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

Abstract

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.

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

“…The fact that DNC degrades to p -NA in aqueous solutions did not exclude other alternatives for residue disappearance in chicken meat subjected to cooking methods. The suggested pathway toward p -NA would be no more than speculation unless this aromatic amine was identified in actual heat-processed fillets previously prepared . Thus, we sought for the detection of p -NA traces in such chicken samples by means of LC-MS/MS to define part of the DNC fate.…”

“…This study was a complementary part of our recent research involving the fate of NCZ residues in chicken meat. All details upon broiler production, breast sampling, thermal processing, general cooking procedures, and sample preparation were previously described …”

“…The remaining four raw portions represented the control samples without heat treatment (identical to the blank samples). All breast portions were freeze-dried according to the previous procedure of sample preparation . Heat-processed control samples were analyzed to confirm that DNC is the only precursor of p -NA throughout thermal processing.…”

“…Although surveillance plans identified noncompliant samples for NCZ residue (>200 μg/kg), , studies have shown the disappearance of incurred DNC in chicken fillets during thermal processing. , However, details behind parent DNC decay in heat-processed chicken meat remain unclear, especially with respect to the proper identification of the degradation products. For instance, when chicken meat is submitted to heat treatment, p -nitroaniline ( p -NA) can be expected from DNC breakdown. , …”

“…p -NA is claimed to cause cancer , and methemoglobinemia. − Its occurrence in cooked chicken tissues is a matter of concern. Therefore, we focused on revisiting the DNC-containing cooked chicken samples, following the research previously initiated in our laboratory to detect, by liquid chromatography tandem mass spectrometry (LC-MS/MS), possible p -NA traces released during thermal processing. As a secondary approach, we verified the p -NA formation from the DNC cleavage in aqueous solution.…”