Fabrication and characterization of water-soluble antimicrobial gliadin nanoparticles

The objective of this work is to fabricate water-soluble and antimicrobial gliadin nanoparticles stabilized by sodium caseinate (NaCas) via the synchronous-assembly process of thymol and gliadin during the anti-solvent approach. Morphological attributes, particle size, antimicrobial properties as well as release profiles of thymol-loaded nanoparticles were investigated. The gliadin/NaCas nanoparticles were spherical in shape and uniform with PDI value of 0.31, possessing the water-solubility and re-dispersibility after freeze-drying. Thymol loading resulted in a slight increase in particle size from ~270 nm to ~300 nm at the thymol-to-gliadin ratios of 1:10~3:4, but did not affect the re-dispersibility of the nanoparticles. Morover, these nanoparticles had strong encapsulation capacity, and the encapsulation efficiency (EE) of thymol was as high as 96%. The nanoparticles sustained the release of thymol, and the accumulative release after 7 day was about 30%. These nanoparticles were also effective in delaying the growth of Staphylococcus aureus in M-H broth at 37°C. This work opens a promising pathway for the manufacture of water-soluble vehicle for antimicrobials to design novel antimicrobial food formulation.