title: Preparation, characterization and evaluation of antibacterial activity of catechins and catechins-Zn complex loaded β-chitosan nanoparticles of different particle sizes.
abstract: 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.
authors.affiliation: Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331-6602, USA; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, PR China.
authors.forename: Hongcai
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331-6602, USA.
authors.forename: Jooyeoun
authors.initials: J
authors.lastname: Jung
authors.affiliation: Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331-6602, USA. Electronic address: yanyun.zhao@oregonstate.edu.
authors.forename: Yanyun
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002392:Catechin / Q000737:chemistry* / Q000494:pharmacology*; D048271:Chitosan / Q000737:chemistry*; D004926:Escherichia coli / Q000187:drug effects; D008087:Listeria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D015032:Zinc / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D002392:Catechin; D048271:Chitosan; D015032:Zinc
keywords: Antibacterial activity; Catechins–Zn complex; Encapsulation; Stability; Structures; β-Chitosan nanoparticles