Integration of freshness monitoring and active packaging technologies for aquatic products.

Aquatic products are nutritionally valuable but highly perishable, with quality loss driven by microbial spoilage, biochemical changes, including total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and histamine, and physicochemical deterioration, including lipid oxidation, gas production and texture loss. Conventional packaging slows these processes but does not report real-time freshness. This review analyzes how active packaging (antimicrobial, antioxidant, enzyme-inhibiting, and oxygen-scavenging systems, including bio- and nanocomposites) can be combined with freshness monitoring technologies (colorimetric/pH indicators, gas sensors, biosensors, and digital tools such as radio frequency identification (RFID) and Internet of Things (IoT) systems) specifically for fish, shrimp, and mollusks. We first map key spoilage mechanisms and markers, then evaluate active systems for aquatic products and compare three main monitoring families in terms of sensitivity, response time, cost-complexity and qualitative technology readiness. Integrated case studies (peptide-grafted films, modified atmosphere packaging (MAP) with time-temperature integrators (TTIs), smart labels with active papers and battery-free near-field communication (NFC) systems) are critically assessed for scalability, cost-effectiveness, safety, and regulatory feasibility. The review concludes that low-cost visual indicators coupled to simple active functions are closest to near-term deployment, while sensor- and biosensor-based systems remain at prototype level. Future work must prioritize marker- and species-specific validation, safe and scalable material systems, techno-economic evaluation, and early integration of regulatory and consumer aspects to justify industrial adoption in aquatic supply chains.