Biodegradable antioxidant film based on guar gum modified with aloe vera gel and date seed powder: Investigation of physicochemical and structural properties

In this study, a biodegradable film based on guar gum (GG) was prepared. Aloe vera gel (AG) and date seed powder (DSP) were used to modify the structure of this film (GG/AG/DSP). The physicochemical and structural properties of GG/AG/DSP films such as thickness, water solubility, water vapor permeability (WVP), moisture, color and antioxidant activity were investigated. The results indicated that the addition of AG and DSP significantly increased the thickness, color indices a and b in the films. Water solubility, transparency and L index showed a significant decrease with the addition of AG and DSP. Moisture content and WVP showed a non-significant decrease when DSP was increased. However, when AG was added, WVP showed a significant decrease and moisture content showed a significant increase. The addition of DSP had no effect on elongation at break (EAB) and tensile strength (TS), but on the contrary, both of them increased significantly with the addition of Aloe vera gel. The SEM images showed that the type and amount of variables affected the surface morphology of the films and caused cracks and crevices in the film. FT-IR results showed electrostatic interaction between the biodegradable films. XRD analysis showed less crystallinity in the biodegradable film with the addition of AG and DSP. According to the TGA results, the thermal stability of the combined and optimized film samples was better than the pure GG film.