The rheological property, antimicrobial stability and release evaluation of soya protein isolate/alginate-based films incorporated with thymol

Summary Soya protein isolate (SPI)/alginate (ALG)/montmorillonite (MMT)/thymol (THY) nanocomposite films were prepared with a codrying process to enhance the antimicrobial stability. The results showed higher gelation point temperature and more stable gelling network were obtained by the addition of MMT. Better thermal stability and sustained release effect was found in the coblended film containing MMT, in which THY release rate at 25 °C decreased with increasing MMT concentration but increased with temperature at a constant relative humidity. The SPI/ALG/THY, SPI/ALG/THY-CO and SPI/ALG/THY-CO-0.6 (MMT content = 0.6 g g−1 SPI) films effectively inhibited the growth of Escherichia coli by 0.95, 0.91 and 0.70 log cfu mL−1 and of Staphylococcus aureus by 0.94, 0.89 and 0.73 log cfu mL−1, respectively, on the surface of raw sausage, compared to the control film.