Occurrence of Aflatoxin M1 in tank bulk goat milk and ripened goat cheese

Prevalence and concentration of aflatoxin M1 and ochratoxin A in cheese: a global systematic review and meta-analysis and probabilistic risk assessment

Exposure to mycotoxins such as aflatoxins can endanger human health, especially infants and children. In this study, an attempt was made to retrieved studies related to the concentration of aflatoxin M1 (AFM1) and ochratoxin A (OTA). Search was performed in international databases such as Embase, PubMed, Scopus, and Web of Science for the period 1 January 2010 to 20 February 2023. Then, the pooled concentration in the defined subgroups was calculated using meta-analysis and the health risk assessment was conducted by margin of exposure (MOEs). Thirty-one scientific papers with 34 data reports (Sample size=2,277) were included in our study. The lowest and highest prevalence of AFM1 in cheese was related to El Salvador (12.18 %) and Serbia (100.00 %). The pooled prevalence of AFM1 was 49.85 %, 95 %CI (37.93-61.78 %). The lowest and highest prevalence of OTA in cheese was related to Türkiye (6.67 %) and Italy (44.21 %). The pooled prevalence of OTA was 35.64 %, 95 %CI (17.16-56.44 %). Health risk of AFM1 revealed that except Pakistan and Iran, MOE in the other countries was lower than 10,000 for adults and also except Pakistan, MOE for other countries was lower than 10,000 for children. Health risk of OTA revealed that except Greece, MOE in the other countries was higher than 10,000 for adults and also except Germany and Greece, MOE for other countries was higher than 10,000 for children. Therefore, it is recommended to conduct control plans to reduce the concentration of mycotoxins in cheese, especially AFM1.

Occurrence of Aflatoxin M1 in Cow, Goat, Buffalo, Camel, and Yak Milk in China in 2016

In this present study, 195 cow milk, 100 goat milk, 50 buffalo milk, 50 camel milk, and 50 yak milk samples were collected in China in May and October 2016. The presence of aflatoxin M1 (AFM1) was determined using enzyme-linked immunosorbent assay method. For all cow milk samples, 128 samples (65.7%) contained AFM1 in concentrations ranging from 0.005 to 0.191 µg/L, and 6 samples (3.1%) from Sichuan province in October were contaminated with AFM1 above 0.05 µg/L (EU limit). For all goat milk samples, 76.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.135 µg/L, and 9 samples (9.0%) from Shanxi province in October were contaminated with AFM1 above 0.05 µg/L. For all buffalo milk samples, 24 samples (48.0%) contained AFM1 in concentrations ranging from 0.005 to 0.089 µg/L, and 2 samples collected in October were contaminated with AFM1 above 0.05 µg/L. Furthermore, 28.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.007 µg/L in camel milk samples, and 18.0% of samples contained AFM1 in concentrations ranging from 0.005 to 0.007 µg/L in yak milk samples. Our survey study has expanded the current knowledge of the occurrence of AFM1 in milk from five dairy species in China, in particular the minor dairy species.

Determination of Aflatoxin M1 in Raw Milk Using an HPLC-FL Method in Comparison with Commercial ELISA Kits-Application in Raw Milk Samples from Various Regions of Greece

The highly toxic Aflatoxin M1 (AFM1) is most often detected in milk using an Enzyme-Linked-Immunosorbent Assay (ELISA) for screening purposes, while High-Performance Liquid Chromatography with Fluorescence Detector (HPLC-FL) is the reference method used for confirmation. The aim of the present study was the comparison between three commercially available ELISA kits and a newly developed HPLC-FL method for the determination of the AFM1 in milk samples. The developed HPLC-FL method was validated for the AFM1 and Aflatoxin M2 (AFM2), determining the accuracy, precision, linearity, decision limit, and detection capability with fairly good results. All three ELISA kits were also validated and showed equally good performance with high recovery rates. Moreover, the Limit Of Detection (LOD) and Limit Of Quantification (LOQ) values were found to be significantly lower than the Maximum Residue Limit (MRL) (50 ng kg-1). After the evaluation of all three commercial kits, the ELISA kit with the optimum performance along with the HPLC method was used for the determination of AFM1 in raw cow's, goat's, and sheep's milk samples (396) obtained from producers in different regions of Greece. The evaluation of both methods showed that this ELISA kit could be considered as a faster and equally reliable alternative method to HPLC in routine analysis for the determination of AFM1 in milk.

Aflatoxin M1 in Brazilian goat milk and health risk assessment

Contamination of goat milk with aflatoxin M₁ (AFM₁) is a public health concern. This study investigated filamentous fungi in goat feed and quantified AFM₁ in milk samples (n = 108) from goat fed forage and concentrate. Based on the detected AFM₁ concentration, risk assessment analyses were performed concerning the Estimated Daily Intake (EDI) for one-year-old children and adults. Filamentous fungi were found in goat feed samples in a range of 3.1 ± 1.9 to 4.2 ± 0.2 log CFU/g. Five genera were identified, to cite Aspergillus, Penicillium, Fusarium, Rhizopus and Acremonium. Aspergillus species comprised A. flavus, A. niger, and A. ochraceus. All goat milk samples were contaminated with AFM₁ (5.60-48.20 ng/L; mean 21.90 ± 10.28 ng/L) in amounts below the limits imposed by regulatory agencies. However, EDI values for AFM₁ through goat milk estimated for one-year-old children were above the Tolerable Daily Intake. The calculated Hazard Index for one-year-old children indicated potential risk of liver cancer due to goat milk consumption. The Margin of Exposure values to AFM₁ in one-year-old children and adults consuming goat milk as the unique milk source indicated increased health risk. Therefore, contamination of goat milk with AFM₁ should be considered a high priority for Brazil's risk management actions.

Purification, characterization, and functional groups of an extracellular aflatoxin M1 -detoxifizyme from Bacillus pumilus E-1-1-1

The experiment was conducted to purify high activity extracellular enzymes, which were produced by a strain that we previously screened was able to degrade aflatoxin effectively, and speculate the functional groups of the enzyme associated with degradation. An extracellular aflatoxin-detoxifizyme (DAFE) from Bacillus pumilus E-1-1-1 was purified through a process including ammonium sulfate precipitation, ultrafiltration, Sephadex chromatography, and ion exchange chromatography. The molecular mass of the enzyme assessed by SDS-PAGE was found to be approximately 58 kDa. The optimum reaction temperature and pH for the purified enzyme were 45°C and pH 7, respectively. The enzyme showed temperature stability of up to 60°C. Ba²⁺ , Ca²⁺ Na⁺ , Mn²⁺ , EDTA, and β-mercaptoethanol showed inhibitory effects on the enzyme activity. Mg²⁺ , Fe³⁺ , Zn²⁺ and K⁺ were the activators of enzymes. This enzyme was composed of at least 15 kinds of amino acids. Lysine, tryptophan, and histidine residues were necessary and major functional groups to maintain enzyme activity, disulfide bonds were observed, serine residues had little effect on the enzyme activity, so it was not the necessary group to reflect the enzyme activity, and arginine had no effect on enzyme activity.

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

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

Monitoring aflatoxin M1 levels in donkey milk produced in Greece, intended for human consumption

Donkey milk is considered as a precious food on nutritional and microbiological grounds. Nevertheless, there is lack of evidence on the issue of chemical contaminants present in donkey milk. Aflatoxin M1 is a contaminant with serious health hazards, that is frequently present in other types of milk. Therefore, this study aimed at assessing the levels of aflatoxin M1 in donkey milk in Greece, intended for human consumption. Thirty-six donkey milk samples were collected over a period of a year from 12 donkey farms, representing 80% of the donkey farms. Samples were analysed with ELISA and analytical results were statistically associated with seasonality and type of feeds used in donkey rearing. Aflatoxin M1 was found in 5 out of 36 samples (13.9%), with a range of 5-26.5 ng/l, while in no sample the toxin was found at a concentration above the EU limit (50 ng/l). There was no statistical difference found among seasons or different types of feed used in donkey farming (P>0.05). Donkey milk in Greece presents very low levels of aflatoxin M1, possibly due to the type of feeds used for donkeys rearing and also due to the very low carryover of aflatoxin B1 to M1 that has been reported for donkeys. Donkey milk is considered as safe with relation to aflatoxin M1, but constant monitoring is advised, as aflatoxin levels in plants for feed are affected by many factors.

Occurrence of aflatoxin M1 in conventional and organic milk offered for sale in Italy

In the present study, 58 samples of milk were analyzed for the presence of aflatoxin M₁ (AFM₁). The samples were purchased during the period April-May 2013 in a random manner from local stores (supermarkets, small retail shops, small groceries, and specialized suppliers) located in the surrounding of Bologna (Italy). The commercial samples of milk were either organic (n = 22) or conventional (n = 36); fresh milk samples and UHT milk samples, whole milk samples, and partially skim milk samples were present in both the two considered categories. For the quantification of AFM₁ in milk, the extraction-purification technique based on the use of immunoaffinity columns was adopted and analyses were performed using HPLC-FD. AFM₁ was detected in 35 samples, 11 from organic production and 24 from conventional production. No statistically (P > 0.05) significant differences were observed in the concentration of AFM₁ in the two categories of product. The levels of contamination found in the positive samples ranged between 0.009 and 0.026 ng mL^-1. No sample exceeded the limit defined at community level for AFM₁ in milk (0.05 μg kg^-1). This demonstrates the effectiveness of the checks before the placing on the market of these food products. Thus, the "aflatoxins" problem that characterized the summer of 2012 does not seem to have had effect on the contamination level of the considered milk samples.

Aflatoxin M₁ in raw, UHT milk and dairy products in Sicily (Italy)

A survey on 73 milk samples from different animal breeds and 24 dairy products samples from Sicily, Italy, was carried out for the presence of aflatoxin M₁ (AFM1) by LC-fluorescence detection after immunoaffinity cleanup. AFM1 was detected in 48% and 42% of the milk and dairy samples at concentration ranges between <5.0-16.0 and <5.0-18.0 ng L⁻¹, respectively. Within the raw milk samples, 92% had an AFM1 content below 5.0 ng L⁻¹, in 7% of the cases it was in the range 5.0-10.0 ng L⁻¹ and 1% was contaminated between 10.0 and 20.0 ng L⁻¹. For the dairy products, ultra-high-temperature treated (UHT) milk, milk cream and cheese, the incidence was 42%, of which 83% contained less than 5.0 ng L⁻¹ and 17% contained 10.0-20.0 ng L⁻¹ AFM1. The levels of contamination found justify continuous monitoring for public health and to reduce consumer exposure.

Short communication: Occurrence of aflatoxin M1 in the Manchego cheese supply chain

The importance of ewe milk lies in the production of high quality cheeses, such as Manchego cheese with a Protected Designation of Origin, whose safety must be guaranteed. In a 2-yr study, 407 bulk tank milk samples from farms and 82 silo milk and curd samples from cheese factories were collected from southeast Spain and tested for aflatoxin M1 (AFM1) using 2 commercial ELISA tests. Of these, 99.3% of the bulk tank samples had AFM1 levels below the European Union (EU) legal limit for milk (50 ng/kg), and well below the limit adopted by the Codex Alimentarius (500 ng/kg). Moreover, 98.8% of the silo milk and curd samples from cheese factories had AFM1 levels below the EU limit for milk. When considering median AFM1 concentrations, an average 4-fold increase was found in the final curd in relation to the corresponding silo milk. Control of AFM1 in Manchega ewe milk would enhance dairy product safety by the possible detection of faults in the manufacture of Manchego cheese.

Developments in mycotoxin analysis: an update for 2007-2008

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2007 and mid-2008. It covers the major mycotoxins: aflatoxins, Alternaria toxins, cyclopiazonic acid, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. Some aspects of natural occurrence, particularly if linked to novel aspects of analytical methods, are also included. The review demonstrates the rise of LC-MS methods, the continuing interest in developing alternative and rapid methods and the modification of well-established mycotoxin analytical methods by individual laboratories to meet their own requirements.