The aim of this study was the synthesis of bimetallic nanoparticles based on Fe2O3/TiO2 and its use in the poly(lactic acid) (PLA) films as an oxygen scavenger in extra virgin olive oil (EVOO) packaging. Bimetallic nanocomposites were prepared by two different precipitation methods (precipitation with ammonia and sodium hydroxide). The characteristics of bimetallic nanoparticles precipitated with sodium hydroxide (Na-Ti0.01Fe0.048O0.08) and bimetallic nanoparticles precipitated with ammonia (NH-Ti0.01Fe0.022O0.09) were compared. Relative amounts of elements in bimetallic nanocomposites and their morphological characteristics were determined using field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometer. Porosity volume and surface area of bimetallic nanoparticles were calculated using adsorption-desorption isotherms and the Brunauer-Emmett-Teller method. The formation/characterization of bimetallic nanoparticles and their location in the matrix of PLA-based nanocomposite film was studied using X-ray diffraction and Fourier transform infrared. In nanocomposite films based on PLA, bimetallic nanoparticles lead to better oxidative stability (peroxide value, p-anisidine index, K232, and K270) of the EVOO and oxygen scavenging during storage compared to free nanoparticles. Mechanical properties of nanocomposite films were improved due to bimetallic nanoparticles, which were better for Na-Ti0.01Fe0.048O0.08. In vitro release modeling of the bimetallic nanoparticles in EVOO proved that Fickian diffusion is the dominant mechanism, and the Peleg model was the best description of the release behavior of nanoparticles.
Keywords: bimetallic nanoparticles; extra virgin olive oil; nanocomposite film; oxygen scavenging; precipitation method.
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