Impact of thermo-mechanical treatments on composition, solids loss, microstructure, and rheological properties of pasta filata–type cheese

The impact of thermo-mechanical treatments on cheese properties was investigated. Curd was mixed at different temperatures (60, 65, or 70 °C), for different lengths of time (3 or 6 min), and at different speeds (6, 9, or 12 rpm) in a torque rheometer. Specific mechanical energy, final curd temperature, and heat load index were measured to predict cheese properties. Considerable changes in cheese composition were observed depending on the mixing treatment, and fat loss was related to the mechanical energy imparted (R2 = 0.92). Microstructural changes in fat were considerable in mixed cheese, as observed by scanning electron microscopy and confocal laser scanning microscopy. Bulk water entrapped in the cheese structure increased with curd temperature and heat load (R2 = 0.60) but was not affected by the mechanical energy imparted. Rheological properties of young cheeses were not affected by the range of mixing treatments imposed.