Development and characterization of a double-layer smart packaging system consisting of polyvinyl alcohol electrospun nanofibers and gelatin film for fish fillet.

This study aimed to develop a double-layer film composed of an intelligent, gelatin-based film integrated with active polyvinyl alcohol electrospun nanofibers (PVANFs). Eggplant skin extract (ESE), a colorimetric indicator, was incorporated into the gelatin-based film at varying concentrations ranging from 0 % to 8 % w/w. The gelatin film containing 8 % ESE was identified as the optimal formulation based on its superior color indication, water barrier, and mechanical properties. Savory essential oil (SEO)-loaded PVANFs were electrospun onto the optimized gelatin film to fabricate the double-layer film. Analysis of the chemical and crystalline structures and the double-layer film's thermal properties confirmed the gelatin film's physical integration with PVANFs. Morphological examination revealed a smooth surface on the film and a uniform fibrillar structure within the PVANFs. Furthermore, the developed double-layer film effectively detected spoilage in trout fish while controlling pH, oxidation, and microbial changes during storage.

A high-strength collagen-based antimicrobial film grafted with ε-polylysine fabrication by riboflavin-mediated ultraviolet irradiation for pork preservation.

In this study, a UV-cured collagen-based film (C-P-H film) with high mechanical strength and antimicrobial properties was developed by riboflavin-mediated ultraviolet irradiation of collagen solution containing histidine-modified ε-polylysine. Fourier transform infrared analysis indicated that covalent cross-linking was formed between the collagen molecule and the histidine-grafted ε-polylysine. Compared with the pure collagen film, the C-P-H film containing 5 wt% histidine-modified ε-polylysine showed higher tensile strength (145.98 MPa), higher thermal denaturation temperature (76.5 °C), lower water vapor permeability (5.54 × 10-11 g m-1 s-1 Pa) and excellent antimicrobial activities against Escherichia coli and Staphylococcus aureus. In addition, the wrapping of the C-P-H film effectively inhibited bacterial growth of pork during storage time, successfully prolonging the shelf-life of pork by approximately 4 days compared to that of plastic wrap. These results suggested that collagen-based film grafted with histidine-modified ε-polylysine via riboflavin-mediated ultraviolet irradiation process had a great potential for pork preservation.

A novel carboxymethyl cellulose/gum xanthan and citric acid-based film that enhances the precision of blackcurrant anthocyanin-induced color detection for beef spoilage tracking.

Leveraging blackcurrant anthocyanin (BC) as an indicator and carboxymethyl cellulose (CMC), gum xanthan (GX), and citric acid (CA) as film fabricating materials, an innovative amine-responsive beef freshness intelligent film, known as CGC-BC, was successfully created. It was found that the physical characteristics, sensitivity to the biogenic amine reaction, and original color of the film were all highly influenced by the pH of the film-forming solutions. The film's freshness monitoring ability was assessed at 4, 25, and 35 °C, and various color changes were employed to monitor beef deterioration. ΔE values and the visual color difference of the low-concentration (SCG-BC-0.08 and SCG-BC-0.16) ammonia-sensitive indicator films demonstrated significant color changes than the high-concentration (SCG-BC-0.24 and SCG-BC-0.32) films. The films biodegradation (37.16 to 51.49%) ability was enhanced with increase in the proportions of BC. As the TVB-N and pH values of beef increased with the different temperatures and time and different color changes were observed from red to pink, black to brown, and yellow.

Effects of pressure-based technologies on food lipids oxidation.

The aim of this paper is to provide a thorough review of recent research on the effects of high pressure processing (HPP) and hyperbaric storage (HS) on lipid oxidation amounts in different food products, as well as the mechanisms of lipid oxidation during processing and storage. Globaly, highly perishable foods showed an increase in lipid oxidation when preserved by HPP. On the other hand, HS using lower pressure levels but much longer time under pressure seems to cause a higher level of secondary lipid oxidation products and a lower level of tertiary products, with HS so decreasing oxidation progress during storage. Existing studies have mainly focused on individual oxidation indicators, highlighting the need for a comprehensive analysis of primary, secondary, and tertiary oxidation products in order to fully understand the progression of oxidation. This comprehensive approach ensures a systematic assessment of lipid oxidation, leading to a clear understanding of the oxidation process.

Gelatin/polyvinyl alcohol films loaded with doubly stabilized clove essential oil chitosomes: Preparation, characterization, and application in packing marinated steaks.

In this study, a promising active food-packaging film of Gelatin/polyvinyl alcohol (GEL/PVA) integrated with doubly stabilized clove essential oil chitosome nanoparticles (CNP) was developed to maintain the freshness of marinated steaks. Results from the XRD and SEM experiments indicated excellent compatibility between the CNP and GEL/PVA matrix. Additionally, CNP was found to introduce more free hydroxyl groups, enhance the water retention and surface wettability of the CNP-GEL/PVA (C-G/P) film, and significantly reduce the swelling index from 963.78% to 495.11% (p < 0.05). Notably, the highest tensile strength and elongation at break (53.745 MPa and 46.536%, respectively) were achieved with the addition of 30% (v/v, based on the volume of gelatin) CNP; UVC was fully absorbed with 40% CNP; and films containing 60% CNP showed optimal inhibition of both Staphylococcus aureus and Escherichia coil, extending the shelf life of marinated steak from 3 to 7 days.

A double-layer film based on the strategy of tannic acid-anthocyanin co-pigmentation and tannic-crosslinked-gelatin/-reduced Ag nanoparticles for beef preservation and monitoring.

A double-layer film was developed with tannic acid (TA) co-pigmented purple potato anthocyanin extract (PAE)-agar as the inner layer, and K-carrageenan-oregano essential oil Pickering emulsion (OPE)/silver nanoparticles (TA-AgNPs) as the outer layer. Molecular docking and FT-IR results elucidated that intermolecular hydrogen bond was the main interaction between components in the agar-carrageenan matrix, with TA and PAE contributing to intensified anthocyanin color through π-π stacking. The incorporation of OPE/TA-AgNPs enhanced the film's hydrophobicity (WCA > 100°) and UV-vis barrier (close to 0% at 200-320 nm, effectively impeding UVA, UVB, and UVC) properties and exhibited outstanding antioxidant (DPPH scavenging rate > 88%) and antimicrobial activities. This film showed a significant color change in the pH range of 2-12 (from pink to yellow) and a considerable sensitivity to volatile amines within 2 min. The films effectively alleviated beef spoilage (extending the shelf life of beef for 1d) and reflected the freshness of beef during storage. Additionally, the digital color information of the film was obtained by a smartphone combined with RGB values analysis to quantify the freshness of beef rapidly. Therefore, this study expands the application of food packaging films with freshness preservation and monitoring in the field of animal-derived food.

Green fabrication of modified lignin/zeolite/chitosan-based composite membranes for preservation of perishable foods.

Chitosan, as a kind of naturally occurring green and degradable material for the preservation of perishable foods, was investigated in this study with the objective of enhancing its preservation performances. Herein, lignin was modified using the solvent fractionation method (modified lignin, ML, including ML1-ML3), while natural clinoptilolite zeolite was modified using the alkali modification method (modified clinoptilolite zeolite, MCZ, including MCZ1-MCZ5). After optimizing the conditions, it was discovered that incorporating both ML3 and MCZ3 into pure chitosan-based membranes might be conducive to fabricate chitosan-based composite membranes for the preservation of perishable foods. As-prepared composite membranes possessed better visible light transmittance, antioxidant activity, and carbon dioxide/oxygen selectivity, resulting in improved preservation effects on the model perishable foods such as bananas, cherry tomatoes, and cheeses. These findings might indicate promising applications for chitosan-based composite membranes with modified lignin and zeolite in the field of eco-friendly degradable materials for the preservation of perishable foods.

Vacuum impregnation: Effect on food quality, application and use of novel techniques for improving its efficiency.

Vacuum Impregnation (VI) act as promising method for rapidly introducing specific concentration solutions into food matrices using a hydrodynamic mechanism and deformation phenomenon to attain a product with specific tailored functional quality characteristics. VI facilitates rapid introduction of specific solutions into the food matrices. This technique allows efficient incorporation of bioactive compounds and nutritional components, meeting the rising consumer demand for functional foods. Furthermore, VI when combined with non-thermal techniques, opens up new avenues for preserving higher quality attributes and enhancing antimicrobial effects. The unique ability of VI to rapidly infuse specific solutions into food matrices, combined with the advantages of non-thermal processes, addresses the growing consumer demand for products enriched with bioactive ingredients. Hence, the present review aims to explore the potential impact of VI, coupled with novel techniques, on food quality, its practical applications, and the enhancement of process efficiency for large-scale industrial production.

Improved moisture barrier and mechanical properties of rice protein/sodium alginate films for banana and oil preservation: Effect of the type and addition form of fatty acid.

Attenuating the moisture sensitivity of hydrophilic protein/polysaccharide-based films without impairing other properties remains a challenge. Fatty acid dispersed in Pickering emulsion was proposed to overcome such issue. An increase in fatty acid chain length slightly reduced the water vapor permeability (WVP) of emulsion films. As the number of fatty acid double bonds increased from 0 to 1, the WVP of emulsion films was significantly decreased by 14.02% while mechanical properties were significantly enhanced. More hydrogen bonds and stronger electrostatic interactions in the presence of fatty acids were observed by molecular dynamics simulation. The weight loss of bananas coated with oleic acid-incorporated film-forming emulsion was 6.81% lower than that of uncoated group after 4 days, and the corresponding film was more effective to delay oil oxidation than the commercial polypropylene film, indicating that the film is a promising alternative to food coating and packaging material.

In-situ electrospinning PVB/Camellia oil/ZnO-TiO2 nanofibrous membranes with synergistic antibacterial and degradation of ethylene applied in fruit preservation.

This work utilizes a handheld electrospinning device to prepare a novel nanofibrous composite membrane in situ for packaging freshness. It can realize pick-and-pack and is easy to operate. The nanofibrous membrane is based on PVB as the matrix material, adding Camellia oil (CO) and ZnO-TiO2 composite nanoparticles (ZT) as the active material. The antimicrobial property of the CO and the photocatalytic activity of the nanoparticles give the material good antimicrobial and ethylene degradation functions. Meanwhile, this nanofibrous membrane has good mechanical properties, suitable moisture permeability and good optical properties. The nanofibrous membrane are suitable for both climacteric and non- climacteric fruits. Its use as a cling film extends the shelf life of strawberries by 4 days and significantly slows the ripening of small tomatoes. Therefore, this nanofibrous membrane has great potential for application in the field of fruit preservation.

Visible light-responsive TiO2-based hybrid nanofiller reinforced multifunctional chitosan film for effective fruit preservation.

In this study, we developed a multifunctional chitosan film with visible light-responsive photocatalytic properties by incorporating a novel nanofiller-a nanohybrid particle of poly(tannic acid) (PTA) and TiO2 (TP-NPs). Firstly, the hybridization of TiO2 with PTA not only improved its dispersion but also obtained TP-NPs with smaller band gaps (from 3.11 eV to 1.55 eV) and higher separation efficiency of photogenerated e--h+ (about 1.5-fold enhancement), thereby producing more reactive oxygen species and enhancing the antibacterial efficacy (compared with TiO2, the antibacterial effect of TP-NPs on Staphylococcus aureus and Escherichia coli was heightened by about 2 times under visible light for 1 h). Secondly, TP-NPs were hydrogen bonded with chitosan, strengthening its mechanical and barrier properties, while imparting exceptional antibacterial efficacy. Moreover, the multifunctional properties enabled the active film to effectively delay the quality deterioration of grapes and kiwifruit. Hence, this study presented a multifunctional active packaging film tailored for fruit preservation.

Janus hydrogel loaded with a CO2-generating chemical reaction system: Construction, characterization, and application in fruit and vegetable preservation.

In this study, we inserted a dynamic chemical reaction system that can generate CO2 into Janus hydrogel (JH) to develop a multidimensional preservation platform that integrates hygroscopicity, antibacterial activity, and modified atmospheric capacity. The double gel system developed using sodium alginate/trehalose at a 1:1 ratio effectively encapsulated 90% of citric acid. Furthermore, CO2 loss was avoided by separately embedding NaHCO3/cinnamon essential oil and citric acid microcapsules into a gelatin pad to develop JH. Freeze-dried JH exhibited a porous and asymmetric structure, very strongly absorbing moisture, conducting water, and rapidly releasing CO2 and essential oils. Furthermore, when preserving various fruits and vegetables in practical settings, JH provided several preservation effects, including color protection, microbial inhibition, and antioxidant properties. Our study findings broaden the application of JH technology for developing chemical reaction systems, with the resulting JH holding substantial promise for cold chain logistics.

Ginkgo biloba leaf polysaccharide-stabled selenium nanozyme as an efficient glutathione peroxidase mimic for the preservation of bananas and cherry tomatoes.

To develop functional, sustainable and eco-friendly active packaging materials as alternatives to plastic films, we successfully prepared Ginkgo biloba leaf polysaccharide-stabilized selenium nanomaterials (Se-GBLP). Se-GBLP with glutathione peroxidase-like activity could efficiently remove harmful reactive oxygen species. As a functional additive, Se-GBLP was incorporated into degradable chitosan (CS) to fabricate CS/Se-GBLP films. The addition of Se-GBLP improved the mechanical properties, UV-visible light barrier performance, water vapor permeability, and antioxidant activity of the films. Preservation experiments demonstrated CS/Se-GBLP film could maintain quality and prolong the storage time of bananas and cherry tomatoes. It was the first time to use selenium-based nanozyme for fruit preservation. This work offered a cost-effective solution to reduce post-harvest losses, increasing sustainability and profitability. Future research should focus on more factors affecting freshness such as variety, maturity, harvest and storage conditions to improve preservation, as well as on the material's safety concern and environmental impact.

Ratiometric fluorescent platform for on-site monitoring of sodium pyrosulfite in preserved fruits.

The rapid detection of pyrosulfites in food chemistry is crucial to food safety and health. Here, a coumarin-type ratiometric fluorescent probe was developed based on the Michael addition reaction to detect sodium pyrosulfite (Na2S2O5). The probe exhibited high selectivity and fast response (t1/2 = 6 s) to Na2S2O5 and a low detection limit (26 nM). Because of its excellent ratiometric response performance, the probe was successfully applied to measure the amount of Na2S2O5 in preserved fruits. Colour information analysis and formula calculations were performed to quickly determine the sodium pyrosulfite amount in an actual sample by using a smartphone. Therefore, the intelligent strategy of combining the sensing process and smartphone provides a convenient and efficient method for the fast monitoring of sodium metabisulfite in actual food.

Zein-based nisin-loaded electrospun nanofibers as active packaging mats for control of Listeria monocytogenes on peach.

Zein-based nanofibers (NFs) functionalized with nisin (NS), reinforced with montmorillonite nanoclay (nMMT) were fabricated by uniaxial electrospinning (ES) for the first time to preserve yellow peach. Spinnability/viscosity/conductivity optimizations generated porous (95.09%), bead-free, ultrathin (119 nm) NFs of low hydrophobicity (26.05°). Glutaraldehyde (GTA) crosslinking fostered positive outcomes of tensile strength (1.23 MPa), elongation (5.0%), hydrophobicity (99.46°), surface area (201.38 m2.g-1), pore size (2.88 nm), thermal stability (Tmax = 342 °C), antioxidant/cytotoxic activities in optimized NFs that released NS sustainably according to Korsmeyer-Peppas model indicating a Fickian diffusion mechanism with R2 = 0.9587. The novel NFs inhibited growth of Listeria monocytogenes/aerobic mesophilic populations in peach after 4 days of abusive storage, evincing their robustness in food contact applications. Simultaneously, quality parameters (moisture/texture/browning/total soluble solids/pH) and peach physical appearance were maintained for up to 8 days, endorsing the practical value of zein-based NFs as a non-thermal postharvest intervention for prolonging fruits storage life.

Novel Halogenated Curcumin-Mediated Photodynamic Inactivation for the Preservation of Small Yellow Croaker (Larimichthys polyactis).

A novel class of halogenated curcumin, X-Cur (X = F, Cl, or Br), was synthesized, and its photosensitivity was evaluated. The results showed that Br-Cur with the highest singlet oxygen (1O2) generation capacity exhibited a better photodynamic inactivation (PDI) effect on the small yellow croaker (Larimichthys polyactis) than curcumin. This was attributed to the heavy atom effect of Br, which resulted in Br-Cur having the smallest singlet-triplet energy difference ΔEst(S1-T3) (0.140 eV) and the largest spin-orbit coupling value (0.642262 cm-1). When L. polyactis was treated with 0.025 wt % Br-Cur and exposed to blue LED irradiation (450 nm, 20 mW/cm2) for 20 min, the increase in the total volatile basic nitrogen content (28.23 ± 2.38 mg/100 g on day 6), pH, and total viable count (6.13 ± 0.06 log CFU/g on day 6) could be effectively controlled. Accordingly, Br-Cur is a promising photosensitizer for PDI preservation.

Effect of ultra-high pressure heat-assisted technology combined with L-cysteine on the color of ready-to-eat shrimp during storage.

This study used ultra-high pressure processing (HPP) heat-assisted technology combined with L-cysteine (L-cys) to process ready-to-eat (RTE) shrimp. Subsequently, the effects of physical field and chemical modifications on the color of RTE shrimp were studied. The results showed that the RTE shrimp treated with HPP-Heat-L-cys showed better performance in terms of brightness value (65.25) and astaxanthin (AST) content (0.71 µg/g) during storage, maintaining the original color of RTE shrimp effectively. In addition, it was observed that the application of HPP-Heat-L-cys significantly delayed phenol oxidation, lipid oxidation, and Maillard reaction compared with traditional HPP or heat treatments. Specifically, the total phenolic content of RTE shrimp treated with HPP-Heat-L-cys was higher than that of other samples, but the TBARS and browning index were lower. Furthermore, HPP-Heat-L-cys could delay the production of dark products (such as 2-methylanthraquinone, p-benzoquinone, lipofuscin and melanin), ultimately safeguarding the color stability of RTE shrimp during storage.

Essential oil-nanoemulsion based edible coating: Innovative sustainable preservation method for fresh/fresh-cut fruits and vegetables.

Utilizing plant-based sources for the preservation of fresh and fresh-cut fruits and vegetables offers a natural and chemical-free method. However, the inherent instability of plant bioactive compounds underscores the necessity for encapsulation techniques. Essential oil-based nanoemulsions (EO-NEs) stand out among food additives due to their distinctive antibacterial and antioxidant properties. This review delves into recent advancements in the application of EO-NEs as edible coatings for fresh and fresh-cut produce. It examines the efficacy of EO-NEs in enhancing the preservation of fruits and vegetables by harnessing their bioactive compounds for antibacterial, antifungal, and antioxidant activities. Additionally, the review accentuates the efficacy of EO-NEs in inhibiting biofilm formation on fruits and vegetables. It reveals that coatings derived from plant-source nanoemulsions exhibit exceptional mechanical, optical, and microstructural qualities, as well as superior water barrier properties. In contrast to conventional emulsions, nanocoatings facilitate the gradual and controlled release of antimicrobial and antioxidant compounds during food storage. This feature enhances bioactivity, extends shelf life, and enhances the nutritional profile of products. By preserving and protecting shelf stability, EO-NEs contribute to the maintenance of vegetable freshness. Nonetheless, ensuring their commercial viability necessitates additional research into the toxicity of EO-based nanoemulsions.

Integrated self-assembly and cross-linking technology engineered photodynamic antimicrobial film for efficient preservation of perishable foods.

A new antibacterial film was constructed to combat the severe spoilage of fruits and vegetables caused by microorganisms. Specifically, photoresponsive cinnamaldehyde-tannic­iron acetate nanospheres (CTF NPs) were prepared using ultrasonic-triggered irreversible equilibrium self-assembly and ionic cross-linking co-driven processes and were integrated into the matrix of κ-carrageenan (KC) (CTF-KC films) as functional fillers. The CTF0.4-KC film (KC film doped with 0.4 mg/mL CTF NPs) showed a 99.99% bactericidal rate against both E. coli and S. aureus, extended the storage period of cherry tomatoes from 20 to 32 days. The introduction of CTF enhanced the barrier, thermal stability, and mechanical strength properties, albeit with a slight compromise on transparency. Furthermore, the biosafety of the CTF0.4-KC film was confirmed through hemolysis and cytotoxicity tests. Together, the aforementioned results demonstrated the outstanding antibacterial and fresh-keeping properties of CTF0.4-KC. These desirable properties highlight the potential use of CTF0.4-KC films in food preservation applications.

Mitigation of mechanical damage and protein deterioration in giant river prawn (Macrobrachium rosenbergii) by multi-frequency ultrasound-assisted immersion freezing.

In order to investigate the effects of multi-frequency ultrasound-assisted immersion freezing (MUIF) on the meat quality of Macrobrachium rosenbergii, tail meat was subjected to different MUIF treatments respectively, namely 20 + 40 kHz (MUIF-20 + 40), 20 + 60 kHz (MUIF-20 + 60), 40 + 60 kHz (MUIF-40 + 60) and 20 + 40 + 60 kHz (MUIF-20 + 40 + 60), and the immersion freezing (IF) as control. Results showed that average diameter of ice crystals was 28 µm in IF, and that was only 8 µm in MUIF-20 + 40 + 60. When compared to IF, MUIF alleviated oxidative deterioration of lipids and proteins, but only at higher ultrasound frequency (MUIF-40 + 60; MUIF-20 + 40 + 60). Carbonyl content of MUIF-20 + 40 + 60 was only 40% of that in IF. Similarly, protein denaturation was inhibited in MUIF (except for MUIF-20 + 40). Transmission electron microscopy showed greater distortion of the ultrastructural components in IF, MUIF-40 + 60, and MUIF-20 + 40 + 60, suggested by bended Z-line. In conclusion, MUIF can be an effective strategy to mitigate mechanical damage and protein deterioration in the meat of Macrobrachium rosenbergii.