Predicting the Kinetics of Ice Recrystallization in Aqueous Sugar Solutions

Area of Science:

• Materials Science
• Physical Chemistry
• Food Science

Background:

• Frozen product quality degrades due to ice crystal growth via recrystallization.
• Ostwald ripening theory is often used to model this, but predictions have been inaccurate.
• Accurate prediction requires accounting for non-ideal, non-dilute solutions and ice volume fraction.

Purpose of the Study:

• To accurately predict recrystallization rates in frozen systems using Ostwald ripening theory.
• To develop a formulation of Ostwald ripening based on Maxwell-Stefan diffusion.
• To simplify the calculation of material properties needed for Ostwald ripening predictions.

Main Methods:

• Developed an alternative Ostwald ripening formulation using Maxwell-Stefan diffusion.
• Related Maxwell-Stefan diffusion coefficients to easily measurable self-diffusion coefficients.
• Validated the approach using a model system of ice in an aqueous sucrose solution.

Main Results:

• Recrystallization rates were accurately predicted for ice in a water-sucrose solution.
• The new formulation simplifies material property calculations by canceling the thermodynamic factor.
• Predicted rates showed good agreement with experimental results (within a factor of 2).

Conclusions:

• Ostwald ripening theory can accurately predict recrystallization rates in frozen systems.
• The Maxwell-Stefan diffusion approach simplifies calculations and improves accuracy.
• This work provides a more reliable method for understanding and controlling ice recrystallization.