Food Packaging and Shelf Life最新文献

In this study, a colorimetric nanofibrous film was developed using polycaprolactone (PCL) and alizarin through electrospinning, and the film was subsequently employed for tracking shrimp freshness. Scanning electron microscopy (SEM) showed that the film was composed of beaded, continuous and smooth nanofibers. In the pH range of 4–13, the nanofibrous films displayed discernible color changes from yellow green to bluish-purple. Furthermore, when used together with shrimps, the films underwent a color change from yellow to purple, demonstrating a robust association with TVB-N and the pH value. Thus, the alizarin-based colorimetric nanofibrous films developed here could be potentially used as an indicator for tracking the freshness of shrimps.

To extend the shelf-life of cherry tomatoes infected with Botrytis cinerea, this study analyzed the effect of Pichia membranifaciens (PM) on a composite film of gelatin (Gel) and trehalose (Tre), and explored the effect of different concentrations of trehalose on the yeast in the bioactive film and its control effect on cherry tomatoes. Scanning electron microscopy showed that Tre/Gel-based film can be applied as effective carriers to protect the cellular integrity of PM. Fourier-transform infrared spectroscopy, thermogravimetric analysis, and tests of mechanical properties showed that there was interaction between PM and the Tre/Gel base film, which maintained the thermal stability of the base film. The addition of PM reduced the water vapor permeability, hygroscopicity, and moisture content of the Tre/Gel base film, effectively extending the active film's storage time. This study also explored the growth curve of PM and found that 15% trehalose was effective in maintaining PM activity and could result in a 30-day survival rate of 62% for PM in Tre/Gel films, with 72.41% inhibition of B. cinerea. Finally, the PM/Tre/Gel film significantly reduced the incidence of decay in cherry tomatoes and improved the storage quality and fungal resistance of the fruit. Thus, PM/Tre/Gel films may be applied as a new antifungal packaging material for the preservation of fresh fruit.

Processors of dry-cured ham often face the challenge of prolonged storage of their products; thus, our aim was to investigate the effect of cold storage of vacuum-packed dry-cured ham Kraški pršut for different periods on various ham characteristics. Three groups of hams stored for either 1 month (control), 4 or 7 months were evaluated for physicochemical, rheological, and sensory properties, as well as volatile profile. The increase in storage time was associated with moisture balance in the ham, as evidenced by lighter colour, softer texture, and higher moisture content, particularly in the superficial (initially more dehydrated) semimembranosus muscle. The differences were most pronounced after 4 months of storage. Further storage for up to 7 months was not associated with any significant changes or degraded quality of the product, as evidenced by the absence of sensory differences between the tested groups. The identified volatile compounds indicate that lipid oxidation was the most important process during ham storage therefore these compounds can be used to distinguish between hams with different storage durations. It can be concluded that prolonged vacuum storage for up to 7 months at refrigeration temperatures does not deteriorate ham quality and even improves the homogeneity of the pieces.

To evaluate linseed oil as a material for producing novel oxygen-scavenging nanoparticles, a six-step closed-loop reaction process was numerically implemented looking to simulate the oxidative behavior of the oil. Reaction rate constants were successfully determined based on observed mass increase during oxidative thermogravimetric analysis (TGA) experiments. This reactive mechanism was integrated into a novel diffusion-reaction model to accurately predict nanocapsules' absorption; the model was experimentally validated. Results showed a 13.89 mL/g oxygen uptake capacity and 0.604 mL/g per day absorption rate for the capsules at 20 °C. A parametric analysis revealed a significant temperature-dependent behavior, with an absorption rate reaching 16.6 mL/g day at 60 °C (27 times higher than at 20 °C). The model indicated that the time to absorb all the headspace oxygen remained constant, irrespective of initial capsules´ concentration: 1.2 g absorbed all oxygen in a 100 mL volume after 40 days (at initial concentrations ranging from 21% to 5%), making this technology suitable for reduced oxygen atmospheres.

Cellulose acetate (CA) is often investigated as a sustainable packaging material, however many factors may impact its degradation rate. In this sense, the degradation in soil of active CA and zein blend films (BL) incorporated with plasticizers (glycerol or tributyrin), and garlic essential oil (GEO) was investigated. The films were studied for 150 days in terms of weight loss, macro and micro changes, molecular alterations, and crystallinity. Polymer mass loss was more noticeable in BL films and in glycerol-plasticized samples. Also, the effect of GEO on polymer mass loss seemed to be plasticizer-dependent: GEO in glycerol-films reduced the mass loss due to polymer degradation; this behavior was not verified in tributyrin-films. Spectra obtained by infrared spectroscopy evidenced plasticizer loss and break of peptide bonds, however, it was not possible to verify deacetylation. X-ray diffraction revealed an increase in the crystallinity degree mainly in BL. This study showed that the degradation of CA-films in soil could depend on the polymer matrix, the plasticizer type, and the active agent presence.

In this study, we developed composite films by crosslinking gelatin with oxidized alginate and anthocyanin through Schiff base linkage, electrostatic interaction and hydrogen bonds. Physicochemical properties of the films can be adjusted by changing the concentration of oxidized alginate. The tensile strength of the film containing 10 wt% oxidized alginate reached 45 MPa, surpassing that of films with 1 wt% and 3 wt% oxidized alginate. As the concentration of oxidized alginate increased, the swelling ratio of the films decreased. The release rate of anthocyanin from the film with 10 wt% oxidized alginate in pH 7.0 water was 15.3%, significantly lower than that of the film lacking oxidized alginate (release rate 42.1%). The antioxidant properties of the composite gelatin films with anthocyanin were about 40% in DPPH radical scavenging activity. Additionally, the color of film with 3 wt% oxidized alginate changed from light pink to green in a solution with a pH range from 3 to 11 and the film was sensitive to acidic or basic vapors. This color-changing capability makes the film a potential indicator for detecting spoilage in fish, pork, and chicken, manifesting color changes from light pink to light green. Furthermore, the composite films exhibited biodegradable characteristics in soil, lakes, and simulated seawater. Notably, the film containing 10 wt% oxidized alginate demonstrated greater stability compared to the film without oxidized alginate. The gelatin film with pH responsive and biodegradable properties can be potentially used in the field of intelligent food packaging.

This study explores, the impacts of incorporating of deep eutectic solvent (DES) as plasticizer on the characteristics of zein films. Investigation focused on examining the mechanical, thermal, surface, and microstructural properties of zein films that were plasticized using DES. The findings of the study revealed that by adding DES to zein films, there was an observed improvement in transparency. Additionally, it was observed that up to a 20% addition of DES led to a reduction in water vapor permeability (WVP). However, beyond this level, the WVP increased as the surface hydrophobicity decreased. The films that were plasticized with DES showed higher tensile and burst strength values than control. However, there was a decrease in the elongation at break and burst distance, except for the film containing 30% DES. The addition of DES as plasticizer resulted in smoother surface morphology compared to the control, and all films revealed homogeneous and non-porous surface and cross-section microstructure. The films plasticized with DES displayed three different thermal degradation temperatures resulting in higher thermal stability. The FT-IR spectrum of films showed similar backbone structure including Amide I, II and III bands. However, 5% DES plasticized film showed different secondary structural peaks of Amide I band due to lower α-helix and higher β-sheet and random coil content. The findings of this investigation indicate that the employment of DES as plasticizer in biodegradable polymer films can yield enhanced mechanical and barrier characteristics compared to conventional plasticizers, thus demonstrating its potential for effective use.

Gelatin is the key biopolymer with the potential uses in numerous sectors since it is biodegradable and biocompatible. But for instance, food packaging material gelatin itself is not so stable and flexible. In order to overcome this drawback, we have constructed a carboxy methyl cellulose (CMC) and gelatin-based polymeric films at a temperature of 55 °C. A polymeric film with the addition of ionic liquid (IL), shows tremendous antibacterial and antioxidant properties towards food packaging. Ionogel films show different properties with different compositions of ionic liquid (IL0%, IL5%, and IL20%). The characterization of prepared polymeric films has been carried out for their surface morphology, thermal stability, UV shielding, optical properties, smoothness, and antimicrobial properties. The antibacterial activity of polymeric film (PF@IL20%) was tested on both Gram-negative E. coli (Escherichia coli) and Gram-positive S. aureus (Staphylococcus aureus) bacteria. In particular, PF@IL20% exhibits potent activity against E. coli and S. aureus with MIC values of 7 ± 2 μg mL⁻¹ and 13 ± 2 μg mL⁻¹ respectively. It was observed that ionogel matrix shows excellent antibacterial and antioxidant properties toward food packaging and their antibacterial mechanism was explored by SEM and AFM analysis. Further, ionogel PF@IL20% was applied for food (red apple) packaging abilities and with inclusion of 20% ionic liquid exhibited exceptional food wrapping applicability, which increases the shelf life of red apples by preventing air-oxidation.

In this research, a novel active bionanocomposite food packaging film was prepared by incorporating zein nanoparticles loaded with chestnut shell extract (CSE) into a pectin and gelatine matrix. Nanocomposite films were developed based on 28 different formulations, and were assessed focusing on physicochemical, mechanical, optical, thermal, structural, and active properties. Using D-optimal combined design, the optimal formulation was determined by considering variables like carbohydrate, protein, glycerol, and zein nanoparticle ratios. The optimum film displayed low water vapor permeability (0.276 g.mm/m².h.kPa) and high elongation at break values (>90%). We also evaluated these films for antioxidant activity (38.47 mg Trolox/100 g dw), oxygen permeability in sunflower oil (11.47 meq O₂/kg), and volatile compounds. The addition of active zein nanoparticles improved film properties and introduced functional characteristics. This study introduces an optimized active bionanocomposite film formulation for potential applications in active food packaging.