Sonocrystallization: effect on lactose recovery and crystal habit

Area of Science:

• Food Science
• Crystallization Engineering
• Process Intensification

Background:

• Sonocrystallization typically controls nucleation, but this study explores its use for rapid, complete crystallization.
• Lactose crystallization is crucial in food processing, but conventional methods can be slow and inefficient.

Purpose of the Study:

• To investigate the rapid crystallization of lactose using ultrasound (sonocrystallization) with an anti-solvent.
• To optimize sonocrystallization parameters for enhanced lactose recovery and crystal properties.
• To compare sonocrystallization with conventional stirring for lactose recovery.

Main Methods:

• Model reconstituted lactose solutions were subjected to sonocrystallization with ethanol as an anti-solvent at 30°C.
• Parameters like sonication time, lactose concentration, protein concentration, and pH were varied for optimization.
• Lactose recovery and crystal size distribution were analyzed and compared to non-sonicated samples.

Main Results:

• Sonocrystallization achieved 91.48% lactose recovery in 5 minutes, compared to 14.63% with stirring.
• Lactose recovery decreased significantly at lower pH values (below 4.2).
• Protein concentration (even at 0.2% w/v) had a substantial impact on lactose recovery.
• The rapid sonocrystallization process resulted in a more uniform crystal size distribution.

Conclusions:

• Sonocrystallization offers a rapid and efficient method for lactose recovery from reconstituted solutions.
• Optimizing parameters like pH and protein concentration is crucial for maximizing recovery.
• Ultrasound-assisted crystallization enhances lactose recovery and improves crystal properties, showing potential for industrial applications.