ELISA to quantify triose phosphate isomerase to potentially determine processing adequacy in ground beef

Triose phosphate isomerase (TPI) was purified from bovine semimembranosus m uscle using acetone precipitation, ammonium sulfate precipitation and catio n exchange chormatography. Anti-TPI polyclonal antibodies (PAbs) were raise d in rabbits. A sandwich ELISA with a limit of detection of 1 mu g TPI/mL w as developed using PAbs for capture and biotinylated PAbs for detection. Cr oss-reactivities of antibodies with other protein in beef muscle extracts a nd with TPI from different animal species were examined, TPI concentration and activity of ground beef decreased (P < 0.0001) as cooking temperature w as increased from 48.9 to 76.7 degrees C, suggesting that these assays migh t be used to monitor processing adequacy of beef products.