A survey of concentration of aflatoxin M1 in dairy products marketed in Turkey

The aim of this study was to examine the presence of aflatoxin M1 (AFM1) in dairy product samples by enzyme-linked immunosorbent assay (ELISA). Aflatoxin M1 were found in 135 (64%) out of 210 analyzed samples. Only 7% of dairy product samples were contaminated at levels above the legal limits. AFM1 was detected in 43 (86%) of milk samples (ranging from 1 to 30 ng/l), in 38 (63%) of cheese (ranging from 12 to 378 ng/kg), in 28 (56%) of yoghurt (ranging from 2.5 to 78 ng/kg) and in 26 (52%) of dairy dessert samples (ranging from 1.5 to 80 ng/kg). None of the raw milk samples contained levels above the Turkish legal limit. The AFM1 levels of 7(14%) yoghurt, 5 (10%) dairy dessert and 3 (5%) cheese samples were above the limits of the Turkish Food Codex. It is emphasized that the presence of AFM1 in dairy products may be regarded as a potential hazard for human health.     

Seasonal variation of aflatoxin M1 contamination in industrial and traditional Iranian dairy products

This study aimed to determine the occurrence of aflatoxin M₁ (AFM₁) contamination in 682 dairy product samples consisting of raw milk of cow, goat and sheep; Lighvan cheese; and industrial and traditional yoghurt, Kashk and Doogh samples collected from popular markets and dairy ranches in four large Iranian cities. Thin layer chromatography (TLC) technique was used for analysis of the samples. Results showed that the incidence and levels of AFM₁ contamination in raw cow milk and industrial products (manufactured from cow milk) were higher than raw goat or sheep milk, and traditional products (made from goat and sheep milk), respectively. Moreover, seasonal variations influenced the concentration of AFM₁ in most of the analyzed dairy products. Owing to the abundance and popularity of the industrial products, contamination of these products in such a level could be a potential hazard for public health.     

Screening of aflatoxin M1 occurrence in selected milk and dairy products in Terengganu,Malaysia

The study was conducted to screen the occurrence of aflatoxin M₁ (AFM₁) in 53 selected milk and dairy product samples (11 liquid milk, 12 powdered milk, 8 3-in-1 beverages, 6 condensed sweetened milk, 2 evaporated milk, 7 cultured milk drink, 5 yogurt and 2 cheese samples). These samples were purchased from selected markets in Terengganu, Malaysia in January 2014 based on a questionnaire survey among 212 respondents on the types and brands of milk and dairy products that were frequently consumed. Based on the responses, 53 milk and dairy products were purchased and the competitive enzyme-linked immune-absorbent assay (ELISA) method was used to determine the level of AFM₁ in the samples. Of 53 samples, 19 samples were positive with AFM₁ (35.8%) ranging from 3.5 to 100.5 ng/L. Although 4/53 (7.5%) of the tested samples had the contamination level greater than the European Commission (EC) limit (>50 ng/L), the contamination levels were still below the Malaysia Food Regulation 1985 limit (less than 500 ng/L). This study provided a pioneering data on the occurrence of AFM₁ in milk and dairy products in Malaysia.     

Analysis of aflatoxin M1 and M2 in commercial dairy products using high-performance liquid chromatography with a fluorescence detector

Aflatoxin M₁ (AFM₁) and M₂ (AFM₂) in commercial dairy products were analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector (FLD). To ensure an accurate analysis, two derivatization methods, bromination and aflatoxin–trifluoroacetic acid derivatization (ATD), were compared. The limits of detection (LODs) of the bromination method were 124.42–151.73 ng/kg, and the recovery rates were between 64 and 102%. The detection rates and concentration levels of AFM₁ were 6–74% and 14.48–270.94 ng/kg, respectively. AFM₁ was detected in 74% of milk powder samples and 36% of ice cream samples. The mean values of AFM₁ in milk powder and ice cream samples were 270.94 and 33.16 ng/kg, respectively. In the case of AFM₂, the detection rates were 2–10%, and the concentration levels were 20.62–55.67 ng/kg in milk and milk powder. Among milk and milk powder samples, ultra heat-treated (UHT) milk had lower AFM₁ contamination levels than pasteurized milk.     

Estimate of aflatoxin M1 exposure in milk and occurrence in Brazil

The presence of aflatoxin M₁ (AFM₁) was investigated in 125 samples of powdered milk, pasteurized milk and ultra high treated (UHT) milk in the city of São Paulo, and estimates of AFM₁ intake were assessed. The samples were analysed using an immunoaffinity column for cleanup and a HPLC-FLD for determining AFM₁. The quantification limit was 10 ng/kg. AFM₁ was found in 119 (95.2%) at levels ranging from 10 to 200 ng/kg with mean concentration of 31 ng/kg. The average daily intake estimated for AFM₁ was 1 ng/kg bw per day for children and 0.188 ng/kg bw per day for adults.     

Occurrence and estimation of aflatoxin M1 exposure in milk in Serbia

The occurrence of AFM1 was investigated in 150 cow's, 10 goat's, 5 donkey's, 10 breasts milk and 1 infant formula samples. Analyses were done using Enzyme Linked Immunosorbent Assay (ELISA) method. AFM1 was detected in 98.7% of analyzed cow's milk samples in concentrations ranged from 0.01 to 1.2 μg/kg. Further, even 129 (86.0%) cow's milk samples contained AFM1 in concentration greater than maximum residue levels (MRL) of 0.05 μg/kg defined by European Union (EU) Regulation. Analysis of other types of milk showed that AFM1 was detected in 80.0% goat's, 60.0% donkey's and 60.0% of breasts milk samples.Although Serbian Regulation for MRL of AFM1 in milk has been changed and harmonized with EU Regulation in 2011, occurrence of AFM1 in milk in Serbia during 2013 resulted in Regulation changes, and MRL were changed from 0.05 to 0.5 μg/kg.On the basis of the obtained concentrations of the AFM1 in cow's milk, collected information about average milk intake and mean body weight (bw) for different age's categories, mean ingestion of AFM1 in ng/kg per bw per day were estimated. Obtained results showed that all age's categories, especially children, are exposed with high risk related to presence of AFM1 in milk.There are only a few published data about occurrence of AFM1 in milk in Serbia and none about intake assessment for AFM1.     

Occurrence of aflatoxin M1 in cheese processed and marketed in Lebanon

Aflatoxin M1 (AFM1) is the principal hydroxylated metabolite of aflatoxin B1 excreted in milk, and subsequently it can be found in a large variety of dairy products thus posing a potential risk to human health when consuming these products. Considering its significant impact on human health, determination of AFM1 levels in dairy products becomes imperative. The present study was undertaken to investigate, for the first time, the levels of AFM1 in various locally processed (halloumi, baladi, shelal, naboulsi, double cream, feta and akkawi) or imported (white and yellow) cheese types available in Lebanese markets. For this purpose a total of 111 cheese samples were randomly collected from local small dairy farms (53 samples), Lebanese leading dairy industries (38 samples) and imported cheeses (20 samples). Aflatoxin M1 was detected in 67.56% out of the 111 samples analyzed in which the levels of AFM1 in 17.33% of the samples were found to exceed the limits (250 ng/kg) allowed by European Commission (EC). Of the analyzed cheese samples, AFM1 levels in 13 cheeses from small local dairy farms were above the limits set by the EC ranging between 255 and 315 ng/kg. None of the cheese samples collected from the Lebanese leading dairy industries or from the imported types exceeded the permissible limit where the highest recorded levels were 77.2 and 3.95 ng/kg, respectively. The results of this study indicate that continuous monitoring of AFM1 levels in commonly consumed cheese in Lebanon should be regularly done. It also shows an alarming situation with respect to cheeses produced from local small farms.     

The seasonal variation of aflatoxin M1 in milk and dairy products and assessment of dietary intake in Punjab,Pakistan

Total 372 samples (169 sample from summer and 203 samples from winter) of milk and dairy products were collected from major cities of Punjab, Pakistan, during 2014–2015. The aflatoxin M₁ (AFM₁) levels were analyzed using HPLC, equipped with floresceⁿce detector. The results have showed that AFM₁ was detected in 77 (45.5%) samples of milk and dairy products from summer at the range of LOD to 229.6 ng/L, and 114 (56.1%) samples from winter at a range of LOD to 345.8 ng/L. The highest mean of AFM₁ i.e. 94.9 ± 5.4 ng/L from summer and 129.6 ± 8.4 ng/L from winter was detected in raw milk samples. The results have shown that 37.5% of milk, 32% of UHT milk, 12.5% of powdered milk, 20% of flavored milk, 20% of yogurt and 16% of flavored milk samples from summer were found exceeded the recommended levels of AFM₁ i.e 50 ng/L (European Union permissible limit), as compared to 38.1%, 37.1%, 15.6%, 21.4%, 27.7% and 40% samples of milk, UHT milk, powdered milk, flavored milk, yogurt and flavored yogurt from winter, respectively. The mean level of AFM₁ in samples of milk, UHT milk and powdered milk samples from winter season has significantly (p˂ 0.05) higher as compared to the mean levels in samples from summer season. The dietary exposures of AFM₁ in milk and dairy products were calculated in five different age groups and the highest level of 3.42 and 3.33 ng/L/day in summer and 4.7 and 4.6 ng/L/day in winter were found in 1–5 years of male and female infants, respectively. The results of present study have shown significant levels of AFM₁ in milk and dairy products from Punjab, Pakistan and could pose considerable thereat to the health of local population.     

Determination of aflatoxin M1 in dairy cattle milk in Khartoum State,Sudan

Aflatoxins are a group of mycotoxins that contaminate various types of food and feedstuff leading to health risk in both humans and animals. Aflatoxin M1 (AfM1), the major metabolite of AfB1, was determined in dairy cattle milk samples of Khartoum State of Sudan using high-performance liquid chromatography (HPLC) with fluorescence detection. A total of 44 bulk dairy cattle milk samples were collected and analyzed. The percentage of AfM1 contamination has been found in 42/44 (95.45%) samples with contamination level ranging between 0.22 and 6.90 μg L⁻¹ and average concentration of 2.07 μg L⁻¹. AfM1 contamination in the samples of dairy cattle milk of Khartoum State of Sudan appears to be prevalent and may pose a public health problem at the moment. Awareness must be conveyed to producers, handlers and specialists.     

Occurrence of aflatoxin M1 in UHT milk and pasteurized milk in China market

In the present study, the contamination of aflatoxin M1 (AFM1) in 153 UHT milk samples collected in July and September 2010, and 26 pasteurized milk samples collected in September 2010, were assessed using the ELISA method. The AFM1 was detected in 54.9% of UHT milk samples with a concentration of 0.006–0.160 μg/L. Moreover, 96.2% of pasteurized milk samples tested positive for AFM1 with concentration levels of 0.023–0.154 μg/L. The occurrence of AFM1 in all positive samples was far below China's national legal limit of 0.5 μg/L. Meanwhile, the AMF1 content in 20.3% of UHT milk samples and 65.4% of pasteurized milk samples exceeds the European Union's legal limit of 0.05 μg/L.     

Assessment of aflatoxin M1 contamination in the milk of four dairy species in Croatia

Aflatoxin M1 (AFM1) concentrations were measured in bulk cow milk samples from eastern Croatia, and in cow, goat, sheep and donkey bulk milk samples from other parts of Croatia during the period July–September 2013. AFM1 levels in milk were measured in the ranges (ng/L): cow 3.65–162.3 (eastern Croatia) and 2.69–44.9 (other regions of Croatia); goat 2.78–40.8; sheep 2.11–5.87; donkey 3.43–10.4. The concentration of AM1 exceeded the EU MRL in 6.7% of cow milk samples from eastern Croatia. The highest level measured was 162.3 ng/L. AFM1 levels exceeded the LOQ value (23.2 ng/L) in only 59 samples of cow milk and two samples of goat milk of the total 402 samples analysed. A significant difference was found between the mean AFM1 concentrations of cow milk from eastern and other regions of Croatia (P < 0.05). The elevated AFM1 levels in cow milk from eastern Croatia indicate the use of contaminated supplementary feedstuff in some farms during the study period.     

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

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

Occurrence of roquefortine C,mycophenolic acid and aflatoxin M1 mycotoxins in blue-veined cheeses

Penicillium roqueforti, a food and feed contaminant, is known for its potential to produce roquefortine C (ROQC) and mycophenolic acid (MPA) amongst other mycotoxins. In blue-veined cheeses, selected P. roqueforti ripening cultures are used for organoleptic development but little is known about mycotoxin occurrence in these products. In this study, aflatoxin M1 (AFM1), ROQC and MPA levels were determined in 86 blue-veined cheeses collected worldwide using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). AFM1 was absent in all samples while 97.7% and 37.2% of cheeses contained quantifiable ROQC and MPA levels, respectively. Overall, the analyzed cheeses contained a large range of mycotoxin concentrations with ROQC and MPA mean levels at 848 ± 1670 μg/kg and 841 ± 1271 μg/kg, respectively. Noteworthy, 75% of cheese samples contained less than 792 μg/kg ROQC and 705 μg/kg MPA.     

Presence of aflatoxin M1 in milk and infant milk products in Tehran,Iran

Aflatoxins are highly toxic, mutagenic, teratogenic and carcinogenic compounds. The purpose of this survey was to determine natural occurrence and level of AFM₁ in pasteurized liquid milk, infant formula and milk-based cereal weaning food consumed in Tehran, Iran.A total of 328 branded milk products and liquid milk samples were collected and investigated by Enzyme Linked Immuno Sorbent Assay (ELISA).The samples of pasteurized liquid milk (n = 128), infant formula (n = 120) and milk-based cereal weaning food (n = 80) showed that the incidence of contamination with AFM₁ is 96.3%, the presence of AFM₁ in each group was 72.2 ± 23.5, 7.3 ± 3.9 and 16.8 ± 12.5 ng/kg, ranging between 31–113, 1–14 and 3–35 ng/kg, respectively.In general, the amount of AFM₁ in 100 (78%) of liquid milk samples and 24 (33%) of milk-based weaning food was higher than the maximum tolerance limit accepted by European Union, but in all of the infant formula samples was lower (European Communities and Codex Alimentarius has prescribed a limit of 50 ng/kg for AFM₁ in milk and 25 ng/kg in infant milk products).     

Occurrence of aflatoxin M1 in pasteurised,UHT milk and milk powder from goat origin

In the present study, 36 samples of pasteurised, ultra-high-temperature (UHT) treated and goat milk powder traded in the city of Campinas, Brazil, were analysed for aflatoxin M₁ (AFM₁), from October to December 2004 and March to May 2005. Results showed 25 (69.4%) positive samples for AFM₁ at levels of 0.011–0.161 μg L⁻¹ of milk, which were below the tolerance limit of 0.500 μg L⁻¹ as adopted for AFM₁ in milk by Brazilian regulations. Mean levels of AFM₁ in pasteurised, UHT and goat milk powder were 0.072 ± 0.048, 0.058 ± 0.044 and 0.056 ± 0.031 μg L⁻¹, respectively. It is concluded that the incidence of AFM₁ in goat milk traded in Campinas is high, but at levels that probably leads to a non-significant human exposure to AFM₁ by consumption of goat milks.     

Detection of aflatoxin M1 in milk products from China by ELISA using monoclonal antibodies

A rapid and sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) method using monoclonal antibody for measuring aflatoxin M1 (AFM1) in milk and milk products has been described. One monoclonal antibody was isolated and characterized after fusion of myeloma cells with spleen cells isolated from BALB/c mice that had been immunized with AFM1 carboxymethyl oxime conjugated with bovine serum albumin (BSA). Cross-reactivities of the anti-AFM1 monoclonal antibody clone were 100, 13.9, 6.7 and <1% against AFM1, aflatoxin B1 (AFB1), aflatoxin G1 (AFG1) and deoxynivalenol (DON), respectively. Assays of milk samples mixed with AFM1 ranging in concentration from 0.1 to 3.2 ng/ml gave mean ELISA recovery of 98%. The limit of detection concentration of AFM1 was 0.04 ng/ml. AFM1 contamination was measured in 12 samples of raw milk, 15 samples of powdered milk, 104 samples of liquid milk and four cheese samples collected from different supermarkets in Northeast of China. Of 135 milk samples tested, 55 (41%) samples contained AFM1 at levels that ranged from 0.32–0.50 ng/ml, 24 (18%) samples contained 0.16–0.32 ng/ml, and 18 (13%) samples contained 0–0.16 ng/ml; in 38 (28%) samples AFM1 was not detected. The results indicate that the necessary precaution will have to be taken to minimize the AFM1 contamination in milk and milk products from Northeast of China.     

Seasonal study of aflatoxin M1 contamination in milk of four dairy species in Yazd,Iran

This survey was conducted to determine the occurrence of aflatoxin M₁ (AFM₁) in samples of raw milk obtained from cow, sheep, goat, and camel herds in Yazd province during different seasons. Aflatoxin M₁ was analyzed using the competitive enzyme-linked immunosorbent assay technique for screening and high-performance liquid chromatography with fluorescence detection for confirmatory purposes. The detection rates of AFM₁ in cow, sheep, goat, and camel milk samples were 46.5%, 21.6%, 20.1%, and 4.03%, respectively. Levels of the toxin in 15.4% of cow milk, 11.5% of sheep milk, and 9.15% of goat milk samples exceeded the legal limit (0.050 μg/kg) recommended by the Institute of Standards and Industrial Research of Iran; while none of the camel milk samples exceeded the legal limit. The occurrence and levels of AFM₁ in cow milk samples from industrial dairy farms was significantly lower (P ≤ 0.05) than those from traditional ones. Seasonal variations influenced the occurrence and levels of AFM₁ in cow, sheep, and goat milk; however, no statistically significant seasonal effect was found for camel milk. This study indicates a high occurrence of AFM₁ in cow milk especially those obtained from traditional dairy farms. Therefore, more supervision is required on these farms; and traditional dairy farms should be gradually replaced by industrial ones.     

Occurrence,seasonal variation and risk assessment of exposure to aflatoxin M1 in Iranian traditional cheeses

A total of 360 traditional cheeses consisted of Lighvan (n = 62), Koozeh (n = 62), Siahmazgi (n = 58), Khiki (n = 58), Talesh (n = 58) and Lactic (n = 62) collected from different parts of Iran were analyzed for aflatoxin M₁ (AFM₁) using an enzyme linked immunosorbent assay (ELISA). Frequency of AFM₁ and its concentration ranges of all the ELISA positive samples were determined by high-performance liquid chromatography with fluorescence detection (HPLC-FD). AFM₁ was detected in 60.3%, 75.8%, 72.4%, 43.5%, 38.7% and 35.4% of Siahmazgi, Khiki, Talesh, Lighvan, Koozeh and Lactic cheeses, respectively with concentration ranging from 50.5 to 308.7 ng/kg, respectively. HPLC analyses confirmed the ELISA results although the rates of contaminated cheese samples were lower than that of ELISA. There was significant difference in AFM₁ level between various cheese types and samples collected from summer and winter seasons (P < 0.05). By comparing our findings with the EU limit, about 10.5% of cheese samples had exceeding values for the toxin. The results of the present study indicates that there is no health risk in consumption of Iranian traditional cheeses due to the presence of AFM₁.     

Estimated daily intake of organochlorine pesticides from dairy products in Brazil

The estimated daily intake (EDI) of organochlorine (OC) pesticides (HCB, α-HCH, lindane, aldrin, p,p′-DDE, p,p′-DDD, and o,p′-DDT) through consumption of dairy products from Rio Grande do Sul State (Brazil) was investigated. Fluid milk and cheese had similar ΣOC levels (26.04 and 26.14 ng g⁻¹ fat, respectively), whereas milk powder had lower levels (2.23 ng g⁻¹ fat). OC levels in UHT milk exhibited a declining trend over time (ΣOC = 27.70 ng g⁻¹ fat in 2000 vs. 1.50 ng g⁻¹ fat in 2009/2010). The EDI of OC pesticides was remarkably higher for children (8.266 ng kg⁻¹ day⁻¹) than for adolescents, adults, and the elderly (ranging from 0.393 ng kg⁻¹ day⁻¹ to 0.614 ng kg⁻¹ day⁻¹). The average EDIs for OC pesticides were below the acceptable daily intakes (ADI), with the exception of aldrin, which greatly exceeded the ADI for children. In addition, some samples (8.8%) exceeded the maximum residue limit for the compounds evaluated.     

Occurrence of aflatoxin M1 in raw milk in South Korea using an immunoaffinity column and liquid chromatography

The level of aflatoxin M₁ (AFM₁) contamination in raw milk produced in South Korea was investigated using immunoaffinity column chromatography and high performance liquid chromatography with fluorescence detector. A total of 100 raw milk samples were collected from 100 cattle ranches located in three different provinces of South Korea. Forty eight out of 100 raw milk samples contained AFM₁ at low level (0.002–0.08 μg/L) with mean value of 0.026 μg/L. Among the AFM₁ contaminated samples, 29 raw milk samples contained only traceable amount of AFM₁ below the limit of LOQ, 0.02 μg/L. None of samples exceeded the maximum level (0.5 μg/L) of Korean regulation for AFM₁ in milk. The limit of detection was 0.002 μg/L. The result of recovery test with 0.5 μg/L AFM₁ in raw milk sample was 96.3% (SD 3.6, n = 5). This is the first pioneering study to investigate the level of AFM₁ in raw milk used in dairy industries in South Korea.