Gelatin-Based Films and Coatings for Food Packaging Applications

Reduction of oxidative rancidification of fungal melanin-coated films in pork lard preservation in trading

Storage of meat has always been challenging due to its deterioration caused by oxidative rancidity and microbial activity, especially in trading. The melanin-coated film acts as a potent antioxidant, prevents the oxidation of fatty acids, and neutralizes the reactive oxygen species (ROS) helping to withstand or perpetuate the oxidative stress of meat. This study emphasizes the production of fungal melanin extracted from Curvularia lunata and the preparation of two different melanin film combinations of gelatin/melanin and agar/melanin at 0.1% and 0.5% formulation for rancidity stability of coated pork lard. Interpretations revealed the delayed rancidity in both peroxide and acid values with 5.76% in 0.5% agar-coated melanin up to the 11th day which was supported by arithmetical analysis showing p < 0.05 are statistically significant. Further, upon testing the brine shrimp assay for melanin toxicity, 7% were in a mortal state at 1000 µg/mL concentration, considered zero lethality. This result implies that modified coatings, particularly when trading meats, that include fungal melanin can effectively prevent the oxidation of pork lard.

Red pepper waste-derived carbon dots incorporated sodium alginate/gelatin composite films for bioactive fruit preservation

The design of cost-efficient and eco-friendly packaging films with multifunctional features such as antimicrobial, antioxidant, and UV protection is important in food industry. Red pepper waste-derived carbon dots (RP-CDs) have been used as reinforcement and active components in the fabrication of advanced packaging materials. The synthesized spherical RP-CDs with an average diameter of 2.5 nm were rich in active functional groups such as -NH2, -OH, -C=O, CO, and C-O-C. Casting method was used to load 1, 2, and 3 wt% of RP-CDs into sodium alginate/gelatin (SA/Gel) polymer matrix. SEM images and FT-IR and XPS analyses confirmed the strong compatibility and potential hydrogen bonding between RP-CDs and the matrix. This interaction improved the mechanical strength and moisture resistance of the composite films. With the addition of 3 wt% RP-CDs, the UV-A barrier, ABTS radical scavenging, and L. monocytogenes bactericidal properties of the composite film increased by 92.5, 100, and 99.9 %, respectively. Fruit preservation results revealed that the prepared SA/Gel/RP-CD3% composite film maintained the freshness of packed grapes and extended their storage life to 24 days. The development of active packaging films with biowaste-derived functional fillers (CDs) offers the dual benefit of extending the shelf life and contributing to food waste management.

Marine collagen bio-composites materials: Interactions with small active molecules and their application in food industry

Collagen, the primary fibrillar protein found in marine organisms has gained significant attention due to its nutritional and functional properties. It plays a crucial role in food quality and textural attributes, making it a valuable ingredient in various food applications. This study focuses on the interactions of marine-derived collagen and its gelatin derivatives with small bioactive molecules, including phenolic compounds, polysaccharides, and others, which are briefly discussed. These interactions are governed by mechanisms such as hydrogen bonding, electrostatic forces, hydrophobic interactions, and van der Waals contacts, resulting in the formation of bio-composites with enhanced stability, bioavailability, and functionality. This article also highlights recent advancements in extraction methods, physicochemical characterization, and the role of collagen-based composites in food applications, such as emulsification, stabilization, and microencapsulation. Furthermore, this review also summarizes the challenges related to the lower thermal stability of marine collagen compared to mammalian sources, along with potential solutions through innovative processing techniques. Finally, the article briefly discusses how marine collagen-based bio-composites offer promising prospects for developing functional and sustainable food products.

3D-printed ultra-sensitive strain sensors using biogels prepared from fish gelatin and gellan gum

The long-term sustainable development of flexible electronic devices is limited by a reliance on synthetic polymers that pose dangers for humans and potentially severe ecological problems, as well as a reliance on conventional processing methods. This work aims to exploit 3D printing to develop natural biogels composed of fish gelatin and high acyl gellan gum for use as flexible sensors. The electrical conductivity and mechanical strength were remarkably enhanced through the environmentally friendly enzyme (transglutaminase) cross-linking and non-toxic ethanol modification treatment, which allows the development of 3D printed sensors for temperature, strain, and stress sensors. The hydrogel exhibits excellent mechanical and electrical properties as strain sensors, with Young's modulus and tensile strength of 20.7 ± 1.38 kPa and 0.14 ± 0.01 MPa, respectively, and an ultimate strain of 270.54 ± 16.23 %, which is conducive to a comfortable wearing experience. Moreover, the obtained sensors exhibited ultra-low latency (6.1 ± 1.47 ms), good durability (withstanding 1000 cyclic stretching) and high monitor sensitivity (GF = 2.37 ± 0.14) to human body movements; furthermore, the biogel fabricated using this method exhibits complete biodegradation within approximately 20 days, offering innovative prospects for the advancement of eco-friendly materials.

Unlocking the Potential of Marine Sidestreams in the Blue Economy: Lessons Learned from the EcoeFISHent Project on Fish Collagen

This review provides a general overview of collagen structure, biosynthesis, and biological properties, with a particular focus on marine collagen sources, especially fisheries discards and by-catches. Additionally, well-documented applications of collagen are presented, with special emphasis not only on its final use but also on the processes enabling sustainable and safe recovery from materials that would otherwise go to waste. Particular attention is given to the extraction process, highlighting key aspects essential for the industrialization of fish sidestreams, such as hygiene standards, adherence to good manufacturing practices, and ensuring minimal environmental impact. In this context, the EcoeFISHent projects have provided valuable insights, aiming to create replicable, systemic, and sustainable territorial clusters based on a multi-circular economy and industrial symbiosis. The main goal of this project is to increase the monetary income of certain categories, such as fishery and aquaculture activities, through the valorization of underutilized biomass.

Biodegradable composite films of barley fibers for food packaging applications: A review

The conventional food packaging is creating a significant cause of environmental hazards, posing challenges in disposal and recycling. Lignocellulose fibers possess remarkable biodegradable properties and can be modified or blended with other polymers. Thus, using lignocellulose biocomposite films derived from barley, a renewable source can mitigate and potentially transform into sustainable, innovative packaging material in the food sectors. Hence, this review focuses on barley lignocellulose fibers incorporated into different film matrix phases, showing promising enhanced mechanical, and functional properties. Barley biocomposites provide the necessary protective functions to replace traditional plastic for food packaging applications and that could reduce the negative effects on the environment. In addition, we highlighted various recently developed barley lignocellulose-based biocomposite films for a variety of food packaging applications. Furthermore, an overview of the environmental impact of plastic pollution and its effects on ecological niches has been emphasized. Additionally, aspects of different sustainable goals (SDGs 9, 12, 13) are discussed. Based on the existing research gaps, this article is concluded with the challenges and discussed further perspectives of biocomposites enriched with barley lignocellulose fibers.

Development of Mucoadhesive Vaginal Films for Metronidazole Delivery Using Methacryloylated, Crotonoylated, and Itaconoylated Gelatin Blends with Poly(vinyl alcohol)

PURPOSE

This work reports the development and characterisation of polymeric films composed of gelatin or its chemically modified derivatives (crotonoylated, itaconoylated, and methacryloylated gelatins) blended with polyvinyl alcohol (PVA). Metronidazole served as an antimicrobial drug in these formulations.

METHODS

The films were produced by casting aqueous solutions of polymers, followed by solvent evaporation. Their structure and physicochemical characteristics were studied using Fourier transform infrared spectroscopy, scanning electron microscopy, and mechanical testing. The thickness of the films, their folding endurance, the surface pH, and transparency were also evaluated. The mucoadhesive performance of the films was evaluated through an ex vivo detachment technique involving freshly excised sheep vaginal tissues. In vitro cumulative drug release studies were conducted using Franz diffusion cells.

RESULTS

The results demonstrate that incorporating unsaturated functional groups into gelatin improves its mucoadhesive properties compared to native gelatin. The drug release experiments conducted in vitro showed that the cumulative release from pure gelatin/PVA films was found to be 49 ± 2%, whereas modified gelatins/PVA (70:30) films released ~ 64-71%.

CONCLUSION

These findings suggest that modified gelatins could serve as effective excipients in designing mucoadhesive formulations for vaginal administration, with potential applications extending to other transmucosal drug delivery systems.

Polymers Derived from Agro-Industrial Waste in the Development of Bioactive Films in Food

This review explores the potential of biopolymers as sustainable alternatives to conventional plastics in food packaging. Biopolymers derived from plant or animal sources are crucial in extending food shelf life, minimizing degradation, and protecting against oxidative and microbial agents. Their physical and chemical properties, influenced by the raw materials used, determine their suitability for specific applications. Biopolymers have been successfully used in fruits, vegetables, meats, and dairy products, offering antimicrobial and antioxidant benefits. Consequently, they represent a functional and eco-friendly solution for the packaging industry, contributing to sustainability while maintaining product quality.

Influence of Sorbitol and Glycerol on Physical and Tensile Properties of Biodegradable-Edible Film From Snakehead Gelatin and κ-Carrageenan

Two plasticizers with distinct properties are carefully studied in this research for their suitability in creating biocomposite edible film products. The study uncovers films' physical, tensile, and biodegradability attributes, using snakehead gelatin and ĸ-carrageenan in different concentrations, with sorbitol or glycerol as plasticizers. The biomaterials of the edible film consist of snakehead gelatin (Channa striata) 2% (w/v); ĸ-carrageenan at concentrations of 1%, 1.5%, and 2% (w/v); and sorbitol/glycerol 15% (v/v). The addition of ĸ-carrageenan up to 2% in the formulation increased the film thickness to 0.046 ± 0.005 mm, tensile strength to 2.05 ± 0.56 MPa, and elongation at break to 35.00% ± 2.92% while decreasing the water vapor transmission rate (WVTR) to 0.17 ± 0.00 g/mm2/h (p < 0.05). The effect of glycerol in the composite did not affect thickness and luminosity (L ∗) (p > 0.05), but the tensile strength increased from 0.18 ± 0.17 to 1.03 ± 0.40 MPa (p > 0.05). Sorbitol increased the value of color difference, elongation at break, and WVTR, namely, 19.77 ± 1.02, 25.20% ± 1.79%, and 0.28 ± 0.02 g/mm2/h, respectively (p < 0.05). The swelling index of the films increased with ĸ-carrageenan concentration, whereas the water content decreased (p < 0.05). The addition of sorbitol reduced the solubility of the film from 71.43% ± 12.39% to 42.67% ± 15.44% (p < 0.05), while glycerol did not affect changes in film solubility (p > 0.05). The presence of sorbitol had no significant effect on the contact angle (p > 0.05) and was more affected by the addition of glycerol at higher ĸ-carrageenan concentrations (p < 0.05). The ability to decompose after 28 days was more remarkable for films containing glycerol than sorbitol. Fourier transform infrared analysis revealed the functional group structures of all samples, indicating that no new compounds were formed in them. The surface structure of the sorbitol-plasticized film was predicted to be rougher and easily cracked, but more compact and dense, while the glycerol-plasticized film tended to be smoother with fainter cracks due to its hygroscopic properties.

Properties, Antioxidant and Antibacterial Activity of Southern Meagre Fish (Argyrosomus hololepidotus) Skin Gelatin Reinforced with Clove Bud Extract

The properties of biopolymer films prepared using Southern meagre fish (Argyrosomus hololepidotus) skin gelatin blends, both with and without clove bud extract (CE) at concentrations of 0.3% and 0.7%, were investigated. The addition of CE enhanced the light barrier properties and decreased water vapor permeability from 1.68 to 0.85 (×10-13 g s-1m-1Pa-1) (p < 0.05) in the films that contained CE. Additionally, the films' water solubility diminished as the concentration of CE increased (89.20 to 69.04%) (p < 0.05). SEM images revealed a smooth, uniform surface without cracks in the samples both with and without CE, whereas the films that included CE displayed a rougher and denser cross-section. FTIR spectra revealed variations in peaks between the films containing CE and those without it. The incorporation of CE raised the glass transition temperature (51.04 to 58.80 °C) and the melting temperature (124.65 to 141.92 °C) of the films. Additionally, the antioxidant activities, assessed through DPPH free radical scavenging activity (86.97%) and reduction power (λ of 0.85), along with moderate antibacterial activities against four distinct foodborne pathogens, improved with increased concentrations of CE. It can be concluded that phenolic compounds, such as eugenol in the clove extract, facilitated the formation of additional bonds between the peptide helixes of the gelatin, thereby enhancing the properties of the CE-incorporated films. Thus, Southern meagre fish gelatin film containing CE is an effective active packaging biomaterial for seafood products, exhibiting satisfactory properties.

Preparation and Characterization of New Biodegradable Packaging Materials Based on Gelatin Extracted from Tenualosa ilisha Fish Scales with Cellulose Nanocrystals

Food packaging industries generally use petroleum-based packaging materials that are non-biodegradable and harmful to the environment. Eco-friendly polymers such as chitosan (CH), gelatin (GE), and cellulose nanocrystals (CNCs) are leading viable alternatives to plastics traditionally used in packaging because of their higher functionality and biodegradability. In this study, an innovative approach has been disclosed to prepare new packaging materials by utilizing chitosan, gelatin, and cellulose nanocrystals (CNCs) through a simple solution casting method. GE and CNCs have been isolated from prawn shells and jute fiber, respectively. Utilization of Hilsa Tenualosa ilisha fish scale biowaste was a new and first approach for gelatin extraction. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis spectroscopy, and scanning electron microscopy (SEM) were used to examine the functional and morphological features of fish scale gelatin, chitosan, CNCs, and the resulting composite films. The synthesized film materials were analyzed for their mechanical strength, solubility, apparent density, swelling behavior, biodegradability, light transmittance, and transparency. The impregnation of CNCs into the polymer amalgam milieu effectively enhanced their physicochemical and biological properties. The degree of swelling in composite matrices was found to be increased gradually, whereas the solubility was decreased due to the cross-linking effect of CNCs. Elongation at break in the gelatin-chitosan (GC) film was observed as 48%. However, the incorporation of CNCs into the GC matrix potentially enhanced the elongation at break property to 64.05%, 62.86%, and 59.21% in GC1, GC2, and GC3 bioplastic films, respectively. The purified chitosan-gelatin films showed a tensile strength of 12.24 N/mm2, which was increased to 13.93 N/mm2 with the addition of 1.00% CNCs. The composite films were found to be highly transparent and stable in an ambient atmosphere. However, 49-60% deformation occurred in the composite materials after 7 days, whereas 71-84% biodegradation was realized after 21 days, when the respective composite films were subjected to a natural soil environment. These novel composite films possess all essential interesting features, such as biocompatibility, transparency, smoothness of surfaces, and biodegradability, making them suitable for use as packaging materials in different industries.

The Effect of Cellulose Nanocrystals on the Molecular Organization, Thermomechanical, and Shape Memory Properties of Gelatin-Matrix Composite Films

Gelatin is a natural hydrocolloid with excellent film-forming properties, high processability, and tremendous potential in the field of edible coatings and food packaging. However, its reinforcing by materials such as cellulose nanocrystals (CNC) is often necessary to improve its mechanical behavior, including shape memory properties. Since the interaction between these polymers is complex and its mechanism still remains unclear, this work aimed to study the effect of low concentrations of CNC (2, 6, and 10 weight%) on the molecular organization, thermomechanical, and shape memory properties in mammalian gelatin-based composite films at low moisture content (~10 weight% dry base). The results showed that the presence of CNCs (with type I and type II crystals) interfered with the formation of the gelatin triple helix, with a decrease from 21.7% crystallinity to 12% in samples with 10% CNC but increasing the overall crystallinity (from 21.7% to 22.6% in samples with 10% CNC), which produced a decrease in the water monolayer in the composites. These changes in crystallinity also impacted significantly their mechanical properties, with higher E' values (from 1 × 104 to 1.3 × 104 Pa at 20 °C) and improved thermal stability at higher CNC content. Additionally, the evaluation of their shape memory properties indicated that while molecular interactions between the two components occur, CNCs negatively impacted the magnitude and kinetics of the shape recovery of the composites (more particularly at 10 weight% CNC, reducing shape recovery from 90% to 70%) by reducing the netting point associated with the lower crystallinity of the gelatin. We believe that our results contribute in elucidating the interactions of gelatin-CNC composites at various structural levels and highlights that even though CNC acts as a reinforcement material on gelatin matrices, their interaction are complex and do not imply synergism in their properties. Further investigation is, however, needed to understand CNC-gelatin interfacial interactions with the aim of modulating their interactions depending on their desired application.

Evaluation of Different Concentrations of Antimicrobial Quaternary Polymers on the Behavior of Gelatin- and Starch-Based Films

Nowadays, incorporating quaternary ammonium groups into polymers is one of the most promising strategies for preparing antimicrobial biomaterials for general applications. The main objective of this work was to evaluate the effect of different concentrations of antimicrobial quaternary polymers in gelatin- and starch-based films for the development of active materials intended for applications in food packaging and medical fields. Two antimicrobial biobased polymers, called MeFPIAx (MeFPIA1 and MeFPIA2), were previously synthesized through the radical polymerization of itaconic acid (IA), followed by their subsequent functionalization and modification. Both polymers were incorporated into a new blend of gelatin and starch (15% w/w, 4:1 mass ratio), using glycerol (30% w/w) as a plasticizer. Films were prepared using the casting technique from aqueous dispersions of the polymers and their structure was characterized by Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR). The findings of this study showed the addition of MeFPIAx had a significant effect (p < 0.05), resulting in films with higher tensile strength (TS) and a higher Young's modulus (YM), with values close to 20 MPa and exceeding 250 MPa, respectively. On the other hand, elongation at break (EB) values lower than 80% were obtained. Additionally, the swelling was reduced from ~400% to 100% and a reduction in water vapor permeability (Pw) was observed, thanks to the increased interaction between the polymeric chains. Differential scanning calorimetry (DSC) scans showed that the addition of MeFPIAx increased the glass transition temperatures (Tg) from 29 °C to 65 °C. Furthermore, thermogravimetry analysis (TGA) indicated an increase in the initial degradation temperatures, suggesting that the films were more thermally resistant. Finally, the films exhibited slight antioxidant activity but significant antimicrobial activity, achieving bacterial reduction values greater than 70% with the incorporation of MeFPIAx polymers against Gram-positive Staphylococcus aureus.

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.

A Current Trend in Efficient Biopolymer Coatings for Edible Fruits to Enhance Shelf Life

In recent years, biopolymer coatings have emerged as an effective approach for extending the shelf life of edible fruits. The invention of biopolymer coverings has emerged as an innovation for extending fruit shelf life. Natural polymers, like chitosan, alginate, and pectin, are used to create these surfaces, which have several uses, including creating a barrier that prevents water evaporation, the spread of living microbes, and respiratory movement. These biopolymer coatings' primary benefits are their environmental friendliness and lack of damage. This study highlights the advancements made in the creation and usage of biopolymer coatings, highlighting how well they preserve fruit quality, reduce post-harvest losses, and satisfy consumer demand for natural preservation methods. This study discusses the usefulness of the biopolymer coating in terms of preserving fruit quality, reducing waste, and extending the product's shelf life. Biopolymer coatings' potential as a sustainable solution for synthetic preservatives in the fruit sector is highlighted as are formulation process advances that combine natural ingredients and environmental implications. This essay focuses on the essential methods, such as new natural additives, as well as the environmental effect of biopolymer coatings, which are safe and healthy commercial alternatives.

Development of Hybrid Electrospun Nanofibers: Improving Effects of Cellulose Nanofibers (CNFs) on Electrospinnability of Gelatin

Cellulose nanofibers (CNFs) were used to improve the electrospinnability of the gelatin protein in a water/ethanol/acetic acid (3:2:3, v/v) solution. The effects of different concentrations of CNFs (0.5-4%) on the important physical properties of the gelatin solution (15%), including rheology, conductivity, and surface tension, were investigated. The apparent viscosity and shear-thinning behavior were increased by increasing the CNF concentration from 0 to 4% at a low shear rate (<10 s-1). CNFs also increased the electrical conductivity and surface tension of the gelatin solution. Scanning electron microscopy (SEM) images revealed uniformly ordered structures with good continuity without fracture or bead formation in all hybrid nanofibers. They also showed that the average diameters of fibers decreased from 216 nm in the pure gelatin nanofibers to 175.39 nm in the hybrid gelatin/CNF (4%) ones. Differential scanning calorimetry (DSC) results showed that CNFs increased Tg, and X-ray diffraction (XRD) analysis showed that the electrospinning process caused the formation of more amorphous structures in the gelatin/CNF hybrid nanofibers. The tensile test indicated that by adding 2% CNFs, the ultimate tensile strength (UTS) and strain at break (SB) of nanofiber mats increased from 4.26 to 10.5 MPa and 3.3% to 6.25%, respectively. The current study indicated that incorporating CNFs at the optimal concentration into a gelatin solution can improve the resulting hybrid nanofibers' morphology, average diameter, and mechanical properties.

Development and characterization of camel gelatin films: Influence of camel bone age and glycerol or sorbitol on film properties

This study developed and evaluated camel bone gelatin films (CBGFs) with glycerol or sorbitol as plasticizers. Gelatin extracted from the bones of camels (Camelus dromedarius) at ages ranging from 2.5 to 7 years was used. A comprehensive analysis was conducted, evaluating a range of properties including thickness, moisture sorption capacity, water vapor permeability (WVP), infrared spectral characteristics, light absorption behavior, solubility, as well as mechanical and thermal attributes. This thorough examination allowed for a nuanced understanding of the diverse characteristics exhibited by the camel gelatin samples across different age groups. The results indicated that camel age, glycerol, and sorbitol had a significant impact on the properties of the film (P < 0.05). Tensile strength ranged from 0.32 MPa to 3.99 MPa, while the percentage of elongation at break varied from 89.42 % to 2.68 %. Film color (lightness, L) ranged from 21.39 to 41.33. Glycerol and sorbitol plasticized films were 100 % water soluble. Moisture sorption increased with temperature (25 °C, 35 °C, and 45 °C), with sorbitol films retaining less water. WVP was low in films from old camel bones and high in glycerol-plasticized CBGF-2.5Y and CBGF-4.5Y. Thermal analysis showed a melting temperature between 158.60 °C and 174.10 °C, depending on bone age and plasticizer. These films demonstrate promise for use in food packaging, coatings, and pharmaceutical applications.

Development of a new kappa-carrageenan hydrogel system to study benthic diatom vertical movements

Benthic diatom vertical movement has been investigated mainly through indirect measurements based on chlorophyll a fluorescence and spectral reflectance signals. The presence of sediment hinders direct imaging and grazers activity renders the work under controlled conditions very difficult. This study provides a tool to study diatoms movement in a 3D hydrogel matrix. Synthetic and natural hydrogels were tested to find the best 3D transparent scaffold where diatoms could grow and freely move in all directions. Polyamidoamines (PAAm) hydrogels were no-cytocompatible and hyaluronic acid (HA) only allowed diatoms to survive for 2-days. Natural hydrogels made of gelatin/Na-alginate, Na-alginate and kappa-carrageenan (KC) were cytocompatible, with KC showing the best properties for diatom growth and movement on a long term (up to 2 months). Comparing Nitzschia spathulata, Gyrosigma limosum and Navicula phyllepta growth in liquid media vs in KC gels, we found that diatoms reached a significantly higher final biomass in the hydrogel condition. Hydrogels were also useful to isolate large size diatom species e.g., Nitzschia elongata, that did not survive in suspension. Finally, we showed three ways to study diatom species-specific movement in KC hydrogels: 1) controlled species mix; 2) natural diatom assemblages with grazers; and 3) natural diatom assemblages without grazers. With our system, single diatoms could be imaged, identified, and counted. In addition, different stimuli, e.g., light intensity and light composition can be applied and their effects on movement and physiology studied without being masked by sediment or impaired by meiofauna.

The multifaceted potential of fenugreek seeds: From health benefits to food and nanotechnology applications

The present lifestyle, dietary patterns, psychological pressure, environmental factors, and the widespread exploitation of processed substances in food production and farming have collectively contributed to a substantial expediting in the development of various health problems. Globally, researchers have been seeking natural pharmaceutical substances with the potential to be employed in treating lifestyle-related diseases or delaying their onset. Fenugreek seeds have gained significant attention in various fields, including health, nutrition, and cutting-edge nanotechnology applications, due to their versatile qualities. The current investigation offers a comprehensive discussion of the nutritional composition and therapeutic potential of fenugreek seeds, with an emphasis on their plentiful reservoir of bioactive compounds. This seed demonstrates promising medicinal potential in addressing a wide range of health issues. Significantly, these findings indicate noteworthy properties, such as antidiabetic, antioxidant, anti-obesity, hypocholesterolemic, anticancer, and cardioprotective effects. Moreover, the components of fenugreek seeds are important in the development of a multitude of foods, which is the reason why they are used extensively in the area of food research. In addition to their nutritional value, their exploration of nanotechnology reveals a promising domain, utilizing the distinctive characteristics of seeds for many purposes, such as nanoparticle synthesis and oil for edible films and nanoemulsions. This review article focuses on a comprehensive analysis of fenugreek seeds, examining their wide-ranging applications in the fields of health, nutrition, food, and nanotechnology.

The multifaceted potential of fenugreek seeds: From health benefits to food and nanotechnology applications

The present lifestyle, dietary patterns, psychological pressure, environmental factors, and the widespread exploitation of processed substances in food production and farming have collectively contributed to a substantial expediting in the development of various health problems. Globally, researchers have been seeking natural pharmaceutical substances with the potential to be employed in treating lifestyle‐related diseases or delaying their onset. Fenugreek seeds have gained significant attention in various fields, including health, nutrition, and cutting‐edge nanotechnology applications, due to their versatile qualities. The current investigation offers a comprehensive discussion of the nutritional composition and therapeutic potential of fenugreek seeds, with an emphasis on their plentiful reservoir of bioactive compounds. This seed demonstrates promising medicinal potential in addressing a wide range of health issues. Significantly, these findings indicate noteworthy properties, such as antidiabetic, antioxidant, anti‐obesity, hypocholesterolemic, anticancer, and cardioprotective effects. Moreover, the components of fenugreek seeds are important in the development of a multitude of foods, which is the reason why they are used extensively in the area of food research. In addition to their nutritional value, their exploration of nanotechnology reveals a promising domain, utilizing the distinctive characteristics of seeds for many purposes, such as nanoparticle synthesis and oil for edible films and nanoemulsions. This review article focuses on a comprehensive analysis of fenugreek seeds, examining their wide‐ranging applications in the fields of health, nutrition, food, and nanotechnology.

Investigation of the Structure-Forming Potential of Protein Components in the Reformulation of the Composition of Edible Films

To optimize the functional properties of edible films or coatings, mixtures of several ingredients are used, including food processing by-products. In this way, pectin from fruit pomace, whey proteins from whey as a by-product of rennet cheese production, and gelatin from by-products of the processing of slaughtered animals can be obtained. The aim and scope of the investigation were to verify the hypothesis of the research, which assumes that the addition of beef broth to edible gelatin films will affect the gelation processes of the tested film-forming solutions and will allow for the modification of the edible properties of the films obtained based on these solutions. Measurements were carried out to determine the visual parameters, mechanical strengths, surface and cross-sectional structures, FTIR spectra, thermal degradation rates, and hydrophilicities of the prepared gelatin films. The water content, water vapor permeability, and course of water vapor sorption isotherms of the films were also examined, as well as the course of the gelation process for film-forming solutions. The addition of broth to film-forming solutions was found to increase their opacity and color saturation, especially for the ones that were yellow. The films with the addition of broth were more uneven on the surface and more resistant to stretching, and in the case of the selected types of gelatins, they also formed a more stable gel. The broth increased the hydrophilicity and permeability of the water vapor and reduced the water content of the films. The addition of broth enables the practical use of edible films, but it is necessary to modify some features.

Synthesis and characterization of polysaccharide- and protein-based edible films and application as packaging materials for fresh fish fillets

The rising packaging industry together with global demand for sustainable production has increased the interest in developing biodegradable packaging materials. The aim of the study was to develop edible films based on pectin, gelatin, and hydroxypropyl methylcellulose and evaluate their applicability as biodegradable packaging materials for gilthead seabream fillets. Mechanical properties, water barriers, wettability of the films through contact angle measurement, optical, and UV-Vis barrier properties were evaluated for food packaging applications. The effective blend of polysaccharide and protein film-forming solutions was confirmed by the produced films with excellent optical properties, acceptable mechanical properties and adequate barriers to water vapor. The contact angle for pectin based and gelatin based films were higher than 90° indicating the hydrophobic films, while HPMC based films had contact angle lower than 90°. The produced films were tested as alternative and environmentally friendly packaging materials for gilthead seabream fillets during refrigerated storage. All tested packaging conditions resulted in similar shelf-life in packed gilthead seabream fillets (i.e. 7-8 days at 2 °C). The results showed that the developed films may reduce the use of conventional petroleum-based food packaging materials without affecting the shelf-life of fish.

Animal derived biopolymers for food packaging applications: A review

It is essential to use environment-friendly, non-toxic, biodegradable and sustainable materials for various applications. Biopolymers are derived from renewable sources like plants, microorganisms, and agricultural wastes. Unlike conventional polymers, biopolymer has a lower carbon footprint and contributes less to greenhouse gas emission. All biopolymers are biodegradable, meaning natural processes can break them down into harmless products such as water and biomass. This property is of utmost importance for various sustainable applications. This review discusses different classifications of biopolymers based on origin, including plant-based, animal-based and micro-organism-based biopolymers. The review also discusses the desirable properties that are required in materials for their use as packaging material. It also discusses the different processes used in modifying the biopolymer to improve its properties. Finally, this review shows the recent developments taking place in using specifically animal origin-based biopolymer and its use in packaging material. It was observed that animal-origin-based biopolymers, although they possess unique properties however, are less explored than plant-origin biopolymers. The animal-origin-based biopolymers covered in this review are chitosan, gelatin, collagen, keratin, casein, whey, hyaluronic acid and silk fibroin. This review will help in renewing research interest in animal-origin biopolymers. In summary, biopolymer offers a sustainable and environment-friendly alternative to conventional polymers. Their versatility, biocompatibility will help create a more sustainable future.

Enzymes Immobilized into Starch- and Gelatin-Based Hydrogels: Properties and Application in Inhibition Assay

The present work is a review of the research on using hydrogels based on natural biodegradable polymers, starch, and gelatin for enzyme immobilization. This review addresses the main properties of starch and gelatin that make them promising materials in biotechnology for producing enzyme preparations stable during use and storage and insensitive to chemical and physical impacts. The authors summarize their achievements in developing the preparations of enzymes immobilized in starch and gelatin gels and assess their activity, stability, and sensitivity for use as biorecognition elements of enzyme inhibition-based biosensors.

The effects of double gelatin containing chitosan nanoparticles-calcium alginate coatings on the stability of chicken breast meat

The effects of gelatin coatings (2% and 4%) containing chitosan nanoparticles (ChNPs; 1% and 2%), in combination with calcium-alginate coatings (CA; 2%), on quality attributes and shelf life of chicken breast meat were evaluated at 4°C for 12 days. The results indicated that double-active gelatin-calcium alginate coatings had significant (p < .05) effects on moisture and protein content. Incorporation of ChNPs into double gelatin-CA coatings led to significant reduction (p < .05) in TBARS, pH, and TVB-N values at the end of storage. The counts of total viable count (TVC), coliforms, yeasts, and molds were significantly (p < .05) lower in all coated samples, particularly in treated samples by 4% gelatin containing 2% ChNPs + 2% CA coatings (6.85, 6.78, and 5.91 log CFU/g, respectively, compared with 8.35, 8.76, and 7.71 log CFU/g in control) at the end of keeping time. The results of sensory attributes showed that the coated samples had higher overall acceptability scores compared with the untreated samples. A synergistic relationship between the concentrations of gelatin and ChNPs was observed in maintaining the quality characteristics of meat samples during storage. Therefore, this study aims to evaluate the performance of double gelatin coating containing ChNPs in combination with CA coating in the storage quality improvement of chicken breast meat stored for 12 days at 4 °C to develop novel and practical coatings for meat and meat products.

Enhancement of Thermal and Gas Barrier Properties of Graphene-Based Nanocomposite Films

Poly(vinyl alcohol) (PVA), a naturally occurring and rapidly decomposing polymer, has gained significant attention in recent studies for its potential use in pollution preventive materials. Its cost-effectiveness and ease of availability as well as simple processing make it a suitable material for various applications. However, the only concern about PVA's applicability to various applications is its hydrophilic nature. To address this limitation, PVA-based nanocomposites can be created by incorporating inorganic fillers such as graphene (G). Graphene is a two-dimensional carbon crystal with a single atom-layer structure and has become a popular choice as a nanomaterial due to its outstanding properties. In this study, we present a simple and environmentally friendly solution processing technique to fabricate PVA and graphene-based nanocomposite films. The resulting composite films showed noticeable improvement in barrier properties against moisture, oxygen, heat, and mechanical failures. The improvement of the characteristic properties is attributed to the uniform dispersion of graphene in the PVA matrix as shown in the SEM image. The addition of graphene leads to a decrease in water vapor transmission rate (WVTR) by 79% and around 90% for the oxygen transmission rate (OTR) as compared to pristine PVA films. Notably, incorporating just 0.5 vol % of graphene results in an OTR value of as low as 0.7 cm m-2 day-1 bar-1, making it highly suitable packaging applications. The films also exhibit remarkable flexibility and retained almost the same WVTR values even after going through tough bending cycles of more than 2000 at a bending radius of 2.5 cm. Overall, PVA/G nanocomposite films offer promising potential for PVA/G composite films for various attractive pollution prevention (such as corrosion resistant coatings) and packaging applications.

Accumulation of polystyrene nanoplastics and triclosan by a model tooth-carp fish, Aphaniops hormuzensis (Teleostei: Aphaniidae)

The presence and effects of nanoplastics (NPs; <1 μm) in the aquatic environment are a growing concern. In this study, a model tooth-carp fish, Aphaniops hormuzensis, has been exposed to different concentrations of fluorescent polystyrene nanoplastics (PS-NP) in its diet (up to 5 mg kg-1) over periods of 28 d and the particle accumulation in different tissues determined. Accumulation was observed in both digestive and non-digestive organs, with concentrations greater in the gut, liver and gill (up to 400 μg kg-1 dw) than in the skin and muscle (<180 μg kg-1 dw), but no dependency on exposure time or dose was evident. The presence of the organic contaminant, triclosan (TCS), in the diet and at concentrations up to 0.5 μg kg-1 did not affect PS-NP uptake by A. hormuzensis, while TCS accumulation in the whole body increased with time (up to 10 μg kg-1) and, likewise, appeared to be unaffected by the presence of PS-NPs. These observations suggest that the two contaminants do not interact with each other or that any interactions have no impact on accumulation. The results of this study add to the growing body of evidence that NPs can be translocated by aquatic organisms after ingestion, and reveal that, for the species and conditions employed, nanoplastics are accumulated more readily than a widely used organic chemical.

Advances in propolis and propolis functionalized coatings and films for fruits and vegetables preservation

Propolis, as a natural active substance, is rich in polyphenols, with low toxicity, antioxidant, antifungal and antibacterial properties, which can be applied to the post-harvest preservation of fruits and vegetables. Propolis extracts and propolis functionalized coatings and films have exhibited good freshness in various types of fruits and vegetables as well as fresh-cut vegetables. They are mainly used to prevent water loss after harvesting, to inhibit the infestation of bacteria and fungi after harvesting and to enhance the firmness and apparent quality of fruits and vegetables. Moreover, propolis and propolis functionalized composites have a small or even insignificant effect on the physicochemical parameters of fruits and vegetables. Furthermore, how to cover the special smell of propolis itself so that it does not affect the flavor of fruits and vegetables, and the application of propolis extract in wrapping paper and packaging bag of fruits and vegetables, are worthwhile to further investigate.

The Effects of Citric Acid Crosslinking on Fabrication and Characterization of Gelatin/Curcumin-Based Electrospun Antioxidant Nanofibers

Nanofibers, produced through the novel method of electrospinning, have a high ratio of surface area to volume, which allows them to have different optical, electrical, thermal, and mechanical properties than macroscale materials. In this study, it was aimed to produce nanofibers with gelatin and curcumin. The effects of gelatin concentration and crosslinking with citric acid on the characteristics of electrospun nanofibers were studied. Gelatin film containing neither citric acid nor curcumin was used as control. Solutions were evaluated by solution conductivity, color analysis, and rheological properties. Obtained nanofibers were characterized by morphological analysis (SEM), antioxidant activity (AA), thermal properties (TGA, XRD, DSC), water vapor permeability (WVP), and Fourier transform infrared (FTIR) analysis. It was found that the functional groups of gelatin were not changed significantly but some degree of crosslinking was seen, as indicated by the changes in AA, crystallinity, etc. Improvement in antioxidant activities was seen, which was the highest for gelatin and curcumin films (32%). The highest melting temperature (78 °C) and WVP (2.365 × 10^-10 gm^-1 s^-1 Pa^-1) was seen for gelatin and curcumin films crosslinked with 0.5% citric acid. Gelatin with curcumin films crosslinked with 1% citric acid showed the lowest crystallinity (1.56%). It was concluded that even though citric acid might not prove to be a stable crosslinking agent for the protein (gelatin), it contributed to the antioxidant nature of the films, along with curcumin. These films are promising candidates to be applied on cut fruits, to reduce water loss and oxidation and hence extend their shelf lives.

Recent Advances in Halal Bioactive Materials for Intelligent Food Packaging Indicator

Food safety and security are top priorities for consumers and the food industry alike. Despite strict standards and criteria for food production processes, the potential for food-borne diseases due to improper handling and processing is always present. This has led to an urgent need for solutions that can ensure the safety of packaged foods. Therefore, this paper reviews intelligent packaging, which employs non-toxic and environmentally friendly packaging with superior bioactive materials that has emerged as a promising solution. This review was prepared based on several online libraries and databases from 2008 to 2022. By incorporating halal bioactive materials into the packaging system, it becomes possible to interact with the contents and surrounding environment of halal food products, helping preserve them for longer periods. One particularly promising avenue of research is the use of natural colourants as halal bioactive materials. These colourants possess excellent chemical, thermal, and physical stabilities, along with antioxidant and antimicrobial properties, making them ideal candidates for use in intelligent indicators that can detect food blemishes and prevent pathogenic spoilage. However, despite the potential of this technology, further research and development are needed to promote commercial applications and market development. With continued efforts to explore the full potential of natural colourants as halal bioactive materials, we can meet the increasing demand for food safety and security, helping to ensure that consumers have access to high-quality, safe, and nutritious foods.

Chitosan Based Biodegradable Composite for Antibacterial Food Packaging Application

A recent focus on the development of biobased polymer packaging films has come about in response to the environmental hazards caused by petroleum-based, nonbiodegradable packaging materials. Among biopolymers, chitosan is one of the most popular due to its biocompatibility, biodegradability, antibacterial properties, and ease of use. Due to its ability to inhibit gram-negative and gram-positive bacteria, yeast, and foodborne filamentous fungi, chitosan is a suitable biopolymer for developing food packaging. However, more than the chitosan is required for active packaging. In this review, we summarize chitosan composites which show active packaging and improves food storage condition and extends its shelf life. Active compounds such as essential oils and phenolic compounds with chitosan are reviewed. Moreover, composites with polysaccharides and various nanoparticles are also summarized. This review provides valuable information for selecting a composite that enhances shelf life and other functional qualities when embedding chitosan. Furthermore, this report will provide directions for the development of novel biodegradable food packaging materials.

Gelatin as a bioactive nanodelivery system for functional food applications

Gelatin has long been used as an encapsulant agent in the pharmaceutical and biomedical industries because of its low cost, wide availability, biocompatibility, and degradability. However, the exploitation of gelatin for nanodelivery application is not fully achieved in the functional food filed. In this review article, we highlight the latest work being performed for gelatin-based nanocarriers, including polyelectrolyte complexes, nanoemulsions, nanoliposomes, nanogels, and nanofibers. Specifically, we discuss the applications and challenges of these nanocarriers for stabilization and controlled release of bioactive compounds. To achieve better efficacy, gelatin is frequently used in combination with other biomaterials such as polysaccharides. The fabrication and synergistic effects of the newly developed gelatin composite nanocarriers are also present.

Recent trends in nanocomposite packaging films utilising waste generated biopolymers: Industrial symbiosis and its implication in sustainability

Uncontrolled waste generation and management difficulties are causing chaos in the ecosystem. Although it is vital to ease environmental pressures, right now there is no such practical strategy available for the treatment or utilisation of waste material. Because the Earth's resources are limited, a long-term, sustainable, and sensible solution is necessary. Currently waste material has drawn a lot of attention as a renewable resource. Utilisation of residual biomass leftovers appears as a green and sustainable approach to lessen the waste burden on Earth while meeting the demand for bio-based goods. Several biopolymers are available from renewable waste sources that have the potential to be used in a variety of industries for a wide range of applications. Natural and synthetic biopolymers have significant advantages over petroleum-based polymers in terms of cost-effectiveness, environmental friendliness, and user-friendliness. Using waste as a raw material through industrial symbiosis should be taken into account as one of the strategies to achieve more economic and environmental value through inter-firm collaboration on the path to a near-zero waste society. This review extensively explores the different biopolymers which can be extracted from several waste material sources and that further have potential applications in food packaging industries to enhance the shelf life of perishables. This review-based study also provides key insights into the different strategies and techniques that have been developed recently to extract biopolymers from different waste byproducts and their feasibility in practical applications for the food packaging business.

Consumer perception of entire male pork coated with spiced edible films as a new product to mask boar taint

Pork production has undergone a shift towards the rearing of entire male pigs, however, its meat might carry with the presence of boar taint and it would be considered "unfit for human consumption". To offer a new alternative to the pork sector tailored to the needs of consumers, a viable option would be the use of edible spiced gelatin films to help minimize boar taint and improve its marketability. The responses of 120 regular meat consumers to entire pork with high levels of boar taint and castrated pork free of boar taint, both coated with spiced gelatin films were evaluated. They showed a similar response between entire and castrated male pork coated with spiced films, regardless of whether consumers usually detected unpleasant odours (as farm/animal) when consuming pork or not. Therefore, the new spiced films offer a new range of products to consumers as they contribute to the improvement of the sensory quality of entire male pork, especially among consumers who tend to buy new products.

Self-assembled fatty acid crystalline coatings display superhydrophobic antimicrobial properties

Superhydrophobicity is a well-known wetting phenomenon found in numerous plants and insects. It is achieved by the combination of the surface's chemical properties and its surface roughness. Inspired by nature, numerous synthetic superhydrophobic surfaces have been developed for various applications. Designated surface coating is one of the fabrication routes to achieve the superhydrophobicity. Yet, many of these coatings, such as fluorine-based formulations, may pose severe health and environmental risks, limiting their applicability. Herein, we present a new family of superhydrophobic coatings comprised of natural saturated fatty acids, which are not only a part of our daily diet, but can be produced from renewable feedstock, providing a safe and sustainable alternative to the existing state-of-the-art. These crystalline coatings are readily fabricated via single-step deposition routes, namely thermal deposition or spray-coating. The fatty acids self-assemble into highly hierarchical crystalline structures exhibiting a water contact angle of ∼165° and contact angle hysteresis lower than 6°, while their properties and morphology depend on the specific fatty acid used as well as on the deposition technique. Moreover, the fatty acid coatings demonstrate excellent thermal stability. Importantly, this new family of coatings displays excellent anti-biofouling and antimicrobial properties against Escherichia coli and Listeria innocua, used as relevant model Gram-negative and Gram-positive bacteria, respectively. These multifunctional coatings hold immense potential for application in numerous fields, ranging from food safety to biomedicine, offering sustainable and safe solutions.

Production, characterization, and antimicrobial activity of almond gum/polyvinyl alcohol/chitosan composite films containing thyme essential oil nanoemulsion for extending the shelf-life of chicken breast fillets

In this study, thyme essential oil (TEO) nanoemulsion was immobilized within composite films based on almond gum (AG), polyvinyl alcohol (PVA), and chitosan (CS). The physical, mechanical, water barrier, microstructural and antimicrobial properties of composite films were assessed. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the intermolecular interactions in the composite film matrix. The results indicated that the incorporation of TEO into the composite films increased thickness, moisture content, and water vapor permeability, while it reduced light transmittance and transparency value. The antimicrobial activity of films against gram-negative and gram-positive bacteria was tested using a disc diffusion method. The effect of composite on the microbiological properties of chicken breast fillets was investigated during refrigerated storage for 21 days. The microbial populations of total mesophilic, psychrotrophic, and lactic acid bacteria of the samples that were coated with the composite containing TEO were lower than the permitted limit after 21 days while for blank samples they were higher than 7 log CFU/g after 7 days which is considered as the maximum acceptable total count limit. Results disclosed that AG/PVA/CS composite films containing TEO nanoemulsion can be applied as eco-friendly active food packaging to enhance the shelf-life of food products.

Combined Effect of Drying Temperature and Varied Gelatin Concentration on Physicochemical and Antioxidant Properties of Ginger Oil Incorporated Chitosan Based Edible Films

In the present work, ginger essential oil (GEO) loaded chitosan (CS) based films incorporated with varying concentrations of gelatin (GE) were fabricated and dried at different conditions (25 °C and 45 °C). The physio-chemical, mechanical and antioxidant potential of the films were determined. Films dried at 45 °C showed better physical attributes and less thickness, swelling degree (SD), moisture content, water vapor permeability (WVP), more transparency, and better mechanical characteristics. Fourier transform infrared spectroscopy (FTIR) revealed the chemical composition and interaction between the functional groups of the film components. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) findings revealed that samples dried at 45 °C had more crystalline structure, were thermally stable, and smoother. Antioxidant results showed that films dried at low temperature showed comparatively more (p < 0.0001) antioxidant activity. Additionally, an increase in gelatin concentration improved the tensile strength and swelling factor (p < 0.05), however, had no significant impact on other parameters. The overall results suggested better characteristics of GEO-loaded CS-GE based edible films when dried at 45 °C.

Active Food Packaging Made of Biopolymer-Based Composites

Food packaging plays a vital role in protecting food products from environmental damage and preventing contamination from microorganisms. Conventional food packaging made of plastics produced from unrenewable fossil resources is hard to degrade and poses a negative impact on environmental sustainability. Natural biopolymers are attracting interest for reducing environmental problems to achieve a sustainable society, because of their abundance, biocompatibility, biodegradability, chemical stability, and non-toxicity. Active packaging systems composed of these biopolymers and biopolymer-based composites go beyond simply acting as a barrier to maintain food quality. This review provides a comprehensive overview of natural biopolymer materials used as matrices for food packaging. The antioxidant, water barrier, and oxygen barrier properties of these composites are compared and discussed. Furthermore, biopolymer-based composites integrated with antimicrobial agents-such as inorganic nanostructures and natural products-are reviewed, and the related mechanisms are discussed in terms of antimicrobial function. In summary, composites used for active food packaging systems can inhibit microbial growth and maintain food quality.

Gelatin-Based Film as a Color Indicator in Food-Spoilage Observation: A Review

The color indicator can monitor the quality and safety of food products due to its sensitive nature toward various pH levels. A color indicator helps consumers monitor the freshness of food products since it is difficult for them to depend solely on their appearance. Thus, this review could provide alternative suggestions to solve the food-spoilage determination, especially for perishable food. Usually, food spoilage happens due to protein and lipid oxidation, enzymatic reaction, and microbial activity that will cause an alteration of the pH level. Due to their broad-spectrum properties, natural sources such as anthocyanin, curcumin, and betacyanin are commonly used in developing color indicators. They can also improve the gelatin-based film's morphology and significant drawbacks. Incorporating natural colorants into the gelatin-based film can improve the film's strength, gas-barrier properties, and water-vapor permeability and provide antioxidant and antimicrobial properties. Hence, the color indicator can be utilized as an effective tool to monitor and control the shelf life of packaged foods. Nevertheless, future studies should consider the determination of food-spoilage observation using natural colorants from betacyanin, chlorophyll, and carotenoids, as well as the determination of gas levels in food spoilage, especially carbon dioxide gas.

The EDLC Energy Storage Device Based on a Natural Gelatin (NG) Biopolymer: Tuning the Capacitance through Plasticizer Variation

A solution casting method has been utilisedto fabricate plasticisednatural gelatin (NG)-based polymer electrolyte films. The NG electrolyte with 50 wt.% glycerol and 13 wt.% sodium nitrate (NaNO₃) attained the highest ionic conductivity of 1.67 × 10^-4 S cm^-1. Numerous techniques were used to characterisethe NG films to assess their electrochemical performance. The data obtained from impedance spectroscopy for the plasticisedsystem, such as bulk resistance (Rb), arerelatively low. Thiscomprehensive study has been focused on dielectric characteristics and electric modulus parameters. The plasticisedsystem has shown eligibility for practice in energy storage devices with electrochemical strength up to 2.85 V. The TNM data based on ion transference number (tion) and electron transference number (te) determine the identity of the main charge carrier, ion. The redox peaks in the cyclic voltammograms have not been observed as evidence of charge accumulation other than the Faradaic process at the electrode-electrolyte interface. The GCD plot reveals a triangle shape and records arelatively low drop voltage. The high average efficiency of 90% with low ESR has been achieved over 500 cycles, indicating compatibility between electrolyte and electrode. The average power density and energy density of the plasticisedare 700 W/kg and 8 Wh/kg, respectively.

Novel Active Food Packaging Films Based on Gelatin-Sodium Alginate Containing Beetroot Peel Extract

Currently, the exploration of natural colorants from vegetal waste has gained particular attention. Furthermore, incorporation of these natural sources into biopolymers is an encouraging environmentally friendly approach to establishing active films with biological activities for food packaging. The present study developed bioactive antioxidant films based on gelatin-sodium alginate (NaAlg) incorporated with aqueous beetroot peel extract (BPE). Firstly, the effects of combining gelatin-NaAlg and BPE at 0.25, 0.5, and 1% on the mechanical, physical, antioxidant, and antibacterial properties of the films were analyzed. With increasing BPE, mechanico-physical properties and antioxidant and anti-foodborne pathogen capacities were enhanced. Likewise, when added to gelatin-NaAlg films, BPE remarkably increased the instrumental color properties. Moreover, during 14 days of storage at 4 °C, the impact of gelatin-NaAlg coating impregnated with BPE on microbial and chemical oxidation and on the sensory characteristics of beef meat samples was periodically assessed. Interestingly, by the end of the storage, BPE at 1% limited the microbial deterioration, enhanced the instrumental color, delayed chemical oxidation, and improved sensory traits. By practicing chemometrics tools (principal component analysis and heat maps), all data provided valuable information for categorizing all samples regarding microbiological and oxidative properties, sensory features, and instrumental color. Our findings revealed the ability of gelatin-NaAlg with BPE as an antioxidant to be employed as food packaging for meat preservation.

The Green Era of Food Packaging: General Considerations and New Trends

Recently, academic research and industries have gained awareness about the economic, environmental, and social impacts of conventional plastic packaging and its disposal. This consciousness has oriented efforts towards more sustainable materials such as biopolymers, paving the way for the “green era” of food packaging. This review provides a schematic overview about polymers and blends of them, which are emerging as promising alternatives to conventional plastics. Focus was dedicated to biopolymers from renewable sources and their applications to produce sustainable, active packaging with antimicrobial and antioxidant properties. In particular, the incorporation of plant extracts, food-waste derivatives, and nano-sized materials to produce bio-based active packaging with enhanced technical performances was investigated. According to recent studies, bio-based active packaging enriched with natural-based compounds has the potential to replace petroleum-derived materials. Based on molecular composition, the natural compounds can diversely interact with the native structure of the packaging materials, modulating their barriers, optical and mechanical performances, and conferring them antioxidant and antimicrobial properties. Overall, the recent academic findings could lead to a breakthrough in the field of food packaging, opening the gates to a new generation of packaging solutions which will be sustainable, customised, and green.

Material and Environmental Properties of Natural Polymers and Their Composites for Packaging Applications—A Review

The current trend of using plastic material in the manufacturing of packaging products raises serious environmental concerns due to waste disposal on land and in oceans and other environmental pollution. Natural polymers such as cellulose, starch, chitosan, and protein extracted from renewable resources are extensively explored as alternatives to plastics due to their biodegradability, biocompatibility, nontoxic properties, and abundant availability. The tensile and water vapor barrier properties and the environmental impacts of natural polymers played key roles in determining the eligibility of these materials for packaging applications. The brittle behavior and hydrophilic nature of natural polymers reduced the tensile and water vapor barrier properties. However, the addition of plasticizer, crosslinker, and reinforcement agents substantially improved the mechanical and water vapor resistance properties. The dispersion abilities and strong interfacial adhesion of nanocellulose with natural polymers improved the tensile strength and water vapor barrier properties of natural polymer-based packaging films. The maximum tensile stress of these composite films was about 38 to 200% more than that of films without reinforcement. The water vapor barrier properties of composite films also reduced up to 60% with nanocellulose reinforcement. The strong hydrogen bonding between natural polymer and nanocellulose reduced the polymer chain movement and decreased the percent elongation at break up to 100%. This review aims to present an overview of the mechanical and water vapor barrier properties of natural polymers and their composites along with the life cycle environmental impacts to elucidate their potential for packaging applications.

Preparation and Physiochemical Characterization of Bitter Orange Oil Loaded Sodium Alginate and Casein Based Edible Films

Biopolymers-based composite edible films are gaining interest in the food packaging industry due to their sustainable nature and diverse biological activities. In the current study, we used sodium alginate (SA) and casein (CA) for the fabrication of composite film using the casting method. We also added orange oil to the edible film and assessed its impact on the biological, chemical, physical, and barrier properties of the films. The fabricated films were analyzed using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). It was observed that CA-SA films loaded with 1.5% OEO had better visual attributes, and a further increase in oil concentration was not found to be as favorable. Mechanical assessment of the films revealed that CA-SA-OEO (1.5%) film showed lower puncture deformation and higher puncture force values. XRD data showed that all samples exhibited peaks at similar positions (21° of 2θ) with different intensities. In FTIR analysis, characteristic peaks of the film components (sodium alginate, casein, and orange oil) were reported at corresponding positions. The thermal stability of films was enhanced after the addition of the OEO (1.5%), however, a greater increase in OEO caused a decrease in the thermal stability, observed during TGA analysis. Moreover, the surface of the blank CA-SA film (FL1) was found to be rough (with cracks) compared to CA-SA films (FL2) containing 1.5% OEO. Additionally, FL2 was found to be relatively better than the other samples in terms of swelling degree (SD), thickness, water solubility (WS), oxygen permeability (OP), water vapor permeability (WVP), moisture content (MC), and transparency (T).