Microstructure alterations in beef intramuscular connective tissue caused by hydrodynamic pressure processing

- HDP causes immediate and sustained improvements in beef semimembranosus tenderness.
- HDP disrupts the microstructure of beef intramuscular connective tissue.
- Shockwave effects on connective tissue integrity contribute to HDP tenderization.

Scanning electron microscopy (SEM) was utilized to evaluate microstructural changes in intramuscular connective tissue of beef semimembranosus muscle subjected to hydrodynamic pressure processing (HDP). Samples were HDP treated in a plastic container (HDP-PC) or a steel commercial unit (HDP-CU). Control and HDP samples were obtained immediately post-treatment and after 14 days of aging for SEM and Warner-Bratzler shear force (WBSF) analysis. Immediately post-treatment, HDP treated samples exhibited lower (P < 0.01) WBSF than did controls. After aging, HDP-PC samples had lower (P < 0.01) WBSF than that of aged controls. SEM analysis indicated that HDP-PC treatment disrupted the integrity of the collagen fibril network of the endomysium in both the non-aged and aged samples. Aging effects on the intramuscular connective tissue were observed in the HDP-PC and control samples. Both WBSF and connective tissue changes were greater in the HDP-PC than in the HDP-CU treated samples. Data suggest that shockwave alterations to connective tissue contribute to the meat tenderization of HDP.