Detoxification of aflatoxin M1 in yoghurt using probiotics and lactic acid bacteria

Probiotics and lactic acid bacteria (LAB) are widely used in food fermentation and preservation. This study was carried out to assess the potential of five strains of LAB and bifidobacteria to remove aflatoxin M1 (AFM1) from yoghurt. The stability of the AFM1 complexes formed with them in both viable and non-viable (heat- or acid-treated) forms was assessed by repetitive aqueous extraction. Strains with high ability in removing AFM1 were selected to study its ability to remove AFM1 from spiked milk during yoghurt production and storage. Three treatments from yoghurt that produced from spiked milk were studied. Treatment A was the control using fermented yoghurt culture (Streptococcus thermophilus and Lactobacillus bulgaricus). Treatment B was fermented by 50% yoghurt culture (S. thermophilus and L. bulgaricus) and 50% Lactobacillus plantrium. Treatment C was fermented by yoghurt culture (S. thermophilus and L. bulgaricus) and 50% Lactobacillus acidophilus. The samples were collected during different storage (5 °C) times (1, 3, 5 and 7 days) to determine the ability of the stains to reduce AFM1. The results indicted that there were significant differences (P < 0.05) between the strains in their ability to reduce AFM1 in MRS broth media in the viable stage, heated stage and acid treatment. L. plantrium was the highest strain capable of removing AFM1. Yoghurt fermented by 50% yoghurt culture (S. thermophilus and L. bulgaricus) and 50% L. plantrium recorded the highest reduction in the level of AFM1 at the end of storage period. The results revealed the possibility of using some strains of LAB and bifidobacteria in detoxification of AFM1-contaminated foods.