Synergistically Antibacterial and Antioxidant Catechaldehyde‐Based Composite Bio‐Coating for Enhanced Strawberry Shelf Life

ABSTRACT Developing safe, non‐toxic and high‐efficiency coating materials for food preservation has become a critical research focus in the field of food packaging. In this study, a catechaldehyde‐cross‐linked gelatin/sodium hyaluronate (GHAP) composite coating was engineered to improve the antibacterial and antioxidant functionalities of gelatin. By optimizing the cross‐linking ratio, a GHAP4 film with superior overall properties was obtained. Fourier transform infrared (FTIR) analysis confirmed that the aldehyde groups of catechaldehyde participated in cross‐linking reactions with the amino groups of the gelatin–sodium hyaluronate matrix. The GHAP4 film exhibited excellent antioxidant activity, achieving a DPPH radical scavenging rate of 96.8%, and showed strong antibacterial effects against Escherichia coli and Staphylococcus aureus . Furthermore, cytotoxicity tests suggested that all concentrations of GHAP4 solution exhibited cell viability exceeding 100%. Zebrafish toxicity tests showed that the GHAP film had no significant toxicity to zebrafish, with no deformities or deaths observed. Preservation experiments using strawberries as a model sample showed that the GHAP4 coating effectively slowed down changes in colour, titratable acidity and soluble solid content, extending the shelf life from 4 to 8 days. This study provides new ideas and a theoretical basis for the application of natural polymer‐based functional coatings in fruit and vegetable preservation.