Esterification of cellulose nanocrystals and its application in food preservation

Cellulose nanocrystals (CNCs) have garnered significant attention across various fields owing to their inherent properties such as biodegradability and high crystallinity. However, the combination of a highly developed surface and hydroxyl-rich surface chemistry endows CNCs with elevated surface energy. This often leads to CNC aggregation and phase separation within the matrix during composite fabrication. Esterification modification has emerged as an effective strategy to enhance the applicability of CNCs. This review outlines the characteristics of native CNCs and their limitations in practical applications, and elaborates on various esterification approaches, including reactions with carboxylic acids and their derivatives, transesterification, deep eutectic solvent-mediated esterification, and isocyanation. It further highlights recent advances in the application of esterified CNCs for bio-composite films, functional and responsive packaging materials, Pickering emulsions, and hydrogel-based materials for food preservation. This article aims to serve as a reference for research on esterified CNCs in the food sector and to provide perspectives on the future development of sustainable food preservation materials.