THE ASSESSMENT OF REDUCING AFLATOXIN M1 IN KEFIR BY SACCHAROMYCES KEFIR AND LACTOBACILLUS CASEI TD4 BY ELISA METHOD

Aflatoxin M1 (AFM1) is the metabolite of the aflatoxin B1 (AFB1) and highly toxic compound. Occurance of AFM1 in milk and dairy products had hazardous effects for human beings especially children and elderly .It has been proposed that the consumption of lactic acid bacteria (LAB) and some of the yeast capable of binding or degrading food-borne carcinogens would reduce human exposure to these deleterious compounds. The purpose of this study was to evaluate the ability of Candida kefir strain and Lactobacillus Casei TD4 to bind AFM1 and create different starters from these strains that have more ability to reduce AFM1 in kefir that made from milk spiked with AFM1. Accordingly, five levels of kefir starter 4, 8, 12, 16 and 20% were used. In addition, L. casei were used at five levels 0.1, 0.3, 0.5, 0.7 and 0.9% with constant amount of kefir starter (8%) separately. The amount of unbound AFM1 was analyzed by competitive ELISA. Results showed that all assessed strains whether L. casei or kefir starter exhibited different degrees of aflatoxin binding in kefir. The sample containing 20% kefir starter had the most reduction of AFM1 (91.91%) and between bacterial samples, Lactobacillus Casei TD4 whit (92.52 %) at 0.9% level had the maximum amount of AFM1 binding. In general, When yeast was used with LAB the removal efficiency of AFM1 significantly increased. These findings supported that specific bacteria and yeast used in this study can offer decontaminating AFM1 kefir.