A Study on PH, Zeta Potential, Optical Behavior, and a Sensing Model for Optical Properties of Ice Slurry




Ly, Vicki

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The ice slurry beverage is a triphasic colloid where ice crystals are formed from a flavoring syrup and water solution while entrapping dissolved CO2. Beverage quality is dependent on a number of factors but of special interest to the theoretical aspect of this study is the ice slurry's full dissolution of CO2 into aqueous phase, ice crystallization, CO2 bubble nucleation, and homogenous phase dispersions. In-line and feedback controls built into the Frozen Slurry Dispenser (FSD) would potentially improve drink homogeneity and prolong the homogenous state of the beverage. Accordingly, this thesis investigated ice crystal formation, CO2 gas bubble dissolution, drink integrity, and consistency using Optical Spectroscopy(OS) and the electrochemical method of Zeta Potential measurements.

Spectral observations have led to realization of binary states recognizable by optical spectroscopy at characteristic wavelengths between a beverage's frozen and unfrozen state. Optical spectra in the UV/VIS and NIR range were analyzed using chemometric methods (Partial Least Squares, Principal Components Analysis, and Multilinear Regression) to create a drink behavior model and showed correlations between the model and certain Ice Slurry Beverage settings. With the ultimate goal of creating a cost effective in-line quality sensing and controls system in a Frozen Slurry Dispenser(FSD), a number of optical sensing methods such as reflection fiber optics, a transmission sensing control, and dynamic light scattering will be explored and applicably adapted.


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Chemometrics, Colloids, Optical Spectroscopy, pH, Sensing, Zeta Potential



Electrical and Computer Engineering