Synthesis, anti-oxidant activity, and biodegradability of a novel recombinant polysaccharide derived from chitosan and lactose

•The rationale of gene recombination was employed to the synthesis of recombinant polysaccharides.•A novel recombinant polysaccharide (RP) based on polysaccharide–disaccharide was synthesized from oligo-chitosan and reducing lactose through Maillard reaction.•Such RP exhibited remarkably improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and biodegradability.

A novel recombinant polysaccharide (RP) based on polysaccharide–disaccharide was synthesized from oligo-chitosan (oligo-CS) and reducing lactose using Maillard reaction with the yield of 85.1%. Chemical structure and thermal stability of RP was characterized by Fourier transform infrared spectrum (FT-IR), solid-state nuclear magnetic resonance spectroscopy (CP/MAS 13C-NMR), and thermo gravimetric analysis (TGA). The anti-oxidant activity of RP was preliminarily investigated by its scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Biodegradability of RP was also examined by the observation of growth status of Aspergillus niger colony. It was demonstrated that RP achieved excellent radical-scavenging efficiency (>80%) at high concentrations of DPPH and its scavenging ability was superior to that of CS, suggesting that anti-oxidant property of CS was remarkably promoted by chemical modification with reducing lactose via Maillard reaction. And biodegradation test revealed that RP had better biodegradability than CS.