Introduction: Aflatoxin M₁ is an important mycotoxin frequently found in milk and dairy products. The main objective of this work was to study the stability of AFM₁ during production and refrigerated storage of probiotic yogurt.

Materials and methods: Two kinds of probiotic yogurt were made by cow’s milk artificially contaminated with aflatoxin M₁ at a level of 100 ng/l, and fermented to reach pH 4.5. The yogurts were stored at 4 °C for up to 21 days. Analysis of aflatoxin M₁ in yogurt was carried out, using immunoaffinity column extraction and liquid chromatography coupled with fluorometric detection.

Results: The aflatoxin M₁ levels in the probiotic yogurts showed a significant decrease (p<0.05) compared with those initially added to milk. During the refrigerated storage the aflatoxin M₁ was lower in‘DELVO-YOG MY 1821’(MY 1821) yogurt than ‘FD-DVS ABY3’ (ABY3), but the difference was not significant (p>0.05). The percentage loss of the initial amount of aflatoxin M₁ in milk was estimated at about 41% and 49% by the end of storage for yogurts made by ABY3 and MY1821 yogurt, respectively. Loss of viability of the probiotic bacteria in presence of aflatoxin M₁ was strain dependent. Aflatoxin M₁ had no remarkable effect on viability of tested bacteria.

Conclusion: The probiotic yogurt can reduce the AFM₁ content of initial milk during production and storage. More studies are needed to investigate the effectiveness of other mixed probiotic cultures with different composition, to reduce the AFM₁ content of milk.

Introduction: Hamburger is a popular type of fast foods consumed all over the world. Sarcocystis spp. is a zoonotic parasitic pathogen which endangers safety of meat and meat products. The present study describes the prevalence rate of Sarcocystis spp. in hamburgers in Yazd, Iran using PCR-RFLP.

Materials and methods: Raw hamburger samples (100 traditional and 90 industrial) from central region of Iran, Yazd were randomly selected. The genomic DNA was extracted using salting out method. Detection and identification of Sarcocystis isolates was performed using PCR-RFLP.

Results: The results showed that 77.9% of all tested hamburger samples were infected with Sarcocystis spp. The infection rate in the traditional hamburger (87%) was significantly (p<0.05) higher than the industrial ones (67.8%). The rate of S. cruzi, S. hirsuta and S. hominis in the traditional hamburger samples, was 39%, 61% and 54% respectively while the rate of S. cruzi, S. hirsuta and S. hominis in the industrial hamburgers was 67.8%, 58.9% and 57.8%. S. cruzi, respectively. The rate was significantly (p<0.05) higher in industrial hamburgers than in the traditional ones. No statistical association was found between percentage of meat content and the rate of contamination in the industrial hamburger (p>0.05).

Conclusion: Having zoonotic significance, considerable infestation rate of S. hominis seems to be high in hamburgers of this region of Iran. To the best of our knowledge, this is the first of its own kind carried out in hamburger samples in Iran.