High pressure induces changes in texture and microstructure of muscles in dry-cured hams

• Some μCT geometric parameters of dry-cured ham muscles are related to hardness.
• Pressurization (HP) at 500 MPa modifies muscle hardness and microstructure.
• HP increases hardness of Biceps femoris and Semimembranosus muscles.
• The μCT parameters related to hardness are not affected by HP processing.
• The compaction of muscles fibres, shown by SEM, is related to hardness increase.

The objective of this paper was to study the changes in the microstructure of Semimembranosus and Biceps femoris muscles of dry-cured hams induced by high pressure (HP) processing and their relationship with the changes in texture. The HP treatment (500 MPa) decreased softness (Y90) in both muscles. Both X-ray microcomputed tomography (μCT) and scanning electron microscopy (SEM) analysis showed differences in microstructure between muscles. Some μCT geometric parameters were negatively (structure thickness of fatty objects, structure separation of lean tissue) and positively (surface/volume and fragmentation index of fatty objects) correlated with hardness, but no one was significantly modified by HP treatment. SEM analysis showed that pressurization had a higher effect on BF muscle than on SM muscle.Industrial relevanceIn ham industry, high pressure (HP) processing is used to achieve the microbial safety of hams and to improve texture, especially in those hams with a reduced salt content. The data presented in this study contributes to the understanding of HP effect on textural traits at microstructural level.