title: Inactivation of penicillin G in milk using hydrogen peroxide.
abstract: Milk antibiotic residues have been a public concern in recent years. The Grade A Pasteurized Milk Ordinance mandates that raw Grade A milk will test negative for beta-lactam antibiotic residues before processing. The purpose of this research was to investigate the ability of various levels of peroxide and heat to inactivate penicillin G in raw milk. Whole milk spiked to a mean of 436 +/- 15.1 (standard error of the mean) ppb of potassium penicillin G was treated with hydrogen peroxide at levels of 0.0, 0.09, 0.17, and 0.34%. Samples at each peroxide level (n = 6 per treatment) were treated as follows: 1) incubated at 54.4 degrees C for 3 h, 2) pasteurized at 62.8 degrees C for 30 min, 3) incubated and pasteurized as in treatments 1 and 2, or 4) received no further treatment. A beta-lactam competitive microbial receptor assay was used for quantification of penicillin G. Concentrations of penicillin in selected samples were determined by HPLC for a comparison of test methods. Treatments were evaluated relative to their ability to reduce milk penicillin G levels to below the safe level of 5 ppb. The 0.09% hydrogen peroxide level was ineffective for all treatments. Hydrogen peroxide at 0.17% lowered the mean penicillin G (+/- SEM) from 436 +/- 15.1 to 6 +/- 1.49 ppb using the incubated and pasteurized heat treatment. The 0.34% concentration of hydrogen peroxide was the most effective, inactivating penicillin G to a level well below the safe level of 5 ppb with the pasteurized heat treatment, with or without incubation.
authors.affiliation: Department of Population Health and Pathobiology, North Carolina State University, Raleigh 27695, USA.
authors.forename: W H
authors.initials: WH
authors.lastname: Hanway
authors.forename: A P
authors.initials: AP
authors.lastname: Hansen
authors.forename: K L
authors.initials: KL
authors.lastname: Anderson
authors.forename: R L
authors.initials: RL
authors.lastname: Lyman
authors.forename: J E
authors.initials: JE
authors.lastname: Rushing
mesh_terms: D000818:Animals; D004350:Drug Residues / Q000032:analysis*; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology*; D008892:Milk / Q000737:chemistry*; D010400:Penicillin G / Q000032:analysis / Q000037:antagonists & inhibitors*
chemical_list: D006861:Hydrogen Peroxide; D010400:Penicillin G