Using state diagrams for predicting colloidal stability of whey protein beverages

Area of Science:

• Food Science
• Colloid Science
• Protein Chemistry

Background:

• Whey protein beverages are susceptible to colloidal instability after thermal processing.
• Understanding protein behavior under different pH conditions is crucial for product development.

Purpose of the Study:

• To establish a method for evaluating colloidal stability of whey protein beverages post-thermal treatment.
• To develop state diagrams predicting beverage stability based on pH and protein behavior.

Main Methods:

• Developed three state diagrams (pH 3-7) for whey protein beverages after ultrahigh-temperature (UHT) treatment.
• Utilized electrophoresis and chromatography to assess protein solubility, turbidity, and aggregation.
• Investigated aggregation propensities of key whey proteins: β-lactoglobulin, α-lactalbumin, bovine serum albumin, and glycomacropeptide.

Main Results:

• High colloidal stability and individual whey protein solubility observed at pH 3.
• Poor solubility, high turbidity, and protein aggregation/gelation occurred at pH 5 (except glycomacropeptide).
• Increased stability at pH 6 due to enhanced α-lactalbumin solubility.

Conclusions:

• Combined state diagrams effectively identify key regions of colloidal stability for whey protein beverages.
• The findings provide a framework for optimizing whey protein beverage formulations for enhanced shelf-life and quality.