Instant infusion pasteurization for gentle heat treatment of milk for cheese making: Rennet coagulation properties

Summary

The rennet coagulation properties of milk samples subjected to instant infusion pasteurization at 72°C, 100°C and 120°C were measured and compared to the rennet coagulation properties of milk subjected to a standard pasteurization at 72°C for 15 s. Two different rheometers were used for the measurements for determination of the rennet coagulation time and the curd firming rate. The results from the two rheometers showed the same trends; the rennet coagulation time increased and the curd firming rate decreased as the temperature of instant infusion pasteurization was increased. This was expected, however, the magnitude of the changes was smaller than expected. Instant infusion pasteurization could thus be a more gentle method than other high temperature heat treatments regarding the rennet coagulation properties of the milk.