Nicarbazin Residue in Tissues from Broilers Reared on Reused Litter Conditions.

Nicarbazin (NCZ) is a worldwide used anticoccidial in poultry farming to avoid coccidiosis disease when chickens are reared on conventional poultry litter. If proper dosage and withdrawal time are not followed, the component dinitrocarbanilide (DNC) of NCZ may be present in chicken tissues, therefore posing a risk to consumers if the residues are above 200 µg/kg. Litter reuse is a common and important practice in commercial chicken production. Literature is lacking about the influence of litter reuse on DNC deposition in chicken tissues and its impact on food safety. We aimed to evaluate DNC residues in breast and liver by LC-MS/MS from broilers from an experiment with 10 consecutive flocks during 2 years. The experiment included three treatments containing NCZ in the diet (T1 = 125 mg/kg, 1−21 d; T2 = 125 mg/kg, 1−32 d; T3 = 40 mg/kg, 1−32 d). DNC residues in chicken breast at 21 d in T1 ranged from 648.8−926 µg/kg, at 32 d in T2 and T3 varied, respectively, from 232−667 µg/kg and 52−189 µg/kg. Regarding liver, DNC residues at 21 days in T1 ranged from 11,754−15,281 µg/kg, at 32 days in T2 and T3 varied, respectively, from 10,168−15,021 µg/kg and 2899−4573 µg/kg. When NCZ was withdrawn from feed, DNC residues dropped to

Detection of p-Nitroaniline Released from Degradation of 4,4'-Dinitrocarbanilide in Chicken Breast during Thermal Processing.

The diphenylurea 4,4'-dinitrocarbanilide (DNC) is the residue of concern left in edible tissues of broilers fed diets containing the anticoccidial nicarbazin. When chicken meat is submitted to thermal processing, p-nitroaniline (p-NA) is expected from DNC degradation. This work aimed at evaluating whether thermal processing of DNC-containing chicken meat induces p-NA appearance. First, a hydrolysis assay was performed in aqueous solutions at 100 °C in different pH, confirming that DNC cleavage yields p-NA. Then a novel LC-MS/MS method was used to detect traces of this aromatic amine in DNC-containing chicken breast fillets subjected to cooking methods. Our evidence showed p-NA occurrence in such chicken meat samples, which corroborated results from hydrolysis assay. The p-NA appearance in fillets was rather discrete during boiling treatment, but its concentration became pronounced over time for grilling, frying, and roasting, achieving respectively 326.3, 640.0, and 456.9 µg/kg. As far as we are concerned, no other research identified degradation products from DNC residue in heat-processed chicken fillets. Therefore, this study leads to additional approaches to assess impacts on food safety.

Degradation of 4,4'-Dinitrocarbanilide in Chicken Breast by Thermal Processing.

Nicarbazin is one of the major anticoccidials used in broiler feeds. The compound 4,4'-dinitrocarbanilide (DNC) is the marker residue of concern left from nicarbazin in chicken meat. The effect of thermal processing on DNC content accumulated in chicken breast was assessed, and samples were analyzed by liquid chromatography-tandem mass spectrometry. Five conventional cooking methods were evaluated: boiling, grilling, microwaving, frying, and roasting. To ensure DNC in meat, broilers were fed nicarbazin without withdrawal period. All heating methods surpassed the 70 °C end point core temperature in chicken breast. Maximum DNC degradation was reached at 10 min for boiling, at 30 min for grilling, and at 2 min for microwaving, and no further reduction was observed for longer thermal processing time. Boiling was more efficient in reducing DNC (69%). Grilling, microwaving, and frying achieved on average 55% of degradation. The outcomes reported herein may be considered in decision-making regarding further review of maximum residue limits.