Active edible sugar palm starch-chitosan films carrying extra virgin olive oil: Barrier, thermo-mechanical, antioxidant, and antimicrobial properties

Starch-chitosan blend films are considered promising raw materials for producing active food packaging film, especially by adding active compounds such as essential oil. Active edible sugar palm starch (SPS)-chitosan (CH) films carrying extra virgin olive oil (EVOO) were fabricated. Tensile strength (TS) and elongation at break (EB), thermal stability, barrier properties, antioxidant and antimicrobial activity of the CH/SPS-EVOO blend films are reported in this study. The structure of produced films associated with compatibility caused by interaction of film components were evaluated by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction. The increase in concentration of EVOO (extra virgin olive oil) in CH/SPS-EVOO blend films increased the thermal stability and antioxidant activity whereas reduction was observed on surface roughness. The addition of EVOO (2.0% w/w) in CH/SPS matrix increased the tensile strength (158.1%) and elongation at break (224.6%). The formation of hydrogen bonds between CH-SPS and EVOO blend was confirmed by the FTIR spectra. Experimental results indicated that the optimum EVOO content for the CH/SPS-based film was 2% w/w, so that the film possesses the potential for the intended application as an active biocomposite film and can replace the use of pure CH/SPS film.

Keywords: Active edible film; Chitosan; Extra virgin olive oil; Sugar palm starch.