Effects of thermal treatment on collagen present in bovine M. Semitendinosus intramuscular connective tissue: Analysis of the chemical, thermal and mechanical properties

Abstract

There is still interest in understanding how the collagen characteristics of the intramuscular connective tissue (IMCT)-perimysium contributes to the tenderness and tenacity in different meat cuts after the cooking process. In the present work, the analysis of the changes in IMCT after thermal treatments is proposed. The study of the thermal treatment (1 h) at different temperatures (25−65 °C) was designed to focus on the chemical, mechanical and thermal properties of the collagen present in isolated IMCT-perimysium. Collagen degradation degree (Deg), the solubility of collagen and proteoglycan components, thermal properties and mechanical stress were studied on treated-IMCT-perimysium. The results showed that collagen Deg increased significantly at 65 °C. The soluble proteoglycan fraction did not show changes among treatments. Thermal properties presented notorious and significant changes at 65 °C. Enthalpies of denaturation (ΔH) increased and denaturation peak temperatures (Tp) decreased in relation with lower thermal-treatments. Finally, there were not significant differences in mechanical properties and load-stress among treatments. Deg at 65 °C might indicate chemical changes in total collagen; labile populations were solubilized while the stable population remained in IMCT-perimysium. The effects of thermal treatment at higher temperatures and the presence of meat enzyme should be investigated in the future.