Detoxification of Aflatoxin M1 in Milk by Lactic Acid Bacteria

Abstract

Background: Aflatoxin M1 is a highly toxic and carcinogenic compound which is found in milk and milk products and it is a hydorxylated metabolite of Aflatoxin B1. When the dairy animal digested AFB1 contaminated feed, it is changed to aflatoxin M1 and transferred to tissues and milk. Aflatoxin M1 is less carcinogenic than AFB1, but it is acutely hepatotoxic as AFB1. Liver is their main target organ in the body. It has been calculated approximately that 0.3- 6.2% of presented AFB1 in animal feed transferred as aflatoxin M1 in milk. Occurrence of AFM1 in milk and milk products is a big concern. Therefore, several countries have standardized the maximum levels of AFM1 in milk and milk products. Methods: In this experiment, the ability of yoghurt bacteria to degrade AFM1 levels in milk and yoghurt were analysed. The starter culture of yoghurt contains Streptococcus thermophilus and Lactobacillus delbrueckii subsp. Bulgaricus (1:1). The experiment is carried out in Glasgow Caledonian University, department of life science in 2010. Result: These bacteria showed the higher binding ability between 90- 100% in milk samples whereas no considerable reduction was observed in yoghurt samples. In some yoghurt samples, an increase of AFM1 level was detected but in overall, concentration of AFM1 was stable in yoghurt. Also, the fat content of milk and yoghurt did not have any negative or positive effect on the concentration of AFM1 in milk and yoghurt.