Abstract:In order to investigate the effect of methyl jasmonate (MeJA) on physical properties of soy protein isolated (SPI) and SPI-MeJA (SPI-M) films, composite films were prepared from SPI incorporated with MeJA and several film-forming additives. Scanning electron microscopy (SEM), X ray diffraction, and fourier transform infrared spectrometer (FTIR) were used to analyze the physical properties of these SPI and SPI-M films. Results showed that the appearance of SPI-M films was quite smooth, indicating that MeJA and SPI matrix were mutually compatible. Addition of MeJA significantly increased thickness, elongation and light barrier properties and moisture barrier properties of the films. SEM revealed that 0.05% MeJA improved the compactness of the inner film structure as compared with the SPI film. In addition, there was a certain interaction between MeJA and SPI matrix based on the FTIR results. These results suggested SPI-M improve the physical properties to broad its application in the field of food packaging and preservation.