Protein Nanofibers as Pickering Emulsion Stabilizers: Impacts of Protein Source and Mechanistic Insights into Emulsion Stabilization

Abstract

Protein nanofibers (PNFs) derived from lysozyme and bovine serum albumin (BSA) were employed as stabilizers for oil-in-water Pickering emulsions. Emulsions containing up to 50 wt % canola oil were prepared and remained stable for ∼6 months, demonstrating highly competitive performance relative to previously reported biobased Pickering stabilizers. Formulation and processing variables were systematically analyzed to determine mechanistic impacts on emulsion formation and stability. Scanning electron microscopy and fluorescence microscopy were used to evaluate protein nanofiber adsorption at the oil–water interface. Both lysozyme and BSA nanofibers produced emulsions with monomodal droplet size distributions, reversible creaming behavior, and resistance to centrifugal stress (10,000 × g); however, lysozyme nanofibers provided superior stabilization compared to BSA nanofibers. This is consistent with the higher surface charge of lysozyme PNFs, which may contribute to increased electrostatic repulsion between droplets, as well as their increased rigidity, leading to more effective interfacial coverage. Taken together, our results demonstrate the potential of protein nanofibers as sustainable and effective Pickering stabilizers with strong potential for the development of biobased products.