Pickering emulsions co-stabilised by cellulose nanofibres and nicotinamide mononucleotide

Abstract

Emulsified solid particles adsorbed at the oil–water interface can stabilise Pickering emulsions by acting as a physical barrier to the coalescence of oil droplets. Cellulose nanofibres (CNFs) have been used in food-grade Pickering emulsions because of their excellent performance as a low cost and sustainable material. Nicotinamide mononucleotide (NMN) is a small-molecule zwitterion with polar functionality capable of interacting with the CNFs. The ability of cationic CNFs and NMN to co-stabilise sunflower oil Pickering emulsions was investigated under various conditions using methods such as contact angle measurement, creaming stability, rheology, microscopy, thermal stability, and water-holding capacity. Emulsions with ultra-high stability, good gelation, and high plasticity were obtained using single-step shear dispersion with 0.25 wt% CNFs, 0.05–0.3 wt% NMN, and near-neutral pH. NMN stabilised the oil–water interface through electrostatic interactions and hydrogen bonding with CNFs. NMN transferred into the aqueous phase and interacted with CNFs to form a complex with a three-dimensional network structure, which improved the bulk viscosity and steric hindrance of the emulsion and created more compact adsorption of CNFs at the oil–water interfaces. Overall, the synergistic effects of various factors allow NMN to effectively co-stabilise Pickering emulsions with CNFs, making it an exciting method that can be used to encapsulate oil-soluble substances.