Dynamic high pressure-induced gelation in milk protein model systems

Area of Science:

• Food Science
• Protein Chemistry
• Rheology

Background:

• Milk proteins' structure-functionality is crucial for food formulation.
• High-pressure homogenization (HPH) is increasingly studied for its effects on food macromolecules.
• Understanding HPH impact on milk proteins is key for novel food applications.

Purpose of the Study:

• To investigate the influence of varying homogenization pressures on the rheological properties of milk protein model systems.
• To evaluate the effects of different concentrations and pasteurization on these systems.
• To determine the conditions for homogenization-induced gelation.

Main Methods:

• Model systems of sodium caseinate (SC) and whey protein concentrate (WPC) were prepared at 1%, 2%, and 4% concentrations.
• Samples underwent pasteurization and homogenization at 0 MPa (control), 18 MPa (CP), 100 MPa (HP), and 150 MPa (HP+).
• Rheological properties were assessed using mechanical spectra and viscosity measurements.

Main Results:

• Viscosity varied with protein type, concentration, pasteurization, and homogenization pressure.
• Homogenization induced cold gelation in WPC and SC dispersions at concentrations ≥4%.
• High pressure (HP) treatment resulted in stronger gels (higher elastic modulus G') compared to conventional pressure (CP).

Conclusions:

• Homogenization pressure, concentration, and pasteurization are critical parameters for controlling milk protein gel properties.
• HPH offers a method to achieve tailored rheological characteristics and gel structures in milk protein systems.
• Optimized processing conditions enable the development of functional food ingredients from milk proteins.