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Highlights: The chemical composition of the Z. multiflora EO extract obtained by supercritical extraction was identified by GC-MS. DPPH assays demonstrated the antioxidant activity of Z. multiflora EO extract. Z. multiflora EO extract was impregnated in PLA films by supercritical impregnation. The operational parameters of the supercritical impregnation process were optimized using FFD. The impregnated samples were characterized by SEM, FTIR, DSC and XRD. Impregnated PLA films showed antibacterial activity against E. coli and S. aureus. In this research, the extraction with supercritical carbon dioxide (SC-CO2) and the subsequent impregnation of the extracted bioactive compounds from Zataria multiflora Boiss (Z. multiflora) into polylactic acid (PLA) films was investigated. The effects of temperature (318 and 338 K), pressure (15 and 25 MPa) and cosolvent presence (0 and 3 mol%) on the extraction yield were studied. The SC-CO2 assisted impregnation runs were carried out in a discontinuous mode at different pressure (15 and 25 MPa), temperature (318 and 328 K), and time (2 and 8 h) values, using 0.5 MPa min−1 as a constant value of depressurization rate. ANOVA results confirmed that pressure, temperature, and time influenced the extraction yield. Moreover, antioxidant activities of extracts of Z. multiflora were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. In addition, the antibacterial activities of the extracts were screened against standard strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The results of this investigation indicated that extracts obtained from the aerial parts of Z. multiflora possessed antioxidant and antibacterial properties. The impregnated samples presented strong antibacterial activity against the selected microorganisms. [ABSTRACT FROM AUTHOR]

Chilled meat is prone to microbial contamination during storage, resulting in a shortened shelf life. This study developed multifunctional biodegradable aerogel with water absorption, antibacterial, and sustained release properties as a preservation pad for meat, using corn straw cellulose nanocrystals (CSCNCs) and acetylated starch (AS) as the structural skeleton and thymol (TMO) nanoemulsions as antimicrobials. The effects of different mass ratios of CSCNCs/AS on the morphology, structure, physical properties, and release behavior of aerogels were systematically analyzed. Additionally, their antibacterial properties, biocompatibility, and biodegradability were investigated. The results showed that the aerogels with CSCNC/AS mass ratio of 1:5 had a tailored structure for loading TMO nanoemulsions, as well as excellent water absorption, mechanical properties, and thermal stability. Due to strong hydrogen bonding and a porous structure, the TMO in the aerogels was continuously and uniformly released into high-water-activity and fatty food simulants, mainly controlled by Fickian diffusion. Furthermore, it exhibited superior antibacterial properties and biocompatibility. The application of aerogels for chilled beef preservation extended the shelf life from 8 days to approximately 12 days, which was superior to commercially available preservation pads. Notably, the aerogels exhibited superior biodegradability in soil. Therefore, the prepared aerogel preservation pads showed great potential in preserving chilled meat. [Display omitted] [ABSTRACT FROM AUTHOR]

Inspired by the natural antimicrobial effect of the topographical features of insect wings, this study prepared urchin-like gold nanoparticles (UGNPs) and deposited them on poly(ε-caprolactone) (PCL)/chitosan (P/C) electrospun nanofiber film to strengthen antibacterial activities of this active packaging. Results showed that L-Dopa was a suitable reducing agent to prepare UGNPs, and the spine length of UGNPs increased from 21.23 to 35.83 nm as the molar ratio of L-Dopa:HAuCl 4 increased from 1 to 3. As the nanofiber film was immersed in the nanoparticle solution for a longer time, the UGNP content in P/C nanofibers increased. As the spine length of UGNPs and depositing UGNP content increased, the inhibition rate against S. aureus and E. coli. of P/C nanofiber film increased. In addition, P/C nanofiber film deposited with UGNPs also exhibited good thermal stability, hydrophilicity, mechanical strength, and water vapor permeability, exhibiting its potential as an antibacterial active packaging. [ABSTRACT FROM AUTHOR]

To address the issue of bacterial growth on fresh-cut fruits, this paper reports the synthesis of nanosized γ-cyclodextrin metal-organic frameworks (CD-MOFs) using an ultrasound-assisted method and their application as carriers of limonene for antibacterial active packaging. The effects of the processing parameters on the morphology and crystallinity of the CD-MOFs are investigated, and the results prove that the addition of methanol is the key to producing nanosized CD-MOFs. The limonene loading content of the nanosized CD-MOFs can reach approximately 170 mg g -1 . The sustained-release behaviors of limonene in the CD-MOFs are evaluated. Molecular docking simulations reveal the distribution and binding sites of limonene in the CD-MOFs. CD-MOFs are deposited on the surfaces of polycaprolactone (PCL) nanofibers via an immersion method, and limonene-loaded CD-MOF@PCL nanofibers are prepared. The morphology, crystallinity, thermal stability, mechanical properties, and antibacterial activity of the nanofibers are also studied. The nanofiber film effectively inhibits bacterial growth and prolongs the shelf life of fresh-cut apples. This study provides a novel strategy for developing antibacterial active packaging materials based on CD-MOFs and PCL nanofibers., (© 2024 Wiley‐VCH GmbH.)

Novel fibers containing different ratios of PVA and d-limonene were fabricated using electrospinning for antibacterial active packaging applications. The PVA/d-limonene fibers were thoroughly characterized using a scanning electron microscope, fourier-transform infrared spectrometry, thermal gravimetry, differential scanning calorimetry, tensile tests, and oxygen permeability tests. The results of these analyses showed that the highest tensile strength and elongation at break values of 3.87 ± 0.25 MPa and 55.62 ± 2.93%, respectively, were achieved for a PVA/d-limonene ratio of 7:3 (v/v) and an ultrasonication time of 15 min during processing. This material also showed the lowest oxygen permeation and the best degradability and bacteriostatic properties of all samples.

Novel fibers containing different ratios of PVA and d-limonene were fabricated using electrospinning for antibacterial active packaging applications. The PVA/d-limonene fibers were thoroughly characterized using a scanning electron microscope, fourier-transform infrared spectrometry, thermal gravimetry, differential scanning calorimetry, tensile tests, and oxygen permeability tests. The results of these analyses showed that the highest tensile strength and elongation at break values of 3.87 ± 0.25 MPa and 55.62 ± 2.93%, respectively, were achieved for a PVA/d-limonene ratio of 7:3 (v/v) and an ultrasonication time of 15 min during processing. This material also showed the lowest oxygen permeation and the best degradability and bacteriostatic properties of all samples. [ABSTRACT FROM AUTHOR]