Development of a Validated Database for the Authentication of Fresh/Chilled and Frozen Pork Using β-Hydroxylacyl-CoA-Dehydrogenases (HADH) Assay

Abstract

Food authenticity such as illegal substitution of frozen meats for fresh meats is one of the public concerns within the food authorities, industry, and consumer groups. An enzymatic method based on the activity of β-hydroxyacyl-CoA-dehydrogenase was used aiming to differentiate between fresh/chilled and frozen pork meats. The β-hydroxyacyl-CoA-dehydrogenase activity for meat samples was respectively determined as received (X0) and after a frozen (for 72 h at -18°C) and thawed cycle (X1). A database of the R1 values (X0/X1) was established from the measurement of β-hydroxyacyl-CoA-dehydrogenase activity of authentic fresh, chilled and frozen meats. Results showed that the R1 values were normally distributed after taking a natural logarithm and were independent on the positions where the porcine samples were taken from the carcasses. The R1 values were significantly higher for frozen meats than others due to the increased release of β-hydroxyacyl-CoA-dehydrogenase from damaged cells. When the literature R1 value was applied to the database, it gave false positive rates ranging from 4.8 to 5.7%. This was probably caused by interspecies variation. A new local cut-off R1 value of 0.60 was then determined from the 99th percentile of the data distribution of authentic fresh and chilled samples. The local cut-off R1 value was validated with market samples and all samples were found to be labelled correctly.