Preparation, characterization and application of SPI-based blend film with antioxidant activity

To investigate the effect of ferulic acid (0, 2.0, 4.0, 6.0 and 8.0 % w/w) as antioxidant and cross-linking agent on the properties of soy protein isolate (SPI)/cellulose nanofiber/ferulic acid blend films, the mechanical properties, barrier properties, antioxidant activity of the blend films were evaluated, and its Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were characterized. Pork wrapped with different blend films were further evaluated with peroxide value and thiobarbituric acid reacting substances. The result showed that the elongation at breakage, water vapor permeability and oxygen permeability of the blend films with 4.0 % ferulic acid decreased by 69.76 %, 90.91 % and 77.55 %, respectively. Moreover, the blend film effectively delayed lipid oxidation process of pork by scavenging free radicals and blocking water, oxygen and ultraviolet light. This study provides a theoretical basis for SPI-based film to prolonging the shelf life of pork.