Preparation and antibacterial properties of high-methoxy pectin oligosaccharide -nisin nanoparticles

Nisin is a cationic polypeptide with high antibacterial activity. In different dosage forms, the immediate bacteriostatic effect of nisin was significantly reduced; and its antibacterial performance was easily affected by high temperature or non-acidic environment, which limited the widespread utilization of nisin. In order to improve the immediate bacteriostatic effect and the stability of nisin, nisin loaded high methoxy pectin oligo-saccharide (HMPOS) nanoparticles were prepared by electrostatic self-assembly. Under the condition of mass ratio (HMPOS: nisin) 4:6 and pH 4.5, the particle size of nisin nanoparticles was 290-300 nm, and the encap-sulation efficiency (EE%) was about 85 %. The analysis of particle size distribution, zeta potential, FT-IR, XRD and SEM suggested that nisin was successfully adsorbed on the surface of HMPOS. The isothermal adsorption results indicated that the combination of HMPOS and nisin was single-molecule layer adsorption. In addition, nisin nanoparticles had strong immediate bacteriostatic effect and good sustained release performance, and its release behavior belonged to Higuchi kinetic model.