Intelligent κ-carrageenan-Based packaging films enhanced with curcumin–anthocyanin–EGCG nanoparticles: Fabrication, characterization, and application

Petroleum-based packaging materials raise serious environmental and food safety concerns, driving the development of sustainable smart packaging derived from natural polymers. In this study, natural pigment-zein-chondroitin sulfate-epigallocatechin gallate-ι-carrageenan (NZCEC) nanoparticles were fabricated and incorporated into κ-carrageenan-based films to enhance their functional properties. The effects of NZCEC addition on the films' physicochemical stability, intermolecular interactions, antioxidant activity, and responsiveness to ammonia and acetic acid vapors were systematically evaluated, along with their application in preserving mandarin fish ( Siniperca chuatsi ). Scanning electron microscopy revealed good compatibility between κ-carrageenan and moderately loaded NZCEC nanoparticles. Incorporation of NZCEC significantly improved the film's optical properties (opacity increased from 4.10 to 23.32 A mm −1 ) and reduced its water vapor permeability (from 8.23 × 10 −9 to 6.93 × 10 −9  g m −1 s −1 Pa −1 ). Moreover, the antioxidant activity was markedly enhanced (from 1.75 % to 77.65 %), along with notable responsiveness to ammonia and acetic acid. Storage trials with mandarin fish demonstrated that the smart film effectively delayed fish spoilage. Additionally, the film displayed distinct chromatic variations in response to freshness, allowing continuous assessment of food quality. These results establish NZCEC nanoparticle-reinforced κ-carrageenan films as a promising intelligent packaging material with improved stability, responsiveness, and food preservation performance.