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 oligosaccharide (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 encapsulation 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.