Effect of cross linking conditions on properties of quercetin cross linked chitosan nanocomposites

The aim of the present study is to evaluate the effects of cross linking conditions on physical, mechanical and barrier properties of chitosan nanocomposite films cross linked with quercetin. The films were selected and investigated for their structure, antioxidant and antimicrobial properties. The results showed that the incorporation of quercetin significantly (p<0.05) improved the physical properties of chitosan nanocomposite films. The CS quercetin 1% films cross-linked for 1 hr showed significantly (p<0.05) lower WVP and better water sorption profiles. The CS films that were incorporated with 3% quercetin and cross linked for 1 hr contained the highest amount of total phenolic content and found to be most active radical scavenger and showed significantly (p<0.05) higher antimicrobial activity against Gram positive (S. aureus) and Gram negative (E. coli) bacteria. The microstructure of the selected nanocomposite films studied using scanning electron microscopy (SEM) showed that the cross sectional surface of chitosan nanocomposite film became coarse when 3% of quercetin was incorporated. The CS quercetin1% films were more homogenous and had compact surface. The results suggested that the degree of crosslinking with quercetin has significant role in formation of nanocomposite films used for application in food packaging.