Ultrasonic process affecting interactions between sodium caseinate and whey proteins

Area of Science:

• Food Science and Technology
• Protein Chemistry
• Ultrasonic Applications

Background:

• Ultrasound is utilized for modifying food materials like proteins.
• Controlling protein aggregation is crucial for food functionality.

Purpose of the Study:

• To investigate the impact of ultrasound on whey protein isolate (WPI) aggregation in the presence of sodium caseinate (NaCas).
• To evaluate how different ultrasound power and time conditions affect protein structure and gelation properties.

Main Methods:

• Solutions of NaCas, WPI, and NaCas:WPI mixtures were subjected to ultrasound under varying power and time parameters.
• Evaluated parameters included particle size distribution, charge density, pH, surface hydrophobicity, circular dichroism, and FTIR spectroscopy.
• Gelation capacity was assessed by measuring stress at rupture and Young's modulus.

Main Results:

• Sodium caseinate (NaCas) demonstrated a protective effect against ultrasound-induced whey protein isolate (WPI) denaturation, indicated by reduced surface hydrophobicity.
• FTIR analysis revealed more ordered protein structures in NaCas:WPI mixtures compared to WPI alone.
• Ultrasound treatment, especially at higher power and shorter times, significantly altered protein structure, leading to reduced stress at rupture and increased Young's modulus, thereby enhancing gelation capacity.

Conclusions:

• Ultrasound conditions, particularly high power and short duration, can effectively modulate protein structure and techno-functional properties.
• NaCas plays a protective role in mitigating WPI denaturation during ultrasound treatment.
• The study highlights the potential for tailoring protein ingredients with specific gelation characteristics through controlled ultrasound application.