Multifunctional Roles of Chlorogenic Acid in Food Packaging Films: Linking Structural Modulation with Active and Intelligent Performance.

The transition toward sustainable food packaging requires the integration of biodegradable materials with functional bioactivity. Chlorogenic acid (CGA), a naturally abundant polyphenol, has emerged as a multifunctional compound with the capacity to simultaneously modulate polymer structure and impart active and intelligent functionalities. This review critically examines recent advances in CGA-containing packaging systems, covering fabrication strategies from physical incorporation and chemical grafting to nanostructured and stimuli-responsive architectures. The analysis reveals that CGA plays a dual role. At the molecular level, it regulates the polymer network structure through hydrogen bonding, covalent interactions, and conformational rearrangement. This, in turn, influences mechanical strength, barrier performance, and optical properties. Functionally, CGA provides antioxidant and antimicrobial activity, although its effectiveness depends strongly on the incorporation strategy and concentration. Notably, nanostructured systems and conjugation approaches enable controlled release and enhanced stability. These methods overcome limitations associated with rapid diffusion and environmental degradation, including oxidation, UV exposure, and pH-related instability. Despite these advances, key challenges remain, including CGA instability, uncontrolled release behavior, and limited regulatory and scalability data. Furthermore, while CGA is well established in active packaging, its application in intelligent systems remains limited in the literature, with only a few studies reported on its intelligent applications. Overall, this review highlights the structure-function relationships governing CGA-containing packaging systems and outlines future directions for the rational design of cost-effective, scalable, and multifunctional packaging systems, positioning CGA as a promising component in sustainable strategies for food preservation and waste reduction.