Effects of Processing on Antibiotic Residues (Streptomycin, Penicillin−G and Tetracycline) in Soft Cheese and Yoghurt Processing Lines

Abstract

Fifty-eight samples (40 cheese and 18 yoghurt samples) were collected from five soft cheese and two conventional yoghurt processors. The samples were collected along the processing lines of these dairy products and analyzed for antibiotic residues (streptomycin, penicillin-G and tetracycline). The mean residual levels for cheese was; streptomycin (0.0040±0.0018), penicillin-G (0.0062±0.0026) and tetracycline (0.0023±0.0008), while levels in yoghurt was; streptomycin (0.0014±0.0010), penicillin-G (0.0017±0.0017) and tetracycline (0.0011±0.0071). Penicillin-G exceeded Maximum Residue Limit (MRL) in raw milk and cheese for 4 out of the 5 processors. In yoghurt processing only powdered milk for processor F exceeded MRLs for penicillin-G. Significant differences (p<0.05) was obtained along the processing lines for all processors. Generally antibiotic residue levels reduced along the processing line of soft cheese and yoghurt. The presence of penicillin-G above MRLS in some of the samples poses a threat to the consumers.