Effects of High-pressure Processing on the Tenderness and Shelf Life of Preconditioned Yak Meat

To investigate the effects of high-pressure processing (HPP) on the tenderness and shelf life of pre-conditioned yak meat, this study used untreated conventional pre-conditioned yak meat as the control group. The changes in tenderness indicators, including shear force, cooking loss, myofibrillar fragmentation index (MFI), protein solubility, surface hydrophobicity, and intrinsic fluorescence spectra, as well as shelf-life indicators, including total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and total viable count were examined under different HPP conditions (100, 200, 300, 400, and 500 MPa). The results demonstrated that HPP significantly improved the tenderness and prolonged the shelf life of yak meat (P<0.05). Among the tested pressures, the 300 MPa treatment achieved the best results. The treated yak meat exhibited a shear force of 11.22±0.25 N, a cooking loss of 25.06%±0.23%, a myofibrillar fragmentation index value of 110.4±0.40, a surface hydrophobicity of 49.41±0.04, a protein solubility of 63.21%±0.04%, a maximum fluorescence peak excitation wavelength of 325 nm, and TBARS, TVB-N, total viable bacterial counts within the permissible safety limits throughout the 15 d storage period, achieving a 9 d shelf life extension compared to the control group.