RHEOLOGICAL BEHAVIOR AND TIME-DEPENDENT CHARACTERIZATION OF ICE CREAM MIX WITH DIFFERENT SALEP CONTENT

摘要

The effect of salep concentration on the rheological characteristics of ice cream mixes (0.5-1.5% salep content), prepared from nonfat cow's milk and sugar, was studied using a controlled stress rheometer. The flow curves and time-dependent flow properties of the ice cream mixes were assessed at different temperatures. The ice cream mixes' samples showed slightly thixotropic behavior, which was reduced as the salep content decreased. The forward and backward measurements of the flow curves of ice cream mixes were modeled with the power law model. The ice cream mixes showed pseudoplastic flow behavior after destruction of the thixotropic structure. In mixes that were first presheared at a high shear rate flow properties could also be described by the power law model. The second-order structural kinetic, first-order stress decay and Weltman models were applied to model the time-dependent flow properties of the ice cream mixes. Among these, the first-order stress decay model was found to fit well the experimental data.