Flow properties, firmness and stability of double cream cheese containing whey protein concentrate

As estimated on-line, the viscosity after cooling of double cream cheese curd containing heat-denatured WPC (DCC+) increased from 1.4 Pa.s to 1.7 Pa.s when cooled to the range of 45 degrees C to 24 degrees C, and then decreased from 1.7 Pa.s to 1.0 Pa.s when cooled from 24 degrees C to 15 degrees C. The viscosity of DCC- (without heat-denatured WPC) increased from 1.5 Pa.s to 2.2 Pa.s at temperature shift from 40 degrees C to 15.5 degrees C. The firmness of stored DCC+ and DCC-, respectively, decreased from 15.1N to 6.5N when cooled to temperatures from 45 degrees C to 15 degrees C, and from 17.9N to 9.9N when cooled from 40 degrees C to 15.5 degrees C, as recorded by cone penetrometry. The structure of DCC+ cooled to 15 degrees C collapsed after penetrometry, and DCC+ cooled to 20 degrees C destabilized during shearing in coaxial cylinder rheometer. A new phase in DCC+ based on milk fat globules liberated by cluster disruption may be the cause of the structural and textural instability.