Hydrophobically modified chitosan microgels stabilize high internal phase emulsions with high compliance

Area of Science:

• Food science and material science
• Colloid and interface science

Background:

• Food-grade microgel-stabilized emulsions are crucial for food formulations.
• Particle emulsifiers are key to stabilizing high internal phase emulsions (HIPEs).

Purpose of the Study:

• To demonstrate the use of hydrophobically modified chitosan microgels (h-CSMs) as novel particle emulsifiers for HIPEs.
• To characterize the properties of h-CSMs and their performance in stabilizing HIPEs.

Main Methods:

• Grafting chitosan (CS) with deoxycholic acid (DA) to create hydrophobically modified chitosan (h-CS).
• Cross-linking h-CS with sodium tripolyphosphate (TPP) to form h-CSMs.
• Characterizing interfacial properties, HIPE formation, microstructure, and rheology.

Main Results:

• h-CSMs exhibited enhanced hydrophobicity compared to CS and h-CS.
• Stable HIPEs with up to 90 wt% oil were formed using low h-CSM concentrations (0.05 wt%).
• h-CSM-stabilized HIPEs showed superior rheological compliance compared to other particle-stabilized HIPEs.

Conclusions:

• h-CSMs are effective and efficient particle emulsifiers for food-grade HIPEs.
• Increased hydrophobicity and viscoelasticity contribute to the strong emulsification properties of h-CSMs.
• This study presents a novel approach for creating stable, high-oil-content emulsions for food applications.