Enhancing emulsion functionality using multilayer technology: Coating lipid droplets with...

Area of Science:

• Food science and technology
• Colloid and surface science
• Biopolymer applications

Background:

• Oil-in-water emulsions are crucial in food products but can be unstable.
• Layer-by-layer electrostatic deposition is a technique to create multilayer coatings on particles.
• Food-grade biopolymers offer potential for creating stable and functional emulsion systems.

Purpose of the Study:

• To investigate the formation and stability of multilayer coatings on lipid droplets using food-grade biopolymers.
• To evaluate the impact of different biopolymer combinations (saponins, polypeptides, polysaccharides) on emulsion stability.
• To assess the influence of pH, salt concentration, and heat on the stability of these multilayered emulsions.

Main Methods:

• Formation of medium chain triglyceride (MCT) lipid droplets using quillaja saponin (QS) as an anionic emulsifier.
• Sequential layer-by-layer electrostatic deposition of poly-L-lysine (PLL) and either pectin (PE) or κ-carrageenan (KC).
• Assessment of emulsion stability under varying salt concentrations, pH levels, and heat treatment (90°C for 30 min).

Main Results:

• Single-layer emulsions with QS exhibited superior resistance to salt, pH, and heat.
• Two-layer emulsions showed better pH stability than three-layer emulsions.
• Three-layer emulsions demonstrated enhanced salt stability compared to two-layer emulsions.
• All tested emulsions were relatively stable to heat treatment.

Conclusions:

• Quillaja saponins are effective emulsifiers for creating stable lipid droplet systems.
• Multilayer technology offers limited advantages for enhancing the physical stability of saponin-coated lipid droplets.
• Further research is warranted to explore the functional benefits of these multilayered emulsions.