Search

The objective of this work was to evaluate the potential application of chitosan/PVA food packaging films incorporating nano-ZnO and purple potato anthocyanins for preserving chilled hairtail pieces. The hairtail pieces were packaged with chitosan/PVA (CP) and chitosan/PVA/nano-ZnO/purple potato anthocyanins (CPZP), respectively, and Control named without any packaging. The changes in pH, total volatile basic nitrogen (TVB-N), total bacterial colony (TVC), thiobarbituric acid (TBA), color value, and sensory evaluation scores of hairtail pieces were periodically determined. Notably, pH, TVC, TVB-N and TBA values of CPZP group on day 15 were 11.67 %, 23.71 %, 80.73 %, and 35.07 %, respectively, lower than Control group. In addition, CPZP group also performed the best in color and sensory evaluation. These results indicated that CPZP, an active food packaging, could extend the shelf-life of hairtail at least 6 days. Overall, chitosan/PVA food films incorporated with nano-ZnO and purple potato anthocyanins (180 mg/100 mL) provides a potential application in food preservation., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, and there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be regarded as influencing the position presented in, or the review of, the manuscript entitled Chitosan/polyvinyl alcohol food packaging incorporated with purple potato anthocyanins and nano-ZnO: Application on the preservation of hairtail (Trichiurus haumela) during chilled storage., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To solve undiscernible freshness changes of printed functional surimi while maintaining printed shape, 4D printable color-changing material were prepared. Firstly, based on results of printing properties and fresh-keeping of Ca 2+ -NS-L-surimi, it showed better printing effects (enhanced mechanical strength) and good preservation (inhibition of amino acids decomposition, bacterial growth). However, freshness changes of printed Ca 2+ -NS-L-surimi were not distinguished directly. To avoid that, 4D printable color-changing material-anthocyanin-hydroxypropyl methyl cellulose-xanthan gum-carrageenan (AHXK) was prepared for indicating freshness through discoloration. Printing results showed AHX with 5 % K had the most suitable mechanical strength (appropriate gel strength, texture, rheology) for printing. Based on that, AHXK had stable color (ΔE fluctuation <5) and was sensitive to pH and ammonia (obvious discoloration; ΔE > 10). Actual freshness monitoring results (co-printing of AHXK-surimi) exhibited significant discolorations, especially for HXK with 0.75 % A. It became green during refrigeration of 3-5 d (keeping fresh, ΔE < 4), brighter green at 7 d (decreased freshness, ΔE > 6), turned yellow at 9 d (spoilage, ΔE > 16), which were distinguished significantly with naked eyes rather than traditional freshness determining. In conclusion, printed AHXK-functional surimi exhibited good printing, preservation and nondestructive freshness monitoring, facilitating application of 3D printed functional surimi., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A novel stable PVA/HPMC/roselle anthocyanin (RAE) indicator film co-pigmented with oxalic acid (OA) was prepared, its properties, application effects and stability enhancement mechanism were investigated correspondingly. The structural characterization revealed that more stable network was formed due to the co-pigmentation facilitated generation of molecular interactions. Meanwhile, the co-pigmentation improved film mechanical and hydrophobic properties compared to both PVA/HPMC/RAE newly prepared (PHRN) or stored (PHRS) film, expressing as higher tensile strength values (12.25% and 14.44% higher than PHRN and PHRS), lower water solubility (7.22% and 10.09% lower than PHRN and PHRS) and water vapor permeability values (33.20% and 21.05% lower than PHRN and PHRS) of PVA/HPMC/RAE/OA newly prepared (PHON) or stored (PHOS) film. Compared with the PHRS film, the PHOS film still presented more distinguishable color variations when being applied to monitor shrimp freshness, owing to the stabilization behaviors of co-pigmentation in anthocyanin conformation. Hence, the co-pigmentation was an effective strategy to enhance film stability, physical and pH-responsive properties after long term storage, leading to better film monitoring effects when applied in real-time freshness monitoring., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The enhancement effects of co-pigmentation on thermal stability of roselle anthocyanin extract (RAE) were investigated. The introduction of organic acids maintained color stability of RAE, and RAE co-pigmented with oxalic acid (OA) presented less color fading rates (19.46 ± 0.33 %) and higher redness (41.33 ± 3.51). Subsequently, suitable co-pigmentation concentration (OA:RAE = 1:2) was obtained regarding with lower ΔE (48.70 ± 2.36). Then, improvement behaviors of co-pigmentation on OA-RAE were evaluated. Results demonstrated that OA-RAE exhibited better thermal stability, as manifested by larger retention rates and more favorable thermal degradation kinetic parameters. Furthermore, both molecular docking simulation and experimental structural characterization revealed that hydrogen bonds and other non-covalent bonds made up the main parts of molecular interactions, leading to formation of stable binary complex. As a result, the aromatic ring of RAE was protected. In conclusion, the co-pigmentation of RAE via introduction of OA was effective in stability enhancement due to the generation of molecular bindings., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

An electrospun nanofiber based on pullulan/chitin nanofibers (PCN) containing curcumin (CR) and anthocyanins (ATH) was developed using an electrospinning technique for active-intelligent food packaging. The results of scanning electron microscopy and attenuated total reflection Fourier transform infrared spectroscopy indicated that CR and ATH were successfully immobilized on the film-forming substrate based on PCN. The physical and chemical properties of nanofibers with no colorant, a single colorant, and double colorants were compared. The nanofiber containing ATH and CR (PCN/CR/ATH) had stronger antioxidant and antimicrobial activities than those of nanofibers containing CR (PCN/CR) or ATH (PCN/ATH). With respect to pH sensitivity, the color of the PCN/CR nanofibers did not change obviously, but the color of the PCN/ATH and PCN/CR/ATH nanofibers changed significantly with the change in pH. Furthermore, the PCN/CR/ATH nanofibers clearly changed color with the progressive spoilage of Plectorhynchus cinctus at room temperature. Therefore, the electrospun PCN/CR/ATH nanofiber have great application potential in active-intelligent food packaging., (Copyright © 2021. Published by Elsevier B.V.)

The roselle anthocyanin extracts (RAE) were immobilized into polyvinyl alcohol (PVA)/hydroxypropyl methylcellulose (HPMC) film matrix, their interaction behavior and mechanism was fully understood for better shrimp freshness monitoring. Structural characterizations revealed RAE was firmly immobilized PVA/HPMC matrix by hydrogen bonds. With increasing RAE contents, dramatic increases of film thickness (from 15.90 ± 0.14 to 23.20 ± 3.35 μm), tensile strength (from 45.66 ± 1.07 to 56.98 ± 0.24 MPa), light barrier and active properties (increased by 83.18% for antioxidant and 146.91%, 59.18% for antibacterial activity against E. coli and S. aureus) were observed, while hydrophobic properties decreased significantly. Owing to great ammonia-sensitive ability, the PVA/HPMC/RAE (PHR) films were applied on shrimp freshness qualitative monitoring and greater visible color variations were identified with increasing RAE contents. Furthermore, mathematical models were established for quantitative monitoring. In conclusion, with the increasing RAE contents, the tighter interaction between RAE and PVA/HPMC matrix contributed to the better functional properties and freshness monitoring effects of PHR films., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, halochromic smart films were produced, characterized, and applied to monitor the freshness of hairtail and shrimp in real-time. Red cabbage anthocyanins (RCAs) solution illustrated significant color variations (red-pink-blue-green) in different pH environments. RCAs were successfully immobilized into chitosan (CS)/oxidized-chitin nanocrystals (OCN) composites through hydrogen bonding, and cohesive film structures were formed. When the proper concentration of RCAs was incorporated into the composites, improved water vapor permeability (WVP), oxygen permeability (OP), mechanical, UV-blocking, and antioxidant properties were observed. Moreover, the smart films exhibited distinguishable changes of color to ammonia vapor and acidic/alkaline environment within short time intervals, which were easy to discern by naked eyes. Finally, the smart films were applied to monitor the freshness of hairtail (Trichiurus lepturus) and shrimp (Penaeus vannamei). The film color changed significantly during storage time, and three stages of product freshness (fresh, medium fresh, and spoiled) were successfully differentiated. Strong correlations among three freshness indicators and two colorimetric parameters were also identified and analyzed. Overall, the smart system assembled from non-toxic and biodegradable components could contribute to monitoring the freshness of seafood, like hairtail and shrimp, in real-time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

pH-sensitive and antibacterial films based on chitosan/polyvinyl alcohol/nano-ZnO (CPZ) containing anthocyanins extracted from purple potato (PPE) or roselle (RE) were developed. When incorporated with PPE or RE, the moisture contents and flexibility of film significantly reduced (P < 0.05), while mechanical resistance of film was significantly enhanced (P < 0.05). Water vapor permeability (WVP) of film was slightly influenced by the addition of PPE or RE (P > 0.05). CPZ-RE film exhibited darker color and lower light transmittance than CPZ-PPE film at the same incorporation level. CPZ-PPE and CPZ-RE films exhibited distinguishable color changes in different pH buffer solutions. CPZ-PPE films exhibited higher antibacterial activity against Escherichia coli and Staphylococcus aureus than CPZ-RE films. Moreover, film could effectively monitor spoilage degree of shrimp when film changed from purple to light-green. Our results suggested CPZ-PPE and CPZ-RE films have promising potential as active and smart packaging materials for applications in food industry., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A novel indicator film incorporating roselle anthocyanin extracts (RAE) was prepared to monitor shrimp freshness. Hydroxypropyl methylcellulose (HPMC) modified polyvinyl alcohol (PVA) was applied as film-forming substrates to obtain better functions. Structural characterization results suggested compositions were well dispersed and confirmed the structural modification. The addition of HPMC would improve film functions through generation of new interactions. The films with a ratio (HPMC-to-PVA) of 3:1 exhibited stronger tensile strength (91.88 ± 0.13 MPa), hydrophobic (moisture content of 10.44 ± 0.65%, water contact angle of 56.40 ± 3.11°), barrier properties and larger color variations in response to pH changes, demonstrating positive influences of physical functions on indication properties. Thus, a relationship among structural, physical and indication functions was proposed. Furthermore, the films were applied for shrimp freshness real-time monitoring. The film color changed from rose-red to light green at 4 d, corresponding to the onset of spoilage, and then turned into yellow at 8 d, when the shrimp was severely spoilage. The strong correlation between total color difference and chemical spoilage indexes (P < .05) was observed. Therefore, the incorporation of HPMC could improve film functional characteristics by structural modification of new interaction formation, and the PVA/HPMC/RAE films could be applied as intelligent packaging for real-time shrimp freshness monitoring., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled Functional characteristics improvement by structural modification of hydroxypropyl methylcellulose modified polyvinyl alcohol films incorporating roselle anthocyanins for shrimp freshness monitoring., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A green nanocomposite film with pH-sensitivity and antioxidant activity based on oxidized chitin nanocrystals (O-ChNCs)/gelatin incorporating black rice bran anthocyanins (BACNs) was prepared in this study. Fourier transform infrared spectrum showed that BACNs were successfully immobilized into the O-ChNCs/gelatin matrix through non-covalent bonds. Scanning electron microscopy and atomic force microscope showed that BACNs was uniformly distributed in the O-ChNCs/gelatin matrix. Although the incorporation of BACNs decreased the mechanical properties of the films, it endowed the films with excellent UV-vis light barrier and antioxidant character. Moreover, the O-ChNCs/gelatin/BACNs films were pH-sensitive and showed remarkable color changes in different buffer solutions, which could be used to monitor the freshness of shrimp and hairtail by visible color changes. The colorimetric films with lower content of BACNs were found more sensitive toward basic volatile amines emitted during storage. Therefore, the developed O-ChNCs/gelatin/BACNs films may have a great potential in the freshness monitoring of high protein foods., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A novel intelligent film was developed by immobilizing 1%, 3% and 5% black rice bran anthocyanins (BACNs) into oxidized-chitin nanocrystals (O-ChNCs)/ chitosan (CS) matrix. The ultraviolet-visible spectrum of BACNs solutions showed color variations from red to greyish green in a range of pH 2.0-12.0. Fourier transform infrared spectrum and atomic force microscope of the films showed that O-ChNC and BACNs were well dispersed into the CS matrix. Although the incorporation of BACNs decreased the mechanical and barrier properties of the CS/O-ChNCs/BACNs (COB) films, it endowed the COB films with excellent UV-barrier, antioxidant and pH sensitivity character. The results of the application trial showed that the COB films containing 3% of BACNs (COB-3) were able to monitor the spoiling of fish and shrimp by visible color changes. Therefore, the developed COB-3 films could be used as an intelligent food packaging for monitoring animal-based protein food spoilage., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The goal of the study is to develop a novel pH-indicating intelligent packaging by using purple potato extractions (PPE), chitosan and surface-deacetylated chitin nanofibers (CN). Since the major pH-sensitive pigment of PPE was anthocyanin (24.3 mg/g), whether anthocyanins could be loaded on a solid phase to prevent its color fading was further tested. The results of Fourier transform infrared spectrophotometry (FT-IR) and differential scanning calorimetry (DSC) indicated that PPE was efficiently attached into the chitosan film. Meanwhile, adding CN (0.450%, w/v) into chitosan film could significantly enhance the tensile strength (TS), the water-resistant ability and the roughness of chitosan film. Whereas higher content of CN (0.600%, w/v) did not further improve mechanical properties and CN would distribute unevenly due to aggregation in the films. In addition to pH-indicating ability, CS-CN-PPE exhibited the extraordinary antioxidant activities and this provides another advantage of packaging readily oxidizable substances. Taken together, the current study provided a novel and biocompatible packaging with strengthened mechanical property and intelligent pH indicator., (Copyright © 2019. Published by Elsevier B.V.)

The enhancement behaviors of polyvinyl alcohol/hydroxypropyl methyl cellulose/roselle anthocyanin (PHR) film on sensory and physico-chemical properties of Penaeus vannamei were investigated. The shrimp packaged by PHR film displayed better sensory profiles with higher sensory scores and lower rejection degree (62.67 ± 2.31%). Compared with control group, the color parameters were improved by PHR film, such as higher lightness (36.30 ± 1.23), lower redness (6.67 ± 1.15), and yellowness (6.67 ± 0.51) as well as less browning effects. Microstructure observation revealed that the PHR film could keep more compact and uniform muscle tissue with less cracks and small fragments. In addition, PHR film was effective in increasing of water holding capacities (80.23 ± 1.70%) and maintenance of flavor characteristics. Meanwhile, the PHR films had abilities to delay protein structure alterations, manifesting as higher total protein contents (23.36 ± 2.58 mg/mL) and less generation of carbonyl groups (5.12 ± 0.16 nmol/mg) and disulfide bonds (3.11 ± 0.07 mol/105 g). Moreover, statistical analysis results demonstrated the close relationship between sensory and physico-chemical properties. Then, the possible enhancement mechanism was proposed that the functional properties of PHR film were responsible for the protein stabilization, leading to less quality deterioration and higher sensory profiles. Thus, the PHR film was a promising food packaging for sensory attribute enhancement and shelf life extension of Penaeus vannamei. [ABSTRACT FROM AUTHOR]

The food's perishable properties and people's eco-friendly requirements have driven the biodegradable active packaging development. In this study, modification behaviors of polyviniyl alcohol/hydroxypropyl methylcellulose/roselle anthocyanin-based (PHR) film on textural profiles of Penaeus vannamei were investigated. Shrimp samples were packaged by PHR film with different roselle anthocyanin contents and stored at 4 ± 1 °C. The results indicated that PHR groups exhibited better texture with higher values of hardness (435.56 ± 75.52 g), springiness (0.53 ± 0.04 mm), chewiness (198.83 ± 40.98 N) and resilience (0.45 ± 0.04). The PHR film exerted positive influences on water migration by reducing drip loss and promoting conversion of free water into immobilized water. Meanwhile, the PHR film retarded protein denaturation via increasing myofibrillar protein and sulfhydryl group contents, decreasing TCA (trichloroacetic acid)-soluble peptide contents and maintaining protein secondary structure (higher α-helix ratio and lower β-sheet ratio). In conclusion, the PHR film improved shrimp texture by rearrangement of water distribution and stabilization of protein conformation. Hence, the PHR film was a novel potential active packaging for shrimp texture enhancement. • The modification behavior and mechanism of PHR film on texture were illuminated. • Water distribution and protein conformation affected textural profiles together. • The PHR film had potential in rearranging water migration positively. • The PHR film was able to delay protein denaturation and stabilize protein structure. The PHR film was a novel food package in texture enhancement and food preservation. [ABSTRACT FROM AUTHOR]

• The TMT-labeled proteomic strategy was used to reveal preservation mechanism of film. • Co-pigmentation maintained film antioxidant and antibacterial functions after storage. • Co-pigmented film (PHO) extended shrimp shelf-life longer than natural film (PHR) • PHO affected biochemical pathways which influenced shrimp quality positively. • 7 DAPs were identified as potential biomarkers showing high correlation with quality. In order to investigate the influences of modified RAE-based film on shrimp quality, the proteomic approach was performed to elucidate preservation mechanism. Results showed that the modified RAE-based film kept better shrimp quality compared with natural RAE-based film in terms of determined biochemical parameters and estimated shelf-life. Totally, 49 differentially abundance proteins (DAPs) were identified compared with shrimp without packaging. Bioinformatics analysis demonstrated that the modified RAE-based film could maintain functional DAPs which were mainly distributed in the binding, catalytic activity, etc., and metabolic signaling pathways like melanogenesis signaling pathway were remarkably enriched. Meanwhile, there were 25 DAPs showing close relationship with quality traits, and some of them, such as myosin chains, troponin I and heat shock protein were considered as the potential biomarkers to evaluate shrimp quality deterioration. In conclusion, this study revealed the preservation mechanism of modified RAE-based active film on shrimp quality at the protein molecular level. [ABSTRACT FROM AUTHOR]