Development of Antioxidant Chitosan Films Incorporated with Quinoa Extract

Abstract

In this study, the antioxidant chitosan (CH) films were prepared by incorporating quinoa extract (QE) (5, and 10%, wt) into CH film solutions. The effect of QE incorporation into CH film was evaluated by physicomechanical, and active properties (antioxidant, and antimicrobial activity). Active compounds were extracted from QE by distilled water at 60°C during 6 hours. The total phenolic content and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of QE were found as 34.35±0.27 mg GAE/100 g (dry weight) and 25.61±1.36 %, respectively. QE included CH films showed higher water vapor permeability values (WVP) and moisture content (p<0.05). The transmittance and L* values of film samples decreased with the increasing QE content whereas opacity and a* values increased (p<0.05). The elastic modulus and tensile strength of CH films did not change significantly by the incorporation of QE, however, the elongation at break values of films increased with the increasing amount of QE. CH films incorporated with QE extract exhibited 15.60±0.68 and 17.92±1.2% of DPPH radical scavenging activity for 5% QE and 10% QE incorporation, respectively. All film samples showed antimicrobial activity against Escherichia coli, and Listeria monocytogenes but QE incorporation did not promote the antimicrobial activity of CH films. CH films with active properties could have a potential to be used as active food packaging films along with conventional packaging films that could reduce the amount of film used.