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In this study, polylactic acid (PLA) films with different nano-ZnO concentration (0, 1, 3, 5, 7, 9, and 15%wt) were obtained by casting method. Overall migration values and specific migration values were studied in different food simulants (10% [v/v] ethanol and isooctane). The results demonstrated that overall migration of the composite films and specific migration of Zn 2+ was higher in 10% (v/v) ethanol solution than in isooctane solution. The release of Zn 2+ was affected by the percentage of nano-ZnO in the composite films and food simulants. The migration of Zn in this study was mainly caused by polymer softening and degradation leading to the dissolution of Zn. Scanning electron microscope analysis indicated that with the migration of Zn 2+ , the structure of the composite films changed greatly. Differential scanning calorimeter analysis indicated that the thermal stability was decreased and the glass transition temperature and crystallization temperature were reduced.

The tilapia (Orechromis niloticus) surimi gels were prepared with high hydrostatic pressure (0, 100, 200, 300, and 400 MPa for 15 min) treatments to investigate the changes in water‐holding capacity, color, gel strength, microstructure, texture, and proteins of the gels. Compared it with cooked gel (40°C/30 min + 90°C/30 min). The whiteness of heat‐induced and HHP‐induced gels were significant (p < .05) higher than that of untreated samples. The gels formed by pressurization were dense and flexible, and formed by cross‐linking based on hydrogen bonding. SDS‐PAGE patterns showed no major change in the actin and tropomyosin protein profiles of gels induced by HHP‐300. Raman spectroscopy confirmed disulfide bonds played an important role in gel formation. A lower intensity ratio observed in HHP‐induced protein supported the tyrosine residues involved in hydrogen bond formation. The changes of secondary structure suggested decreased α‐helix content and increased β‐sheet.