Multilayer polycaprolactone - pullulan nanofiber mats incorporated with the antimicrobial palindromic peptide LfcinB (21-25)Pal as a potential application in active packaging

Food losses are generated by microbial contamination due to the lack of packaging that not only functions as a barrier but releases compounds against such organisms. Electrospinning was used to develop multilayer nanofiber mats using poly-(ε-caprolactone) (PCL) in the outer layer and encapsulating the peptide LfcinB (21-25)Pal in an inner pullulan (PUL) layer. The nanofiber mats were characterized by Fourier Transformed Infrared Spectroscopy (FTIR). FTIR spectra showed the presence of the peptide in PUL nanofiber mats, the presence of both polymers in multilayer nanofiber mats, and the absence of chemical changes. In addition, a High Performance Liquid Chromatography (HPLC) was performed for peptide quantification, where an encapsulation efficiency of 65 % in the nanofiber mat was observed, and a maximum load of 50 mg peptide / g PUL. The antioxidant capacity of the peptide, evaluated through the inhibition of radical DPPH, showed an antiradical activity of 5.21 × 10−4 mg ± 1.12 × 10−5 gallic acid/mg nanofiber mat. Finally, the antimicrobial activity showed a minimum inhibitory concentration of 15 ± 0.01 μM against Escherichia coli. In conclusion, the multilayer nanofiber mat can potentially be used as part of active packaging to prolong the shelf life of foodstuff susceptible to microbial contamination.