All-Natural, Plant-Based Nanofibrils from Citrus Fiber and Glycyrrhizic Acid for Stabilization of Edible Emulsion Gels

Fibrillar nanostructures (i.e., nanofibrils) obtainedfrom twonatural plant biomolecules, citrus fiber (CF) and glycyrrhizic acid(GA), are efficacious structural building blocks for fabricating foodemulsions and emulsion gels. In this work, the emulsion propertiesof a combination of CF and GA nanofibrils were investigated to understandthe effect of interfibrillar interactions among this unique dual nanofibrilsystem on the emulsion gel formation and stabilization. The obtainedresults demonstrate that the structural and functional propertiesof edible emulsion gels made with the nanofibril mixtures are highlydependent on the interactions between rigid semicrystalline CF nanofibrilsand soft semiflexible GA nanofibrils. At low GA concentrations (0.05-0.1wt %), the simultaneous adsorption of these two nanofibrils at theinterface decreases the size of oil droplets but increases their inhomogeneity,leading to a weak gel structure. In contrast, when the GA concentrationexceeds a critical concentration (& SIM;0.25 wt %), the GA nanofibrilswith higher interfacial activity mainly dominate the interfacial adsorption,forming smaller emulsion droplets with a more homogeneous size distribution.Further, the formation of compact and ordered fibrous networks atthe interface and in the continuous phase through multiple hydrogen-bondinginteractions within this dual nanofibril system endows the emulsiongels with satisfactory mechanical properties and high viscoelasticity.Particularly, the continuous network appears to be predominantly constructedby the GA nanofibrils, and the CF nanofibrils interpenetrate intothe GA fibrillar network, forming the reinforced composite gel matrix.This study highlights the combined use of all-natural, plant-basednanoscale building blocks for the development of edible emulsion gelswith many sustainable applications. A unique dualnanofibril system consisting of natural plant-basednanofibrils from citrus fiber and glycyrrhizic acid was explored foredible emulsion gels.