Improved microbiological assay for penicillin residues in tissues and stability of residues under cooking procedures
Katz, S.E.; Fassbender, C.A.; Depaolis, A.M.; Rosen, J.D.
Journal - Association of Official Analytical Chemists 61(3): 564-568
1978
ISSN/ISBN: 0004-5756 PMID: 649548 Document Number: 125715
The microbiological assay for penicillin residues was improved by using centrifugation to remove physical barriers to diffusion, a small buffer/meat extraction ratio, and a more sensitive 2-layer assay system. Recoveries from muscle, kidney, and liver tissues ranged between 70.1 and 86.7% with measurable levels of 0.03--0.05 unit/g. By comparison, the Food and Drug-suggested methodology yielded recoveries of 45.9--54.0% and levels of detectability of 0.08--0.10 unit/g. Cooking of hamburger, steaks, and port chops indicated that procaine penicillin withstood cooking conditions, and significant levels of the original activity remained.