Abstract: Composite coating films with good preservation performance were prepared by a casting method based on the modification of chitosan (CS) as the film-forming matrix by in-situ synthetic nano-SiOx with the addition of lysozyme (LZM) and tea polyphenol (TP) as additives, and they were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Meanwhile, their physicochemical properties were determined. The preservation effect of the coatings was evaluated on sea bass fillets. The results showed that the addition of nano-SiOx, LZM and TP increased intermolecular interactions in CS coatings, resulted in a more compact structure, and improved the microstructure and physicochemical properties. After being modified by nano-SiOx, the preservation performance of CS coatings was enhanced, extending the shelf life of fish fillets by 3–4 days compared with the untreated fish fillets. After adding LZM or TP to the modified SiOx/CS coatings, the preservation performance was further improved, inhibiting the increase in the total number of colonies, pH, thiobarbituric acid (TBA) value, K value, and total volatile basic nitrogen (TVB-N) content in fish fillets, and slowing the changes in texture properties, and consequently extending the shelf life by 4–7 days compared with the untreated fish fillets. The best preservation performance was obtained upon their addition together, extending the shelf life by 8–10 days. Therefore, the in-situ synthetic nano-SiOx/LZM/TP/CS coatings had improved physicochemical and preservation performance, and could be potential for applications in the field of food preservation.

Key words: chitosan; in-situ synthetic nano-SiOx; lysozyme; tea polyphenol; composite preservative coating; sea bass