The Evaluation of Mechanical, Thermal, Optical and Microstructural Properties of Edible Films with Solid Lipid Nanoparticles-Xanthan Gum Stored at Different Temperatures and Relative Humidities

Solid lipid nanoparticles (SLN) were obtained using the hot homogenization method and incorporated into a xanthan gum matrix (XG) to prepare edible films. The effects of SLN content (60, 65, 70, and 75 g/L) on the mechanical, color, thermal and microstructural properties, and water vapor permeability (WVP) were studied. The SLN film-forming systems remained stable for 7 weeks. Particle size was in the range of 222-257 nm. The mechanical properties of the films improved significantly when the SLN were introduced into the polymeric network to provide greater strength and flexibility with elongation at breaking of 2-9 %, affected by temperature (4-25 A degrees C), SLN concentration (60-75 g/L), and relative humidity (60-90 %). WVP was lower when edible films based on XG were incorporated with SLN at values of 0.50-0.70 g m-2 h-1 kPa(-1). The distribution of the SLN in the XG matrix was observed under scanning electron microscopy and showed changes in the arrangement as a function of SLN concentration. This explains the positive effect on the properties of the film of SLN-XG at 60 and 65 g/L. Total color difference (Delta E) increased with SLN content at values of 3.5-14. Thermal analysis showed that higher SLN content increased the melting temperature, while the plasticizer reduced it.