Novel Polymer-Free Antimicrobial System Based on Octyl Gallate/Hydroxypropyl- β -Cyclodextrin Inclusion Complex Electrospun Nanofibers for Chinese Giant Salamander Preservation

Octyl gallate (GAC8) as a bioactive compound has excellent antibacterial effectiveness, but its poor hydrophilicity limits its applications. In this work, GAC8 was encapsulated into hydroxypropyl- β -cyclodextrin (HP β CyD) cavity to form an inclusion complex (GAC8/HP β CyD-IC), and their antibacterial activities were investigated. Phase solubility test suggested that the aqueous solubility of GAC8 was prominently enhanced after forming the inclusion complex. The aqueous solution of GAC8/HP β CyD-IC yielded uniform fiber morphology with ~ 900 nm average fiber diameter. The fabricated GAC8/HP β CyD-IC nanofibers (GAC8/HP β CyD-IC NFs) were characterized by 1 H NMR, FT-IR, XRD, DSC, and TGA, revealing successful synthesis of GAC8/HP β CyD-IC NFs and the thermal stability of GAC8 was enhanced by inclusion complexation with HP β CyD. Furthermore, GAC8/HP β CyD-IC NFs possessed antibacterial activity against E. coli (12.5 mm zone of inhibition), S. aureus (18.5 mm zone of inhibition). The results of DNA and protein leakage in the experiment indicated that GAC8/HP β CyD-IC NFs can disrupt the membrane integrity of bacteria. Meanwhile, GAC8/HP β CyD-IC NFs suppressed the colony growth of E. coli on Chinese giant salamander meat. Overall, the nanofibers encapsulating GAC8/HP β CyD-IC were potential antibacterial food packaging materials.