---

Introduction: Themilk traditional sterilization methods are notable to eliminate it, so the evaluation of the biological approaches such as utility of lactic acid bacteria is necessary for the reduction and removal of this toxin. In this study, the ability of Lactobacillus rhamnosus was assessed to decrease aflatoxin M₁adsorption for its reduction and adsorption in probiotic yogurt during shelf life.

Material & methods: Three concentrations of the remained aflatoxinM₁ in yogurt supernatants; 0.1,0.5and 0.75ppb; were determined during first, seventh, fourteenth and twenty first days after yogurt processing, determined by ELISA procedure and confirmed by HPLC.

Findings: The results showed that in both of the regular and probiotic yogurt, the lowest pH is related to treated yogurt samples by the low concentrations of toxin (0.1ppb) and its maximum rate is for yogurt which contains the high concentrations of toxin (0.75ppb).The reduction logarithmic cycle was 0.5 after21 days. Viability was high in all of three different aflatoxin M₁ levels at the first day after processing. The results suggest that Lactobacillus rhamnosus is able to adsorb more than99% aflatoxin M1 in 0.1 ppb, while the toxin adsorption in 0.5 and 0.75ppb were 92%and 93%, respectively.

Discussion & conclusions: The results of this study indicated Lactobacillus rhamnosus GG is able to reduce significantly the high toxin levels. Finally, ELISA procedure and HPLC results compared statistically and conformed that HPLC is able to be replaced by ELISA method to reduce the measurement costs of aflatoxin M₁. 

---

Introduction: Aflatoxin M₁ which is one of the aflatoxin B₁ metabolites may be in milk of animals via which they have been fed the contaminated feed. According to the important role of milk and dairy products in human nutrition, it is necessary to consider the quality and safety aspects of this worthy food. On the other hand, its contamination by aflatoxin M₁ is a threat for the consumers’ health; therefore, to use the procedures to remove or non-activation of aflatoxin M₁ in milk and dairy products is required. Microbial detoxification is one of the removal methods of aflatoxins, such as, aflatoxin M₁. In this research, the effect of Lactobacillus casei to reduce or eliminate aflatoxin M₁ in yogurt during its shelf life has been detected. Lactobacillus casei as probiotic yogurt starter bacteria was cultivated.
 
Materials & methods: Modified milk was infected by aflatoxin M₁ in four levels of 0.05, 0.1, 0.5 and 0.75 ppb. The samples were inoculated by Lactobacillus casei as probiotic yogurt starter bacteria. The amounts of residual aflatoxin M₁ were evaluated after centrifuging the samples in the first, seventh, fourteenth and twenty-first days by ELISA.
 
Findings: The results of this research indicate that the presence of Lactobacillus casei was effective on reducing toxin. It was also found the various amounts of aflatoxin M₁ don’t affect significantly on descending of toxin.
 
Discussion & conclusions: These findings imply that Lactobacillus casei using can be as one of the removal techniques among the microbial detoxification methods of the contaminated food by aflatoxin M₁.