Ability of Different Treatments of Saccharomyces cerevisiae to Surface Bind Aflatoxin M 1 in Yoghurt

Abstract

Microbial detoxification is considered as one of th e most common methods used for the elimination of aflatoxins. Reports indicate that S. cerevisiae can be effective in removing aflatoxins through the adsorption of aflatoxins to their cell wall. In the current research, the ability of S. cerevisiae (viable, acid-, heat- and ultrasound-treated yeast s) to bind aflatoxin M 1 was assessed in yoghurt. To this end, firstly, rec ombinant milk containing 12% solids, non-fat skimmed milk powder was prepare d. Next, the samples were spiked by aflatoxin M 1 using different concentrations (100, 500 and 750 p g mL -1 ). When the starter bacteria were added to the milk, the treate d yeasts were added as well. The concentration of aflatoxin M 1 residue in the supernatant of the yoghurt samples after different storage times (1, 7, 14 and 21 days) was measured using the ELISA method. The results showed that all treatments containing viabl e, acid-, heat-, ultrasound-treated yeast and starter bacteria were able to adsorb aflatoxin M 1 , and the ability of the treated yeast was significant as compared with the control (P< 0. 05). Among the treated yeasts, the ability of the acid-treated yeasts was higher in to xin binding. Overall, it can be concluded that using S. cerevisiae for the biological adsorption of aflatoxin M 1 is effective in fermented dairy products. Keywords: Biological adsorption, Cell wall, Fermentation, Man nan, Yeast.