Effect of Coatings Using Titanium Dioxide Nanoparticles and Chitosan Films on Oxidation during Storage on White Button Mushroom

White button mushroom or (Agaricus bisporus) is known as a healthy foodstuff with several nutrients, polyphenols, proteins, and dietary fibers. Mushrooms have a short shelf-life, approximately three to four days at commercial storage and about eight days under chilling conditions. In the current study, titanium dioxide nanoparticles and chitosan films were used as novel active coating materials with the addition of thymol and tween (T and T) as food preservatives to prolong mushroom shelf life up to 12 days. Chitosan, Chitosan-Nano, and Chitosan-Nano/TT were used as coating materials, while water was used as control. Chitosan-Nano/TT film reported the lowest peroxidase activity (0.005 U kg−1 FW) and the highest superoxide dismutase activity (4.033 U kg−1 FW), while catalase activity in Chitosan-Nano film was (0.45 U kg−1 FW). Chitosan-Nano film enhanced the reactive oxygen species production levels, DPPH radicals (74.70%), and malondialdehyde content (1.68 µmol kg−1FW). Chitosan-Nano/TT film preserved the respiration rates (O2 consumption −0.026 mmol s−1kg−1, CO2 production −0.004 mg CO2 kg−1s−1) and increased the phenolic contents (0.38 g kg−1). The results suggested that nano-coating films can increase the oxidation processes which enhanced the quality of the mushrooms.