Small peptides (<5 kDa) found in ready-to-eat beef meat

Dietary proteins can have biological properties, many attributed to bioactive peptides (2–50 amino acids). Since little is known about peptides in meat, we investigated the postmortem occurrence of low molecular weight peptides (<5 kDa) in bovine Pectoralis profundus muscle, after 14 days storage at 4 °C and vacuum cooking for 90 min at 75 °C. The study combined quantitative (amino acid analysis) and qualitative approaches (mass spectrometry). Eighty-nine percent of peptidic amino acids in fresh muscle corresponded to carnosine, anserine and glutathione. Levels of these compounds were lower in cooked meat compared to fresh muscle. Concomitantly, numerous larger compounds, most probably peptides, were generated in a very reproducible manner during ageing and even more during cooking of meat. Seven peptides (fragments of troponin T, nebulin, procollagen and cypher proteins) were identified in cooked meat extracts.