Exploiting Salt Induced Microphase Separation To Form Soy Protein Microcapsules or Microgels in Aqueous Solution

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Native glycinin self-assembly is crucial for food texture and functionality.
• Understanding protein-protein interactions is key to controlling assembly outcomes.

Purpose of the Study:

• To investigate glycinin self-assembly under varying pH and NaCl concentrations.
• To explore the formation of microdomains, microcapsules, and microgels.
• To assess the impact of β-conglycinin on glycinin assembly.

Main Methods:

• Confocal laser scanning microscopy to observe microphase separation.
• Controlled variations in pH and NaCl concentration.
• Thermal treatment to induce microcapsule formation.

Main Results:

• Glycinin formed microdomains, which coalesced into phases or clusters based on conditions.
• 0.1 M NaCl and heating above 60°C transformed glycinin microdomains into stable microcapsules (3-30 μm).
• β-conglycinin inhibited phase separation and led to stable microgels instead of microcapsules.

Conclusions:

• pH and NaCl concentration significantly influence glycinin self-assembly and microdomain formation.
• Thermal treatment enables the creation of stable glycinin microcapsules with tunable sizes.
• β-conglycinin acts as a modulator, directing glycinin assembly towards microgel formation.