Effect of Collagen on Microstructural and Rheological Properties of Cheese Spreads

Hydrolyzed collagen modifies the structure of cheese spreads: it develops a hybrid casein-collagen matrix and stabilizes the fat emulsion. This research featured the effect of hydrolyzed collagen on the microstructure and rheology of cheese spreads. The study involved experimental cheese spread with 3.1% hydrolyzed collagen and a collagen-free control sample. The method of optical microscopy and image analysis (Fiji ImageJ2) made it possible to study the microstructure. The rheological profile was investigated on an experimental Reokon tensile strength tester with a knife indenter. Hydrolyzed collagen improved the structural and mechanical properties of the finished product. As the protein matrix grew more compact and the fat emulsion became more stable, the average size of fat globules dropped from 26.5 to 14.8 μm without coagulating or clustering. In addition, the porosity of the protein matrix reduced by 20% while the aqueous phase distribution became more homogeneous. Hydrolyzed collagen improved the adhesion and viscosity properties of the experimental cheese spread by 40% but not its tensile strength. As a result, viscosity prevailed over elasticity, and the experimental cheese spread retained its plasticity. Hydrolyzed collagen proved to be an effective component in the formulation of cheese spreads that require high adhesion and plasticity. However, it is likely to spoil the targeted structural properties of smoked or sliced cheeses. The results open up new prospects for further optimization of the texture of domestic cheese spreads.