Pickering emulsion system of cellulose nanocrystals (CNCs)-stabilized essential oils (EOs) and their effect on food...

Essential oils (EOs) contain diverse volatile constituents but are poorly soluble in water, limiting their direct use in food-active packaging. Pickering emulsions of essential oils stabilized by cellulose nanocrystals (CNCs) (hereafter EO/CNC-PEs) offer robust, surfactant-free carriers for bioactive molecules. This article reviews interfacial mechanisms and formulation variables that govern the EO/CNC-PEs stability and their effects on food packaging performance. Stability arises from CNCs' adsorption at the EOs-water interface, forming a rigid particle shell. Combined steric and electrostatic barriers (quantified by zeta potential, ζ) suppress droplet coalescence, while pH and ionic strength modulate ζ value via deprotonation and electrostatic screening. The droplet size is controlled by the CNCs and EOs concentration, the EOs type, and storage, and increasing CNCs typically reduces size until interfacial coverage saturates, whereas excess EOs increases size due to incomplete coverage. Electrostatic repulsion from anionic CNCs reduces droplet aggregation, improving PEs stability and dispersion. When loaded into packaging materials, EO/CNC-PEs modify mechanical behavior and enhance ultraviolet (UV) blocking, antimicrobial, and antioxidant performance, while increasing opacity. They often reduce water vapor transmission rates and enable controlled (sustained) release of EOs' bioactive compounds. Critical factors influencing the properties of active packaging are also discussed. Overall, leveraging EO/CNC-PEs enhances EOs bioactivity and helps maintain the quality and extend the shelf life of fruits, vegetables, and meat products.