Interfacial and enhanced emulsifying behavior of phosphorylated ovalbumin

Area of Science:

• Food Science
• Protein Chemistry
• Biochemistry

Background:

• Ovalbumin (OVA) is a key protein in egg white with functional properties.
• Improving emulsifying properties of proteins is crucial for food industry applications.
• Phosphorylation is a method to modify protein functionality.

Purpose of the Study:

• To phosphorylate ovalbumin (OVA) using wet-heating and sodium tripolyphosphate.
• To investigate the impact of phosphorylation on OVA's emulsifying capacity and stability.
• To elucidate the structural mechanisms behind the enhanced emulsification.

Main Methods:

• Ovalbumin phosphorylation via wet-heating with sodium tripolyphosphate.
• Characterization of phosphorylated OVA (P-OVA) with varying phosphorus content.
• Assessment of emulsifying activity and stability.
• Structural analysis using Fourier transform infrared spectroscopy, circular dichroism, and scanning electron microscopy.
• Measurement of surface zeta-potential and surface hydrophobicity.

Main Results:

• Phosphorylated OVA (P-OVA) showed increased emulsifying activity (26%) and stability (109%) compared to native OVA (N-OVA).
• Structural studies revealed increased molecular flexibility and reduced particle size in P-OVA.
• Increased phosphorus content led to higher absolute values of surface zeta-potential and hydrophobicity, inhibiting protein aggregation.
• Enhanced protein adsorption onto oil droplet surfaces was observed, improving emulsion stability.

Conclusions:

• Phosphorylation effectively improves the emulsifying properties of ovalbumin.
• The enhanced emulsification is attributed to increased molecular flexibility, reduced aggregation, and improved protein adsorption.
• P-OVA demonstrates significant potential for applications in the food industry requiring enhanced emulsifiers.