Development of low-density polyethylene antioxidant active films containing α-tocopherol loaded with MCM-41(Mobil Composition of Matter No. 41) mesoporous silica

Antioxidant active packaging films are always prepared to help protect fatty food safety. In this study, a new LDPE (Low-Density Polyethylene) film containing α-tocopherol adsorbed on MCM-41 mesoporous molecular sieve was prepared by extrusion. The synthesized MCM-41 were thoroughly characterized before and after loading with α-tocopherol by powder X-ray diffraction, nitrogen adsorption isotherms, infrared spectroscopy, and thermogravimetric analysis. Physical properties of the new films including tensile strength, oxygen and water barrier properties were studied. In particular, the effect of loading α-tocopherol onto MCM-41 on the migration behavior of α-tocopherol from active films was investigated. Migration test were performed at 40 °C, using 95%(v/v) ethanol as fatty food simulants on LDPE films with pure α-tocopherol and the assembly of α-tocopherol and MCM-41. The results showed that, after being adsorbed on MCM-41, the releasing period of α-tocopherol in LDPE were prolonged by about 36%, and the diffusivity of the antioxidant decreased by 53%. Moreover, DPPH radical scavenging assay proved the effectiveness of the antioxidant in the new film. These demonstrated that the new kind of active film can be potentially used for controlled release antioxidant food packaging application.