Bacterial Cellulose Nanocrystal-Stabilized Water-in-Water Pickering Emulsions: Stability, Amylopectin Partitioning,...

Area of Science:

• Food Science and Technology
• Materials Science
• Biotechnology

Background:

• Aqueous two-phase systems (ATPS) offer potential for food applications but face stabilization challenges due to ultra-low interfacial tension.
• Bacterial cellulose nanocrystals (BCNCs) are explored as food-grade stabilizers for water-in-water (W/W) Pickering emulsions.

Purpose of the Study:

• To develop and characterize food-grade W/W Pickering emulsions stabilized by BCNCs.
• To evaluate the ability of these emulsions to regulate starch digestibility.
• To investigate the impact of formulation parameters on emulsion properties and stability.

Main Methods:

• Systematic investigation of dextran (Dex), maltodextrin (MD), and BCNC concentrations on emulsion microstructure, rheology, and stability.
• Fourier-transform infrared spectroscopy (FTIR) for BCNC confirmation.
• Contact angle analysis for BCNC wettability.
• In vitro digestion studies using amylopectin (AMP) and α-amylase.

Main Results:

• Optimal formulation (24 wt% Dex, 14 wt% MD, 0.24 wt% BCNCs) yielded stable emulsions with uniform droplets.
• BCNCs demonstrated preferential wettability towards the Dex-rich phase, enhancing interfacial adsorption and stabilization.
• Emulsions showed stability across pH 3.0-7.0 but were sensitive to ionic strength (>7 mM NaCl).
• BCNC-stabilized emulsions significantly inhibited AMP hydrolysis by α-amylase, reducing hydrolysis extent from ~54% to 14%.

Conclusions:

• BCNCs are effective natural stabilizers for W/W Pickering emulsions.
• These emulsions form a physical barrier that retards starch digestion.
• This research provides a sustainable strategy for designing slow-digestible, low-glycemic-index food systems for functional foods and pharmaceuticals.