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

- Samples (56%) of milk and dairy products from winter were positive with AFM1.
- Highest mean of AFM1 was found in raw milk samples from winter i.e. 129.6 ± 8.4 ng/L.
- Samples 30.5% of dairy products from winter were found higher than the EU limits.
- Dietary intake 4.7 ng/L/day was found from winter samples in 1-5 year male infants.
- Dietary intake 4.6 ng/L/day was found from winter samples in 1-5 year female infants.

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.