Cooking effects on sulfonamide residues in chicken thigh muscle

This paper presents the net change by cooking on residues of sulfadiazine (SDZ), sulfamethoxazole (SMX), sulfamonomethoxine (SMM) and sulfaquinoxaline (SQ) in chicken muscles. These sulfonamides (SAs) were fed to chickens at a dietary concentration of 100 mg/kg (each drug) for 7 successive days. On the 7th day of feeding, they were killed and thigh muscles were collected. Muscle was ground, mixed and formed into 10-g meatballs. SA residues were determined by high-performance liquid chromatography. By using the usual cooking methods, boiling, roasting and microwaving, the muscles containing SAs were treated for the specified times. Net residues in the muscles cooked by boiling were reduced 45-61% in 12 min. In roast cooking, the SMX, SMM and SQ residues, except for SDZ, were reduced 38-40% in 12 min. No significant reduction of SDZ was found. By the microwave cooking, the four SAs residues were reduced 35-41% in 1 min. Reducing half-lives, of SAs in chicken muscles cooked were estimated as follows: 9.3 min for SDZ and 13.2 min for SMX, SMM and SQ in boiling; 18.3 min for SMX, SMM and SQ in roasting; 1.6 min for all the SAs in microwaving. (C) 2002 Elsevier Science Ltd. All rights reserved.