Physicochemical properties and stability of model sauces stabilized by heat-modified whey protein concentrate...

Area of Science:

• Food Science and Technology
• Colloid and Surface Science
• Biomaterials Engineering

Background:

• The food industry is shifting towards natural emulsifiers and stabilizers.
• Dairy proteins are emerging as viable alternatives to traditional synthetic additives.
• Whey protein concentrate (WPC80) can be modified for enhanced functionality.

Purpose of the Study:

• To investigate heat-treated whey protein particles (WPPs) as Pickering stabilizers for high-oil emulsions.
• To mimic commercial sauce formulations at pH 5.
• To evaluate the impact of WPPs on emulsion properties under varying conditions.

Main Methods:

• Preparation of WPPs via heating and sonication of WPC80.
• Systematic evaluation of protein concentration (3-5%), oil content (3-50%), and ionic strength (20-400 mM NaCl or 20 mM CaCl2).
• Analysis of droplet size, zeta-potential, rheology, microstructure, and stability (storage and thermal).

Main Results:

• Increased protein concentration reduced droplet size and increased viscosity.
• Higher oil content, with sufficient WPPs, decreased droplet size, indicating good interfacial coverage.
• Salt addition (NaCl or CaCl2) improved emulsion homogeneity, stability, and viscosity, with optimal formulations matching commercial sauces.
• High-protein/high-oil emulsions showed excellent stability over 60 days.
• High NaCl concentrations prevented coalescence during thermal stability tests.

Conclusions:

• Heat-modified whey protein particles are effective Pickering stabilizers for high-oil emulsions.
• Optimized WPP-stabilized emulsions exhibit desirable properties (small droplet size, stability, viscosity) comparable to commercial products.
• WPPs offer a natural, ingredient-friendly solution for sauce formulations.