• Modelling the changes in viscosity during thermal treatment of milk protein concentrate using kinetic data

      Ho, Quang Tri; Murphy, Kevin M.; Drapala, Kamil P.; Fenelon, Mark A.; O'Mahony, James A.; Tobin, John; McCarthy, Noel; Enterprise Ireland; TC/2014/0016 (Elsevier, 2018-10-24)
      This work aimed to model the effect of heat treatment on viscosity of milk protein concentrate (MPC) using kinetic data. MPC obtained after ultrafiltration was subjected to different time-temperature heat treatment combinations. Heat treatment at high temperature and short time (i.e., 100 or 120 °C×30 s) led to a significant increase in viscosity in MPC systems. Second-order reaction kinetic models proved a better fit than zero- or first-order models when fitted for viscosity response to heat treatment. A distinct deviation in the slope of the Arrhenius plot at 77.9 °C correlated to a significant increase in the rate of viscosity development at temperatures above this, confirming the transition of protein denaturation from the unfolding to the aggregation stage. This study demonstrated that heat-induced viscosity of MPC as a result of protein denaturation/aggregation can be successfully modelled in response to thermal treatment, providing useful new information in predicting the effect of thermal treatment on viscosity of MPC.