Comparison of yogurt test with commercial Kit for detection of antibiotic residues in raw and pasteurized milk producing in Chaharmahal va Bakhtiari – Iran

Antibiotics are widely used for the treatment of livestock. Their inappropriate use leads to various disorders in humans, through consuming animal products. Milk is among foods which are significantly affected by the used antibiotics. The objective of this study was to identify the antibiotic residue in raw and pasteurized milk in Chaharmahal and Bakhtiari - Iran, by using yogurt, four-plate, and Copan tests. To do so, 146 samples of raw milk and 54 samples of pasteurized milk were selected randomly from dairy farms and dairy products suppliers. The presence of antibiotics was evaluated by using yogurt, four-plate as well as Copan tests. Also, the sensitivity of the three tests to tetracycline and penicillin was compared. Totally 8.9% of raw milk and 12% of pasteurized milk samples contained antibiotics, but in 2% of the positive samples, the levels of antibiotic residues were higher than MRL. Regarding the results, there are significant differences between four plate test and yogurt test (P < 0.05), but between the positive results of yogurt and coupon tests no significant differences was observed (P > 0.05). Thus yogurt test could be used as an inexpensive, easy and sensitive method for identification of antibiotic residues in milk.

Keywords:

Antibiotic residue , Milk , Yogurt test , Commercial kit