Search

Smart packaging systems with multiple functions have recently received great attentions. In this study, a bilayer film with antibacterial activity and indicating ability was developed by electrospinning method for simultaneously preserving and monitoring Lateolabrax japonicus freshness. The lower layer, serving as the antibacterial layer, was composed of zein (ZN), gelatin (GA) and carvacrol (CA). The upper layer, working as the indicating layer, was composed of chitosan (CS), polyvinyl alcohol (PVA) and blueberry anthocyanins (BBA). It was found that the film had strong antibacterial activity against common foodborne bacteria, suggesting it could prolong the shelf life of fish by 24 h during storage at 4 °C. Meanwhile, the bilayer film was sensitive to NH3, with a LOD value of 0.03357 μM. It exhibited a red-to-blue color change when was used to monitor the freshness of fish, due to the increasing content of volatile amines of fish. [ABSTRACT FROM AUTHOR]

To improve the biological and water-barrier properties of gelatin film, we incorporated the red roselle extract (RRE), ZnO nanoparticles (ZnO), and Litsea cubeba oil Pickering emulsion (LCON) into the GE film. The effect of RRE, ZnO, and LOCN on the properties of GE film was assessed using Box–Behnken response surface design (BBD). The BBD results revealed that these compounds greatly affect the properties of the film, especially the contribution of ZnO/LCON on the mechanical and water barrier properties of the film. The optimal antifungal (80.15%), antibacterial (31.24 mm), antioxidant (73.00%), tensile strength (42.03 MPa), elongation at break (25.50%), water vapor permeability (18.01 g mm·m−2·Kpa−1·h−1), and water contact angle (110.2°) of the film were obtained at 1.10% RRE, 1.51% ZnO and 2.38% LCON. The X-ray diffraction pattern and FTIR spectra results indicated the change of molecular interactions and semi-crystalline structure in the film. The scanning electron microscopy, fluorescence image, and energy dispersive X-ray results revealed that the excellent dispersion of RRE, ZnO, and LCON in the GE matrix led to an even and smooth structure in the film. This structure offers a positive effect on improving the mechanical and barrier properties of the film. The colorful patterns were successfully printed on the film to provide essential product information. Due to its excellent biological, mechanical, and barrier properties, the optimized film was applied for mango preservation. The optimized GE/RRE/ZnO/LCON film significantly controlled the postharvest quality and anthracnose in mango. Thus, the GE/RRE/ZnO/LCON film has great potential for mango preservation in active packaging applications. [Display omitted] • Litsea cubeba oil Pickering emulsion (LCON) was stabilized by pectin/β-cyclodextrin. • The gelatin-based nanocomposite film was optimized using Box–Behnken design. • LCON/ZnO greatly improved the water barrier and mechanical properties of the film. • The optimized red roselle extract, ZnO, LCON were 1.10, 1.51 and 2.38, respectively. • The optimized film improved the postharvest quality and anthracnose in mango. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gelatin/gellan gum bilayer film was prepared as a novel probiotic carrier material. • Blueberry anthocyanin extract (BE) improved the probiotic viability in the film. • Baobab seed oil (BO) improved water and oxygen barrier properties of the stored film. • BO/BE loaded-bilayer film obtained the greatest Bifidobacterium longum viability. • BO/BE loaded-bilayer film maintain satisfactory B. longum viability in steamed bread. The gelatin/gellan gum based-bilayer emulsion film was developed in this work to improve the survivability of Bifidobacterium longum during the storage process. The baobab seed oil (BO) was added to the gelatin (GE) matrix to develop emulsion film as the barrier outer layer. The blueberry anthocyanin extract (BE) was incorporated into the gellan gum (GG)-based inner layer to enhance the viability of B. longum. The SEM and FTIR results revealed that the probiotics were successfully entrapped in BO/BE-loaded bilayer film. The greatest survivability and viable cell numbers of the B. longum during the storage period were observed in the BO/BE loaded bilayer film. Furthermore, the stability of the colorful patterns by electrochemical writing was also evaluated in this work. Finally, the GE/BO-GG/BE/BM maintain satisfactory probiotic viability in steamed bread coating application. Hence, the GE/BO-GG/BE/BM bilayer film could be considered a novel material to deliver and protect the probiotics in food applications. [ABSTRACT FROM AUTHOR]

• ZnO nanoparticles improved the UV-blocking property and color stability of the bilayer film. • Different patterns could be printed on the bilayer colorimetric film by electrochemical writing. • The bilayer colorimetric film showed a limit of detection of 0.01 mM to NH 3. • The bilayer colorimetric film with written patterns can monitor crucian freshness in real-time. Bilayer colorimetric films were developed for monitoring fish spoilage by using gelatin (GN) incorporated with ZnO nanoparticles as the upper layer (GN-ZnO), and gellan gum (GG) incorporated with mulberry anthocyanins (MBA) as the lower layer (GG-MBA). The color stability of the bilayer colorimetric films under visible and ultraviolet light was improved with the increase of ZnO nanoparticles content. Meanwhile, the bilayer films had good NH 3 sensitivity. The limit of detection of the GG-MBA/GN-2.0% ZnO film to NH 3 was 0.01 mM. The electrochemical writing ability of the bilayer films was also identified, indicating the feasibility of inks-free printing on biopolymer films. Finally, the GG-MBA/GN-2.0% ZnO film with an electrochemical writing pattern was used to monitor crucian spoilage. The GG-MBA/GN-2.0% ZnO film with electrochemical writing pattern showed visible color changes with the crucian spoilage. In conclusion, the bilayer colorimetric film was expected to be a good fish spoilage indicator in smart packaging. [ABSTRACT FROM AUTHOR]