Microencapsulation of oils using whey protein/gum Arabic coacervates

Area of Science:

• Food Science
• Colloid and Surface Chemistry
• Materials Science

Background:

• Complex coacervation using whey protein/gum arabic (WP/GA) is a promising technique for microencapsulation.
• Understanding the influence of pH and droplet size on microcapsule formation and stability is crucial for optimizing delivery systems.

Purpose of the Study:

• To investigate the microencapsulation of sunflower oil, lemon, and orange oil flavors using WP/GA complex coacervation.
• To determine the optimal pH conditions for stable microcapsule formation and high oil payload.
• To evaluate the impact of capsule size and cross-linking on flavor release in a food matrix.

Main Methods:

• Complex coacervation of whey protein and gum arabic at varying pH levels.
• Microencapsulation of oil droplets and characterization of capsule shell formation.
• Emulsion stability studies, including creaming rate and zeta potential measurements.
• Flavor release assessment of microcapsules incorporated into Gouda cheese.

Main Results:

• Optimal microencapsulation occurred near pH 4.0, yielding smooth biopolymer shells and high oil payloads (>80%).
• Smaller oil droplets were more effectively encapsulated than larger ones.
• Emulsion stability was pH-dependent, with higher creaming rates observed at pH 4.0 due to near-neutral zeta potential.
• Larger microcapsules and covalently cross-linked capsules exhibited stronger and lower flavor release, respectively.

Conclusions:

• WP/GA complex coacervation is effective for microencapsulating oils, with pH being a critical factor for shell formation and stability.
• Capsule size and cross-linking significantly influence flavor release kinetics, offering tunable delivery properties for food applications.