Evaluation of oscillatory and shear strain behaviour for thermo-rheological plasticisation of non-ripened cheese curd: Effect of water, protein, and fat

Non-ripened cheese curd with different dry matter (34.5–47.0 g 100 g−1), protein (13.4–30.4 g 100 g−1), and fat (0.5–25.9 g 100 g−1) contents were produced from pre-acidified milk (citric acid, pH 5.8) with different fat-to-protein ratios (0, 0.18, 0.33, 0.79, 1.60) and different curd cooking times (15 min, 30 min, 85 min). From small angle oscillatory temperature sweep and large strain capillary rheology shear experiments it was deduced that the protein content increases and fat decreases maximal loss tangent and storage modulus. This is discussed in relation to suggested changes in casein micelle voluminosity with temperature. A critical shear stress above which the flow behaviour changes from regular to melt fracture behaviour was observed. This is explained by shear jamming and the frequency dependency of the sol–gel transition.