Production of nanofibers with plant extract via electrospinning method and use for sausage coating

In the first stage of this study, pullulan and pullulan/whey protein nanofibers containing 5% (w/w) clove extract and black cumin waste extract were obtained by electrospinning method. The diameters of the obtained nanofibers ranged from 168 to 600 nm. Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) results showed a close interaction between the obtained nanofibers and clove and black cumin waste extract. The phenolic content of the nanofibers varied between 0.62-48.05 mg GAE/g km and the antioxidant activity varied between 274-4174 µmol TE/g km. Some of the obtained nanofibers show antimicrobial activity against S. aureus, M. luteus and C. albicans. In the second stage of the study, four of the conditions used in the first stage were selected, and 30% (w/w) clove and black cumin waste extract containing pullulan and pullulan/whey protein nanofibers were obtained under these conditions. The phenolic content of the fibers obtained varied between 26.17-167.02 mg GAE/g km and the antioxidant activity varies between 1905-17165 µmol TE/g km. Pullulan nanofiber containing clove extract showed antimicrobial activity against S. aureus, M. luteus, E. coli, C. albicans and A. flavus, while pullulan nanofiber containing black cumin waste extract at the same ratio showed antimicrobial activity against S. aureus, and E. coli bacteria. In the third stage of the study, two of the nanofibers produced in the second stage, which are produced continuously, with high antibacterial activity, antioxidant activity and homogeneous morphology, were selected and used in coating the sausage samples.. The pH of the sausage samples coated with extract-added nanofibers increased more slowly than the pH of the control group. The L* (brightness) colour values of the sausage samples coated with extract-added nanofibers were higher than the control group. The a* value of sausage samples coated with extract-added nanofibers decreased during the storage, but this decrease occured more slowly than the control group. Sausage samples coated with nanofibers containing clove extract and black cumin waste extract decreased the TBARS value by 20% and 17%, the count of E. coli by 1.98 and 1.01 log, and the count of L. monocytogenes by 1.33 and 0.87 log, respectively, compared to the control group.