Xylan chitosan conjugate - A potential food preservative

Xylan, a hemicellulose extracted from corn cobs, was co-heated with chitosan to prepare a polysaccharide-based food preservative. UV absorbance, browning and fluorescence changes indicated the presence of Maillard reaction between the two reactants. Antioxidant capacities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH·) radical-scavenging activity and reducing power, showed that the xylan-chitosan conjugates possessed excellent antioxidant activity depending on the heating time while chitosan or xylan alone did not possess any. The antimicrobial activity of the conjugates against Escherichia coli and Staphylococcus aureus was higher than chitosan. These results indicated that the Maillard reaction conjugate of xylan and chitosan was a promising preservative for various food formulations to enhance microbial safety and extend shelf life.