Studying of the effect of low density poly ethylene (LDPE) based antimicrobial nanocomposite packaging containing TiO2 nanoparticles on the shelf-life extension of button mushroom (Agaricus bisporus)

The aim of this research was to develop an antimicrobial active packaging for shelf life extension of button mushrooms (Agaricus bisporus). TiO2 nanoparticles at three levels of 0, 0.5 and 1.5% were added to the low density polyethylene (LDPE) film and nanocomposite films were produced by blowing extrusion method. These films were used for packaging of fresh mushrooms. Also, UV irradiation was used on the packaged samples for 15 min to stimulate the antimicrobial activity of the films. Evaluation of antimicrobial properties of films revealed that the inhibitory effect against growth of E. coli and S. aureus increased by increasing TiO2 content and also by UV irradiation. Mushroom samples were stored for 15 days at refrigerator and physicochemical and microbial tests were applied on them. Weight loss, decreasing of phenolic compounds and also losing of vitamin C were decreased by using nanocomposite films and this effect increased by increasing TiO2 content. Browning index and color difference with fresh mushroom was the lowest for 1.5% TiO2 loaded and UV irradiated samples. Microbial counts of mushrooms increased during storage but active films were able to control this increment. Generally, this research indicated that the using of TiO2 in the LDPE film as a non-contact active packaging along with UV irradiation is able to increase the shelf life of mushroom and preserve its quality attributes during the supply period.