Mechanical Properties of Cheese, Cheese Analogues and Protein Gels in Relation to Composition and Microstructure

Samples of commercial Cheddar cheese, experimental Cheddar cheeses made from heated, ultrafiltration-concentrated mllks, processed cheese analogues and whey protein gels of defined composition were examined microscopically and some fracture and deformation properties were determined. Surfaces of cheese prepared by critical point drying and those examined frozen were comparable in microstructure. As the concentration factor of the milk used for experimental c heesemaking increased, the cheese became more resistant to reversible deformation, the work required to cut with a wire or break wf th a hammer increased and the microstructure showed that the protein matrix was coarser. The force to deform o r work to cut cheese analogues depended on the composition. The work to deform and break whey protein gels depended on the composition , microstructure and testing direction . In genera 1, gels containing more j.l-lactoglobult n were less easy to break and formed tighter gels. Microscopy of surfaces formed by impact fracture indicated that the combination of cutting and cracking may vary between samples