Abstract: In this study, modified polyvinyl alcohol (PVA) films added separately with nano SiO2 and nano TiO2 at different concentrations were prepared to improve the mechanical properties and permeability and broaden the application of PVA films in the field of edible mushroom preservation. The effect of these nano films on preserving the quality of Agaricus bisporus was evaluated by measuring mass loss, hardness, whiteness and sensory evaluation and compared with that of commercial polyethylene (PE) film. Results showed when nano SiO2/TiO2 were added at 1%, the CO2 permeability decreased by 35.66% and 12.58%, respectively, and the water vapor permeability decreased by 9.05% and 13.96%, respectively. The tensile strength, elongation at break and Young’s modulus increased by 23.86% and 23.41%, 1.59% and 0.84%, and 72.89% and 96.24%, respectively. After 5 days of storage, the percentage mass loss of Agaricus bisporus packed with the 1% nano SiO2 and 1% nano TiO2 incorporated films decreased by 31.06% and 32.87% as compared with pure PVA films, respectively, and the hardness decreased by 13.16% and 13.05% as compared with PE films, respectively. In addition, the whiteness of Agaricus bisporus packed with the 1% nano TiO2 incorporated film was the highest, 86.18. According to the sensory indicators including the opening degree of caps, color, hardness and odor, the 1% nano TiO2 incorporated film showed a better preservation effect on Agaricus bisporus. Therefore, incorporation of 1% nano SiO2/TiO2 could improve the mechanical properties and preservation effect of PVA films.

Key words: Agaricus bisporus, polyvinyl alcohol, nanocomposite films, preservation effect