RESUMEN
Cellulose paper packaging materials have gained considerable attention as substitutes for petroleum-based plastics owing to their biodegradability, renewability, flexibility, and good mechanical strength. However, high hydrophilicity and the absence of essential antibacterial activity limit their application in food packaging. In this study, a facile and energy-saving method was developed to improve the hydrophobicity of cellulose paper and endow it with a long-acting antibacterial effect by integrating cellulose paper substrate with metal-organic frameworks (MOFs). A dense and homogenous coating of regular hexagonal ZnMOF-74 nanorods was in-situ formed on a paper surface by layer-by-layer assembly followed by low-surface-energy polydimethylsiloxane (PDMS) modification to prepare a superhydrophobic PDMS@(ZnMOF-74)5@paper. Excellent anti-fouling, self-cleaning, and antibacterial adhesion performances were obtained for this superhydrophobic paper. In addition, active carvacrol was loaded into the pores of ZnMOF-74 nanorods on PDMS@(ZnMOF-74)5@paper to combine antibacterial adhesion together with bactericidal ability, ultimately resulting in a completely "bacteria-free" surface and sustained antibacterial performance. The resultant superhydrophobic papers not only showed overall migration values within the limit of 10 mg/dm2 but also good stability against various harsh mechanical, environmental, and chemical treatments. This work gave insights into the potential of in-situ-developed MOFs-dopped coating as a functionally modified platform for preparing active superhydrophobic paper-based packaging.
Asunto(s)
Estructuras Metalorgánicas , Embalaje de Alimentos , Zinc , Antibacterianos/farmacología , CelulosaRESUMEN
An environmental-friendly composite films containing waste fish scale-derived gelatin (FSG), sodium alginate (SA) and carvacrol loaded ZIF-8 (CV@ZIF-8) nanoparticles were designed and fabricated to develop active food packaging materials capable of sustained antibacterial activity. The microstructure and physicochemical properties of the FSG/SA/CV@ZIF-8 composite films were investigated. The incorporation of CV@ZIF-8 into FSG/SA matrix significantly enhanced the UV-light blocking and the elongation at break, improved water resistance and reduced water vapor permeability, and improved the thermal stability of composite film. The FSG/SA/CV@ZIF-8 film not only exhibited strong antioxidant activity with DPPH radical scavenging rate of 92.35 %, but also showed the satisfactory and long-acting antibacterial ability against E. coli and S. aureus due to slow release of CV from composite film. Strawberry preservation experiment revealed that FSG/SA/CV@ZIF-8 film decelerated the texture deterioration and retarded the growth of spoilage microorganism, resulting in the prolonged shelf-life of 8 days under ambient condition, indicating its promising application prospect in food preservation packaging.
Asunto(s)
Embalaje de Alimentos , Nanopartículas , Animales , Embalaje de Alimentos/métodos , Alginatos/química , Gelatina/química , Escherichia coli , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
A green and facile method was proposed to prepare robust and fully bio-based modified paper in this study, which involved in layer-by-layer deposition of chitosan (CS) and mussel adhesive protein-mimetic polymer (dopamine-grafted carboxymethyl cellulose, CMC-g-DA) on paper surface and subsequent oxidative cross-linking by sodium periodate. The mechanical, barrier and antibacterial properties of the cross-linked multilayer-modified paper significantly improved with the increased bilayer numbers. Compared with unmodified paper, cross-linked (CS/CMC-g-DA)6 multilayer-modified paper exhibited 71.6 % improvement in tensile strength, 69.2 % and 56.3 % decline in air and water vapor permeability, as well as above 90 % antibacterial efficiency against S. aureus and E. coli. Particularly, the cross-linked multilayer-modified paper maintained outstanding functional stability even after suffering from vigorously corrosive treatment. The obtained functional paper effectively extended the shelf-life of Agaricus bisporus to 6 days under ambient conditions. We believed that the prepared robust functional paper in this study will have promising application prospect in food packaging field.
Asunto(s)
Quitosano , Embalaje de Alimentos , Embalaje de Alimentos/métodos , Carboximetilcelulosa de Sodio , Staphylococcus aureus , Escherichia coli , Antibacterianos , Resistencia a la TracciónRESUMEN
Poly(lactic acid) (PLA)-based composite films reinforced with acetylated cellulose nanocrystals (ACNC) (1 wt%) and ZnO nanoparticles at different content (1, 3, 5 and 7 wt%) were prepared by solution-casting method. The surface acetylation of cellulose nanocrystals improved its dispersion in the PLA matrix. The morphologies, optical, mechanical, barrier, thermal and antibacterial properties of PLA/ACNC/ZnO ternary composite films were investigated. SEM images showed that ACNC and ZnO were evenly distributed in the PLA matrix to form homogenous film when the content of ZnO was ≤5 wt%. The PLA/ACNC/ZnO composite films showed improved UV blocking, mechanical strength, oxygen and water vapor barrier. This ternary composite also exhibited excellent antibacterial activity against E. coli and S. aureus. The migration amounts of Zn2+ from PLA/ACNC/ZnO composite film to food simulants were below the specific migration limit (5 mg/kg). Overall, the desirable properties of the resulting PLA/ACNC/ZnO ternary composite film highlighted the potential application as a promising option for active food packaging materials.