Development of anti-insect multilayered films for brown rice packaging that prevent Plodia interpunctella infestation

The aim of this study was to develop a multilayered insect-proof film that prevents contamination with Plodia interpunctella (Hübner; Lepidoptera: Pyralidae) insect larvae. The anti-insect activities of five essential oils (EOs), allyl disulfide (AD), and allyl mercaptan isolated from garlic and onion, respectively, were evaluated. Subsequently, fumigation insecticidal assays were performed to identify the anti-insect agents, their optimal concentrations. Garlic, onion EOs and their compounds were chosen as efficient anti-insect agents for application to rice flour-based multilayered plastic films. Penetration tests were then used to evaluate the ability of multilayered films to resist invasion by P. interpunctella larvae. Films containing 5% AD (AD-5) had the strongest resistance to penetration by insects. Thus, AD-5 was applied to brown rice packaging to measure protection from insects and to assess sensory properties. In these analyses, AD-5 showed insect-proofing effects and no undesirable changes to the sensory properties of the rice after cooking. Hence, this novel multilayer film could be used as an active packaging material with effective anti-insect activities and desirable physical properties.