Seydim and Sarikus (2006) stated that the useof 2% (w/v) OEO was required for whey protein isolate (WPI) filmsto reach the minimum inhibitory concentration against S. aureus,S. enteritidis, L. monocytogenes, Lactobacillus plantarum, and E. coliO157:H7. The antibacterial effect has been mainly attributed to oregano’s terpenoid fraction comprised of carvacrol, thymol, and p-cymene (Corrales et al., 2014). It was expressed that carvacrolforms channels through the bacterial membrane by pushing apartthe fatty acid chains of the phospholipids, allowing ions to leave thecytoplasm (Burt, 2004). Representative pictures of the inhibitory effect of biocomposite films incorporated with 1.2% (w/v) OEO against four test microorganisms in comparison with the control are shown in Fig. 6.