Determination of rendering plant sterilization conditions using a commercially available ELISA test kit developed for...

A commercially available enzyme-linked immunosorbent assay (ELISA) test kit developed for detection of cooked beef in meat samples was used to determine appropriate heat treatment of rendered materials. An improved extraction procedure increased the absolute difference in R-values between 2 rendered materials treated under different conditions (average temperature 129 and 134 degrees C, respectively). To evaluate the influence of the main sterilization parameters on ELISA results, a factorial design approach was used. The parameters investigated were temperature, time, particle size, and meat composition. Lean meat samples containing beef and pork were sterilized under strictly controlled conditions in a laboratory autoclave. The experiments demonstrated that the R-values obtained with the ELISA test kit for beef are strongly influenced by temperature and time, whereas particle size has a minor influence. The proportion of bovine material did not have any impact on R-values. Autoclave-processed lean meat samples were analyzed by using an ELISA test kit for pork, which was validated in a collaborative trial. The ELISA test kit for pork proved to be more sensitive for the investigated parameters, thus verifying and extending previous investigations.