Effect of Glass Transition Temperature on the Viscosity of Carbohydrate Solutions and Fruit Juices as Functions of Temperature and Solute Concentration.

The effects of temperature and solute concentration on the viscosity of various carbohydrate solutions including fruit juice were investigated, and the applicability of a viscosity-predictive approach based on the glass transition temperature (T_g) was discussed. Maltodextrin, maltose, and calcium maltobionate-maltose mixture showed Newtonian behavior. Mango juice and mango puree showed pseudo-plastic and plastic behaviors, respectively, depending on the solute concentration. Results from all solutions except for those from mango puree were applied to the Vogel-Fulcher-Tammann (VFT) equation, and a constant (T₀) in the VFT equation was determined. The T_g values, on the other hand, were calculated by the Gordon-Taylor (GT) equation using literature values. From the relationship between the predicted T_g and determined T₀, it was found that the T₀ decreased linearly with decreasing T_g depending on the solute, and the lines converged at the point for pure water. This result improves the applicability of a viscosity-predictive approach of which GT and VFT are combined (GT-VFT). The GT-VFT equation will be useful for the prediction of viscosity of carbohydrate solutions as functions of temperature and solute concentration based on minimal experimental results. [ABSTRACT FROM AUTHOR]