Study of gellan gum films reinforced with eggshell nanoparticles for the elaboration of eco-friendly packaging

Development of eco-friendly materials based on biopolymers and agro-food waste has increased due to severe pollution caused using plastic materials. The aim of this work was to obtain nanoparticles by high-energy milling at different times (1–3 h) from eggshells as they are a source of calcium carbonate and was study using microscopy and spectroscopy techniques. Particle size distribution and mean particle size were determined. After 2 h of milling, the smallest particles (84 ± 40 nm, with 91 % ≤ 100 nm) were obtained. The effect of the addition of eggshell nanoparticles (ENP) at different concentrations (1–3 wt%) on different functional properties of gellan gum (GG) films was studied. The results indicated that addition of ENP (3 wt%) improves hydrophobic, water barrier, mechanical, and thermogravimetric properties of the ENP/GG film in comparison with GG film. X-ray diffraction analysis and infrared spectroscopy provided information to propose a descriptive model to explain the chemical interactions between ENP and GG. Consequently, the films could be used to fabricate eco-friendly materials for use in the food sector in the elaboration of dishes and shockproof protective netting for delicate fruits. [Display omitted] •High-energy milling allowed obtaining a large amount of eggshell nanoparticles.•Obtained nanoparticles are mainly constituted of calcium carbonate in the form of calcite.•Chemical interactions between gellan gum and nanoparticles were elucidated.•Eggshell nanoparticles improved the structure-function of gellan gum films.