Universal compression behaviour of semi-hard cheeses: A basis for designing plant-based cheese alternatives?

In this study, we explored the fracture and rheological behaviour semi-hard cheeses varying in age (0–15 weeks), composition (dry matter 43–58%, protein 22–25% and fat 10–30%) and processing history, through microstructural observation after stepwise uniaxial compression and assessment of the shear deformation within and beyond the linear viscoelastic regime. The semi-hard cheeses exhibited similar behaviour at high deformation regimes despite the compositional variation. Both visual observations and compressive deformation showed significant fracture of the various semi-hard cheeses at 70% strain, leading to subsequent propagation throughout the cheese matrices. Microscopic failure, however, already commenced at ∼30% compression and 10 kPa stress for all cheeses, as determined through image analysis of micrographs from confocal laser scanning microscopy after 0–90% compression. A (semi-)dynamic imaging approach allowed the demonstration and quantification of the structural changes in cheese matrices at different length scales. Insights into the universality of the fracture behaviour of the semi-hard cheese investigated in our study serve as a valuable reference for designing protein-continuous plant-based cheeses.