Aflatoxin M1 In Milk Research Articles

Aflatoxin M1 in milk and dairy products: The state of the evidence for child growth impairment

Aflatoxin M1 (AFM1) is a metabolite of the more toxic aflatoxin B1 (AFB1) a mycotoxin produced by the fungi Aspergillus flavus and A. parasiticus; which contaminates maize, peanuts, tree nuts, and oilseeds, among other crops in warm regions of the world. When mammals consume AFB1 in these foods, they secrete AFM1 in milk. A recent analysis indicated negligible cancer risk associated with AFM1 exposure, but whether AFM1 impairs children's growth is important to understand because children consume relatively more milk than adults worldwide. Our paper reviews the evidence on the link between AFM1 exposure and child growth impairment. We find that the existing studies are contradictory and necessitates further studies on this question; in particular, those that control for potentially confounding factors such as household socioeconomic status, children's overall diets, hygienic factors, and agroecological zone. Though many nations have policies for maximum AFM1 limits in dairy foods, they are not based on an explicit health risk analysis of AFM1 but on conversion rates of AFB1 levels to AFM1 in dairy products. Future studies on AFM1's potential harmful effects on child growth will help to better inform policies on maximum allowable AFM1 in milk and other dairy products.

Fate of aflatoxin M1 in milk during various processing treatments

The focus of this research was to investigate the fate of aflatoxin M1 (AFM1) in naturally contaminated milk samples during various processing treatments such as skimming, boiling, sterilisation, pasteurisation and fermentation. The raw milk samples were collected, and AFM1‐contaminated samples were subjected to different processing treatments and analysed using AFM1 quantitative rapid test strip. Processing treatments like skimming and pasteurisation did not change the AFM1 content in milk, whereas high temperature heat treatments like boiling and sterilisation reduced AFM1 content up to 20%. Fermentation of milk with Streptococcus thermophilus reduced AFM1 up to 8%.

Removal of aflatoxin M1 in milk using magnetic laccase/MoS2/chitosan nanocomposite as an efficient sorbent

The current study tries to find the impact of the integration of laccase enzyme (Lac) onto magnetized chitosan (Cs) nanoparticles composed of molybdenum disulfide (MoS2 NPs) (Fe3O4/Cs/MoS2/Lac NPs) on the removal of AFM1 in milk samples. The Fe3O4/Cs/MoS2/Lac NPs were characterized by FT-IR, XRD, BET, TEM, FESEM, EDS, PSA, and VSM analysis. The cytotoxic activity of the synthesized nanoparticles in different concentrations was evaluated using the MTT method. The results show that the synthesized nanoparticles don't have cytotoxic activity at concentrations less than 20 mg/l. The ability of the prepared nanoparticles to remove AFM1 was compared by bare laccase enzyme, MoS2, and Fe3O4/Cs/MoS2 composite, indicating that the Fe3O4/Cs/MoS2/Lac NPs the highest adsorption efficiency toward AFM1. Besides, the immobilization efficiency of laccase with a concentration range of 0.5–2.0 was investigated, indicating that the highest activity recovery of 96.8% was obtained using 2 mg/ml laccase loading capacity. The highest removal percentage of AFM1 (68.5%) in the milk samples was obtained by the Fe3O4/Cs/MoS2/Lac NPs at a contact time of 1 h. As a result, Fe3O4/MoS2/Cs/Lac NPs can potentially be utilized as an effective sorbent with high capacity and selectivity to remove AFM1 from milk samples.

The Efficiency of Lactic Acid Bacteria Strains Isolated from Cottage Cheese (Khiki) to Aflatoxin M1 Reduction in Milk

: Aflatoxin M1 (AFM1) is a hepatic hydroxylated metabolite of aflatoxin B1 that is found in the milk of lactating animals fed contaminated diets. Efficient and safe strategies for the degradation or detoxification of AFM1 in contaminated milk are rare. Given that probiotic bacteria are known for their ability to bind aflatoxins, the present study aimed to evaluate the potential of lactic acid bacterial strains, including Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus paracasei isolated from a cottage cheese named Khiki, for the reduction of AFM1 in PBS and milk. The results showed that all selected strains had a significant AFM1-binding ability. The highest AFM1 reduction was achieved by Lactobacillus paracasei in PBS (71.35%) and in milk (68.53%). The assessment of AFM1 reduction over contact time (1 to 48 hours) with Lactobacillus paracasei and contaminated milk showed a reduction of 67% to 71.2%, with most adsorption occurring within the first 12 hours. Since the studied probiotic strains were able to reduce AFM1 in milk, their use in the dairy industry could be recommended as a safety enhancement approach.

A 20-Year Data Review on the Occurrence of Aflatoxin M1 in Milk and Dairy Products in Mediterranean Countries—Current Situation and Exposure Risks

Aflatoxin M1 (AFM1) is a major carcinogenic compound found in milk and dairy products, posing a constant risk to consumers in the Mediterranean region. This study systematically reviewed AFM1 presence in these products in Mediterranean countries over a period of 20 years and estimated the relevant nutritional exposure for consumers. Using data from three databases, 596 articles were retrieved with 123 meeting the inclusion criteria. The frequency of AFM1 occurrence was 40% regardless of milk type, with non-cow milk showing an increasing trend. Moreover, the Estimated Daily Intake of AFM1 from milk and dairy product consumption and the associated Hazard Index were determined. Notably, Southeastern Mediterranean countries presented higher contamination levels, leading to elevated Estimated Daily Intake and Hhazard Index values. Thermally processed milk showed high contamination levels, and among dairy products, cheeses were the most contaminated. This review highlights AFM1 as a persistent hazard in the dairy sector, underscoring the need for effective interventions throughout the milk production stages.

Aflatoxin M1 levels in urine and breast milk of lactating mothers in Kuala Lumpur, Malaysia

Aflatoxins are carcinogens that can contaminate food and affect various body organs especially liver and kidney. When consumed, aflatoxin B1 (AFB1) is partially metabolised into aflatoxin M1 (AFM1), which is excreted in the urine. Breast milk may also contain AFM1 due to maternal dietary intake from contaminated food. This cross-sectional study aimed to determine the levels of AFM1 in both urine and breast milk among breastfeeding mothers (n = 256). The mother’s demographic information was collected during recruitment. Mothers were then scheduled for an appointment to provide a morning urine sample along with five to ten mL samples of breast milk. AFM1 levels in both samples were analysed using an enzyme-linked immunosorbent assay (ELISA). Spearman’s rho and Chi-square were used to determine the associations between mean levels of AFM1 in urine and breast milk. Findings show 68.0% of urine samples were contaminated with AFM1 (mean levels = 0.08 ± 0.04 ng/mL), while 14.8% of breast milk samples had AFM1 (mean levels = 5.94 ± 1.81 ng/kg). Urine AFM1 levels were not significantly associated with AFM1 levels in breast milk (p > 0.05). This study can act as a baseline for future research examining long-term aflatoxin exposure among both mothers and infants.

Fiber Optic LSPR Sensing AFM1 in Milk with Enhanced Sensitivity by the Hot Spot Effect Based on Nanogap Construction.

The detection of the amount of aflatoxin M1 (AFM1) in milk is crucial for food safety. Here, we utilize a fiber optic (FO) localized surface plasmon resonance (LSPR) biosensor by constructing gold nanoparticle (AuNP) multimers, in which the nanogaps amplified the LSPR signal by the hot spot effect, and achieved a highly sensitive detection of f AFM1. Through the optimization of parameter conditions for the fabrication of the sensor and detection system, a high performance result from the FO LSPR biosensor was obtained, and the method for AFM1 detection was established, with a wide detection range of 0.05-100 ng/mL and a low limit of detection (LOD) of 0.04 ng/mL, and it has been successfully validated with the actual sample milk. Therefore, it is a good strategy to fabricate highly sensitive FO LSPR sensors for detecting AFM1 by constructing AuNP multimers, and this approach is suitable for developing other biosensors.

Risk Assessment of AFM1 in Raw Milk and Dairy Products Produced in Armenia, a Caucasus Region Country: A Pilot Study.

This paper presents the first assessment of dietary exposure to aflatoxin M1 (AFM1) and associated health risks through milk and dairy product consumption in Armenia. Data on AFM1 in raw milk were obtained from an annual residue monitoring program. Additionally, commonly consumed dairy products (pasteurized milk, cheese, sour cream, curd cheese) were sampled, considering the sources of raw milk used by dairy companies. Per capita consumption of raw milk was sourced from national food balance databases, while individual consumption data for dairy products was collected via a 24 h recall survey with 1400 adult respondents. Detectable levels of AFM1 were observed in 7.14% of raw milk samples (up to 0.334 μg/kg) and, albeit at lower amounts (up to 0.009 µg/kg), in 30% and 40% of sour cream and curd cheese, respectively. The AFM1 levels were lower than the national maximum permitted level (0.5 μg/kg); however, levels in raw milk exceeded the EU ML (0.05 μg/kg). The estimated margin of exposure values for dairy products indicated no significant risk, whereas a reasonable worst-case estimate, using the measurable levels of AFM1 in raw milk consumption indicated a potential public health concern. This study provides a scientific basis for evaluating aflatoxin issues in the Caucasus area.

Aflatoxins in cattle concentrate feed and potential carry-over of aflatoxin B1 into milk in Dar es Salaam, Tanzania

Aflatoxin contamination of animal feed threatens livestock production and can harm human health when aflatoxin B1 (AFB1) is carried over as aflatoxin M1 (AFM1) into milk for human consumption; therefore, aflatoxins in cattle concentrate feeds sold in Dar es salaam, Tanzania were determined in this study. Aflatoxins in cattle concentrate feeds were determined using Enzyme-linked Immuno-sorbent Assay (ELISA) and High-Performance Liquid Chromatography with a Fluorescent Detector (HPLC-FLD) and potential carry-over was determined using carry-over equations. Aflatoxins were found in 78% of the concentrate feed samples in the range LOD to 161.32 µg/kg. The mean total aflatoxins (TAFs) was 25.89 ± 3.3 µg/kg, higher than WHO/US-FDA limit of 20 µg/kg in feed although the difference was insignificant (P = 0.81). AFB1 mean was 18.87 ± 2.45 µg/kg and significantly exceeded the WHO/US-FDA limit of 5 µg/kg of AFB1 in dairy feed (P = 3.05 × 10–10). Aflatoxins B2, G1 and G2, were also detected ranging from ND – 75.06 µg/kg. The calculated AFM1 in milk was in the range 0.001 – 0.363 µg/L in low milkers, 0.002–0.666 µg/L in medium milkers and 0.002–0.806 µg/L in high milkers. Carry-over was estimated to range from 1.2 to 1.7%. This study revealed that concentrate feed sold in Dar es salaam was highly contaminated with aflatoxins; noteworthy aflatoxin B1 exceeded the WHO/US-FDA limit implying potential carry-over into milk which could expose milk consumers to aflatoxins, hence livestock feed chain participants need to be sensitized.

Aflatoxin M1 in milk and dairy products in Brazil: a review of characteristics, contamination, human exposure and health risks

This paper aimed to present a review of the presence of aflatoxin M1 in milk and dairy products in Brazil, along with its characteristics and potential risks to human health. Overall, most studies analyzed during the defined period of this review (2013 to May 2023) reported average concentrations of AFM1 within the limits established by Brazilian legislation for milk, powdered milk, and cheese. However, considering the consumption of milk and dairy products by more vulnerable groups, such as children, two studies reported levels of AFM1 above the limits established for aflatoxins in different regions of Brazil. Thus, a more rigorous inspection by the responsible Brazilian authorities is necessary. Furthermore, since AFM1 is the only mycotoxin present in milk relevant to public health, it is important to continue conducting studies on the detection and determination of aflatoxins in milk and dairy products. This is necessary to monitor these contaminants and estimate the levels to which the population is exposed.

The content of aflatoxin M1 in the milk of cows from Turkish farms: the effect on milk quality and the effectiveness of mycotoxin binding by a claybased adsorbent

The aim of this study was to evaluate the concentration of aflatoxin M1 (AFM1) in milk from Holstein-Friesian cows on local farms located in two different cities in Turkey, to investigate the effect of this mycotoxin on milk quality and seasonal variation, and to investigate the efficacy of a commercial clay-based binder. As part of the study, milk samples from 144 dairy cows were analyzed for the presence of AFM1 prior to the use of a clay-based toxin binder. As a result of this analysis, 26.9% of milk samples from individual animals had AFM1 levels exceeding the U.S. permissible limit of 0.5 µg/kg. In addition, AFM1 was detected in 36.5% of winter and 18.6% of summer milk samples. The presence of AFM1 caused a decrease in milk fat, dry matter, and protein levels. The affected animals were further divided into two groups: control group (n = 14) and experimental group (n = 26). The animals of the experimental group were fed 25 g/animal of clay-based binder toxin daily. The treatment group showed a gradual decrease in AFM1 levels by 24.4% on day 4 and 48.9% on day 7. In addition, the fat, non-fat solids, and protein content of milk increased significantly. As a result, a high level of AFM1 contamination in milk was detected, which can be assumed to negatively affect the quality of milk production. The use of clay-based toxin binders may be an effective method to improve milk quality and protect animal and consumer health.

Study protocol to assess aflatoxin M1 health risks versus benefits of dairy consumption in Ethiopian children: an epidemiological trial and risk-benefit analysis

IntroductionIn Sidama, Ethiopia, animal-source foods can be difficult to access. Milk has important nutrients for child growth, but carries the risk of aflatoxin M1 (AFM1) contamination. AFM1 is a metabolite...

An automated fluorescent immunoassay for on-site screening of AFM1 in raw milk at the ppt level

In the dairy industry, the quality of raw milk as it is collected from dairy farmers must be strictly ensured. Therefore, when on-site screening of typical carcinogens in raw milk, this technology must simultaneously be convenient to operate and highly sensitive. Here, an automated and fluorescent immunoassay system for screening trace amounts of aflatoxin M1 (AFM1) in raw milk was developed. The whole immunoassay procedure can be processed in a true “sample-to-results” paradigm, avoiding the tedious manual operation of the traditional indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) method. In addition, we designed an integrated fluorescent spectrometer that can quantitatively measure fluorescent signals with high sensitivity. The automated and fluorescent immunoassay system can screen AFM1 in raw milk samples with an ultra low limit of detection (4.7 pg/mL in raw milk). The half maximal inhibitory concentration (IC50) was 8.3 pg/mL, which is approximately 4-fold lower than that of traditional ic-ELISA. When the system was applied to screen actual raw milk samples, the recovery rates ranged from 79.4% to 104.6%, with a coefficient of variation ranging from 8.9% to 15.2%. Overall, we believe that the automated and fluorescent immunoassay system can provide a one-stop solution that is user-friendly and highly sensitive for screening trace AFM1 contaminants in raw milk.

Reduction and binding of aflatoxin M1 in milk by Lactobacillus plantarum and Lactobacillus brevis isolated from Siahmazgi cheese

This study aimed to diagnose the ability of two probiotic strains isolated from Siahmazgi cheese to reduce the concentration of aflatoxin M1 (AFM1), which was able to reduce it up to 50%. Two strains of Lactobacillus isolated from local Siahmazgi cheese, were inoculated into raw milk containing 10 ng/mL AFM1. AFM1 levels were assessed by HPLC at 0, 24, 48 and 72 h. Also, for the assessment of the possible reduction of AFM1 by non-viable bacterial cells, heat treatment was applied in milk. In general, significant differences were observed between the control group and AFM1 contaminated milk samples containing probiotics during 72 h of refrigeration (p < 0.05). In the presence of Lactobacillus brevis, Lactobacillus plantarum and mixture probiotics, the concentrations of AFM1 ranged from 0.102 ± 0.004 ng/mL to 0.052 ± 0.002 ng/mL, 0.114 ± 0.002 ng/mL to 0.074 ± 0.003 ng/mL and 0.108 ± 0.003 ng/mL to 0.065 ± 0.002 ng/mL, respectively. Also, in the heated group, just a decrease was observed in the first 24 h. The results showed that native Iranian strains of Lactobacillus have good potential in reducing AFM1 in milk. The time factor is effective in reducing AFM1 by living bacterial cells.

Detection of aflatoxin in raw and pasteurized milk by high-performance liquid chromatography (HPLC) in central Ethiopia

Aflatoxins are a group of structurally related mycotoxins produced by the Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius species as secondary metabolites. Well-known forms of Aflatoxin are AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2. aflatoxin B1 is the most prevalent one. It can be metabolized in the liver and excreted as aflatoxin M1 in milk. Both forms have mutagenic and carcinogenic effects. In Ethiopia, there is limited information on the occurrence and contamination level of aflatoxin in raw and pasteurized milk. The present study was conducted in the Addis Ababa milk shed area to detect and quantify the level of Aflatoxin M1 in raw and pasteurized milk. A cross-sectional study was conducted from October 2020 to May 2021 on a total of 114 cow milk samples consisting of 60 raw milk and 54 pasteurized milk samples with the aim of detecting and quantifying the amount of aflatoxin M1 in raw and pasteurized milk in central Ethiopia by high-performance liquid chromatography (HPLC) using C18 column with fluorescence detector. AFM1 was detected in 79 (69.3%) of the 114 tested milk samples. The maximum and mean concentrations were 0.893 µg/L and 0.0465 µg/L, respectively. 25.4% of them contain AFM1 above the maximum limit of EU (0.05 µg/L), and 1.8% contained above the maximum limit of CES278 and FDA (0.5 µg/L). 26.7% of the samples from Sebata and 6.7% from Sululta contain above the maximum limit of EU (0.05 µg/L). Higher contamination of AFM1 was detected in pasteurized milk (96.3%) than in raw milk (16.7%). 35.2% of pasteurized and 16% of raw milk contained AFM1 above the maximum limit of EU0.05 µg /L. The study results showed a significant difference in AFM1 occurrence with feed type, storage time, and milk type. The current AFM1 concentration level in raw and pasteurized milk was not safe for human consumption in the study areas. Due to its heat resistance, AFM1 is found in pasteurized milk and has great health effects. Creating awareness of feed management for feed producers and farmers and developing risk mitigation methods are crucial in order to reduce public health threats.

Feeding Silicoglycidol reduces aflatoxin M1 in dairy cow milk

Aflatoxin M1 (AFM1) is a pathogenic metabolite often transferred from feed into milk from aflatoxin (AF) B1, B2, G1, and G2; thus, it poses a human health risk. Therefore, effective mitigation strategies are needed to reduce animal and human exposure to AF. Study objectives were to evaluate a dietary adsorbent (Silicoglycidol, ATX) as a sequestering agent in AF contaminated feed and to broadly examine how AF affects liver function and the immune system. Primiparous Holstein cows (n = 12, 279 ± 88 DIM and 675 ± 19 kg BW) were used in a replicated 3 × 3 Latin square design with 21-d periods in which d 1–14 were considered adaptation and data collected on d 15 to 21 were used for analysis. Treatments were: 1) control (CON) consisting of a basal diet; 2) AF diet consisting of CON + AF challenge (100 µg of AFB1/kg dry matter intake [DMI]); and 3) AF + ATX supplemented at 0.10% of dietary DMI. Feed intake and milk yield were recorded daily, fecal samples were collected on d 20 of each period, blood and urine samples were collected on d 21 of each period, and milk samples were collected on the last 2 d of each period. Data were analyzed using the MIXED procedure of SAS. Milk yield and DMI were unaffected by treatment (26.8 ± 1.3 kg/d and 24.0 ± 0.9 kg/d, respectively). Similarly, neither milk composition nor DMI digestibility were affected by treatment. No AFM1 was detected in CON cow's milk or urine. Supplementing ATX reduced AFM1 in milk (1.57 vs. 1.14 ± 0.1 µg/L for AF and AF+ATX, respectively) and urine (9.9 vs. 5.6 ± 1.1 µg/L for AF and AF+ATX, respectively). Consuming AF did not affect biomarkers of liver health or immune activation including ALT, AST, GGT, haptoglobin (Hp), and immunoglobulin G (IgG). In summary, feeding ATX reduced the absorption and transfer of dietary AF to milk and urine.

Aflatoxin M1 contamination in milk: A serious issue to be tackled

This comprehensive review addresses the critical issue of Aflatoxin M1 contamination in milk, emphasizing its presence, detection methods, permissible levels, and associated health risks. Aflatoxin M1, a carcinogenic byproduct of Aflatoxin B1, poses significant concerns for the safety of milk, a crucial source of essential nutrients. Regulatory standards from entities like the European Union, U.S. FDA, and FSSAI highlight the need for monitoring and controlling contamination to protect public health. The review extensively explores diverse detection techniques, with ELISA standing out for its speed and precision. Preventive measures, including inhibiting contaminated feed intake, vaccination strategies, and judicious feed usage, are discussed as effective means to minimize Aflatoxin M1 in milk. However, complete elimination remains challenging, leading to the exploration of additional detoxification methods. The review covers various approaches during milk processing, such as pasteurization, sterilization, and the potential roles of probiotics. Absorption materials like bentonite and activated carbon show promise in binding and removing Aflatoxin M1, while chemical approaches with ammonia and hydrogen peroxide are examined with a cautious note on potential risks. Novel detoxification techniques involving plant extracts, including black cumin, garlic, and broccoli, is highlighted for their antioxidant properties. In conclusion, this review provides a foundational understanding of the multifaceted challenge of Aflatoxin M1 contamination in milk, offering insights for future research and the development of effective strategies to ensure the safety and quality of this dietary staple.

Seasonal variation and risk assessment of exposure to aflatoxin M1 in milk, yoghurt, and cheese samples from Ilam and Lorestan Provinces of Iran

The current study aimed to evaluate aflatoxin M1 (AFM1) contamination in a total number of 240 samples collected during four consecutive seasons (from January to November 2022) from two western Iranian provinces (Ilam and Lorestan). AFM1 was determined by high-performance liquid chromatography with a fluorescence detector after the toxin extraction with immunoaffinity columns. The results showed 100% of AFM1 contamination in all the surveyed matrices. Considering the seasonal variability, AFM1 mean values in milk, cheese, and yoghurt samples collected during the summer were significantly higher than those detected in samples from other seasons (p < 0.01), and the lowest concentrations were observed in samples collected during the winter. AFM1 levels in cheese samples appeared safe, but an alarming rate of 46.6% of milk samples and 100% of the yoghurt samples exceeded the maximum permissible limit set by the European Union (50 ng/kg). Moreover, while the deterministic risk assessment demonstrated no risk of developing liver cancer in adults through the consumption of these dairy products, it showed significant concerns for children consuming milk and yoghurt (hazard index above 1). Overall, the results of this research indicate the necessity of a periodical monitoring program for AFM1 in milk and other dairy products.

Recent aflatoxin levels in maize, feed mixtures, milk and cheese in Serbia

Aflatoxins are the most widespread mycotoxins primar?ly produced by fungi of the genus Aspergillus such as A. flavus and A. parasiticus, infecting grains during storage, spices, nuts, milk and animal feed. Even in low concentrations, they are highly toxic. Major forms of aflatoxins include B1, B2, G1, G2, and M1. Mammals that ingest AFB1 contaminated food eliminate amounts of the main hepatic metabolite known as milk toxin or aflatoxin M1 (AFM1) via milk. The incidence of contamination of aflatoxin in maize, feed mixtures, milk and cheese samples collected from Serbian producers was investigated by using the competitive enzyme linked immunosorbent assay (ELISA) technique. In this study, a total of 22 samples of maize, 25 samples of feed mixtures, 284 samples of raw, pasteurised and UHT milk and 20 samples of cheese were examined in 2021. Aflatoxin B1 (AFB1) was quantified in 3 samples (13.6%) of maize, at levels ranging from 2.45?g/kg to 48.31?g/kg and 12 samples (48%) of feed mixtures at levels ranging from 2.04 ?g/kg to 21.48 ?g/kg. On the other hand, AFM1 was quantified in 51 samples (17.90%) of milk at levels ranging 0.02 ?g/kg to 0.26 ?g/kg and 15 samples (75%) of cheese at levels ranging from 0.15 ?g/kg to 0.46 ?g/kg. In the Republic of Serbia, maximum limit of AFB1 in maize used for livestock is 30 ?g/kg and for feed mixtures for dairy cows is 5 ?g/kg. On the other hand, maximum limit of AFM1 in milk is 0.25 ?g/kg. Maximum limit of AFM1 in cheese is not set. These results suggest the obvious presence of AFB1 in maize and the fact that number of feed mixture, milk and cheese samples contaminated with aflatoxins is not negligible. The occurence of aflatoxins in raw milk and comercially available milk is one of the most serious problems, as milk is a key source of nutrients for infants and young children. There?fore, continuous monitoring over milk is necessary as well as further research and risk analysis on AFM1 presence in cheese.

Aflatoxin M1 Concentrations, Adulterants, Microbial Loads, and Physicochemical Properties of Raw Milk Collected From Nekemte City, Ethiopia.

Milk is an essential part of the human diet and is a nutrient-rich food that improves nutrition and food security. The aim of this study was to determine the presence and concentration of aflatoxin M1 (AFM1), adulterants, microbial loads, and physicochemical properties of raw cow's milk (CM) in Nekemte City, Ethiopia. A total of 12 samples of fresh CM were purposefully collected from four kebeles in the city (Bake Jama, Burka Jato, Cheleleki, and Bakanisa Kese) based on the potential of each milk production and distributor site. The AFM1 concentration was determined by high-performance liquid chromatography (HPLC) with a Sigma-Aldrich standard (St. Louis, MO, USA). The concentrations of AFM1 in Bake Jama, Burka Jato, Cheleleki, and Bakanisa Kese were found to be 0.01-0.03 g/L, 0.31-0.35 g/L, 0.19-0.21 g/L, and 0.04-0.07 g/L, respectively. The concentrations of AFM1 in the present study varied significantly (p < 0.05) and ranged from 0.01 g/L to 0.35 g/L. These results show that of the 12 samples tested, all were positive for AFM1 and contaminated to varying degrees. The results of this study also revealed that the concentration of AFM1 in 7 (58%) of the 12 milk samples was above the European Union's (EU) maximum tolerance limit (0.05 g/L). The present study also revealed that of the investigated adulterants, only the addition of water had positive effects on three milk samples, while the remaining adulterants were not detected in any of the milk samples. The total bacterial count (TBC) and total coliform count (TCC) were significantly (p < 0.05) different and ranged from 5.53 to 6.82 log10cfumL-1 and from 4.21 to 4.74 log10cfumL-1, respectively. The physicochemical properties of the milk samples in the present study were significantly (p < 0.05) different and ranged from 2.8% to 5.75% fat, 7.03% to 9.75% solid-not-fat (SNF), 2.35% to 3.61% protein, 3.33% to 5.15% lactose, 11.54% to 13.69% total solid, 0.16% to 0.18% titratable acid, 26.7 to 32.1°C, 6.35 to 6.55 pH, and 1.027 to 1.030 specific gravity. The physicochemical parameters of the raw milk in the study area met the required quality standards. Hence, further studies are required to determine the extent of the problem and the factors associated with high levels of AFM1 in raw milk in the study areas, including the detection of aflatoxin B1 (AFB1) in animal feed.