Electrospun alginate fibers can also be applied as antibacterial food packaging materials. It has been reported that T4 bacteriophage after being incorporated into the fiber core via electrospinning still exhibits full bacteriophage viability after storage for weeks at 4℃. The morphology of electrospun nanofibers from pure PEO and from a PEO/ bacteriophage/alginate emulsion is displayed respectively in Fig. A-D. The lytic activity of T4 phage after each process of encapsulation is displayed in Fig. E. According to Fig. E, T4 phage released from fiber after coaxial electrospinning still maintains full activity. However, T4 phage released from fiber after emulsion electrospinning or after suspension electrospinning or released from Ca-alginate capsules after emulsification shows drop inactivity.