Evaluations of Different Sources of Saccharomyces cerevisiae to Binding Capacity of Aflatoxin B1 Utilizing their Adsorption Isotherms

Abstract

The aim of the present study was to determine the ability of four different sources of Saccharomyces cerevisiae (autolyzed yeast, brewer’s yeast, cell wall yeast and inactivated yeast) to adsorb aflatoxin B1 through adsorption isotherms. For this, a phosphate buffered saline solution containing 2 μg of AFB1/ml was prepared and the yeast with a variant concentration of 0.05 g to 1.0 g was added and incubated at 10, 20 and 30 mins. After the incubation time the quantification was made by high performance liquid chromatography. It was verified through the isotherms that the absorption of aflatoxins increased as a result of yeast concentration and that the best time for action was 20 mins. Also, the application of the extended Langmuir model was more adequate for brewer’s yeast and cell wall, and these were more effective in the adsorption. In contrast, the autolyzed and inactivated yeast presented an inverse behavior, reducing the percentage of adsorption by increasing the amount of free aflatoxin; being able to be recurrent of the reversibility of the reaction (30 min) and reduction in the adsorptive capacity (10 min); related to the state of the β-D-glucans present in the cell membrane and the occupation of the yeast binding sites; adapting better to the Freundlich model.