Study of fast in-line measurement techniques for water ice characterization

Three analytical tools (conductivity, torque measurements and near-infrared spectroscopy (NIR)) were investi-gated for characterization of ice fraction (phi ice) and viscosity (mu) of water ices. Sucrose water ices with varying sugar content (Csuc, 5-55 wt.%) were used as model water ices. A predictive model for ice fraction analysis using conductivity measurements was developed for Csuc >= 25 wt.%. Due to instrument limitation, the model only provided a rough estimation of the amount of ice formed, however the results show the potential of the technique and further studies are required. The increasing phi ice can be related to the increasing mu, obtained using torque measurements. An empirical model was proposed to describe the evolution of the water ices viscosity with ice fraction, and a good correlation was found (R2=0.986). Although NIR spectroscopy proved not adequate for ice fraction analysis, the method has been applied by other authors for characterization of ice cream mixes, including rheological properties.