Interfacial features of emulsions stabilized by hemicellulose-coated lignin nanoparticles

Lignin nanoparticles (LNPs) are emerging as a versatile way of functionalizing lignin, including as tailorable Pickering emulsifiers. Yet, they are prone to aggregation in acidic conditions, which limit their application in food-based emulsions. Coating the LNPs with hemicelluloses, either enzymatically by laccase or by unassisted adsorption, has so far improved their stability in acidic conditions. However, the implications of such modification towards their behaviour at the oil-water interface is not yet fully characterized, especially in relation to the structure of the interfacial layer. Therefore, we aim to use small-angle neutron scattering (SANS), with the capability to vary the contrast between the LNPs, oil, and aqueous phase, to probe the structure of the interfacial layers formed by the modified LNPs on the surface of the oil droplets. Particularly, we aim to determine the thickness of the interfacial layer and the structural integrity of the LNPs at the interface, comparing different types of lignin and modification methods. Full understanding of the LNPs’ interfacial behaviour will allow a rational design strategy to tailor the LNPs surface properties for different emulsion purposes, such as in food or cosmetic products. Consequently, this will pave a way to a more circular, high-value, and sustainable use of lignocellulosic biomass.