Survey of meat collected from commercial broiler processing plants suggests low levels of semicarbazide can be created during immersion chilling

Authors: Mitchell, Trevor; Glenn, Anthony - Tony; Gold, Scott; Lawrence, Kurt; Berrang, Mark; Gamble, Gary; Feldner, Peggy; Hawkins, Jaci; Miller, Christine; Olson, Drew; Chatterjee, Debolina; McDonough, Callie; Pokoo-Aikins, Anthony

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2022
Publication Date: 2/10/2022
Citation: Mitchell, T.R., Glenn, A.E., Gold, S.E., Lawrence, K.C., Berrang, M.E., Gamble, G.R., Feldner, P.W., Hawkins, J.A., Miller, C.E., Olson, D.E., Chatterjee, D., Mcdonough, C.M., Pokoo-Aikins, A. 2022. Survey of meat collected from commercial broiler processing plants suggests low levels of semicarbazide can be created during immersion chilling. Journal of Food Protection. 85(5):798-802. https://doi.org/10.4315/JFP-22-012.
DOI: https://doi.org/10.4315/JFP-22-012

Interpretive Summary: Due to the potential for human health concerns, feeding the antibiotic nitrofurazone to food animals has been banned by many countries including the USA since the early 2000s. Detection of the nitrofurazone breakdown product, semicarbizide (SEM), in meats has been used as a marker for nitrofurazone use. However, there have been studies that suggest SEM can be found in meat due to causes other than the feeding of a banned antibiotic. We hypothesized that SEM can be formed in chicken meat under legal and acceptable slaughter and processing conditions and therefore detection of SEM is not a reliable indicator of nitrofurazone use during animal rearing. We collected 535 samples from 23 different broiler processing plants. Thigh meat was collected from early in processing (two locations prior to cooling) and late in processing (two locations after cooling). All samples were analyzed for presence and concentration of SEM. SEM was detected in 13.6% of samples. Of the positive samples, a statistically significant majority (72.6%) were from meat collected late in processing after the cooling step. Furthermore, of all positive samples, those collected late in processing had significantly higher mean concentration of SEM than those collected early in processing. These data show that SEM can be formed in chicken meat during processing and suggest that detection of SEM is not a good indicator for the use of the banned antibiotic nitrofurazone.

Technical Abstract: Semicarbazide (SEM) is routinely employed as an indicator for the use of nitrofurazone, a banned antimicrobial. Yet, the validity of SEM as a nitrofurazone marker has been scrutinized due to other possible sources of SEM. Nonetheless, a U.S. trade partner rejected skin-on chicken thighs due to SEM detection and suspected nitrofurazone use. Since nitrofurazone has been banned in U.S. broiler production since 2003, we hypothesized that incidental de novo SEM formation occurs during broiler processing. To assess this possibility, raw leg quarters were collected from 23 commercial broiler processing plants across the U.S. and shipped frozen to our laboratory where LC-MS was used to quantitatively assess for SEM. Leg quarter samples were collected at four points along the processing line: “hot rehang” (transfer from kill line to evisceration line), “pre-chill" (prior to chilling process ), “post-chill” (immediately following chilling), and at the “point of pack”. Thigh meat with skin attached was removed from 535 leg quarters and analyzed in triplicate for SEM, which was detected above the 0.5 ppb regulatory decision level in 73 samples (13.6% overall). Fifty three of the 73 positive samples (9.89% overall, 72.6% of the positive samples) were collected post-chill or at point of pack. Only nine of the 73 positive samples (1.68% overall, 12.3% of positive samples) were detected at hot rehang. There was a highly significant (p<0.0001) difference in both prevalence and concentration of SEM detected before and after chilling. These data confirm our hypothesis that SEM detection in raw broiler meat is related to de novo creation of the chemical during processing.