Development of antimicrobial/antioxidant nanocomposite film based on fish skin gelatin and chickpea protein isolated containing Microencapsulated Nigella sativa essential oil and copper sulfide nanoparticles for extending minced meat shelf life

Fish skin gelatin and chickpea protein isolated (G-CP) edible blend films incorporated with 0.25 and 0.5% copper sulfide nanoparticle (CuSNP) and Nigella sativa essential oil (MEO) (0.015 and 0.03%, w/w of protein) were prepared and optimized by the response surface methodology based on the central composite design (RSM-CCD). Antimicrobial activity, infrared spectroscopy (FTIR), X-ray diffraction (XRD), morphological characteristics and thermal attributes of composite films were examined. In general, the effect of CuSNPs and MEO on the properties of blended films, besides their inherent nature, is related to their interactions with the protein matrix and the synergistic effect on each other. As authenticated by the FTIR and XRD, the simultaneous use of CuSNPs and MEO because of the synergistic effect of CuSNPs on the antibacterial attributes of MEO and raising the content of antimicrobial components in the blend film expressed the highest antimicrobial functionality against E. coli. and S. aureus. Also, the results of microbiological and chemical tests of packaged minced meat revealed that the simultaneous use of MEO and CuSNP in the film has a positive synergistic effect in increasing the storage life of minced meat, as compared to the other samples.