Properties of soy protein isolate/nano-silica films and their applications in the preservation of Flammulina velutipes

This work evaluated the properties of soy protein isolate (SPI)/nano-silica (nano-SiO2) films. The particle size distribution of the film solutions and the Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy of films indicated that there were hydrogen bonds and coordinate bonds between the SPI and nano-SiO2. Scanning electron microscopy images indicated that an appropriate increase in the nano-SiO2 content improved the morphology of the films. Finally, the effect of SPI-based nanocomposite films on the preservation of Flammulina velutipes at 4 +/- 1 degrees C was investigated. After 10 days of storage, the weight loss and browning degree of F. velutipes in SPI films with 6% nano-SiO2 were significantly lower (p < .05), and the use of SPI/nano-SiO2 films could mitigate the losses of the total soluble solids and soluble protein contents. Therefore, SPI/nano-SiO2 films can prolong the shelf life and optimize the production of F. velutipes. Practical applications Fresh F. velutipes is nutritious and contains essential amino acids, vitamins, minerals, proteins, and fats. However, F. velutipes quickly undergoes browning, aging, and decomposition. Therefore, research in the F. velutipes preservation technology has important practical significance. In food packaging, the application of nanotechnology is gradually replacing traditional food packaging. However, no studies have reported the effects of SPI-based nanocomposite materials on the shelf life of F. velutipes. Therefore, the present study aimed to evaluate the properties of films and applications with F. velutipes.