Microstructural evolution and mechanics behavior of postmortem meat subjected to resonance

Abstract

The tenderness of meat is determined by muscle components, mainly including myofibrillar and connective tissues. In the present study, the microstructures evolution and mechanics behavior of yak postmortem muscle subjected to resonance vibration treatment was investigated by experimental and numerical investigation, in order to illustrate the resonance tenderization mechanism and the mechanical relationship of muscle components. The results show that there are three orders of natural frequencies of the raw yak meat, and the resonance frequency is determined as 26 Hz. By vibration treatment at this frequency, the shear force and MFI of the vibrated meat is 35.70 N and 62, respectively, exhibiting remarkable tenderizing effect compared with the raw sample and other frequencies treated samples. The microstructures and vibration modal simulation have revealed that the stress concentration happens in the junction of muscle fibers and extracellular matrix (collagenous connective tissues), leading to the detachment of endomysium connective tissues from muscle fibers and the disappearance of M-bands in myofibrils, thus resulting the significant tenderization. The resonance also causes the stress-strain behaviors of meat transiting from plastic deformation to elastic deformation. The experimental and numerical results reveal that the physical destruction of the cross-linkings or interactions between muscle fibers and endomysium connective tissues induced by resonance, plays a crucial role in the detachment of muscle components, transformation of stress-strain behavior and the significant tenderization effect.