Valorizing protein-polysaccharide conjugates from sugar beet pulp as an emulsifier

Area of Science:

• Food Science
• Biochemistry
• Material Science

Background:

• Sugar beet pulp (SBP) pectin is known for emulsion stability.
• The hydrophobic protein fraction in SBP is a potential source of interfacial activity.

Purpose of the Study:

• To extract and characterize protein-polysaccharide conjugates (AEC) from SBP.
• To evaluate the emulsifying performance and stability of AEC.
• To investigate the structure-function relationship of AEC in emulsions.

Main Methods:

• Hot alkaline extraction of AEC from depectinized SBP.
• Characterization of AEC composition and structure (protein, polysaccharide, hydrodynamic radius).
• Interfacial tension measurement and emulsion preparation (oil-in-water, high internal phase emulsions).
• Enzymic modification to study structure-function relationships.

Main Results:

• AEC is protein-rich (57.20%) with a rhamnogalacturonan-I-like structure.
• AEC significantly reduced interfacial tension and demonstrated superior emulsification performance and stability compared to controls.
• Emulsion droplet size remained small (0.438-0.479 μm) after storage.
• Intact macromolecular structure and neutral sugar (NS) fraction were crucial for emulsifying activity and stability.
• AEC effectively stabilized high internal phase emulsions at low concentrations and high ionic strength.

Conclusions:

• Alkaline extracted protein-polysaccharide conjugates (AEC) from SBP possess significant emulsifying capabilities.
• AEC is a promising functional ingredient for stabilizing various emulsion types.
• Valorization of AEC offers a pathway for high-value utilization of SBP processing by-products.