Effect of residence time in the cooker-stretcher on mozzarella cheese composition, structure and functionality

To manufacture mozzarella cheese with customized attributes the relationships between processing parameters and cheese functionality need to be identified. In this study, cooking residence time (CRT) and stretching residence time (SRT) of cheese curd in the cooker-stretcher were determined to differentiate the effect of the cooking and stretching processes on cheese properties. Residence times were linked to cheese composition, micro- and macro-structural characteristics (microstructure, fat globule size, anisotropy and rheology) and functional properties (meltability, oiling-off, browning and stretchability). In the stretcher used, CRT was significantly longer than SRT independent of curd temperature or screw speed. Linear correlations were found between CRT and cheese composition, anisotropy and storage modulus. SRT had a less significant effect on cheese properties, due to the low specific mechanical energy 0.15–0.46 kJ kg⁻¹ and relatively short SRT. It was concluded that CRT and SRT are promising factors to understand and control mozzarella cheese characteristics during manufacture.