Preparation and characterization of active films based on chitosan incorporated tea polyphenols

Carboxymethyl cellulose/polyvinyl alcohol-based antioxidant film strengthened by physical/chemical bonding of cinnamaldehyde-tannin-metal nanoparticles

Carboxymethyl cellulose (CMC) is a potentially biodegradable substrate widely used in antioxidant food packaging films. However, the rigid structure and large number of hydroxyl groups of CMC films result in poor mechanical properties and are prone to hygroscopicity, which limits their practical application. In this study, we developed a self-assembled multifunctional cinnamaldehyde-tannin-metal composite nanoparticle (CIN-TA metal nanoparticle) that coats cinnamaldehyde via catechol bonds between metal ions and tannic acid to form nanocomposites that produce physical and chemical crosslinks with the CMC matrix. This modification significantly improved the mechanical properties of the CMC-based composite film (tensile strength of 69.78 MPa and elongation at break of 104.4 %), while improving its hydrophobicity (contact angle of 119.31°) and DPPH radical scavenging rate up to 89.4 %. This method is convenient and promising for the preparation of CMC-based food packaging films with mechanical strength, hydrophobicity and antioxidant properties.

A novel LA@Cu-MOF film with dual response to pH and humidity: Preparation, antibacterial activity, and fruit preservation

At present, fruits still undergo extensive decay and deterioration after harvesting. α-Lipoic acid (α-LA) is a natural, pollution-free, and low-cost preservative, which can effectively inhibit the senescence of postharvest fruits. To better utilize the preservation potential of α-LA, in this study, it was reacted with Cu-metal-organic framework (Cu-MOF) and loaded in large quantities onto the Cu-MOF, known as LA@Cu-MOF. On this basis, an antibacterial film with dual responsive release was prepared. The results indicated that LA@Cu-MOF exhibited a significant inhibitory effect on S. aureus, E. coli, and B. cinerea. Additionally, the release of α-LA in the film demonstrated superior response release in weakly acidic and high humidity environments. Moreover, the coating film could maintain the appearance and quality indicators of fruits for at least 6 days. Therefore, this method effectively extended the shelf life of fruits while maintaining their quality, making it a promising intelligent responsive fruits preservation material.

Effect of modified starch-chitosan coating incorporated with Gongju extract on the shelf life of salted duck

This study developed and characterized acetylated distarch adipate/chitosan (ADA/CS) coating incorporated with Gongju extract (GE), investigating its effects on the quality of salted duck during storage. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) results confirmed the formation of hydrogen bonds among ADA, CS and GE, leading to tightly cross-linked polymerization. The incorporation of GE disturbed the internal interactions within the matrix, thereby reducing the barrier, mechanical and thermal properties of the coating. The coating exhibited superior antioxidant activity during cold storage, with DPPH scavenging rates ranging from 44 % to 64 %. The ADA/CS/GE coating effectively delayed lipid and protein oxidation in salted duck by releasing antioxidant components. At the end of storage, the total volatile basic nitrogen (TVB-N) value of the ADA/CS/GE group was 5.51 mg/100 g lower than that of the control group. Additionally, the total viable count (TVC) and Pseudomonas count were reduced by 1.92 and 0.66 log CFU/g, respectively. The salted duck treated with the ADA/CS/GE coating maintained pH, texture and moisture content, ensuring the overall quality of the product. These results indicated that the ADA/CS/GE coating effectively extended the shelf life of salted duck by 8 days at 4 °C.

Obtention and Characterization of Chitosan from Exuviae of Tenebrio molitor and Sphenarium purpurascens

Chitosan is a versatile biopolymer with applications in various industries due to its biocompatibility and biodegradability. While crustacean shells are the primary source of chitosan, the extraction process can be environmentally taxing. This study focuses on evaluating chitosan from Tenebrio molitor and Sphenarium purpurascens, two insect species that offer a more sustainable alternative and require fewer resources for cultivation and produce large amounts of chitin-rich biomass. The acid-alkali method was applied using three experimental conditions (M1, M2, and M3) that involved modification in the demineralization, deproteinization, and deacetylation steps. The chitosan samples were characterized by determining the degree of deacetylation, solubility, molecular weight, antimicrobial activity, and swelling capacity and furthermore by measuring deproteinization and impurity content. Also, Fourier-transform infrared spectroscopy (FTIR) analysis was also performed on the chitosan samples. Samples M3 from the exuvia of T. molitor (DD 55.62% ± 0.79 and solubility 24.13% ± 2.07) and M1 from S. purpurascens (DD 61.86% ± 4.98 and solubility 27.31% ± 1.87) presented the best performance. The molecular weight was calculated between 75 kDa and 118 kDa. On the other hand, data obtained for swelling tests suggested that the film obtained from sample M1 (T. molitor, 5.07% ± 0.11) proved to be more resistant to degradation in an aqueous environment, suggesting that this chitosan could be used for designing a film with high resistance. By exploring these insect sources, this research aims to contribute to the development of chitosan production practices, with potential applications in water treatment, biomedicine, and food packaging, thereby expanding the availability and uses of this valuable biopolymer.

Biodegradable Films with Polysaccharides, Proteins, and Bioactive Compounds from Lobosphaera sp.: Antioxidant and Antimicrobial Activities

Microalgae are a sustainable source of bioactive compounds and nutrients that do not compete with crops for arable land. Lobosphaera sp. was used to produce biodegradable films. Bioactive compounds, polysaccharides, and proteins were extracted from this microalga. The total phenolic content (TPC) and antioxidant activity (ABTS, DPPH, and ORAC) of the bioactive-rich extract were determined, and its composition was analyzed for phenolics using LC-ESI-QqTOF-HRMS and for lipids using GC-FID. The cytotoxicity of this extract on Caco-2 cells was also assessed. Different types of films were produced based on alginate (2%) (film A) and alginate with polysaccharides-rich (PS-rich) extract (0.5%) (film B); PS-rich extract and bioactive-rich extract (0.25%) (film C); protein-rich (P-rich) extract (0.5%) (film D); and P-rich extract and bioactive-rich extract (film E). The antioxidant activity and physical parameters of the films, such as thickness, color, water vapor permeability, solubility, tensile strength (TS), and elongation at break (EAB), were determined. The TPC of the bioactive-rich extract was 1.07 ± 0.05 mg GAE/100 mg DW, and its antioxidant activity was 2.44 ± 0.27, 1.67 ± 0.15, and 11.90 ± 1.22 µmol TE/100 mg DW for ABTS, DPPH, and ORAC, respectively. The extract showed no cytotoxicity to gut cells at concentrations equal to or below 1.0 mg/mL. Film E obtained the best results for the antioxidant activity, 451.06 ± 14.68 and 212.81 ± 39.12 µM TE/mg film for ABTS and DPPH, respectively. In addition, the films enriched with the bioactive-rich extract (films C and E) presented antimicrobial activity against Listeria monocytogenes. These films controlled the mold and yeast growth in strawberries during a four-day storage at 25 °C. All films were completely soluble in water and hydroethanolic solutions but only partially solubilized in acetic acid (3%). TS and EAB were not significantly different among the films. It was possible to produce biodegradable films using microalga Lobosphaera sp. with good bioactivity and physical characteristics.

Post-harvest quality preservation of red globe grapes using grape juice-based edible coatings combined with UVC treatment

This study assesses the impact of grape juice-based alginate or chitosan edible coatings, followed by UVC treatment, on the preservation of post-harvest quality of Red Globe grapes. Coated grapes were stored at 5 °C for 28 days, and their physical, chemical, microbiological, and sensory properties were assessed during the storage period. Films were prepared with grape juice using alginate and chitosan and exposed to 32.4 J/m2 UVC irradiation, then characterized for thickness, color, puncture resistance, elongation at break, permeability, and water solubility. Alginate films were more resistant, soluble, and permeable than chitosan films. Coated and/or UVC-treated grapes showed reduced weight loss, minimal color changes, pH, titratable acidity, total soluble solids, and decreased microbial count compared to uncoated grapes. Sensory attributes remained stable for seven days, while control grapes' firmness significantly decreased (p < 0.05). This sustainable approach enhances the preservation of Red Globe, appealing to consumers who prefer natural preservatives.

Influence of chitosan-capped quercetin nanoparticles on chitosan/poly(vinyl) alcohol multifunctional films: A sustainable approach for bread preservation

Food packaging industries are growing to meet consumer demand and prevent pollution by adopting significant biopolymer advancements. Therefore, this study aimed to develop functionally active chitosan (CS)/polyvinyl alcohol (PVA)-based biopolymer films and evaluate the effect of Justicia Adhatoda extract (JAE), pure quercetin (Q), and CS-capped quercetin nanoparticles ((Q)CS NPs) on sustainable bread packaging. CS was successfully loaded onto (Q) by the one-pot method, which was confirmed by light absorption spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The fabricated films were examined using different analytical techniques. FTIR and XRD patterns confirmed that the CS/PVA matrix had molecular interactions through hydrogen bonds with JAE, (Q), and (Q)CS NPs. SEM micrograms revealed a uniform distribution and denser surface with small aggregations by adding (Q)CS NPs. The (Q)CS NPs added CPE(Q)CS nanocomposite exhibited excellent UV light shielding (99.99 % UV-A and UV-B blocking), water resistance ability (contact angle:99.44°, WVP:3.68×10-7 gh-1m-1Pa-1), and oxygen (0.614×10-6gh-1 m-1 atm-1) barrier properties. Adding (Q)CS NPs enhanced the antimicrobial properties of CPE(Q)CS against foodborne microbes (E. coli:15.45 mm, P. aeruginosa:14.50 mm, B. subtilis:14.25 mm, S. aureus:13.52 mm, and C. albicans:15.16 mm). In addition, incorporating (Q)CS NPs, increased the shelf life of bread compared to unpacked and polyethylene-packed bread samples.

Synthesis of chitosan and carboxymethyl cellulose connect flavonoid (CH-Fla-CMC) composite and their investigation of antioxidant, cytotoxicity activities

This study successfully synthesised and characterised composites combining chitosan (CH), carboxymethyl cellulose (CMC), and various flavonoids (Fla). This innovative approach demonstrates the potential for developing functional materials with antioxidant and food preservation properties. The composites CH-Fla-CMC (1-5) was characterised using advanced techniques such as FT-IR, UV-Vis, XRD, SEM, TEM, and TGA, providing robust data on their structural, morphological, and thermal properties. CH-connected CMC has been used to prevent many diseases, based on the findings of this study. Therefore, dietary flavonoids (Fla = 1. 3-Hydroxyflavone; 2. rhamnetin; 3. natsudaidain; 4. isorhamnetin; 5. myricetin) was used to prepare the composites in this study. Dietary flavonoids play an important role in the prevention of degenerative diseases. In addition, oxygen permeability (OP), water solubility (WS), and moisture content (MS) were analysed. The synthesised composites were screened for antioxidant and cytotoxic activities. Multiple antioxidant assays (DPPH, H₂O₂, NO, ABTS•+, and AAPH) were conducted, confirming the superior radical scavenging activity of CH-Fla-CMC-5 compared to standards such as BHT and Trolox. The synthesised composite CH-Fla-CMC 5 was more active than the standard butylated hydroxytoluene (BHT) against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2), and nitric oxide (NO) radical scavenging activity (DPPH: 10.30 vs. 33.88 μg/ml; H2O2: 13.26 vs. 27.16 μg/ml, and NO: 13.56 vs. 31.73 μg/ml), whereas 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS•+) decolourisation assay and lipid peroxidation method (AAPH) CH-Fla-CMC 5 was more active than the standard Trolox (ABTS: 91.26 ± 0.59 % vs. 85.28 ± 0.97 %; AAPH: 91.02 ± 0.01 % vs. 62.39 ± 0.35 %). The synthesis and characterisation methods are laboratory-based. This study primarily focused on in vitro antioxidant and cytotoxicity assays. The performance of these composites in living organisms and real-life food packaging scenarios remains untested. Cytotoxicity against only check these cell lines such as MCF-7, HeLa, HepG2, and normal Vero cancer cell lines was assessed. Only five flavonoids were tested, potentially limiting the generalisability of the findings to other dietary flavonoids. In the future, we plan to compare more cell lines with flavonoids. These laboratory-based methods have been converted into industrial production. The CH-Fla-CMC-5 composite performed better than the other compounds in all tests. Based on our findings, the synthesised CH-Fla-CMC-5 composite could be used to pack dishes that are watery, acidic, or alcoholic, as well as to coat freshly cut fruits.

Development of Bioactive Edible Film and Coating Obtained from Spirogyra sp. Extract Applied for Enhancing Shelf Life of Fresh Products

The growing interest in environmentally friendly food packaging has led to the development of bio-edible alternatives. This study developed novel, edible, active films and coatings to enhance the shelf life of fresh products. Crude bioactive algal extract (CBAE) was obtained from the ethanol extraction of Spirogyra sp. and incorporated into chitosan-based films and coatings at varying concentrations. The CBAE was rich in phenolic compounds and had antioxidant activity and potential antibacterial properties. The films were prepared using a solvent-casting method and characterized for their biochemical and physical properties. The incorporation of CBAE enhanced the antioxidant activity and improved the tensile strength of the films by 80%. Additionally, film transparency and water vapor permeability were reduced by 13% and 50%, respectively, compared to the control. The developed CBAE coating solution exhibited biocompatibility with human colon adenocarcinoma (HT-29) and mouse subcutaneous connective tissue (L929) fibroblast cells. A shelf-life evaluation using a coating-dipping method on okra showed that the CBAE-coated samples maintained better weight retention and firmness than the uncoated samples over 5 days of storage at ambient temperature. Based on these findings, the CBAE-based edible films and coatings could serve as sustainable alternatives for extending the shelf life of fresh products.

Characterization of thyme essential oil microcapsules and potato starch/pectin composite films and their impact on the quality of chilled mutton

This study used chitosan-embedded thyme essential oil (TEO-CN) microcapsules to prepare a potato starch-pectin (P-P) composite film. The effects of different concentrations of TEO-CN microcapsules (0 %, 0.25 %, 0.5 %, 1.0 %, and 2.0 %) on the physical, mechanical, antioxidant, and antimicrobial properties of P-P composite films were investigated. The results revealed that the TEO-CN microcapsules were cross-linked with the P-P film matrix and could be uniformly distributed. Additionally, the water vapor permeability [1.98 ± 0.32 mg.m.(m2.h.kPa)-1] and elongation at break exhibited (28 ± 0.32 %) minimum values in P-P composite films containing 1 % TEO-CN microcapsules. Moreover, the P-P composite films containing TEO-CN microcapsules exhibited excellent antioxidant and antibacterial properties. Among them, the P-P composite film containing 2 % TEO-CN microcapsules showed an inhibitory circle diameter of 4.34 mm and 4.98 mm against Escherichia coli and Staphylococcus aureus, respectively. The application of TEO-CNs/P-P composite films in chilled mutton packaging can extend shelf life up to 15 days.

Green approach to synthesis polymer composites based on chitosan with desired linear and non-linear optical characteristics

The current study used sustainable and green approaches to convey polymer composites with desired optical properties. The extracted green tea dye (GTD) enriched with ligands was used to synthesize zinc metal complexes. Green chitosan biopolymer incorporated with green synthesized metal complex using casting technique was used to deliver polymer composites with improved optical properties. The FTIR-ATR was used to identify the functional groups of the GTD, pure CS, and functional groups surrounding the synthesized zinc metal complex. Distinguished ATR bands were observed in green tea dye spectra, such as OH, C = O, and NH functional groups ascribed to various polyphenols. The ATR bands of the zinc metal complex compared to GDT established that GDT is crucial to capturing zinc cations and producing the Zn2+-metal complex. The broadness of the bands observed in CS-based composites inserted with the Zn2+- metal complex confirms strong interaction among the components of polymer composites. The XRD achievements confirm that CS films with different Zn2+- metal complex concentrations transferred to an amorphous composite. The XRD pattern of composite films establishes that the zinc metal complex scarified the crystalline phases of chitosan. Linear optical properties such as absorption, refractive index (n), and optical dielectric parameters were improved. The absorption edge of the composite's films shifted to lower photon energies. Various models were used to determine the optical band gap. The band gap drops from [Formula: see text] when chitosan is loaded with a 36% Zn2+-metal complex. The Spitzer-Fan method is used to get the dielectric constant, and the Drude Lorentz oscillator model was used to calculate vital optical parameters, including N/m*, τ, and µopt. The W-D single oscillator model was used to determine the Eo and Ed parameters. The values of optical moments (M-1 and M-3) were calculated with the help of the W-D model. The oscillator's strength ([Formula: see text]) and wavelength ([Formula: see text]) were determined via the Sellmeier model using the linear refractive index. The first-order nonlinear ( [Formula: see text]), second-order non-linear ([Formula: see text]) and third-order nonlinear optical susceptibility ([Formula: see text]) were determined for all the films.

Development of Pectin-Based Films with Encapsulated Lemon Essential Oil for Active Food Packaging: Improved Antioxidant Activity and Biodegradation

This study evaluated the physicochemical, morphological, and functional properties of pectin-based films incorporated with lemon essential oil (EO) to assess their potential as biodegradable food packaging materials. The results showed that EO incorporation significantly influenced the film's characteristics. The control film exhibited a smooth surface, while the EO-containing film had a rougher texture with globular structures and interconnected channels, likely representing dispersed EO droplets and matrix alterations. The mechanical analysis revealed increased elongation at break (20.05 ± 0.784%) for EO-incorporated films, indicating improved flexibility, while tensile strength and Young's modulus decreased, suggesting reduced stiffness. Film thickness increased slightly with EO (0.097 ± 0.008 mm) compared to the control (0.089 ± 0.001 mm), though the difference was not statistically significant (p > 0.05). Moisture content decreased in EO-containing films (28.894%) compared to the control (35.236%), enhancing water resistance. Water solubility increased slightly (16.046 ± 0.003% vs. 15.315 ± 0.040%), while the swelling rate decreased significantly (0.189 ± 0.003 vs. 0.228 ± 0.040; p < 0.05), indicating greater structural stability in aqueous environments due to the hydrophobic nature of EO. Transparency tests showed that EO slightly increased film opacity (0.350 ± 0.02 vs. 0.290 ± 0.012), aligning with trends in UV-protective materials. The EO-incorporated films also exhibited moderate antibacterial activity against Staphylococcus aureus and Escherichia coli. Antifungal tests revealed strong inhibition of Botrytis cinerea (100%) and moderate inhibition of Alternaria alternata (50%) in EO-containing films. These results demonstrate that EO incorporation improves the functional properties of pectin films, enhancing their flexibility, antimicrobial activity, and environmental stability, making them promising candidates for sustainable food packaging applications. These novel active food packaging materials exhibit strong physical properties and significant potential in maintaining food quality and prolonging shelf life.

Structural properties and antioxidant capacity of different aminated starch-phenolic acid conjugates

Different aminated starch (AS) [EEAS (introducing ethylenediamine into starch using cross-linking-etherification-amination method (CEA)), EPAS (introducing o-phenylenediamine using CEA), OEAS (introducing ethylenediamine using cross-linking-oxidation-amination method (COA)), and OPAS (introducing o-phenylenediamine using COA)] were synthesized. The AS-phenolic acids [gallic acid (GA), syringic acid (SA), and vanillic acid (VA)] conjugates were prepared by laccase-catalyzed reaction. The grafting efficiency of EEAS on GA, SA, and VA was 36.59%, 69.71%, and 68.85%, respectively. SA reduced the maximum depolymerization rate of EEAS. The relative crystallinity of EEAS and EPAS grafted phenolic acid increased, and their particles showed severe breakage in appearance. OEAS-phenolic acid conjugates lost its granular structure and behaved as flakes and lumps, while the surface of OPAS-phenolic acid conjugates remained smooth after grafting phenolic acid. GA increased the DPPH· scavenging efficiency of EEAS from 16.12% to 79.92%. The increased antioxidant capacity of the conjugates suggested that AS-phenolic acids conjugates have high potential for applications.

Novel food preservation strategy using sprayed PVA/chitosan-based coatings activated by macroemulsions of chamomile essential oil adsorbed on activated carbon

Active films based on polyvinyl alcohol (PVA) and chitosan (CS) were developed by encapsulating chamomile essential oil using an emulsification process, followed by adsorption onto activated carbon (AC) to stabilize the oil droplets. Microscopic analysis showed that the average size of the micelles was between 0.1 μm and 1.5 μm. The micelles obtained were incorporated into PVA/CS film formulations with different concentrations of chamomile essential oil (5 %, 10 %, 15 % w/w), and the optical, physical, mechanical, antibacterial, and antioxidant properties as well as the release rate of the encapsulated oil were studied to test their application in food packaging. The SEM images showed a homogeneous dispersion of the EO in the polymer matrix containing AC, due to the formation of hydrogen bonds, which is confirmed by the FTIR results and is accompanied by an increase in the viscosity of the film-forming solutions, a decrease in the crystallinity and an improvement in mechanical properties by an increase in elongation at break (15.95 ± 0.10 to 47.02 ± 0.06 %) of the films produced. In addition, some properties of the PVA/CS films were increased by the addition of EO-AC, notably thickness (0.097 ± 0.12 to 0.144 ± 0.01 mm) and opacity (1.632 ± 0.11 to 8.266 ± 0.12), while the water absorption rate and solubility of the films decreased. PVA/CS-EO-AC films exhibit good antioxidant and antibacterial activity against E. coli and S. aureus, high barrier properties (UV-blocking) and a controlled release of bioactive molecules contained in EO. The PVA/CS/EO-AC coating reduced the weight loss of the tested apples to (3.31 ± 0.29 %) compared to apples packaged in polyethylene film, and maintained their appearance after 3 weeks of storage. These results offer the possibility of reducing food waste through this new coating strategy based on the encapsulation of EO.

Enhancing Strawberry Freshness: Multifunction Sustainable Films Utilizing Two Types of Modified Carbon Nanotubes for Photothermal Food Packaging

Currently, antimicrobial films with stable and efficient antibacterial activities are receiving considerable attention in the food packaging industry. Herein, a chemically/physically linked konjac glucomannan-sodium alginate (KGM-SA)@carbon nanotubes (CNTs)/Fe3+ composite film with outstanding resistance to ultraviolet radiation, oxidation, and bacteria, as well as excellent photothermal effects and mechanical properties, was successfully prepared using a solvent flow method. Tannic acid-modified carboxyl-functionalized CNTs (TCCNTs), l-cysteine-modified carboxyl-functionalized CNTs (LCCNTs), and Fe3+ were incorporated into the prepared film. The film structure of KGM-SA@CNTs/Fe3+ was characterized using various methods, confirming the formation of a dual-cross-linked network through metal-coordination bonds and hydrogen bonding. This unique structure endowed the film with excellent water vapor permeability (3.58 g mm/m2 day kPa), water resistance (water contact angle = 93.66°), and thermal stability. Further, the film exhibited outstanding photothermal conversion efficiency and stability under near-infrared irradiation (300 mW/cm2) as well as excellent bactericidal properties against Staphylococcus aureus and Escherichia coli, achieving a bacterial inhibition rate of >99%. In a strawberry preservation experiment, the KGM-SA@CNTs/Fe3+ composite film exhibited remarkable preservation effects, extending the shelf life of strawberries by 4-6 d. Thus, this photothermal antibacterial film offers a new approach for the application of CNTs in food packaging.

Development of chitosan-based edible film incorporated with purified flavonoids from Moringa oleifera: Structural, thermal, antibacterial activity and application

Purified flavonoids (PF) from Moringa oleifera leaves were incorporated in chitosan (CS) polymer at different concentrations (0.5-4%) to produce a novel edible film. The physical, structure, mechanical, and bio-functional characterizations of the film were evaluated. The incorporation of PF significantly (p < 0.05) improved the thickness, solubility, swelling, and color of CS-films. Incorporating 4% of Moringa oleifera purified flavonoids (MOPF) improved the water vapor permeability from 8.85 to 2.47 g-1 s-1 Pa-1, and increased the film surface heterogeneity observed by SEM. Results also indicated that PF enhanced the mechanical properties and thermal stability of CS-films. The FTIR results indicated alterations in the CS-MOPF composite films' characteristics. Additionally, the incorporation of MOPF increased the antioxidation capacity. Furthermore, 4% of MOPF inhibited the activity of pathogenic bacteria in packed beef burgers. These results suggest that CS-MOPF composite films with enhanced technological and bio-functional properties could be industrially applied to increase the shelf-life of packaged foods.

Gelatin-chitosan interactions in edible films and coatings doped with plant extracts for biopreservation of fresh tuna fish products: A review

The preservation of tuna fish products, which are extremely perishable seafood items, is a substantial challenge due to their instantaneous spoilage caused by microbial development and oxidative degradation. The current review explores the potential of employing chitosan-gelatin-based edible films and coatings, which are enriched with plant extracts, as a sustainable method to prolong the shelf life of tuna fish products. The article provides a comprehensive overview of the physicochemical properties of chitosan and gelatin, emphasizing the molecular interactions that underpin the formation and functionality of these biopolymer-based films and coatings. The synergistic effects of combining chitosan and gelatin are explored, particularly in terms of improving the mechanical strength, barrier properties, and bioactivity of the films. Furthermore, the application of botanical extracts, which include high levels of antioxidants and antibacterial compounds, is being investigated in terms of their capacity to augment the protective characteristics of the films. The study also emphasizes current advancements in utilizing these composite films and coatings for tuna fish products, with a specific focus on their effectiveness in preventing microbiological spoilage, decreasing lipid oxidation, and maintaining sensory qualities throughout storage. Moreover, the current investigation explores the molecular interactions associated with chitosan-gelatin packaging systems enriched with plant extracts, offering valuable insights for improving the design of edible films and coatings and suggesting future research directions to enhance their effectiveness in seafood preservation. Ultimately, the review underscores the potential of chitosan-gelatin-based films and coatings as a promising, eco-friendly alternative to conventional packaging methods, contributing to the sustainability of the seafood industry.

Properties of Guar Gum/Pullulan/Loquat Leaf Extract Green Composite Packaging in Enhancing the Preservation of Chinese Water Chestnut Fresh-Cut Fruit

Loquat leaf extract (LLE) was added to guar gum and pullulan as an environmentally friendly packaging film (GPE) to preserve Chinese water chestnuts (CWCs). The effect of the amount of LLE on the guar gum/pullulan composite film was investigated. The optimal amount of LLE was 4% (GPE4), with lower water vapor permeability (WVP) and greater mechanical strength, antioxidant, and comparable antibacterial performance than many pullulan-based films. Upon packing the CWCs for 4 days, the weight loss rate of GPE4 was only 1.80 ± 0.05%. For GPE4, the POD activity, the soluble solid content, and the vitamin C (Vc) content of the CWCs were 21.61%, 36.16%, and 26.22% higher than those of the control sample, respectively. More importantly, GPE4 was effective in preserving the quality of CWCs after 4 days of storage, better or at least comparable to non-biodegradable plastic wrapping (PE). Therefore, it can be concluded that GPE films hold significant promise as a sustainable alternative packaging material for preserving fruit-based foods like CWCs, potentially replacing PE in the future.

Fabrication of Abelmoschus manihot gum/pullulan/magnesium L-ascorbate green composite packaging film and its excellent performance in preserving fresh-cut carrots

Pullulan-based composite film can be a potential alternative packing material to non-environmentally friendly plastic wrap (PE) to preserve fresh-cut carrots. However, many developed pullulan-based composites either have high water vapor permeability (WVP) and high mechanical strength or vice versa, which limits the practicality of the developed packaging materials for potential commercialization. Herein, Abelmoschus manihot gum (AMG)/pullulan/magnesium L-ascorbate (MLA) was created as a green composite film (APL) to preserve fresh-cut carrots. The optimal amount of MLA was found to be 10 % (APL10), demonstrating a balance of lower WVP and greater mechanical strength and antioxidant performance than many pullulan-based films. This effectively solved many problems faced by other pullulan-based packaging films. After the fresh-cut carrots were packed with the composite film for 4 days, it was found that APL10 was effective in preserving the quality of carrots, in terms of freshness, weight loss rate, Vitamin C (VC), and malondialdehyde (MDA) content after 4 days of storage, much better than non-biodegradable PE. Thus, based on these findings, it is concluded that APL films have huge potential as a green packaging material for food to replace PE in the future.

Active Polysaccharide-Based Films Incorporated with Essential Oils for Extending the Shelf Life of Sliced Soft Bread

Active, fully biobased film-forming dispersions (FFDs) with highly promising results for sliced soft bread preservation were successfully elaborated from carboxymethyl cellulose (CMC) and chitosan (CH) using a simple method based on pH adjustments. They consisted of the association of polysaccharides and oleic acid (OL) added with cinnamon (CEO) or ginger (GEO) essential oils. The chemical compositions of the commercial essential oils were first determined via GC/MS, with less than 3% of compounds unidentified. The films obtained from FFDs were characterized by SEM, FTIR and DSC, indicating specific microstructures and some interactions between essential oils and the polymer matrix. CEO-based films exhibited higher antioxidant properties and a lower minimal inhibitory concentration in terms of antifungal properties. From experiments on sliced soft bread, the ginger-based films could increase the shelf life up to 20 days longer than that of the control. Even more promising, cinnamon-based films led to complete fungal inhibition in bread slices that was maintained beyond 60 days. Enumeration of the yeasts and molds for the FFD-coated breads revealed complete inhibition even after 15 days of storage with the FFDs containing the highest concentration of CEO.

Green synthesized CeO2 nanoparticles-based chitosan/PVA composite films: Enhanced antimicrobial activities and mechanical properties for edible berry tomato preservation

The current study is intended to enhance unique bioactive and eco-friendly composite films following a simple solvent-casting approach by incorporating cerium oxide nanoparticles (CeO2 NPs) with a chitosan (CS)/polyvinyl alcohol (PVA) matrix. Antimicrobial activity, preservation impact, mechanisms for the edible berry tomatoes and physicochemical properties of the produced films were tested. FTIR, SEM-EDX, XRD, UV-vis spectroscopy and contact angle were used to characterize the films. Incorporated (3.0 wt%) CeO2 NPs practically developed composite film's thermal stability, structural, mechanical, bioactive, antioxidant, barrier and wettability properties. The tomatoes' look, weight loss and stiffness were better preserved after 25 days of storage at room temperature (25 ± 5 °C) when 3.0 wt% CeO2 NPs films were used instead of the original CS/PVA film. CS and CeO2 NPs have unique physiochemical and antibacterial properties. Food packaging extensively investigates the modified films as antimicrobials and preservatives to increase the shelf life of packaged foods, owing to their ability to inhibit gram-positive bacteria (Bacillus cereus and Staphylococcus aureus), gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa), and filamentous fungi (Bipolaris sorokiniana, Fusarium op., and Alternaria sp.). Our findings indicated that the CeO2/CS/PVA composite films could be used as effective wrapping materials for food preservation.

Examining the potential of peppermint essential oil-infused pectin and kappa-carrageenan composite films for sustainable food packaging

Essential oils are key ingredients in the development of edible films and provide a diverse approach to improving food preservation, as well as sensory qualities. The pectin and kappa-carrageenan composite films were obtained by adding peppermint essential oil in different quantities. The films after their fabrication were thoroughly evaluated for their attributes, which included mechanical, barrier, optical, chemical, thermal, and antioxidant properties. The visual assessment of the films demonstrated that PEO-loaded films showed a uniform, homogenous, and slightly yellowish appearance. There was an increase in the thickness (0.045 ± 0.006 to 0.060 ± 0.008 mm), elongation at break (12.73 ± 0.74 to 25.05 ± 1.33 %), and water vapor permeability (0.447 ± 0.014 to 0.643 ± 0.014 (g*mm)/(m2*h*kPa)) was observed with the addition of PEO. However, tensile strength (45.84 ± 3.69 to 29.80 ± 2.10 MPa) and moisture content (25.83 ± 0.046 to 21.82 ± 0.23 %) decreased with the incorporation of PEO. Furthermore, thermal and antioxidant properties were enhanced by the inclusion of PEO. The presented investigation can be employed to synthesize food packaging material with antioxidant properties with potential applications in food packaging.

Effects of biodegradation of starch-nanocellulose films incorporated with black tea extract on soil quality

This study aimed to investigate the biodegradation behaviour of starch/nanocellulose/black tea extract (SNBTE) films in a 30-day soil burial test. The SNBTE films were prepared by mixing commercial starch, nanocellulose (2, 4, and 6%), and an aqueous solution of black tea extract by a simple mixing and casting process. The chemical and morphological properties of the SNBTE films before and after biodegradation were characterized using the following analytical techniques such as field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and fourier transform infrared (FTIR). The changes in soil composition, namely pH, electrical conductivity (EC), moisture content, water holding capacity (WHC), soil respiration, total nitrogen, weight mean diameter (MDW), and geometric mean diameter (GMD), as a result of the biodegradation process, were also estimated. The results showed that the films exhibited considerable biodegradability (35-67%) within 30 days while increasing soil nutrients. The addition of black tea extract reduced the biodegradation rate due to its polyphenol content, which likely resulted in a reduction in microbial activity. The addition of nanocellulose (2-6% weight of starch) increased the tensile strength, but decreased the elongation at break of the films. These results suggest that starch nanocellulose and SNBTE films are not only biodegradable under soil conditions but also positively contribute to soil health, highlighting their potential as an environmentally friendly alternative to traditional plastic films in the packaging industry.

Improving Structural, Physical, and Sensitive Properties of Sodium Alginate-Purple Sweet Potato Peel Extracts Indicator Films by Varying Drying Temperature

Sodium alginate (SA)-purple sweet potato peel extracts (PPE) from industrial waste indicator films were developed at different drying temperatures (25, 30, 35, 40, 45, 50, and 55 °C). The effects of drying temperatures on the film's structural, physical, and sensitive properties were investigated. On the structural properties, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction indicated that compactness, intermolecular interactions, and crystallinity of indicator films were improved at a lower drying temperature. On the physical properties, with the drying temperature increasing, elongation at the break increased significantly (p < 0.05); ΔE and water-vapor permeability decreased significantly (p < 0.05); and thickness and tensile strength initially increased significantly (90.46 → 98.46, 62.99 → 95.73) and subsequently decreased significantly (98.46 → 71.93, 95.73 → 55.44) (p < 0.05), with the maximum values obtained at 30 °C. On sensitivity, the corresponding colors of the films became lighter as the drying temperature increased, and the films exhibited relatively excellent pH and NH3 sensitivity, with easily discernible color changes at lower temperatures. The results of this paper revealed that the overall film characteristics are improved at lower drying temperatures, which will provide valuable references for selecting the drying temperature for preparing indicator films as a guide for industrialized production.

Evaluation of Different Pectic Materials Coming from Citrus Residues in the Production of Films

This article explores the use of citrus residues as a source of different pectic materials for packaging film production: a water-soluble orange residue extract (WSE) (~5% pectin), semi-pure pectins extracted in citric acid (SP) (~50% pectin), and commercial pure citrus pectins (CP). First, these materials were characterized in terms of chemical composition. Then, films were produced using them pure or mixed with chitosan or glycerol through solvent-casting. Finally, antioxidant activity, functional properties (e.g., mechanical and gas barrier properties), and visual appearance of the films were assessed. WSE films showed the highest antioxidant activity but the lowest mechanical strength with the highest elongation at break (EB) (54%); incorporating chitosan increased the films' strength (Young's modulus 35.5 times higher). SP films showed intermediate mechanical properties, reinforced by chitosan addition (Young's modulus 4.7 times higher); they showed an outstanding dry O2 barrier. CP films showed a similar O2 barrier to SP films and had the highest Young's modulus (~29 MPa), but their brittleness required glycerol for improved pliability, and chitosan addition compromised their surface regularity. Overall, the type of pectic material determined the film's properties, with less-refined pectins offering just as many benefits as pure commercial ones.

Development of bioactive and environmentally friendly chitosan-based film using waste of pistachio dehulling process as a novel promising food packaging material

Chitosan films containing different amounts of pistachio hull methanol extract (PHE) (2 %, 4 %, 8 % w/v) were produced. LC-MS/MS analysis demonstrated that tannic acid (207.74 mg/g PHE), gallic acid (46.63 mg/g PHE), protocatechuic acid (27.79 mg/g PHE), quinic acid (16.41 mg/g PHE), isoquercitrin (15.2 mg/g PHE) were the most abundant phenolic compounds in PHE. The biological activity test results indicated that PHE enhanced the antioxidant and antibacterial activities of chitosan films. Chitosan-based films with 8 % PHE showed significant antimicrobial activity on all microorganisms tested. Chitosan films containing even the lowest concentration of PHE effectively inhibited DPPH free radicals, indicating a significant antioxidant activity. The increase in the amount of PHE caused a decrease in the L* value and an increase in the a* and b* values. It was found that the tensile strength and elongation at break of the films containing PHE were higher than those of the control film. Chitosan film with 4 % PHE exhibited the highest values of tensile strength (10.72 ± 1.06 MPa) and elongation at break (198.57 ± 10.34 %). FTIR analysis showed that PHE modified the intermolecular interactions in the film matrix, leading to the expansion of the CC bond and an increase in the intensity of the CO bands. Thermal analysis displayed that chitosan films incorporating PHE exhibited higher thermal stability compared to control films. PHE can be used as a bioactive supportive material in food packaging.

High-compatibility properties of Aronia melanocarpa extracts cross-linked chitosan/polyvinyl alcohol composite film for intelligent food packaging

Although the active and intelligent properties of rich in anthocyanin extracts added to films have been extensively studied, there remains a sparsity of research pertaining to the miscibility of blended films. This work focused on the miscibility of the chitosan/polyvinyl alcohol (CP) film caused by the addition of Aronia melanocarpa extracts (AME), which are rich anthocyanins and phenolic acids, and its effect on physicochemical and functional properties. AME facilitated the amidation reaction and ionic interaction of chitosan in CP films, leading to loss of the crystallinity degree of chitosan. Furthermore, the crystal disruption promoted the formation of hydrogen bonds with polyvinyl alcohol (PVA) with the promoted miscibility. CP film incorporated with 8 % AME possessed the highest tensile strength (26.79 MPa), and elongation at break (66.38 %) as well as excellent ultraviolet-visible (UV-vis) light barrier property, water vapor barrier properties, due to its high miscibility degree. Moreover, this film also showed excellent antioxidant, antibacterial activity, and pH response function, which could be used to monitor the storage of highly perishable shrimp. Hence, the AME provided extra functionality and improved miscibility between chitosan and PVA, which showed great potential for the preparation of high-performance bioactive-fortified and intelligent food packaging films.

Konjac glucomannan-based highly antibacterial active films loaded with thyme essential oil through bacterial cellulose nanofibers/Ag nanoparticles stabilized Pickering emulsions

The aim of this study was to develop novel konjac glucomannan (KGM)-based highly antibacterial active films, where five types of films were prepared and compared. The microstructure results showed that KGM-based films loaded with thyme essential oil (TEO) through bacterial cellulose nanofibers/Ag nanoparticles (BCNs/Ag nanoparticles) stabilized Pickering emulsions (Type V films) displayed the smoothest surface and the most evenly dispersed TEO droplets as compared with the other four types of films. Moreover, Type V films showed the highest contact angle value (86.28°), the best thermal stability and mechanical properties. Furthermore, Type V films presented the highest total phenol content (13.23 mg gallic acid equivalent/g film) and the best antioxidant activity (33.96 %) as well as the best sustained-release property, thus showing the best antibacterial activity, which was probably due to that BCNs/Ag nanoparticles and TEO displayed a synergistic effect to some extent. Consequently, Type V film-forming solutions were used as coatings for tangerines. The results showed that the tangerines treated with Type V coatings displayed excellent fresh-keeping properties. Therefore, the coatings, KGM-based film-forming solutions loaded with TEO through BCNs/Ag nanoparticles stabilized Pickering emulsions, have great potential for the preservation of fruits and vegetables.

Chitosan-fucoidan encapsulating cinnamaldehyde composite coating films: Preparation, pH-responsive release, antibacterial activity and preservation for litchi

In this study, an edible composite film with pH-responsive release was prepared by the formation of Schiff-base imine bonds between chitosan (CS) and oxidized fucoidan (CS-FU) and encapsulating cinnamaldehyde (CA). Fourier-transform infrared, 1H nuclear magnetic resonance, X-ray photoelectron spectroscopy and gel permeation chromatography confirmed the formation of CS-FU. The result showed that, oxidation degree of FU, degrees of substitution, average molecular weight and yield of CS-FU were 25.57 %, 10.48 %, 23.3094 kDa and 45.63 ± 0.64 %, respectively. Scanning electron microscopy revealed that CA was encapsulated within the CS-FU matrix. Increasing the CA content could improve the mechanical properties and ultraviolet and visible-light resistances of the CS-FU coating films but enhance their water vapor permeabilities. The release of CA increased as the pH decreased, and the antibacterial rate at pH 5 was 2.3-fold higher than that at pH 7, indicating good pH-responsive release and antibacterial properties in mildly acidic environments. Owing to their excellent properties, the CA/CS-FU-0.1 coating films maintained the appearance and quality indices of litchis for at least eight days. Hence, multifunctional composite coating films are prospective eco-friendly and intelligently responsive controlled-release packaging materials for fruit preservation.

Chitosan/teff flour active films incorporated with citric acid and beetroot leaf extract: Physicochemical properties and mathematical modeling of phenolic release

Active compounds are integrated into food packaging films to enhance their food protection capabilities. Understanding the release of these components in films, particularly in crosslinking scenarios, is crucial. This study aimed to mathematically model the release of phenolic compounds from chitosan/teff flour films to understand how active compounds gradually release. Moreover, it was aimed to study the effects of incorporation of beetroot leaf extract and citric acid crosslinking. The collective observations, encompassing increased density and thermal stability, alongside concurrent reductions in moisture content, water solubility, water vapor permeability and swelling index following citric acid addition, strongly suggested the presence of crosslinking. Applying Fick's law and the finite element method revealed a substantial influence of the crosslinking agent on diffusion coefficients. The model exhibited strong agreement with experimental data, as reflected in low root mean square error values ranging from 3.02 to 8.50 mmol/m3 for films. Furthermore, the influence of citric acid crosslinking on the release of TPC was evident, as indicated by a decrease in average diffusion coefficient values from 3.499 × 10-13 m2 s-1 to 1.770 × 10-13 m2 s-1 with the formula with 1.5 % citric acid and 0.5 % beetroot leaf extract. This showcases the impact of various parameters on controlled release in food packaging.

Synthesis, characterization and antifungal properties of maleopimaric anhydride modified chitosan

Fruit spoilage can cause huge economic losses, in which fungal infection is one of the main influencing factors, how to effectively control mould and spoilage of fruits and prolong their shelf-life has become a primary issue in the development of fruit and vegetable industry. In this study, rosin derivative maleopimaric anhydride (MPA) was combined with biodegradable and antifungal chitosan (CS) to enhance its antifungal and preservative properties. The modified compounds were characterized by FTIR, 1H NMR spectra and XRD, and the in vitro antifungal properties of the modified compounds were evaluated by the radial growth assay and the minimal inhibitory concentration assay. The preservation effect on small mandarin oranges and longan was studied. The analysis revealed that the modification product (CSMA) of MPA access to C6-OH of CS had a better antifungal effect. In addition, CSMA was more environmentally friendly and healthier than the commercially available chemical preservative (Imazalil), and had the same antifungal preservative effect in preserving small mandarin orange, and was able to extend the shelf life to >24 d. In the preservation of longan, CSMA was more effective against tissue water loss and was able to maintain the moisture in the longan pulp and extend the shelf life. Therefore, CSMA has good application potentials in longan keeping-fresh.

Preparation, characterization and application of antioxidant packaging films based on chitosan-epicatechin gallate conjugates with different substitution degrees

In this study, chitosan (CS) was conjugated with epicatechin gallate (ECG) to prepare CS-ECG conjugates with different substitution degrees (5.18 %, 6.36 % and 7.74 %). Then, antioxidant packaging films were fabricated by blending CS and CS-ECG conjugates. The impact of CS-ECG conjugates' substitution degree on the functionality of CS/CS-ECG films was determined. CS-ECG conjugates showed UV absorption at 275 nm, proton signal at 6.85 ppm and infrared absorption at 1533 cm-1, assigning to the conjugated ECG. As compared with CS, CS-ECG conjugates exhibited less crystalline state but higher antioxidant activity. The structural characterization of CS/CS-ECG films showed CS and CS-ECG conjugates formed hydrogen bonds. CS/CS-ECG films displayed 26.35 %-29.23 % water solubility, 85.61°-86.96° water contact angle, 3.11-3.41 × 10-11 g m-1 s-1 Pa-1 water vapor permeability, 0.29-0.34 cm3 mm m-2 day-1 atm-1 oxygen permeability, 31.54-36.20 MPa tensile strength, 50.12 %-56.40 % elongation at break, as well as potent antioxidant activity and oil oxidation inhibitory ability. Notably, the film containing CS-ECG conjugate with 7.74 % substitution degree had the strongest barrier ability, mechanical property, antioxidant activity and oil oxidation inhibitory ability. Results suggested the substitution degree of CS-ECG conjugates was positively correlated with the barrier, mechanical and antioxidant properties of CS/CS-ECG films.

Effect of apricot kernel seed extract on biophysical properties of chitosan film for packaging applications

Chitosan is a natural biodegradable biopolymer that has drawbacks in mechanical and antibacterial properties, limiting its usage in biological and medicinal fields. Chitosan is combined with other naturally occurring substances possessing biological antibacterial qualities in order to broaden its application. Ethanolic apricot kernel seed extract was prepared, analyzed, and incorporated into chitosan film with different concentrations (0.25, 0.5, and 0.75 wt%). Furthermore, the effect of AKSE and γ-radiation (20 Gy and 20 kGy) on the physical properties of the film was studied. The prepared films were characterized by Fourier transform infrared spectroscopy (FTIR), which revealed that AKSE did not cause any change in the molecular structure, whereas the γ-irradiation dose caused a decrease in the peak intensity of all concentrations except 0.75 wt%, which was the most resistant. In addition, their dielectric, optical, and antimicrobial properties were studied. Also, AKSE-enhanced optical qualities, allowed them to fully block light transmission at wavelengths of 450-600 nm. The dielectric properties, i.e., permittivity (ε'), dielectric loss (ε''), and electrical conductivity (σ), increased with increasing AKSE concentration and film irradiation. The antimicrobial studies revealed that the antimicrobial activity against Escherichia coli and Canodida albicans increased with AKSE incorporation.

Effects of alkaline pH and gallic acid enrichment on the physicochemical properties of sesame protein and common vetch starch-based composite films

In this study, sesame (Sesamum indicum L.) meal protein and common vetch (Vicia sativa L.) starch were extracted and used to obtain biodegradable composite films at different pH values (7, 9, and 11). Films were plasticized with glycerol (2.5 %) and enriched with gallic acid (0.25 %). Increasing pH promoted mechanical properties of the films with the developed barrier and thermal characteristics. Gallic acid addition at pH 7 resulted in lower tensile strength and higher elongation by reducing intermolecular forces, and a shift of diffraction peaks through lower angles due to crystal lattice expansion, as compared to neutral films without gallic acid. On the other hand, gallic acid-enriched films at neutral pH exhibited superior antioxidant properties. The mild alkalinity with gallic acid provided the lowest water vapor permeability, high thermal stability, improved mechanical properties and light barrier property due to deprotonation and subsequent interactions with biopolymers. The FTIR spectrum confirmed intense interactions, such as crosslinking and covalent bonding, promoted by mild alkalinity. Therefore, sesame protein and common vetch starch-based composite film with gallic acid incorporation at pH 9 can be recommended to be used in biodegradable active food packaging applications.

Effect of apple polyphenols on physicochemical properties of pea starch/pulp cellulose nanofiber composite biodegradable films

A pea starch (PS) and pulp cellulose nanofibers (CNF-P) hybrid matrix biodegradable film was prepared using apple polyphenol (AP) as the active substance. SEM and thermogravimetric analyses showed that apple polyphenols could be uniformly distributed and form hydrogen bonds with the matrix, and the increase in crystallinity improved the thermal stability of the films (the final residue of the films increased from 22.66 % to 31.82 %). The TS and EAB of the films reached their maximum values of 11.14 ± 1.73 MPa and 71.55 ± 8.8 %, respectively, at an AP content of 1.5 %. It should be noted that the antioxidant properties of the films were significantly positively correlated with the AP content, and the DPPH radical scavenging rate of the films reached 73.77 % at an AP content of 4.5 %, which was about 49 times higher than that of the control film. The same trend was observed in the UV-vis spectra. In addition, the total color difference and water solubility of the membranes increased from 4.29 ± 0.29 to 31.86 ± 1.90 and from 20.01 ± 0.97 % to 21.70 ± 1.99 %, respectively, and the biodegradability also showed an upward trend. These findings provide a theoretical basis and data support for the development of multifunctional biodegradable food packaging materials.

Effects of Balsa Fish Skin Gelatin, Lentinula edodes Mushrooms, Soy Protein Isolate, and Starch on the Sensory Quality and Characterization of Physicochemical and Antioxidant Properties of New Sausage

Sausages are loved by people for their unique texture, satisfying chewiness, and pleasant flavor. However, in the production of sausages, red meat and a large amount of fat are mainly used, and long-term consumption will increase the risk of diseases such as obesity, heart disease, hypertension, and cancer. Our previous studies have shown that the intake of red meat and fat can be reduced through the replacement of lean meat and fat in sausages by Lentinula edodes and Pleaurotus eryngii mushrooms, but this will lead to the deterioration of the gel of sausage products and seriously affect the sensory quality of sausages. In this study, the response surface method was used to optimize the amount of balsa fish skin gelatin, soy protein isolate, and starch added to, and the proportion of Lentinula edodes mushrooms replacing lean meat in, the new sausage, with Pleaurotus eryngii mushrooms replacing fat. The results show that Lentinula edodes mushrooms replaced 36.1% of the lean meat, and the addition of 0.96% balsa fish skin gelatin, 10.61% starch, and 9.94% soy protein isolate resulted in the highest sensory score and the sensory quality being the closest to that of traditional sausages. Compared with the control group, this novel sausage exhibits characteristics such as lower fat and saturated fatty acid content, reduced energy levels, and higher levels of amino acids (aspartic acid, glutamic acid, cysteine, methionine, and proline) and polyunsaturated fatty acids. The total phenolic content of the novel sausage is 12.52 times higher than that of the control. In comparison with the control group, the novel sausage demonstrates a 65.58% increase in DPPH radical scavenging activity and a 3.88-fold improvement in ABTS+ radical scavenging activity. These findings highlight the outstanding antioxidant performance of the novel sausage. This study provides new ideas for improving the sensory quality of new sausages, promoting the healthy development of the sausage industry, and promoting the high-value utilization of edible mushrooms.

UV- shielding and antioxidant properties of chitosan film impregnated with Acacia catechu modified with calcium carbonate for food packaging

Acacia catechu contains polyphenolic compounds such as catechin and tannins, which exhibit antioxidant and antimicrobial properties that have the potential to be used in food packaging applications. In this study, chitosan-based (CH) antioxidant films were developed with the incorporation of calcium carbonate (CC) and Acacia catechu (CT). The films were fabricated by the solvent-casting method, and the effects of the different concentrations of Acacia catechu were analyzed. The physicomechanical, antioxidant, and UV shielding properties of the films were determined. The addition of Acacia catechu and calcium carbonate has significantly increased the tensile from 2.30 MPa to 4.95 MPa, respectively, for neat CH and CH/CC/CT-4 film. At the same time, there is a reduction in the elongation at break from 26.75 % in neat CH film to 12.11 % in CH/CC/CT-4 film. The CH/CC/CT-4 film has shown the highest ferric-reducing antioxidant power (FRAP) of 0.440 mg Trolox/g dried weight of the film and 2,2 diphenyl picrylhydrazyl (DPPH) radical scavenging activity of 93.05 %. The UV transmittance of CH/CC/CT-4 film was 0.46 %, the lowest compared to the rest of the fabricated films. These active properties depict that CH/CC/CT-4 film has the potential to be utilized for the packaging of light and oxygen-sensitive food products.

Effect of tea polyphenols on chitosan packaging for food preservation: Physicochemical properties, bioactivity, and nutrition

Chitosan packaging has been widely studied for food preservation, the application of which is expanded by the incorporation of tea polyphenols. This paper reviews the influence of tea polyphenols incorporation on chitosan-based packaging from the perspectives of physicochemical properties, bioactivity used for food preservation, and nutritional value. The physicochemical properties included optical properties, mechanical properties, water solubility, moisture content, and water vapor barrier property, concluding that the addition of tea polyphenols improved the opacity, water solubility, and water vapor barrier property of chitosan packaging, and the mechanical properties and water content were decreased. The bioactivity used for food preservation, that is antioxidant and antimicrobial properties, is enhanced by tea polyphenols, improving the preservation of food like meat, fruits, and vegetables. In the future, efforts will be needed to improve the mechanical properties of composite film and adjust the formula of tea polyphenols/chitosan composite film to apply to different foods. Besides, the identification and development of high nutritional value tea polyphenol/chitosan composite film is a valuable but challenging task. This review is expected to scientifically guide the application of tea polyphenols in chitosan packaging.

Development, characterization and application of starch-based film containing polyphenols of piper betle L. waste in chicken meat storage

The current study aimed to develop a sustainable solution to extend the shelf life of chicken meat by developing starch-based functional film embedded with polyphenolic extract of waste petioles of betel leaf (BLP). The results showed that loading of the extract significantly (p < 0.05) improved flexibility, thickness, water solubility, DPPH radical scavenging activity, and UV light protection ability by enhancing intermolecular interactions among potato starch, guar gum, and the extract. The developed film showed optimum mechanical and water barrier properties at a 4% BLP extract concentration computed through TOPSIS method (A multi-criteria decision-making approach). During the shelf life study, the extract embedded film maintained the quality of chicken meat for up to 12 days at refrigerated temperature. Biodegradation time of the extract-blended films was considerably decreased to 14 days from 28 days for the native film, indicating suitable alternative to non-biodegradable film for storing the raw meat.

Synthesis, characterization and antifungal properties of dehydroabietic acid modified chitosan

The bioactivities of pristine chitosan are considerable weak compared with the commercial chemicals, which has restricted its broad application prospects in food packaging and preservation. In order to obtain a safe, biologically derived fruits preservative with excellent antifungal properties, dehydroabietic acid (DHA) was used to modify chitosan (CS). The structural characterization of modified chitosans were identified by FTIR and 1H NMR spectra. The XRD pattern showed the modified chitosan changed the crystal structure due to the modification of the amino and/or hydroxyl groups on the chitosan. Their antifungal activities against Penicillium digitutim and Penicillium italicum were investigated in vitro using the radial growth assay and the minimal inhibitory concentration assay. The study also examined the differences in antifungal effect among three modified chitosans. The results showed that DHA only conjugated thehydroxyl group at C-6, bearing free amino group at C-2, exhibited the strongest antifungal effect, with a minimum inhibitory concentration (MIC) of 200 μg/mL. In addition, a comparison of the antifungal activity of the modified compounds with different concentrations of Imazalil demonstrated that the modified biologic antifungal agent was as effective as Imazalil. CSDA can achieve 100 % inhibition of P. digitutim at concentrations >100 μg/mL and remain unchanged for a long time. Because CSDA can enhance the shelf life of longans, DHA-CS, chitosan derivatives, have tremendous promise for use in fruits preservation.

Gelatin-sodium alginate packaging film with date pits extract: An eco-friendly packaging for extending raw minced beef shelf life

Gelatin-sodium alginate-based active packaging films were formulated by including date pits extracts (DPE), as bioactive compound, in raw minced beef meat packaging. The DPE effects at 0.37, 0.75 and 1.5% (w/w, DPE/ gelatin-sodium alginate) on physical, optical, antioxidant and antibacterial properties of established films were assessed. Findings showed that film lightness decreased with the incorporation of DPE. Physical, antioxidant and anti-food-borne pathogens capacities were enhanced by increasing DPE concentration in the films. For 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), the films with 1.5% DPE had the greatest levels (94 and 88%, respectively). DPE films (1.5%) also exhibited the highest anti-Listeria moncytogenes activity, with an inhibition zone of 25 mm. Moreover, during 14 days at 4 °C, the bio-preservative impact of gelatin-sodium alginate film impregnated with DPE at three levels on microbial, chemical, and sensory characteristics of meat beef samples was evaluated. By the end of the storage, DPE at 1.5% enhanced the instrumental color, delayed chemical oxidation and improved sensory traits. By chemometric techniques (principal component analysis (PCA) and heat maps), all data allowed to obtain helpful information by segregating all the samples at each storage time. PCA and heat maps could connect oxidative chemical changes, instrumental color parameters, and microbiological properties to sensory attributes. These data offer an approach to well interpreting the sensory quality and how they are affected by chemical and microbiological changes in the studied meat samples. Our findings indicated the potential of the gelatin-sodium alginate film incorporated with DPE for enhancing meat safety and quality.

Characterization of active films of chitosan containing nettle Urtica dioica L. extract: Spectral and water properties, microstructure, and antioxidant activity

Chitosan films enriched with aqueous nettle extract (Urtica dioica L.) were evaluated by measuring their solubility, equilibrium moisture, water vapor permeability, spectral and antioxidant properties, and microstructure. Nettle extract showed a significant effect on the analyzed film properties. The addition of nettle extract manifested a sharp decrease in water vapor permeability, decreasing from 5.64 · 10-11 to 2.22 · 10-11 g/m·s·Pa. The chitosan- nettle extract films exhibited a high free-radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Incorporation of nettle extract into the chitosan matrix was successfully carried out to obtain antioxidant films. The results obtained showed that the incorporation of nettle extract allowed obtaining chitosan films with antioxidant properties, including a total phenolic content up to 1.57 mg GAE/g film. Furthermore, the films with nettle extract boast an UV shielding ability with transmittance values close to zero in the UV region and a water solubility up to 1 %. The inherent biodegradability is also a strong advantage of the developed active films.

Development of gelatin/agarose active coatings functionalized with Ocimum gratissimum L. essential oil for enhancing storability of 'Booth 7' avocado

Novel active coating from gelatin/agarose (GA) functionalized with Ocimum gratissimum L. essential oil (OGO) had been developed as a medium to evaluate their properties before being applied for avocado preservation. The resultant coating films showed enhanced mechanical, water-barrier, bactericidal, antioxidant, and UV-shielding properties by adding OGO. The best tensile strength (2.91 MPa) and flexibility (45.82 %) was found in the GA film containing 5 % (w/w) of OGO (GA-OGO-5). Furthermore, this coating formulation presented moderate antibacterial activities against Listeria, Pseudomonas, Salmonella, and Escherichia. The GA-OGO-5 coating film also divulged the highest hydrophobicity and adequate antioxidant function (30.75 μg/mL) and thus, was chosen to coat on 'Booth 7' avocados by dipping method. The GA-OGO-5 coating layers were to be efficient to decline the respiration rate of avocado during 6-day storage at 25 °C and 64 %RH. Peel color, weight loss (5.22 %), total soluble solids (8.14 %), and solution pH (6.79) at the end of storage also indicated that the GA-OGO-5 coating presented the best effectiveness for enhancing the storability of avocado as compared to uncoated and GA-treated fruit. Therefore, the GA-OGO coating has been considered as an alternative post-harvest technique to enhance the avocado storability and could be further commercialized for industry application.

Carboxymethyl cellulose based films enriched with polysaccharides from mulberry leaves (Morus alba L.) as new biodegradable packaging material

The objective of this study was to determine the properties of a new active packaging film developed by the addition of mulberry leaves polysaccharides (MLP) into carboxymethyl cellulose (CMC). Biodegradable CMC-MLP films were fabricated by casting method with various concentrations of MLP (1, 5 and 10 % w/w). The addition of MLP into the CMC matrix resulted increased thickness (0.126 to 0.163 mm) and roughness of the films. Also, the decline in moisture content from 27.91 to 14.12 %, water vapor permeability from 8.95 to 5.21 × 10-10 g-1 s-1 Pa-1, and a swelling degree from 59.11 to 37.45 % were observed. With the increasing concentration of MLP, the mechanical properties of the films were improved and higher dispersion of UV light were noted. Fourier transform - infrared spectroscopy (FT-IR) and X-ray diffraction revealed good inter-molecular interaction between CMC matrix and MLP. The prepared films showed excellent thermal stability, antioxidant and antibacterial properties as well as susceptibility to biodegradation in the soil environment. Moreover, it was proved that the films have ability to retard oil oxidation. Overall, it was concluded that CMC-MLP films constitute a promising biomaterial that may be applied as active food packaging.

Liposomal and Liposomes-Film Systems as Carriers for Bioactives from Paeonia tenuifolia L. Petals: Physicochemical Characterization and Biological Potential

Paeonia tenuifolia L. (steppe peony) petal extract was proficiently encapsulated into liposomes and biopolymer films in the current work, both times utilizing a single-step procedure. The encapsulation efficiency, size of the particles, and index of polydispersity (PDI), as well as the ζ potential of the obtained liposomes were determined, whereas in the case of films, the test included moisture content and mechanical property assessment. Fourier transform infrared spectroscopy (FT-IR) was used to evaluate the chemical composition and existence of numerous interactions in the systems. All the obtained encapsulates were subjected to antibacterial, antifungal and antibiofilm activity testing of the pathogens associated with human skin. The results indicated that the liposomes prepared using Phospholipon had the highest encapsulation efficiency (72.04%), making them the most favorable ones in the release study as well. The biological assays also revealed that Phospholipon was the most beneficial phospholipid mixture for the preparation of liposomes, whereas the film containing these liposomes did not have the ability to inhibit pathogen growth, making the double encapsulation of P. tenuifolia L. petal extract needless. These findings may be a first step toward the potential use of steppe peony extract-loaded films and liposomes in pharmaceutical and cosmetical industries.

An electrochemical sensor based on CS-MWCNT and AuNPs for the detection of mycophenolic acid in plasma

For patients receiving organ transplants, monitoring the blood concentration of MPA can provide timely information on whether MPA has reached the effective therapeutic window to better function while reducing the incidence of rejection or adverse reactions. In this study, an electrochemical sensor for the detection of MPA was built using a nanocomposite made of CS-MWCNT and AuNPs. At the same time, the high performance liquid phase (HPLC) method for MPA was established and compared with this sensor. The surface morphology, structure, and roughness of the material on the electrode were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and atomic force microscopy (AFM). In addition, the electrochemical behavior of the modified electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The standard curve was obtained in blank plasma, not pure buffer solution. The peak current was linearly related to the MPA concentration in the linear range of 0.001-0.1 mM with a detection limit of 0.05 μM and good anti-interference ability. Moreover, the sensor was employed with success for the determination of MPA in rat plasma with good recovery. The electrochemical sensor presented here is eco-friendly, and sensitive, and offers a great possibility for practical applicability.

Development and characterization of edible films based on flaxseed gum incorporated with Piper betle extract

There has been a shift from use of petroleum-based plastics, causing serious environmental pollution, towards innovative and biodegradable edible packaging. The present study documents the development of composite edible films based on the flaxseed gum (FSG) modified by the incorporation of betel leaf extract (BLE). The films were assessed for physicochemical, mechanical, morphological, thermal, antimicrobial and structural characteristics. Scanning electron microscopy images indicated that the roughness decreased with an increase in BLE concentration. The water vapor permeability of the FSG-BLE films ranged from 4.68 to 1.59 × 10-9 g s- 1 m- 2 Pa- 1, lower than that of the control sample (6.77 × 10-9 g s- 1 m- 2 Pa- 1). The BLE4 (containing 10 % BLE) films had the highest tensile strength of 32.46 MPa compared to the control sample (21.23 MPa). Similarly, EAB and seal strength of the films incorporated with BLE were ameliorated. X-ray diffraction pattern and FTIR illustrated the shift of amorphous to crystalline behavior and a significant interaction among the BLE and FSG functional groups. Furthermore, the thermal stability of the treated films was not affected significantly however, they showed improved antimicrobial activity with the highest diameter of inhibition zone in the BLE4 sample. This study concluded that the FSG-BLE composite films (BLE4 in particular) can be considered as novel packaging material for food conservation coupled with a potential to enhance the shelf life of perishable food products.

Composite films of sodium alginate and konjac glucomannan incorporated with tea polyphenols for food preservation

At present, food waste has become a serious issue and the use of petroleum-based food packaging films has resulted in a series of potential hazards. Therefore, more attention has been focused on the development of new food packaging materials. The polysaccharide-based composite film loaded with active substances considered to be an excellent preservative material. A novel packaging film based on sodium alginate and konjac glucomannan (SA-KGM) blended with tea polyphenols (TP) was prepared in the present study. The excellent microstructure of films was shown by atomic force microscopy (AFM). It was indicated by FTIR spectra that the components could interact with each other through hydrogen bonds, which was also confirmed by molecular docking simulation. Meanwhile, the mechanical properties, barrier property, oxidation property, antibacterial activity, and stability of the structure of the TP-SA-KGM film were significantly improved. The AFM images and results of molecular docking simulation indicated that TP could affect the cell wall of bacteria by acting with peptidoglycan. Finally, the film showed excellent preservation effects in both beef and apples, which suggested that TP-SA-KGM film could be a novel bioactive packaging material with wide application potential in food preservation.

Advances in formulation, functionality, and application of edible coatings on fresh produce and fresh-cut products: A review

With the increasing population of the world food demand is also increasing but unfortunately, many countries in the world are lacking suitable and economical postharvest preservation techniques to minimize increasing postharvest losses. To ensure food security advanced production technologies, distribution systems and minimum losses should be ensured to give accessibility of food to all population groups. Innovative preservation techniques should be adopted by the agriculture sector to meet intercontinental distribution and demand for fresh produce. The application of the edible coating is a novel technique in postharvest preservation due to its simple application, ecofriendly nature, and effectiveness. Edible coatings can also improve the quality and safety aspects of fresh produce and thus extends shelf life. This review aimed to update information about recent advances in edible coating formulation and application mainly on fresh-cut /minimally processed fruits and vegetables. This information will be helpful for processors to select the best coating material and its effective concentration for different fresh and minimal processed vegetables.

Tyrosinase Magnetic Cross-Linked Enzyme Aggregates: Biocatalytic Study in Deep Eutectic Solvent Aqueous Solutions

In the field of biocatalysis, the implementation of sustainable processes such as enzyme immobilization or employment of environmentally friendly solvents, like Deep Eutectic Solvents (DESs) are of paramount importance. In this work, tyrosinase was extracted from fresh mushrooms and used in a carrier-free immobilization towards the preparation of both non-magnetic and magnetic cross-linked enzyme aggregates (CLEAs). The prepared biocatalyst was characterized and the biocatalytic and structural traits of free tyrosinase and tyrosinase magnetic CLEAs (mCLEAs) were evaluated in numerous DES aqueous solutions. The results showed that the nature and the concentration of the DESs used as co-solvents significantly affected the catalytic activity and stability of tyrosinase, while the immobilization enhanced the activity of the enzyme in comparison with the non-immobilized enzyme up to 3.6-fold. The biocatalyst retained the 100% of its initial activity after storage at -20 °C for 1 year and the 90% of its activity after 5 repeated cycles. Tyrosinase mCLEAs were further applied in the homogeneous modification of chitosan with caffeic acid in the presence of DES. The biocatalyst demonstrated great ability in the functionalization of chitosan with caffeic acid in the presence of 10% v/v DES [Bet:Gly (1:3)], enhancing the antioxidant activity of the films.