Stable Emulsions Constructed From Whey Protein Isolate-Arabinogalactan Conjugates: Preparation, Characterization, and...

Area of Science:

• Food Science and Technology
• Biomaterials Science
• Nutritional Science

Background:

• Emulsion stability is crucial for delivering lipophilic bioactive compounds.
• Whey protein isolate-arabinogalactan (WPI-AG) conjugates offer potential as natural emulsifiers.
• Optimizing emulsion structure enhances physical and chemical stability.

Purpose of the Study:

• To investigate the stability of WPI-AG conjugate emulsions.
• To evaluate the impact of ultrasonication on emulsion properties and beta-carotene delivery.
• To establish a theoretical basis for using WPI-AG emulsions as delivery vehicles.

Main Methods:

• Formulation of WPI-AG conjugate oil-in-water (O/W) emulsions.
• Optimization of emulsion parameters (pH, oil volume fraction).
• Application of ultrasonication and assessment of physical/chemical stability.
• Confocal laser scanning microscopy (CLSM) for interfacial layer analysis.
• In vitro digestion model to determine beta-carotene bioaccessibility.

Main Results:

• Optimal emulsion stability achieved at pH 7.0 and 25% oil volume fraction, characterized by high zeta potential and low interfacial tension.
• Ultrasonication reduced droplet size, increased zeta potential, and improved interfacial structure.
• Enhanced physical stability against ionic, thermal, and pH stresses.
• Enhanced chemical stability during storage and light exposure.
• Ultrasonicated emulsions (400W) showed significantly higher beta-carotene bioaccessibility (81.98%) compared to control (49.55%).

Conclusions:

• WPI-AG conjugate emulsions provide a stable system for lipophilic compounds.
• Ultrasonication is an effective method to enhance emulsion stability and bioactive delivery.
• These findings support the use of WPI-AG emulsions as natural delivery systems for enhanced nutrient bioavailability.