Study of Fast In-Line Measurement Techniques for Water Ice Characterization

Three analytical tools (conductivity, torque measurements and near-infrared spectroscopy (NIR)) were investigated for characterization of ice fraction (ϕ_ice) and viscosity (μ) of water ices. Sucrose water ices with varying sugar content (C_suc, 5-55 wt.%) were used as model water ices. A predictive model for ice fraction analysis using conductivity measurements was developed for C_suc≥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 ϕ_ice can be related to the increasing μ, 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.