The antioxidant activity of the films incorporating ZEO was mea-sured by the method of Brand-Williams et al. [35]. This test is basedon the hydrogen atom or electron donation abilities, and is evaluated by measuring the bleaching of the bluish-red or purple-coloredmethanol solution of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) as areagent. In its radical form, DPPH is absorbed at 517 nm but, upon exposure to an antioxidant, its radical-scavenging ability increasesand its solution absorbance decreases. Briefly, 25 mg of each film sample was dissolved in 5 ml of distilled water by continuous stir-ring, then a 0.1 ml of film extract solution was added to 3.9 ml ofthe DPPH solution (0.1 mM methanol solution) followed by 60 min incubation in darkness at ambient temperature. The absorbance was measured at 517 nm against pure methanol and the percent-age of DPPH radical-scavenging activity was calculated using the following equation: