Effect of storage and processing on tetracycline residues in meat and bones.

A semiquantitative microbiological screening test for antibiotics, a sensitive and quantitative microbiological assay, and a fluorometric method specific for tetracyclines are described. Using these procedures, tetracycline residues in animals derived from feed can be detected in tissues like organs, muscles, and bones. Meat contaminated with chlortetracycline (CTC) and oxytetracycline (OTC) and stored at +8 degrees C and -22 degrees C showed very little decrease in antibiotic concentration; however, heating above 65 degrees C reduced the tetracycline content in meat. Temperatures above 130 degrees C were necessary to destroy CTC in bones, CTC in bones was insoluble above pH 4. Manufacturing products with contaminated meat reduced the tetracycline content only if heating was involved.