Immobilization of Saccharomyces cerevisiae on Perlite Beads for the Decontamination of Aflatoxin M1 in Milk

Aflatoxin M1 (AFM1) contamination presents one of the most serious concerns in milk safety. In this study, the immobilization of Saccharomyces cerevisiae was used to detoxify AFM1-contaminated milk. The yeasts were immobilized on perlite for 24 and 48 hr, and the best immobilization time was achieved at 48 hr. Microscopic examination confirmed successful immobilization. The milk samples with 0.08, 0.13, 0.18, and 0.23 ppb AFM1 contamination were passed through the biofilter for 20, 40, and 80 min. The results showed a significant reduction in AFM1 concentration for all the milk samples with various initial AFM1 contents. The contaminated milk with 0.08 ppb AFM1 was completely cleared after 40 min of circulation while for the milk solution with 0.23 ppb, the highest AFM1 reduction was obtained at about 81.3% after 80 min circulation. In addition, the biofilter was saturated after the third step of milk circulation, containing 0.23 ppb AF, in which each step duration was 20 min. This study showed the excellent capability of the immobilized cells on the perlite beads to detoxify the AFM1-contaminated milk without any side effects on its physicochemical properties.

Practical application: The immobilization of Saccharomyces cerevisiae cells on perlite beads can be used to detoxify AFM1-contaminated milk. The perlite can provide a perfect support for immobilization. With respect to qualitative properties, 20 min, was suggested as the optimum time for milk decontamination. This study indicated that the detoxification of contaminated milk using immobilized S. cerevisiae cells on the perlite support did not affect the different properties of detoxified milk. This method can lead to a practical solution to address aflatoxin contamination in dairy products considered high-risk foods.