A. Camaj Ibrahimi, B. Berisha, A. Haziri, A. Camaj Isa, H. Dibrani Sopjani, S. Muriqi, N. Shala and I. Hoxha*
Aflatoxin M1 (AFM1), a toxic byproduct of aflatoxin B1 (AFB1) produced by Aspergillus fungi, is a carcinogenic mycotoxin that can contaminate various agricultural commodities. It can be transferred from AFB1-contaminated feed to milk and dairy products, including yogurt, posing a potential health risk to consumers. In spring 2023, a total of 74 yogurt samples were collected from the largest food suppliers in Kosovo for analysis, including samples produced in Kosovo and seven other countries: Albania, North Macedonia, Bosnia and Herzegovina, Slovenia, Greece, Italy, and Germany. A rapid and sensitive analytical method, Enzyme-linked immunosorbent assay (ELISA), was used for the analysis. The results of the study highlight discernible differences in the maximum tolerable levels of AFM1 between the countries. More specifically, yogurt samples from Slovenia and Germany had lower levels than those from other countries. Additionally, the median levels of AFM1 in samples from Slovenia and Germany were significantly lower. The mean concentrations of AFM1 in yogurt samples from Kosovo and other countries were 0.071 µg/kg and 0.080 µg/kg, respectively. Out of all samples, 66 (89%) exceeded the maximum tolerable limit of 0.05 µg/kg. Among the exporting countries, Albania had the highest median AFM1 level of 0.085 µg/kg and the highest maximum level of 0.195 µg/kg. Slovenia had the lowest median AFM1 level, while Germany had the lowest maximum AFM1 level. All samples from Albania, Greece, and Bosnia and Herzegovina exceeded the maximum tolerable limit. High prevalence was also observed in samples from Kosovo, North Macedonia, and Slovenia. Considering the average daily consumption of about 250 grams of yogurt, and the total median value of Aflatoxin M1 concentration (0.071 µg/kg), the estimated daily intake was calculated to be 0.017 µg. These findings highlight the importance of monitoring and enforcing regulatory limits to ensure yogurt safety and to protect public health. Efforts should be focused on mitigating AFM1 contamination and implementing measures to minimise its presence in dairy products, especially in regions where levels exceed the established limits.
Key words: yogurt; ELISA; aflatoxin M1; food; contamination
AFM1 = Aflatoxin M1
AFB1 = Aflatoxin B1
ELISA = Enzyme-linked immunosorbent assay
Aflatoxin M1 (AFM1) is a toxic metabolite of aflatoxin B1 (AFB1), a carcinogenic mycotoxin produced by Aspergillus fungi that can contaminate various agricultural commodities (IARC, 2002). AFM1 can be transferred from AFB1-contaminated feed to milk and dairy products, including yogurt, posing a potential health risk for humans who consume them (Prandini et al., 2009). Approximately 0.3–6.2% of AFB1 is converted into metabolised AFM1 and excreted in milk, depending on various factors (Iqbal et al., 2015). The International Agency for Research on Cancer (IARC) has classified AFM1 with AFB1 as a Group 1 carcinogen (IARC, 2002). Studies have shown that the presence of AFM1 in milk and milk products, including yogurt, is a health issue due to their regular consumption by all age groups (Iqbal et al., 2015). The main harm of AFM1 is its carcinogenicity and mutagenicity, which can destroy human and animal liver tissue, resulting in hepatocarcinoma and even death. AFM1 alone can also cause damage to DNA by covalently binding to it, which may enhance the genotoxicity already caused by AFB1 (Saha Turna et al., 2021).
The presence of AFM1 in milk and dairy products has been known for several decades and is an important problem worldwide, especially for developing countries (Iqbal et al., 2015).
Aflatoxin-producing fungi are found in areas with hot, humid climates and aflatoxins in food are a result of both pre- and post-harvest fungal contamination (EFSA et al., 2020). Climate change is anticipated to impact the presence of aflatoxins in food in Europe. Aflatoxin M1 has stable physical and chemical properties and is not destroyed by pasteurisation. According to Iha et al. (2013), processing and storage have little effect on AFM1 content in milk and milk products, with total AFM1 mass in milk being reduced by 3.2% in cheese and 6% in yogurt (pH 4.4).
The European Commission has specified that AFM1 in milk should not exceed 0.05 μg/kg (European Commission, 2006). Kosovo has adopted several EU regulations and standards for food safety and quality, including those related to dairy products such as yogurt. Dairy products are an important part of Kosovo’s diet and economy, with significant annual per capita consumption of milk and cheese (Kosovo Agency of Statistics, 2018). In Kosovo, only a few studies have been conducted on AFM1 in milk in recent years, and no research has been published on the presence of AFM1 in yogurt.
According to a 2016 study in Kosovo by Camaj et al. (2018), a high percentage of milk samples were found to be non-compliant with maximum AFM1 levels. This suggests that efforts are needed to reduce contamination levels of aflatoxin B1 in cow feed in Kosovo. In the Balkan region, several studies have been conducted over the past ten years on the incidence of aflatoxin M1 in milk and dairy products (Camaj et al., 2018; Ilievska et al., 2022; Topi et al., 2022), indicating further efforts are needed to reduce the contamination levels of AFB1 in cow feed, and regular monitoring of the milk is needed.
The objective of this research was to assess the occurrence of AFM1 in yogurt samples found in markets and major food suppliers in Kosovo during spring 2023.
These samples were produced in Kosovo and in countries exporting to Kosovo.
This study will contribute to safeguarding consumer health and promoting the production and consumption of safe and high-quality yogurt.
Materials and methods
Out of this total, the 74 samples of yogurt were collected from markets (largest food suppliers) in Kosovo during spring 2023, for analysis of the quantity of AFM1 toxin. Of the 74 samples, 40 samples were produced in Kosovo and 34 in other countries: North Macedonia (5), Albania (7), Bosnia and Hercegovina (6), Slovenia (6), Greece (6), Italy (2), and Germany (2).
The samples were tested immediately after collection.
The quantitative analysis of AFM1 in the yogurt samples was done using enzyme-linked immunosorbent assay (ELISA) method, one of several methods used for the detection of AFM1 in dairy products. It offers many advantages including a shorter analysis time, simultaneous analysis of many samples, limited use of organic solvents, absence of complicated sample preparation steps, simple analytical procedure compared to long-lasting and expensive chromatographic techniques (Jukić et al., 2020). To test AFM1, we used the MEIZHENG BioTech Co. Aflatoxin M1 ELISA Test Kit, following the manufacturer`s instructions, and summarised as follows. Each testing reagent kit offered a certificate with the validation results (Table 1). While the specific ELISA protocol was not validated in our laboratory for this determination, it is important to note that this method is well-established and routinely used in our lab for aflatoxin M1 testing, and the reagent kit offered a validation certificate.
Our lab has extensive experience with this methodology, ensuring reliability and reproducibility of results.
All samples were tested at room temperature (20-25°C) immediately after collection. The dilution factor was 1. For testing, 1 g of each sample was measured and diluted with 4 mL of sample diluting buffer I, and vortexed for 2 minutes. Then samples were centrifuged for 5 minutes at 4000 rpm. For the assay, 50 μL of the sample dilution was measured.
The principle of the Aflatoxin M1 ELISA Test Kit is an indirect competitive enzyme-labelled immunoassay. The aflatoxin M1 antigen is precoated on the wells. The aflatoxin M1 in the sample competes with the aflatoxin M1 antibody with aflatoxin M1 antigen on the well, while the AFM1 antibody combines with the enzyme conjugate. Then the substrate solution is pipetted to the wells to convert the colour. The colour of the unknown samples is compared to the colour of the standards and the aflatoxin M1 concentration is derived. The absorbance values were obtained using a plate reader set at 450 nm, and the level of AFM1 was calculated using a logarithmic standard curve, and the average of duplicates was used as the result. According to the manufacturer’s certificate, sensitivity was 0.015 μg/kg (the same as the LOD of this kit for raw milk determination), which seems to suggest it should be capable of detecting aflatoxin M1 at levels lower than the LOD.
Sensitivity is usually the concentration of the second standard (Table 1). Recovery was 100%±30%, and the precision for intra-lab assay was CV% < 10%.
In the current study, it is essential to note that the Limit of Detection (LOD) of the employed kit for fermented milk and milk beverage is 0.075 µg/kg, which is higher than the maximum tolerable limit of aflatoxin M1 in yogurt as set by the regulatory guidelines (0.05 µg/kg). Interestingly, we observed results that were lower than the specified Limit of Detection (LOD) of the kit (0.075 µg/kg). These results indicate that some of the yogurt samples have very low or even undetectable levels of aflatoxin M1.
Aflatoxin M1 ELISA Test Kit standard summary
Table 1 provides the absorbance values A450, B/B0 ratios, and CV% values, for different concentrations of Aflatoxin M1 standards used in the ELISA test Kit validation, as provided on the certificate of analysis by the manufacturer. These values serve as reference points for comparing the results obtained from samples tested with the Aflatoxin M1 ELISA Test Kit.
CV% (Coefficient of Variation) is calculated as CV= (SD/μ) x 100%, where SD is the standard deviation of the replicates (two replicates for each concentration of the standard), and μ is the average of replicates.
Statistical analysis was performed using SPSS. The results were grouped into two categories by country of production (Kosovo vs. other countries). The results obtained for the AFM1 content were expressed as mean values with standard deviation (SD), as median, and as maximum concentration of AFM1.
We used statistical tests to determine if there were any significant differences between the groups. For two groups, we used student’s t-test and for three or more groups, we used One-Way Analysis of Variance (ANOVA) with a significance level of P < 0.05 for both tests. To confirm the outcomes of the independent t-test, we used effect size as an additional variable (Dankel et al., 2017). Effect size is a measure of the disparity between two group means (Lakens, 2013). Both substantive importance (effect size) and statistical importance (P value) must be presented to interpret the findings (Sullivan and Feinn, 2012).
Results and discussion
Table 2 presents the analysis of yogurt samples for the presence of AFM1 (in μg/kg). The samples are categorised into two groups by country of production, i.e., Kosovo and imported from other countries.
Out of these samples, 40 samples of yogurt produced in Kosovo were tested and had a median AFM1 level of 0.070 µg/kg, with a maximum level of 0.110 µg/kg. Of these, 16 samples (40%) exceeded the LOD (0.075 µg/kg) and 37 (92%) exceeded the maximum level of 0.05 µg/kg.
In comparison, 34 samples of yogurt produced in other countries were tested and had a median AFM1 level of 0.072 µg/kg, with a maximum level of 0.195 µg/kg.
Of these, 11 samples (32%) exceeded the LOD (0.075 µg/kg) and 29 (85%) exceeded the maximum level of 0.05 µg/kg.
In total, out of the 74 samples tested, the median AFM1 level was 0.071 µg/kg and the maximum level was 0.195 µg/kg.
Of all samples, 27 (36%) exceeded the LOD and 66 (89%) exceeded the maximum level of 0.05 µg/kg.
Table 3 shows the corresponding values of AFM1 for the samples produced and imported from seven other countries.
Table 3 shows that yogurt produced in Albania had the highest median AFM1 level of 0.085 µg/kg and the highest maximum level of 0.195 µg/kg among all countries. All seven samples (100%) exceeded the maximum level of 0.05 µg/kg. In comparison, yogurt produced in North Macedonia had a lower median AFM1 level of 0.070 µg/kg and a lower maximum level of 0.075 µg/kg. None of these samples exceeded the LOD and four (80%) exceeded the maximum level of 0.05 µg/kg. Yogurt produced in Bosnia and Herzegovina had a median AFM1 level of 0.090 µg/kg, which is higher than that of North Macedonia but lower than that of Albania. The maximum level was 0.150 µg/kg, which was also higher than that of North Macedonia but lower than that of Albania. All six samples (100%) exceeded the maximum level of 0.05 µg/kg.
Yogurt produced in Greece had a median AFM1 level of 0.072 µg/kg and a maximum level of 0.100 µg/kg, both lower than those of Albania and Bosnia and Herzegovina but higher than those of North Macedonia. All six samples (100%) exceeded the maximum level of 0.05 µg/kg. Yogurt produced in Slovenia had the lowest median AFM1 level among all countries at 0.057 µg/kg and a low maximum level of 0.065 µg/kg. None of these samples exceeded the LOD and four (67%) exceeded the maximum level of 0.05 µg/kg. Yogurt produced in Italy had a median AFM1 level of 0.077 µg/kg and a maximum level of 0.110 µg/kg, both higher than those of Slovenia but lower than those of Albania, Bosnia and Herzegovina, and Greece. Yogurt produced in Germany had the lowest maximum AFM1 level among all countries at 0.055 µg/kg and a low median AFM1 level of 0.042 µg/kg, which is lower than the median of all other countries.
In total, of the 34 samples tested from these countries, the median AFM1 level was 0.070 µg/kg and the maximum level was 0.195 µg/kg.
According to the data calculated in Table 4, the findings of this study revealed that no statistically significant disparities (x̄ Kosovo = 0.071 µg/kg, x̄ other countries = 0.080 µg/kg, t=-0.1.307, P=0.198) were observed between Kosovo and other countries with respect to AFM1 concentrations. The mean concentrations of Aflatoxin M1 (AFM1) in the analysed yogurt samples were 0.071 ± 0.018 µg/kg and 0.080± 0.037 µg/kg for yogurt from Kosovo and other countries, respectively.
The current study aimed also to investigate the variations in average levels of Aflatoxin M1 (AFM1) in yogurt across seven distinct countries that import yogurt into Kosovo (Table 5).
The findings from this study highlight discernible differences in the maximum tolerable levels of AFM1 among countries. More specifically, yogurt samples from Slovenia and Germany had lower levels than those from other countries. Additionally, the median levels of AFM1 in samples from Slovenia and Germany were significantly lower. The mean AFM1 levels were as follows: Albania (0.11 ± 0.05 µg/kg), North Macedonia (0.08 ± 0.04 µg/kg), Bosnia and Hercegovina (0.08 ± 0.17 µg/kg), Greece (0.07 ± 0.01 µg/kg), Slovenia (0.05 ± 0.00 µg/kg), Italy (0.07 ± 0.04 µg/kg), and Germany (0.04 ± 0.001 µg/kg).
Means that share the same letter are significant.
A two-year survey of aflatoxin M1 in milk marketed in Albania, by Topi et al. (2022) found that AFM1 was detected in 62 out of 119 milk samples (52.10%) and that AFM1 contamination in pasteurised milk was higher than that in UHT milk samples (59.68% and 43.86%, respectively). Seven milk samples (5.88%) contained AFM1 at levels exceeding the European Union maximum residue permitted level. A study published in 2022 (Ilievska et al.) revealed a high incidence of AFM1 in UHT milk and dairy products marketed in North Macedonia. According to this study, the highest incidence of AFM1 was found in yogurt samples (93.8%), with 178 yogurt samples tested.
Calculating Risk Assessment for aflatoxin M1 in yogurt
To estimate the exposure to aflatoxin M1 from yogurt, we need to calculate the estimated daily intake based on consumption patterns and the concentration of aflatoxin M1 detected in yogurt. The formula to calculate the estimated daily intake is as follows:
Estimated Daily Intake (in micrograms) = average yogurt consumption (in grams) x aflatoxin M1 concentration (in micrograms per kilogram) / per body weight
The Dietary Guidelines for Americans 2020–2025 recommends 3 cups of dairy per day for anyone over the age of 9 years. Each cup of yogurt counts as 1 cup of dairy, or about 250 grams daily. Based on this recommendation, if we consider that the average yogurt consumption per day is one cup, or about 250 grams, and if we take the total median value (0.071 µg/kg) as per aflatoxin M1 concentration, then the estimated daily intake would be as follows:
Estimated Daily Intake (in micrograms) = 0.25 kg x 0.071 µg/kg = 0.017 µg
According to this assumption, if a grown person consumes one cup of yogurt per day, or about 250 grams, the estimated daily intake of aflatoxin M1 from yogurt is 0.017 micrograms per body weight of the individual (in kg). Because no regulatory agency has set a tolerable daily intake (TDI) for AFM1, it is not possible to compare exposure estimates to a TDI to determine at-risk populations (Saha Turna et al., 2021). According to Mollayusefian et al. (2021), the aflatoxin level in food commodities should be reduced to the lowest possible level.
In conclusion, the findings from this study highlight discernible differences in the maximum tolerable levels of AFM1 among countries. More specifically, yogurt samples from Slovenia and Germany had lower levels than those from other countries. Additionally, the median levels of AFM1 in samples from Slovenia and Germany were significantly lower.
The mean concentrations of AFM1 in yogurt samples from Kosovo and other countries were 0.071 µg/kg and 0.080 µg/kg, respectively. Out of the total number of samples, 66 (89%) exceeded the maximal tolerable limit of 0.05 µg/kg. Among the countries that export to Kosovo, yogurt produced in Albania had the highest median AFM1 level of 0.085 µg/kg and the highest maximum level of 0.195 µg/kg among all countries. Yogurt produced in Germany had the lowest maximum AFM1 level among all countries at 0.055 µg/kg and the lowest median AFM1 level of 0.042 µg/kg. All the samples from Albania, Greece, and Bosnia and Hercegovina exceeded the maximum tolerable limit for AFM1. A high prevalence was shown in samples from Kosovo, North Macedonia, and Slovenia.
Considering the average yogurt consumption of one cup or about 250 grams per day and considering the total median value of aflatoxin M1 concentration (0.071 µg/kg), the estimated daily intake was calculated to be 0.017 µg. The risk assessment for aflatoxin M1 in yogurt was conducted to estimate the exposure to this toxin based on consumption patterns and its concentration in yogurt samples.
It is important to note that no regulatory agency has established a tolerable daily intake (TDI) for AFM1. Therefore, comparing exposure estimates to a TDI to identify at-risk populations is not possible. However, existing research suggests that aflatoxin levels in food commodities should be minimised to the lowest possible level to ensure food safety.
These findings emphasise the importance of monitoring and enforcing regulatory limits to ensure the safety of yogurt and to protect public health. Efforts should be made to mitigate AFM1 contamination and implement measures to minimise its presence in dairy products, particularly in regions where levels exceed the set limits. These measures will contribute to safeguarding consumer health and promoting the production and consumption of safe and high-quality yogurt.
The authors acknowledge the University “Haxhi Zeka” in Peja, Kosovo, for funding the research, and the Food and Veterinary Agency of Kosovo for hosting the laboratory work.
References [… show]
1. CAMAJ, A., K. MEYER, B. BERISHA, T. ARBNESHI and A. HAZIRI (2018): Aflatoxin M1 contamination of raw cow’s milk in five regions of Kosovo during 2016. Mycotoxin Res. 34, 205-209. 10.1007/s12550-018-0315-4
2. DANKEL, S. J., K. T. MATTOCKS, M. B. JESSEE, S. L. BUCKNER, J. G. MOUSER, B. R. COUNTS and J. P. LOENNEKE (2017): Frequency: The Overlooked Resistance Training Variable for Inducing Muscle Hypertrophy? Sports Med. 47, 799-805. 10.1007/s40279-016-0640-8
3. Dietary Guidelines for Americans 2020-2025, Make Every Bite Count with the Dietary Guidelines, USDA, December 2020, https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf
4. EFSA PANEL ON CONTAMINANTS IN THE FOOD CHAIN (CONTAM), D. SCHRENK, M. BIGNAMI, L. BODIN, J. K. CHIPMAN et al. (2020): Risk assessment of aflatoxins in food. EFSA J., 18(3) e06040. 10.2903/j.efsa.2020.6040
5. EUROPEAN COMMISSION (2006): Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Off. J. Eur. Union, L 364/5. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:364:0005:0024:EN:PDF
6. EUROPEAN COMMISSION (2018): Kosovo* 2018 Report. Brussels: European Commission.
7. EUROPEAN COMMISSION (2018): Kosovo* 2018 Report. Commission Staff Working Document. https://neighbourhood-enlargement.ec.europa.eu/system/files/2019-05/20180417-kosovo-report.pdf
8. IARC (2002): Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene. IARC Monogr. Eval. Carcinog. Risks Hum. 82. Lyon, France: International Agency for Research on Cancer. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4781602/
9. IHA, M. H., C. B. BARBOSA, I. A. OKADA and M. W. TRUCKSESS (2013): Aflatoxin M1 in milk and distribution and stability of aflatoxin M1 during production and storage of yogurt and cheese. Food Control 29, 1-6. 10.1016/j.foodcont.2012.05.058
10. ILIEVSKA, G., B. STOJANOVSKA-DIMZOSKA, D. KOCEVA, G. STOJKOVIĆ, A. ANGEESKA and E. DIMITRIESKA-STOJKOVIC (2022): Dietary Exposure and Health Risk Assessment of Aflatoxin M1 in Dairy Products Consumed by Population in North Macedonia. J. Food Qual. Hazards Control 9, 142-152. 10.18502/jfqhc.9.2.6868
11. IQBAL, S. Z., S. JINAP, A. A. PIROUZ and A. R. FAIZAL (2015): Aflatoxin M1 in milk and dairy products, occurrence, and recent challenges: A review. Trends Food Sci. Technol. 46, 110-119. 10.1016/j.tifs.2015.08.005
12. JUKIĆ, H., S. DEDIĆ, M. RODIĆ, Z. JUSUF HODŽIĆ and D. DEMIROVIĆ (2020): Determination of Aflatoxin M1 in Raw Milk by the ELISA Method in the Una-Sana Canton. In IFMBE Proc. Springer. 78, 10.1007/978-3-030-40049-1_33
13. KOSOVO AGENCY OF STATISTICS (2018): Results of the Household Budget Survey 2017. Pristina: Kosovo Agency of Statistics. https://ask.rks-gov.net/media/4169/results-of-the-household-budget-2017.pdf
14. LAKENS, D. (2013): Calculating and reporting effect sizes to facilitate cumulative science: A practical primer for t-tests and ANOVAs. Front. Psychol. 4. 10.3389/fpsyg.2013.00863
15. TURNANIKITA, S. and F. WU (2021): Aflatoxin M1 in milk: A global occurrence, intake, & exposure assessment. Trends Food Sci. Technol. 110, 183-192. 10.1016/j.tifs.2021.01.093
16. PRANDINI, A., G. TANSINI, S. SIGOLO, L. FILIPPI, M. LAPORTA and G. PIVA (2009): On the occurrence of aflatoxin M1 in milk and dairy products. Food Chem. Toxicol. 47, 984-991. 10.1016/j.fct.2007.10.005
17. SULLIVAN, G. M. and R. FEINN (2012): Using Effect Size – Or Why the P Value Is Not Enough. J. Grad. Med. Educ. 4, 279-282. 10.4300/JGME-D-12-00156.1
18. TOPI, D., J. SPAHIU, A. REXHEPI and N. MARKU (2022): Two-year survey of aflatoxin M1 in milk marketed in Albania. Food Control 136, 108831. 10.1016/j.foodcont.2022.108831
Pojavnost aflatoksina M1 u uzorcima jogurta pronađenima na tržištu u Kosovu tijekom proljeća 2023.
Arieta CAMAJ IBRAHIMI, PhD, Assistant Professor, Faculty of Agribusiness, University “Haxhi Zeka”, Peja, Kosovo; Bajram BERISHA, PhD, habil., Full Professor, Faculty of Agriculture and Veterinary, University of Prishtina, Kosovo; Arben HAZIRI, PhD, Full Professor, Faculty of Math and Science, University of Prishtina, Kosovo; Aferdita CAMAJ ISA, MSc., Kosova Medicines Agency, Prishtina, Kosovo; Hata DIBRANI SOPJANI, MSc., Food and Veterinary Agency, Prishtina, Kosovo; Shyhrete MURIQI, PhD, Assistant Professor, Faculty of Agribusiness, University “Haxhi Zeka”, Peja, Kosovo; Nexhdet SHALA, PhD., Full Professor, Faculty of Agribusiness, University “Haxhi Zeka”, Peja, Kosovo; Ibrahim HOXHA, PhD, Associate Professor, Faculty of Agribusiness, University “Haxhi Zeka”, Peja, Kosovo
Aflatoksin M1 (AFM1), toksični nusproizvod aflatoksina B1 (AFB1) kojeg proizvode gljivice Aspergillus kancerogeni je mikotoksin koji može kontaminirati različite poljoprivredne proizvode; može se prenijeti iz hrane za životinje kontaminirane s AFB1 na mlijeko i mliječne proizvode, uključujući i jogurt, predstavljajući potencijalni rizik za zdravlje potrošača. U proljeće 2023. godine prikupljena su ukupno 74 uzoraka jogurta od najvećih dobavljača hrane na Kosovu za analizu, uključujući uzorke proizvedene u Kosovu i u sedam drugih zemalja: Albaniji, Sjevernoj Makedoniji, Bosni i Hercegovini, Sloveniji, Grčkoj, Italiji i Njemačkoj. Za analizu je rabljena brza i osjetljiva analitička metoda, enzimski povezani imunosorbentni test (ELISA). Rezultati studije ukazuju da nalazi ove studije naglašavaju velike razlike u maksimalno dopuštenim razinama AFM1 između različitih zemalja. Točnije, u uzorcima jogurta iz Slovenije i Njemačke uočene su niže razine od onih iz drugih zemalja. Uz to, srednje razine AFM1 u uzorcima iz Slovenije i Njemačke bile su značajno niže. Srednje koncentracije AFM1 u uzorcima jogurta s Kosova i iz drugih zemalja bile su 0,071 µg/kg, odnosno 0,080 µg/kg. Od svih uzoraka, 66 (89 %) bilo je više od dopuštenog ograničenja od 0,05 µg/kg. Od zemalja uvoznica, Albanija je imala najveću srednju razinu AFM1 od 0,085 µg/kg i najveću maksimalnu razinu od 0,195 µg/kg. Slovenija je imala najnižu srednju razinu AFM1, a Njemačka najnižu maksimalnu razinu AFM1. Svi uzorci iz Albanije, Grčke i Bosne i Hercegovine bili su veći od maksimalno dopuštene razine. Visoka prevalencija zamijećena je i u uzorcima s Kosova, iz Sjeverne Makedonije i Slovenije. Razmatrajući prosječnu dnevnu konzumaciju od jedne čašice od oko 250 g jogurta i ukupnu srednju vrijednost koncentracije aflatoksina M1 (0,071 µg/kg), izračunat je procijenjeni dnevni unos od 17,75 µg. Ovi nalazi naglašavaju važnost nadziranja i provođenja regulatornih ograničenja kako bi se osigurala sigurnost jogurta i zaštitilo zdravlje ljudi. Potrebno je uložiti napore za smanjenje kontaminacije AFM1 i provedbu mjera za smanjenje njegove prisutnosti u mliječnim proizvodima, posebice u regijama u kojima razine prekoračuju utvrđena ograničenja.
Ključne riječi: jogurt, ELISA, aflatoksin M1, hrana, kontaminacija