Physicochemical, thermal and mechanical characterization study of perimysial collagen of two bovine muscles

Chemical, thermal and mechanical collagen characteristics of intramuscular perimysial connective tissue (IMCT) from bovine Semitendinosus (ST) and Pectoralis profundus (PP) muscles were studied. Furthermore, these collagen characteristics in presence/absence of other extracellular matrix components were analyzed for both muscles. Differences between muscles were observed for collagen content; all IMCT-PP perimysial samples were higher than ST samples. In addition, for both muscles, IMCT-alkali resistant samples allowed the highest trypsin soluble collagen. The main differences between muscles were recorder for thermal and mechanical properties. The denaturation of collagen in the perimysium evidenced differences in total denaturation energy (ΔH) and peak temperatures (Tp). The ΔH resulted higher for IMCT-PP than for IMCT-ST tissues in all samples. By the tensile test it was observed that the maximum loads were constant and higher in all PP samples. In the FTIR assay, the peaks for the main amides were registered in both tissues. However, slight differences between ST and PP-IMCT were detected on hydrogen bond interactions and in secondary structure of the protein. The results reinforce the hypothesis of the presence of different IMCT-perimysial-collagen pools. In this study, chemical, thermal and mechanical characteristics were considered and quantified. However, the mechanical function and development of muscle in-vivo could be the main influence on the extracellular collagen characteristics as well as its interactions with non-collagen compounds. Its formation is essential for muscle function.