Lubrication performance of sustainable microgels

Abstract

The conjugation of plant proteins with phenolic compounds has been acknowledged as an efficient strategy to improve the techno-functional properties of these proteins and such conjugates can act as emulsifiers. However, undesirable sensory aspects (e.g., astringency) that phenolic compounds can impart to these new emulsifiers have not yet been studied. In principle, it is assumed that the covalent conjugation between the plant-based protein and the phenolic compound may hinder the accessibility of phenolic compounds to interact with salivary proteins, attenuating the perception of astringency. However, if this hypothesis is not confirmed, we propose fabricating plant protein-phenolic compound conjugates into soft deformable microgels of hundreds of nanometers size range with tailored viscoelastic properties, aiming at attenuating the astringency perception caused by phenolic compounds. The influence of plant proteins and phenolic compounds on oral friction individually has been successfully assessed by tribological measurements, but the frictional dissipation of plant protein-phenolic compound conjugates remains so far elusive. In this context, the aim of this project is to compare the rheological properties, adsorption kinetics, lubrication performance and astringency perception of lupin protein-grape seed extract conjugates in two forms (conjugates and microgelled conjugates) using a combination of surface adsorption, tribology using bioinspired tongue-like surface, rheology, surface wettability and other physicochemical characterization techniques. Furthermore, this pivotal study will provide insights into the sensory perception of novel plant-based emulsifiers, which may encourage the food industry to apply such systems in food formulations. (AU)