Preparation, characterization and evaluation of antibacterial activity of catechins and catechins-Zn complex loaded β-chitosan nanoparticles of different particle sizes

Carbohydr Polym. 2016 Feb 10;137:82-91. doi: 10.1016/j.carbpol.2015.10.036. Epub 2015 Oct 22.


This study used β-chitosan nanoparticles (β-CS NPs) of different particle sizes to encapsulate catechins (CAT) or CAT-Zn complex by ionic gelation technology. The antibacterial activity of CAT or CAT-Zn complex loaded β-CS NPs against Escherichia coli and Listeria innocua were investigated based on bacterial growth curve, minimum inhibitory concentration (MIC), and minimum bacterial concentration (MBC). Fourier transform infrared spectrometer (FT-IR) was employed to study the incorporation of CAT or CAT-Zn complex into β-CS NPs. The CAT-Zn complex loaded β-CS NPs had particle size of 208-591 nm, polydispersity index (PDI) of 0.377-0.395, and positive Zeta-potential of 39.17-45.62 mV. The CAT-Zn complex loaded β-CS NPs of smaller particle sizes showed higher antibacterial activity than that of larger particle size ones. The MIC and MBC of CAT-Zn complex loaded β-CS NPs of the smallest particle size against L. innocua and E. coli were 0.031 and 0.063 mg/mL, and 0.063 and 0.125 mg/mL, respectively. This study suggested that encapsulation of CAT-Zn complex in β-CS NPs improved the antibacterial activity of CAT and CAT-Zn complex, and the encapsulators have great potential to be used as antibacterial substances for food and other applications through either direct addition or incorporation into packaging materials.

Keywords: Antibacterial activity; Catechins–Zn complex; Encapsulation; Stability; Structures; β-Chitosan nanoparticles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology
  • Catechin / chemistry*
  • Catechin / pharmacology*
  • Chitosan / chemistry*
  • Escherichia coli / drug effects
  • Listeria / drug effects
  • Microbial Sensitivity Tests
  • Nanoparticles / chemistry*
  • Particle Size
  • Zinc / chemistry*


  • Anti-Bacterial Agents
  • Catechin
  • Chitosan
  • Zinc