The effect of temperature and concentration on rheological behaviour of freeze dried soursop juice concentrates were investigated using a rheometer over a wide range of temperatures (10-70 C) and concentrations (10-50 Brix) at shear rates of 0-400 1/s. The Power law is the best fitted model to the rheological data due to the high value of coefficient of determination (R2 = 0.9989). The soursop juice concentrates exhibited shear thinning or pseudoplastic behaviour with n < 1. The consistency coefficients dependency on temperature and concentration were well described by Arrhenius relationship and exponential relationship respectively. The flow activation energy of soursop juice concentrates were 8.32-30.48 kJ/mol. The superposition technique with Power law model sufficiently modelled the overall rheological characteristics of soursop juice concentrates into a single master curve using shift factors based on double shifting steps with R2 = 0.9184. This technique also showed that the soursop juice concentrates increases in viscosity and pseudoplasticity behaviour with concentration. © 2013 Elsevier Ltd. All rights reserved.
Quek, M. C., Chin, N. L., & Yusof, Y. A. (2013). Modelling of rheological behaviour of soursop juice concentrates using shear rate-temperature-concentration superposition. Journal of Food Engineering, 118(4), 380–386. https://doi.org/10.1016/j.jfoodeng.2013.04.025