A non-destructive method to monitor changes in a troponin T peptide in beef drip with a monoclonal antibody.

ABSTRACT

To simplify the monitoring of postmortem beef aging, we established a system to detect a troponin T (TnT) peptide fragment in bovine muscle drip (natural exudates) with an original monoclonal antibody. The antibody was raised against a synthetic peptide APPPPAEVPEVHEEVH corresponding to the N-terminal region of bovine fast-type TnT. In a competitive enzyme-linked immunosorbent assay (ELISA), our antibody detected the standard peptide dose-dependently. According to the monitoring examination with a competitive ELISA during 22days postmortem, the concentration of the peptide in both the drip and trichloroacetic acid extracts from the longissimus muscle (n=4) significantly increased in parallel, up to 10nmol/ml and 16.4nmol/g at day 14 postmortem, respectively. These events were accompanied by an increase in the conventional 30kDa fragment in western blot analysis and a decrease in the Warner-Bratzler shear force value of the beef from 5.0 to 2.4N/cm(2). The peptide detection system using drips with the antibody has advantages applicable to a non-destructive, simple, quick, and on-site monitoring method, such as immunochromatography.