pasteurized milk (n = 64) and cheese (n = 32) was analyzed. Quantitative analysis of AFM1 was conducted using enzyme-linked immunosorbent assay (ELISA). The results indicate that AFM1 was detected in all milk products. Results along value chains show that the concentration of AFM1 in raw milk from collectors was significantly higher than from producers, and in pasteurized milk from processors and retailers (p < 0.05). However, no significant (p > 0.05) difference was observed in cottage cheese value-chain actors in all regions. Comparison of AFM1 mean values among all dairy products shows that raw milk had a significantly higher concentration of AFM1 followed by pasteurized milk and cottage cheese. However, there was no significant difference between raw and pasteurized milk (p > 0.05). The mean AFM1 contamination in milk products ranged from 0.137 to 0.319 µg/L (mean value 0.285 µg/L). The contamination percentages of AFM1 in raw milk (62.50%), pasteurized milk (67.20%) and cottage cheese (25%) were above the regulatory limit set by the European Union (EU) (0.05 µg/L). According to USA/Ethiopian Standard (US/ES) (0.50 µg/L), 21.87%, 25% and 1% exceeded the regulatory limit for the above products, respectively. The overall prevalence (56.88%) was above the EU regulatory limit and 19.38% over US/ES regulations. Therefore, to provide accurate information about the health risk to consumers, there is a need to conduct risk assessment studies in consumers of milk and dairy products at different age groups.

The prevalence of aflatoxin M1 (AFM1) in conventional and industrial dairy products (yogurt, cheese, kashk and dough) of Iran: a systematic review and meta-analysis

Aflatoxin is a toxic metabolite produced mainly by Aspergillus spp. which may occur in dairy products because of biotransformation. In this work, a systematic and meta-analysis approach has been considered on the topic of aflatoxin M1 (AFM1) content in dairy Iranian products. Based on the literature review, AFM1 was the most common aflatoxin contamination in dairy product. Additionally, studies revealed that higher levels of AFM1 were produced during cold seasons includes winter and autumn. Although, immunochemical technique (ELISA) was the frequent and rapid test, thin-layer chromatography (TLC) and chromatographic methods (HPLC) were commonly used as confirmative techniques to determine the level of aflatoxin. Meta-analyzing of the results showed that AFM1 can be found in the dairy products with overall prevalence percentage of 63.53 (95% confidence interval [CI]: 56.28-70.78) and 54.05 (95% CI: 43.09-65.02) based on the sample type and production process, respectively. The higher prevalence percentage of AFM1 of 73.96 (95% CI: 60.27-87.66) and 69.91 (95% CI: 62.00-78.83) was found in yoghurt and industrial production type of samples, respectively. In general, 17.8% of cheese, 14% of yogurt, 12.63% of kashk, and 2.1% of doogh contained AFM1 in concentrations exceeding the permitted level of standards. Totally, results showed that 88.89% of dairy products were contaminated by AFM1 exceeding from standard limits.

S. M. Montenegro MC, Rodríguez-Díaz JM. Contaminants in the cow's milk we consume? Pasteurization and other technologies in the elimination of contaminants

Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health. A comparative approach highlights the poor efficacy and effects of the pasteurization process with other methods used in the treatment of cow's milk. Despite pasteurization and related techniques being the most widely applied to date, they have not demonstrated efficacy in eliminating contaminants. New technologies have appeared as alternative treatments to pasteurization. However, in addition to causing physicochemical changes in the raw material, their efficacy is not total in eliminating chemical contaminants, suggesting the need for new research to find a solution that contributes to improving food safety.

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.

Quantitative risk assessment for aflatoxin M1 associated with the consumption of milk and traditional dairy products in Argentina

A quantitative risk assessment for exposure to aflatoxin M1 (AFM₁) related to the consumption of milk and traditional dairy products of Argentina was developed. The frequency and concentration of AFM₁ was modelled at various stages through the milk processes, considering Argentinean practices. Concentration of AFM₁ (0.046 μg/l, 95%CI = 0.002-0.264 μg/l) in raw milk was estimated. The AFM₁ concentration in milk was sensitive to the carry-over rate (r = 0.80), and milk yield in the first third of lactation during the spring-summer season (r = 0.11). AFB₁ levels in silage (r = 0.22), pasture during the spring-summer season (r = 0.11), concentrate (r = 0.08), and cotton seed (r = 0.05) were the factors most correlated with AFM₁ concentrations. Although the results showed that MoE values for the mean and median exposure to AFM₁ were < 10,000 in infants, toddlers, and other children, the additional cancer risk due to exposure to AFM₁ in infants, toddlers, and other children was 0.007, 0.005, and 0.0009 additional cases per year per 100,000 individuals, respectively, which indicates no health concern. In addition, the percentages of the population exceeding HI values (HI > 1) for exposure to AFM₁ for infants, toddlers, and other children were 45%, 49.1%, and 40.6%, respectively. Under this scenario, the most susceptible population at risk was children < 10 years old; therefore, it is necessary to establish measures to prevent contamination of AFM₁ in milk and milk products.

Detection of aflatoxin M1 in bovine milk from different agro-climatic zones of Chhattisgarh, India, using HPLC-FLD and assessment of human health risks

Concerns regarding food safety and 'One Health' are increasing globally. Aflatoxin M₁ (AFM₁), a human carcinogenic toxin, is excreted by lactating animals in their milk after consumption of feed contaminated with aflatoxin B₁. The present cross-sectional study aimed to determine the occurrence of AFM₁ in cattle and buffalo milk produced in rural and peri-urban areas under different agro-climatic conditions of Chhattisgarh, India, and assesses human health risks. Analyses of 545 milk samples by validated high-performance liquid chromatography revealed high level of AFM₁ contamination in 224 (41.1%) samples with mean concentration of 0.137 ± 0.029 μg/L. Statistically significant differences (p< 0.05) were observed in the levels and frequency of AFM₁ occurrence among different agro-climatic zones. AFM₁ was more frequently detected in milk samples from Northern hills (64%) followed by Bastar plateau (40.7%) and Chhattisgarh plain (27.3%), with mean concentration levels of 0.396 ± 0.099 μg/L, 0.081 ± 0.025 μg/L and 0.013 ± 0.002 μg/L, respectively. Species wise no significant difference was observed in the detection frequency and concentration of AFM₁ in milk from cattle and buffalo. AFM₁ contamination above maximum permissible limits established by European commission and Food Safety and Standard Authority of India was detected in 21.3% and 4.4% of samples, respectively. The estimated daily intakes for AFM₁ were found to be higher than tolerable daily intakes for both adults and children, especially of Northern hills implying a potentially high risk to consumer's health. This study provides valuable information on the contamination status of milk in one of the fastest developing state of India. It also highlights the importance and need for continuous farmers' awareness on good animal husbandry practices, routine surveillance of mycotoxins in animal feeds and food commodities to safeguard human health.

Assessment of aflatoxin contamination in dairy animal concentrate feed from Punjab, India

Aflatoxins are one of the major environmental contaminants in animal feed and pose a potential threat to human health due to their secretion in the milk of lactating animals. The present study was conducted with the objectives to determine the occurrence of aflatoxins (B1, B2, G1, and G2) in dairy animal concentrate feed and to evaluate the effect of season, spatial variation, and dairy farm size on the levels of aflatoxins contamination. A total of 189 dairy animal concentrate feed samples were tested for aflatoxins with enzyme-linked immunosorbent assay (ELISA) as screening and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) as confirmatory techniques. Of the total, 59% feed samples were found positive for aflatoxins, while 44% samples were detected with total aflatoxins levels higher than the tolerance limit established by the Food and Drug Administration (FDA) and 58% samples were found with aflatoxins B1 (AFB1) levels above the European Commission (EC) legal limit. AFB1 levels in dairy animal concentrate feed were found significantly higher during rainy (41.6 μg kg^-1) and winter (35.9 μg kg^-1) seasons as compared to the summer season (25.5 μg kg^-1). The theoretical extrapolation of the AFB1 carry-over from animal feed to milk (aflatoxins M1) in different seasons may lead to 50-100% contamination of milk at levels above the EC tolerance limit. The incidence and levels of aflatoxins especially AFB1 in animal feed, not only pose a direct effect on animals but may also pose a concern for food safety in relation to the occurrence of aflatoxins M1 in milk. Therefore, continuous surveillance of aflatoxins in dairy animal feeds is required to reduce animal and consequently human exposure.

Survey of Aflatoxin M1 in Commercial Liquid Milk Products in China

ABSTRACT

The objective of this study was to investigate the occurrence of aflatoxin M1 (AFM1) in Chinese liquid milk products. A total of 190 liquid milk samples, including 168 ultrahigh-temperature-treated milk samples and 22 pasteurized milk (PM) samples, were collected in August 2019. A screening assay with the Charm rapid test kit and a confirmation method with high-performance liquid chromatography were used for AFM1 analysis. Nine (4.74%) samples were screened positive, of which 5 (2.11%) samples were confirmed with concentration levels of 0.022 to 0.049 μg/kg. The AFM1 levels confirmed were all below the maximum residue levels set by China, the European Union, the United States, and the Codex Alimentarius Commission. The detection rate of AFM1 in domestic milk samples was 3.39%, while no AFM1 was detected in samples of imported milk. The prevalences of AFM1 detected in three groups of brands were as follows: group I, the major brands of China, 2.70%; group II, the local city domestic brands, 4.55%; and group III, the brands imported into China, 0. The detection rate of AFM1 was significantly higher in PM samples (9.09%) than in ultrahigh-temperature-treated samples (1.19%) (P < 0.05). Although the residue level of AFM1 did not exceed the maximum residue levels in any of the samples, the higher detection rate in local Chinese brands, especially in PM samples, deserves the attention of the Chinese government and consumers.

HIGHLIGHTS

Potential of Cold Plasma Technology in Ensuring the Safety of Foods and Agricultural Produce: A Review

Cold plasma (CP) is generated when an electrical energy source is applied to a gas, resulting in the production of several reactive species such as ultraviolet photons, charged particles, radicals and other reactive nitrogen, oxygen, and hydrogen species. CP is a novel, non-thermal technology that has shown great potential for food decontamination and has also generated a lot of interest recently for a wide variety of food processing applications. This review discusses the potential use of CP in mainstream food applications to ensure food safety. The review focuses on the design elements of cold plasma technology, mode of action of CP, and types of CP technologies applicable to food applications. The applications of CP by the food industry have been demonstrated for food decontamination, pesticide residue removal, enzyme inactivation, toxin removal, and food packaging modifications. Particularly for food processing, CP is effective against major foodborne pathogenic micro-organisms such as Listeria monocytogenes and Salmonella Typhimurium, Tulane virus in romaine lettuce, Escherichia coli O157:H7, Campylobacter jejuni, and Salmonella spp. in meat and meat products, and fruits and vegetables. However, some limitations such as lipid oxidation in fish, degradation of the oligosaccharides in the juice have been reported with the use of CP, and for these reasons, further research is needed to mitigate these negative effects. Furthermore, more research is needed to maximize its potential.

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.

Two-year survey on the seasonal incidence of aflatoxin M1 in traditional dairy products in Egypt

The most popular and economically important traditional dairy products in Egypt are raw milk, Karish cheese (an Arabian dairy product made from defatted cow milk) and Zabady (an Arabian yoghurt made from buffalo and cow milk). In this study, 302 traditional dairy samples including raw milk (120), white Karish cheese (118), and Zabady (64) were analyzed for aflatoxin M1 (AFM1) during different seasons in 2016 and 2017. Contamination of raw milk samples with AFM1 was 21.6% and 18.3% in samples collected in the two respective years with percentages of 100% and 90.9% exceeding the legal European limit (0.05 µg L^-1). In Karish cheese samples, the contamination level was 33.9% and 44.6%, in the 2 years examined with percentages of 90.47% and 80% that were above the European limit (0.25 µg kg^-1). In the case of Zabady, the AFM1-positive samples were 12.5% and 18.75%, and all of them were above the European limit (0.25 µg kg^-1). However, average toxin concentration in Zabady was lower than that detected in milk and cheese. Despite the seasonal variations influencing the occurrence of AFM1 in the three dairy products, the AFM1 levels in samples collected in winter were significantly (P ≤ 0.001) greater than those collected in summer. The contamination levels of AFM1 in the traditional dairy products consumed in Egypt; represent a serious health risk. It is urgent to inspect dairy farms for contamination with aflatoxins in a regular manner.

Aflatoxin M1-Binding Ability of Selected Lactic Acid Bacteria Strains and Saccharomyces boulardii in the Experimentally Contaminated Milk Treated with Some Biophysical Factors

There is a growing concern regarding the recurrent observation of aflatoxins (AFs) in the milk of lactating animals. Regarding this, the present study was conducted to assess the aflatoxin M1 (AFM1)-binding ability of three species, namely Lactobacillus rhamnosus, L. plantarum, and Saccharomyces boulardii, inAFM1-contaminatedmilk. The mentioned species were administeredatthe concentrations of107 and 109 CFU/mLto skimmed milk contaminated with 0.5 and 0.75 ng/mL AFM1 within the incubation times of 30 and 90 min at 4&amp;deg;C and 37&amp;deg;C. Lactobacillus rhamnosus was found to have the best binding ability at the concentrations of 107 and 109 (CFU/ml), rendering 82% and 90% removal in the milk samples with 0.5 and 0.75 ng/ml AFM1, respectively. Accordingly, this value at 107 and 109 CFU/ml of L. plantarum was obtained 89% and 82% with 0.75 ng/ml of AFM1, respectively. For S. boulardii at 107 and 109 CFU/ml, the rates were respectively estimated at 75% and 90% with 0.75 ng/ml of AFM1. The best AFM1-binding levels for L. rhamnosus, L. plantarum, and S. boulardii were 91.82&amp;plusmn;10.9%, 89.33&amp;plusmn;0.58%, and 93.20&amp;plusmn;10.9, respectively, at the concentrations of 1&amp;times;109, 1&amp;times;107, and 1&amp;times;107 CFU/ml at 37, 4, and 37&amp;deg;C, respectively. In this study, the maximum AFM1 binding (100.0&amp;plusmn;0.58) occurred while a combination of the aforementioned probiotics was employed at a concentration of 1&amp;times;107 CFU/ml at 37&amp;deg;C with 0.5 ng/ml AFM1, followed by the combination of L. rhamnosus and L. plantarum (95.86&amp;plusmn;10.9) at a concentration of 1&amp;times;109 CFU/ml at the same temperature with 0.75 ng/ml AFM1. It was concluded that the use of S. boulardii in combination with Lactobacillus rhamnosus and L. plantarum, which bind AFM1 in milk, can decrease the risk of AFM1 in 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.

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.

The Occurrence and Risk Assessment of Exposure to Aflatoxin M1 in Ultra-High Temperature and Pasteurized Milk in Hamadan Province of Iran

Objectives

Aflatoxins are a category of poisonous compounds found in most plants, milk and dairy products. The present research was carried out to detect the presence of aflatoxin M₁ (AFM₁) in samples of milk collected from Hamadan province, Iran.

Methods

Twenty five samples of ultra-high temperature (UHT) and 63 samples of pasteurized milk were collected and the amount of AFM₁ was measured by an Enzyme-Linked Immunosorbent Assay method. In addition, the estimated daily intake (EDI) and hazard index (HI) of AFM₁ was determined by the following equations:(EDI= mean concentration of AFM₁ × daily consumption of milk/body weight; HI= EDI/Tolerance Daily Intake).

Results

AFM₁ was detected in 21 (84%) UHT milk samples and in 55 (87.30%) pasteurized milk samples. Seven (28%) samples of UHT and 21 (33.33%) pasteurized milk samples had higher AFM₁ content than the limit allowed in the European Union and Iranian National Standard Limits (0.05 μg/kg). None of the samples exceeded the US Food and Drug Administration limit (0.5 μg/kg) for AFM₁. EDI and HI for AM₁ through milk were 0.107 ng/kg body weight/day, and 0.535, respectively.

Conclusion

A significant percentage of milk produced by different factories in Iran (84% of UHT and 87.3% of pasteurized milk) was contaminated with AFM₁. Therefore, more control and monitoring of livestock feeding in dairy companies may help reduce milk contamination with AFM₁. As the HI value was lower than 1, it can be assumed that there was no risk of developing liver cancer due to milk consumption.

Assorted Methods for Decontamination of Aflatoxin M1 in Milk Using Microbial Adsorbents

Aflatoxins (AF) are carcinogenic metabolites produced by different species of Aspergillus which readily colonize crops. AFM1 is secreted in the milk of lactating mammals through the ingestion of feedstuffs contaminated by aflatoxin B1 (AFB1). Therefore, its presence in milk, even in small amounts, presents a real concern for dairy industries and consumers of dairy products. Different strategies can lead to the reduction of AFM1 contamination levels in milk. They include adopting good agricultural practices, decreasing the AFB1 contamination of animal feeds, or using diverse types of adsorbent materials. One of the most effective types of adsorbents used for AFM1 decontamination are those of microbial origin. This review discusses current issues about AFM1 decontamination methods. These methods are based on the use of different bio-adsorbent agents such as bacteria and yeasts to complex AFM1 in milk. Moreover, this review answers some of the raised concerns about the binding stability of the formed AFM1-microbial complex. Thus, the efficiency of the decontamination methods was addressed, and plausible experimental variants were discussed.

A study on the aflatoxin M1 rate and seasonal variation in pasteurized cow milk from northwestern Iran

Present study aims to assess aflatoxin M1 (AFM1) contamination in 100 samples of pasteurized milk which were conventionally gathered during spring, summer, autumn, and winter from supermarkets located in Maragheh city of northwestern Iran. Samples were evaluated for AFM1 with a high-performance liquid chromatography (HPLC) method and with fluorimetric detection. The results showed that approximately 44% (11.25) of samples in winter, 32% (8.25) of samples in spring, 24% (6.25) of samples in summer, and 20% (5.25) of samples in autumn had AFM1 concentrations that exceeded the limit (0.05 μg/l) set by the European, Codex Alimentarius Commission and Iran standards. According to the statistical analysis of the data, there was no significant variation between the mean content of AFM1 during different seasons (P = 0.076). The results of our study suggest a high level of contamination of AFM1 in pasteurized milk in all seasons which may be due to the fact that milk supply for dairy factories is provided from dairy farms that are low in livestock feed quality. In Iran, pasteurized milk is consumed more than other milk products by all age groups. The total daily aflatoxin intake from contaminated milk and possibly other food products will be a significant risk to public health.

Label-Free and Redox Markers-Based Electrochemical Aptasensors for Aflatoxin M1 Detection

We performed a comparative analysis of the sensitivity of aptamer-based biosensors for detection mycotoxin aflatoxin M₁ (AFM1) depending on the method of immobilization of DNA aptamers and method of the detection. Label-free electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) for ferrocene labeled neutravidin layers were used for this purpose. Amino-modified DNA aptamers have been immobilized at the surface of polyamidoamine dendrimers (PAMAM) of fourth generation (G4) or biotin-modified aptamers were immobilized at the neutravidin layer chemisorbed at gold surface. In the first case the limit of detection (LOD) has been determined as 8.47 ng/L. In the second approach the LOD was similar 8.62 ng/L, which is below of allowable limits of AFM1 in milk and milk products. The aptasensors were validated in a spiked milk samples with good recovery better than 78%. Comparative analysis of the sensitivity of immuno- and aptasensors was also performed and showed comparable sensitivity.

Immobilization of Saccharomyces cerevisiae on Perlite Beads for the Decontamination of Aflatoxin M1 in Milk

Aflatoxin M1 (AFM1) contamination presents one of the most serious concerns in milk safety. In this study, the immobilization of Saccharomyces cerevisiae was used to detoxify AFM1-contaminated milk. The yeasts were immobilized on perlite for 24 and 48 hr, and the best immobilization time was achieved at 48 hr. Microscopic examination confirmed successful immobilization. The milk samples with 0.08, 0.13, 0.18, and 0.23 ppb AFM1 contamination were passed through the biofilter for 20, 40, and 80 min. The results showed a significant reduction in AFM1 concentration for all the milk samples with various initial AFM1 contents. The contaminated milk with 0.08 ppb AFM1 was completely cleared after 40 min of circulation while for the milk solution with 0.23 ppb, the highest AFM1 reduction was obtained at about 81.3% after 80 min circulation. In addition, the biofilter was saturated after the third step of milk circulation, containing 0.23 ppb AF, in which each step duration was 20 min. This study showed the excellent capability of the immobilized cells on the perlite beads to detoxify the AFM1-contaminated milk without any side effects on its physicochemical properties.

PRACTICAL APPLICATION

The immobilization of Saccharomyces cerevisiae cells on perlite beads can be used to detoxify AFM1-contaminated milk. The perlite can provide a perfect support for immobilization. With respect to qualitative properties, 20 min, was suggested as the optimum time for milk decontamination. This study indicated that the detoxification of contaminated milk using immobilized S. cerevisiae cells on the perlite support did not affect the different properties of detoxified milk. This method can lead to a practical solution to address aflatoxin contamination in dairy products considered high-risk foods.

A comparative study of procedures for binding of aflatoxin M1 to Lactobacillus rhamnosus GG

Several strains of lactic acid bacteria (LAB), frequently used in food fermentation and preservation, have been reported to bind different types of toxins in liquid media. This study was carried out to investigate the effect of different concentrations of Lactobacillus rhamnosus GG (ATCC 53103) to bind aflatoxin M1 (AFM1) in liquid media. AFM1 binding was tested following repetitive washes or filtration procedures in combination with additional treatments such as heating, pipetting, and centrifugation. The mixture of L. rhamnosus GG and AFM1 was incubated for 18h at 37°C and the binding efficiency was determined by quantifying the unbound AFM1 using HPLC. The stability of the complexes viable bacteria-AFM1 and heat treated bacteria-AFM1 was tested. Depending on the bacterial concentration and procedure used, the percentages of bound AFM1 by L. rhamnosus GG varied from as low as undetectable to as high as 63%. The highest reduction in the level of unbound AFM1 was recorded for the five washes procedure that involved heating and pipetting. Results also showed that binding was partially reversible and AFM1 was released after repeated washes. These findings highlight the effect of different treatments on the binding of AFM1 to L. rhamnosus GG in liquid matrix.

Aflatoxin M1 in human breast milk in Shahrekord, Iran and association with dietary factors

This survey was conducted to determine the occurrence and levels of aflatoxin M₁ (AFM₁) in 250 breast milk samples of lactating mothers, obtained from urban and rural regions of Shahrekord, Iran. Moreover, the association between AFM₁ occurrence levels and dietary factors was assessed. AFM₁ analysis was carried out using the competitive enzyme-linked immunosorbent assay technique for screening and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for confirmatory purposes. The toxin was detected in 39 samples (15.6%), ranging from 11.1 to 39.3 ng/l, of which 8 samples (3.2%) had levels above the Iranian national standard limit (25 ng/l). AFM₁ occurrence and levels in breast milk samples obtained from rural regions were significantly higher (P ≤ 0.05) than those obtained from urban ones. It might be due to the different dietary patterns in these regions. It was found that dietary habits with more tendencies to consume bread, rice and non-alcoholic beer beverage significantly increased (P ≤ 0.05) the risk of AFM₁ occurrence in breast milk. In addition, higher consumption of bread, olive and traditional cream significantly increased (P ≤ 0.05) the levels of AFM₁ in breast milk samples. Further investigations should be performed to determine more precisely the association between AFM₁ occurrence and dietary factors and also the risk of infant exposure to this mycotoxin.

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.

Sensitive and rapid detection of aflatoxin M1 in milk utilizing enhanced SPR and p(HEMA) brushes

The rapid and sensitive detection of aflatoxin M1 (AFM1) in milk by using surface plasmon resonance (SPR) biosensor is reported. This low molecular weight mycotoxin is analyzed using an indirect competitive immunoassay that is amplified by secondary antibodies conjugated with Au nanoparticles. In order to prevent fouling on the sensor surface by the constituents present in analyzed milk samples, an interface with poly(2-hydroxyethyl methacrylate) p(HEMA) brush was employed. The study presents a comparison of performance characteristics of p(HEMA)-based sensor with a regularly used polyethylene glycol-based architecture relying on mixed thiol self-assembled monolayer. Both sensors are characterized in terms of surface mass density of immobilized AFM1 conjugate as well as affinity bound primary and secondary antibodies. The efficiency of the amplification strategy based on Au nanoparticle is discussed. The biosensor allowed for highly sensitive detection of AFM1 in milk with a limit of detection (LOD) as low as 18pgmL(-1) with the analysis time of 55min.