ELISA based Monitoring and Quantification of Tetracycline Residues in Fresh and Powdered Cow Milk Commercialized in Constantine Region (Northeast Algeria)

Background: This study aimed to identify tetracycline residues in milk consumed in the region of Constantine (northeast Algeria) using ELISA based tetracyclin kit. Methods: A total of 180 samples were analyzed (fresh cow milk and imported powdered milk). To compare ELISA and HPLC detection values, 22 fresh milk ELISA positive samples were confirmed by HPLC analysis. Result: 92.5% of fresh milk samples contained tetracycline residues at values between 5 and 74 µg/L and 33.3% of the samples showed concentrations between 49 and 74 µg/L, that exceed the MRLs recommended by the FDA. No significant differences (p greater than 0.01) were found between the values obtained by the two methods.