Submitted to: Poultry Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/25/2002
Publication Date: 10/1/2002
Citation: Jones, D.R., Fletcher, D.L., Lyon, C.E. 2002. Variations in levels of acid phosphatase present in chicken whole leg meat. Poultry Science. 81:1567-1570. Interpretive Summary: Acid phosphatase (ACP) activity was examined in raw and cooked chicken dark meat as a potential endpoint temperature indicator. Multiple sample lots from the same flock of chickens were analyzed. Within a sample lot, ACP activity was consistent for raw and cooked samples. When sample lots were compared, differences were seen between all sample lots for both raw and cooked levels. These results indicate ACP is not well-suited as an endpoint temperature indicator in processed poultry.
Technical Abstract: Acid phosphatase (ACP) has been identified as a potential biomarker for endpoint temperature determination in further processed poultry. Multiple analyses of the same sample for ACP have produced consistent results. The degree of variation in ACP levels present in different production lots has not been identified. This study was conducted utilizing a single flock of broilers. Birds were slaughtered on four separate days (replications) and whole leg, without skin, was homogenized. Proximate composition was analyzed for each replication. Water-soluble proteins were extracted from raw meat and assessed for initial ACP levels. Samples of meat were cooked to an internal temperature of 71.1C. There were significant (P<0.05) differences between replications for both moisture and fat content. When dry fat content was analyzed, no significant differences occurred between replicates. Initial ACP levels were significantly (P<0.0001) different between replicates (500.33 to 348.97 units of activity/kg). Levels of ACP activity after cooking were also significantly (P<0.0001) different between replicates (17.61 to 10.82 units of activity/kg). Percent degradation of activity during cooking was similar (96.98 to 95.89%) between replicates. ACP levels were consistently measured within a replicate. Differences between replicates for both initial and cooked levels indicate a threshold level for determination of thermal endpoint would be difficult to establish. ACP may not be a sensitive measure to estimate the degree of doneness of meat samples in which initial ACP concentration is unknown. Identical raw sample required for such a comparison would be difficult for the processing industry to maintain.