Development of antimicrobial active films based on poly(vinyl alcohol) containing nano-TiO2 and its application in macrobrachium rosenbergii packaging

The antimicrobial poly(vinyl alcohol) (PVA) films incorporated with nano-TiO2 were prepared by solution blending-casting method. The effects of different nano-TiO2 addition of 0%, 0.5%, 1%, 3%, 5%, and 7% on the characterization of PVA films were studied. The tensile strength of the film incorporated with 0.5% nano-TiO2 was highest. Compared with the pure PVA film, the oxygen transmission rate, swelling ratio and water vapor uptake ratio of the films containing 0.5%-7% nano-TiO2 reduced 0.4%-0.8%, 22.82%-81.79%, and 3.59%-10.7%, respectively. The transparency reduced significantly. The thermal stability and antimicrobial activity against Staphylococcus aureus and Escherichia coli were improved. The storage study of macrobrachium rosenbergii indicated that the Shewanella spp., Pseudomonas putida and Aeromonas hydrophila could be inhibited by PVA films added with nano-TiO2 and their shelf-life was extended for 1-2 days. It was indicated that there's a good prospect for application of these PVA films in the antimicrobial food packaging. Practical applications Poly(vinyl alcohol) (PVA) is a biodegradability and nontoxicity synthetic polymer, which has been widely used in food packaging materials. This paper proved that the PVA films incorporated with nano-TiO2 showed good antimicrobial activity. For the application in macrobrachium rosenbergii packaging, it showed that the Shewanella spp., Pseudomonas putida and Aeromonas hydrophila could be inhibited by PVA films added with nano-TiO2 and their shelf-life could be extended for 1-2 days. There is a great advantage that the antimicrobial activity of the films could be motivated by UV-light irradiating before packaging process to avoid that the common active packaging films are in the excited state after prepared. This antimicrobial packaging film could be used as inner layer of the composite packaging film to improve the food quality and prolong the shelf-life of the food.