Bound chlortetracycline residues in bones: release under acidic conditions

Tetracycline residues were frequently found in the bones of slaughtered ani mals. These bound residues will contaminate products for human consumption, such as mechanically deboned meat. The aim of this study was to examine th e behaviour of bound residues of chlortetracycline during in vitro digestio n. Dough batches containing poultry meat and 2.5% by weight of bone splinte rs and bone meal with chlortetracycline residues were incubated with hydroc hloric acid and pepsin at 40 degreesC. With the aid of HPLC and agar diffus ion tests, evidence was obtained that these bound residues of chlortetracyc line could be released during in vitro digestion and become antimicrobially active. Hens fed with chlortetracycline containing meat and bone meal were also able to release bound tetracycline residues. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.