A New Paradigm for Sustainable Food Packaging: Construction, Properties, and Applications of Multifunctional Hydrogels

Conventional petroleum-based plastic packaging is facing formidable challenges in terms of both environmental sustainability and precise quality regulation of food products, compelling the food packaging industry to pivot toward biodegradable, recyclable, and intelligent solutions. Hydrogels, characterized by their unique three-dimensional network architecture, high water content, and excellent biocompatibility, have emerged as promising candidates for constructing next-generation sustainable food-packaging systems. This review presents a structured critical overview of the recent progress in multifunctional hydrogels derived from natural and synthetic polymers for food packaging applications. We begin by summarizing the structural characteristics and functional attributes of various polymeric substrates from different sources. Subsequently, we place emphasis on elucidating the molecular design and microstructural engineering strategies that enable enhanced mechanical properties, confer antimicrobial and antioxidant activities, and impart pH/gas-responsive intelligent functionalities. Furthermore, the regulatory mechanisms of forming and processing technologies—including solution casting, electrospinning, and three-dimensional printing—on the structure and performance of hydrogel-based packaging materials are discussed in depth. Finally, in view of the key bottlenecks currently impeding the widespread adoption of hydrogel packaging materials, particularly regarding water resistance, scalable production, and cost control, we outline future directions toward multifunctional synergism and quantitatively evaluated life-cycle performance. This review aims to provide a systematic theoretical basis and technical reference for the rational design of high-performance, intelligent, and sustainable food packaging systems for the future.