The Construction of pH-Sensitive Starch-Based Carrier to Control the Delivery of Curcumin for Fish Preservation

Controlled release of curcumin by a pH-sensitive carrier provides long-term preservation, which extends the shelf lives of fish. FTIR, XRD, ¹H NMR, zeta potential, swelling ratio, and TG analyses indicated that a pH-sensitive starch-based carrier with a narrow pH-sensitivity range (pH 6–7) was fabricated from the carboxymethyl starch grafted with methacrylic acid and then cross-linked with β-cyclodextrin to achieve dual functionality. FTIR, XRD, and fluorescence spectroscopy revealed that the mechanism by which curcumin was encapsulated in the starch-based carriers involved hydrophobic interactions and intermolecular hydrogen bonding. The encapsulated curcumin showed improved stability, higher antioxidant activity, antibacterial activity, and biocompatibility. The pH, TVB-N, TVC, and drip loss tests confirmed that the use of the carrier-curcumin complex at a concentration of 10 mg/mL for the preservation of yellow catfish extended the shelf life for 2–4 days during cold storage and improved the storage quality of the resulting fillets. This work provides a dual functionality strategy for constructing a pH-sensitive starch-based carrier to deliver curcumin and offers a promising choice for fish preservation.