Physical and antioxidant properties of alginate films prepared from Sargassum fulvellum with black chokeberry extract

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.

Advances and recent trends in plant-based materials and edible films: a mini-review

Plant-based materials and edible films have emerged as promising alternatives to conventional packaging materials, offering sustainable and environmentally friendly solutions. This mini-review highlights the significance of plant-based materials derived from polysaccharides, proteins, and lipids, showcasing their renewable and biodegradable nature. The properties of edible films, including mechanical strength, barrier properties, optical characteristics, thermal stability, and shelf-life extension, are explored, showcasing their suitability for food packaging and other applications. Moreover, the application of 3D printing technology allows for customized designs and complex geometries, paving the way for personalized nutrition. Functionalization strategies, such as active and intelligent packaging, incorporation of bioactive compounds, and antimicrobial properties, are also discussed, offering additional functionalities and benefits. Challenges and future directions are identified, emphasizing the importance of sustainability, scalability, regulation, and performance optimization. The potential impact of plant-based materials and edible films is highlighted, ranging from reducing reliance on fossil fuels to mitigating plastic waste and promoting a circular economy. In conclusion, plant-based materials and edible films hold great potential in revolutionizing the packaging industry, offering sustainable alternatives to conventional materials. Embracing these innovations will contribute to reducing plastic waste, promoting a circular economy, and creating a sustainable and resilient planet.

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.

Development of smart colorimetric indicators for tracking kimchi freshness by loading aronia extract in agar, κ-carrageenan, and cellulose nanofiber films

Color indicator films incorporating aronia extract powder (AEP) and biopolymers like agar, carrageenan, and cellulose nanofiber (CNF) were developed to monitor kimchi freshness. AEP-containing films showed strong UV-barrier properties, and reduced light transmittance by 99.12 % for agar, 98.86 % for carrageenan, and 98.67 % for CNF-based films. All AEP-films exhibited high sensitivity to pH changes and vapor exposure to ammonia and acetic acid. Color change notably influenced by the polymer type, particularly evident with ammonia vapor exposure, especially in the AEP/carrageenan film. The chemical structure and thermal stability of the biopolymers remained unchanged after AEP-addition. Tensile strength increased by 24.2 % for AEP/CNF but decreased by 19.4 % for AEP/agar and 24.3 % for AEP/carrageenan films. AEP-containing films displayed strong antioxidant activity, with 99 % free radical scavenging in ABTS and ~ 80 % in DPPH assays. Alkalized AEP-indicator films were more effective in detecting color changes during kimchi packaging tests. Among the labels, alkalized AEP/agar film showed the most obvious color change from green-gray (fresh kimchi, pH 5.5, acidity 0.48 %) to pale brown (optimal fermentation, pH 4.6, acidity 0.70 %), and pale violet-brown (over-fermented, pH 3.80, acidity 1.35 %). Alkalized AEP-indicator films offer promising real-time detection of packed fermented foods like kimchi.

Enhancing the bioavailability and antioxidant activity of natamycin E235-ferulic acid loaded polyethylene glycol/carboxy methyl cellulose films as anti-microbial packaging for food application

This study investigated the development of biodegradable films made from a combination of polyethylene glycol (PEG), carboxymethyl cellulose (CMC) and mixtures from natamycin and ferulic acid. The films were characterized for their surface microstructure, antioxidant activity, thermal stability, mechanical properties, permeability and antifungal/bacterial activity. The addition of natamycin and ferulic acid to the film matrix enhanced antioxidant activity, thermal stability, antimicrobial activity, reduced the water vapor permeability (WVP) to 1.083 × 10-10 g × m-1s-1Pa-1, imparted opaque color and increased opacity up to 3.131 A mm-1. The attendance of natamycin and ferulic acid inside films created a clear roughness shape with agglomerates on the surface of films and caused a clear inhibition zone for Aspergillus niger, E. coli and C. botulinum. The utilization of PG/CMC/N-F packaging material on Ras cheese had a noticeable effect, resulting in a slight decrease in moisture content from 34.23 to 29.17 %. Additionally, it helped maintain the titrable acidity within the range of 0.99 % to 1.11 % and the force required for puncture from 0.035 to 0.052 N with non-significant differences. Importantly, these changes did not significantly affect the sensory qualities of Ras cheese during the storage period.

Gelatin/agar pH-indicator film based on cranberry extract loaded with linalool nanoparticle: Survey on physical, antimicrobial, and antioxidant properties

In this study, linalool-nanoparticles (L-NPs) were prepared (encapsulation efficiency was 68.54 %) and introduced pH-indicator film based on cranberry-extract (CEF) to develop multifunctional smart films. XRD analysis and FTIR spectroscopy indicated that cranberry-extract (CE) and L-NPs were uniformly distributed in the gelatin/agar matrix and could change the intermolecular structure of the film. Color change of smart films showed that CE endowed the film with pH-sensitive property. As CE and L-NPs were added to the film, the water contact angle (WCA) was increased from 57.03° to 117.73°, the elongation at break (EAB) was increased from 12.30 % to 34.60 %. Additionally, the introduction of L-NPs enhanced the antioxidant activity (DPPH free radical scavenging rate increased from 26.80 % to 36.35 %) and antibacterial activity (against S. aureus and E. coli) of the smart film, which were verified by its retarding effect on pork spoilage.

Modified polysaccharides for food packaging applications: A review

Development of new food packaging materials is crucial to reduce the use of single-use plastics and to limit their destructive impact on the environment. Polysaccharides provide an alternative solution to this problem. This paper summarizes and discusses recent research results on the potential of modifying polysaccharides as materials for film and coating applications. Modifications of polysaccharides significantly affect their properties, as well as their application usability. Although modifications of biopolymers for packaging applications have been widely studied, polysaccharides have attracted little attention despite being a prospective, environmentally friendly, and economically viable packaging alternative. Therefore, this paper discusses approaches to the development of biodegradable, polysaccharide-based food packaging materials and focuses on modifications of four polysaccharides, such as starch, chitosan, sodium alginate and cellulose. In addition, these modifications are presented not only in terms of the selected polysaccharide, but also in terms of specific properties, i.e. hydrophilic, barrier and mechanical properties, of polysaccharides. Such a presentation of results makes it much easier to select the modification method to improve the unsatisfactory properties of the material. Moreover, very often it happens that the applied modification improves one and worsens another property, which is also presented in this review.

Enhanced physical properties, antioxidant and antibacterial activity of bio-composite films composed from carboxymethyl cellulose and polyvinyl alcohol incorporated with broccoli sprout seed extract for butter packaging

This study investigated the development of biodegradable films made from a combination of carboxymethyl cellulose (CMC), Polyvinyl alcohol (PVA), and purified extract of broccoli sprout seed (BSSE). The films were characterized for their color, physical properties, surface morphology, crystallinity, mechanical properties, and thermal properties. The addition of BSSE up to 1.4 % to the film matrix imparted opaque color and increased opacity up to 3.652. The films also became less moisture-absorbent 8.21 %, soluble 19.16 %, and permeable to water vapor 1.531 (× 10-10 g.m-1 s-1 pa-1). By utilizing 0.7 % from BSSE inside films, the surface of the films became smoother but became rough with higher concentrations 2.1 % of BSSE. Fourier transform infrared (FT-IR) analysis showed that there was physical interaction between the BSSE extract and the PV/CM matrix. The films showed good thermal stability, and the incorporation of BSSE improved their ability to preserve the acidity, TBARS, peroxide value, and total color differences of butter during cold storage.

A critical review on biodegradable food packaging for meat: Materials, sustainability, regulations, and perspectives in the EU

The development of biodegradable packaging is a challenge, as conventional plastics have many advantages in terms of high flexibility, transparency, low cost, strong mechanical characteristics, and high resistance to heat compared with most biodegradable plastics. The quality of biodegradable materials and the research needed for their improvement for meat packaging were critically evaluated in this study. In terms of sustainability, biodegradable packagings are more sustainable than conventional plastics; however, most of them contain unsustainable chemical additives. Cellulose showed a high potential for meat preservation due to high moisture control. Polyhydroxyalkanoates and polylactic acid (PLA) are renewable materials that have been recently introduced to the market, but their application in meat products is still limited. To be classified as an edible film, the mechanical properties and acceptable control over gas and moisture exchange need to be improved. PLA and cellulose-based films possess the advantage of protection against oxygen and water permeation; however, the addition of functional substances plays an important role in their effects on the foods. Furthermore, the use of packaging materials is increasing due to consumer demand for natural high-quality food packaging that serves functions such as extended shelf-life and contamination protection. To support the importance moving toward biodegradable packaging for meat, this review presented novel perspectives regarding ecological impacts, commercial status, and consumer perspectives. Those aspects are then evaluated with the specific consideration of regulations and perspective in the European Union (EU) for employing renewable and ecological meat packaging materials. This review also helps to highlight the situation regarding biodegradable food packaging for meat in the EU specifically.

Polysaccharide-Based Edible Films/Coatings for the Preservation of Meat and Fish Products: Emphasis on Incorporation of Lipid-Based Nanosystems Loaded with Bioactive Compounds

The high water and nutritional contents of meat and fish products make them susceptible to spoilage. Thus, one of the most important challenges faced by the meat industry is extending the shelf life of meat and fish products. In recent years, increasing concerns associated with synthetic compounds on health have limited their application in food formulations. Thus, there is a great need for natural bioactive compounds. Direct use of these compounds in the food industry has faced different obstacles due to their hydrophobic nature, high volatility, and sensitivity to processing and environmental conditions. Nanotechnology is a promising method for overcoming these challenges. Thus, this article aims to review the recent knowledge about the effect of biopolymer-based edible films or coatings on the shelf life of meat and fish products. This study begins by discussing the effect of biopolymer (pectin, alginate, and chitosan) based edible films or coatings on the oxidation stability and microbial growth of meat products. This is followed by an overview of the nano-encapsulation systems (nano-emulsions and nanoliposomes) and the effect of edible films or coatings incorporated with nanosystems on the shelf life of meat and fish products.

Biodegradable sodium alginate films incorporated with lycopene and β-carotene for food packaging purposes

Incorporating carotenoids into sodium alginate films can give them functional properties for food packaging applications. The lycopene and β-carotene were included in the biopolymer matrix at 0.1%, 0.3%, and 0.5% (g carotenoid/g polymer). There was no significant difference (p > 0.05) in film thickness (45 ± 1 μm) of sodium alginate films with carotenoids. Nevertheless, the low quantity of carotenoids was enough to promote significant variations in the tensile properties of films. The films with lycopene or β-carotene showed lower tensile strength and elongation at break than control films. The carotenoid incorporation promoted a reduction (p < 0.05) in water vapor permeability, mainly by adding 0.5%. In the same way, it improved the light transmission and thermal stability of films and did not affect the water solubility of films. The scanning electron microscopy of films showed a homogeneous surface, but the films with lycopene or β-carotene showed a more compact structure than the control film. The sodium alginate films incorporated with 0.3% lycopene or β-carotene showed a remarkable protective effect on sunflower oil against oxidation compared with traditional commercial plastic packaging under accelerated storage conditions (heat and light). Therefore, they can be considered a potential material for food packaging purposes.

Agaricus blazei Murill extract-loaded in alginate/poly(vinyl alcohol) films prepared by Ca2+ cross-linking for wound healing applications

This work aimed the development and evaluation of the wound healing activity of films based on sodium alginate, polyvinyl alcohol (PVA) and Ca²⁺ loaded with Agaricus blazei Murill hydroalcoholic extract (AbE). Firstly, AbE was prepared using a previously standardized methodology. The films were prepared by casting technique and cross-linked with Ca²⁺ using CaCl₂ as cross-linking agent. The physicochemical, morphological and water vapor barrier properties of the films were analyzed and the pre-clinical efficacy was investigated against the cutaneous wound model in mice. The films showed barrier properties to water vapor promising for wound healing. AbE showed physical and chemical interactions between both polymers, noticed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermal analysis. The delivery of AbE in alginate/PVA films enhanced the antioxidant and wound healing properties of these polymers. Consequently, a reduction of malondialdehyde levels was observed, as well as an increase of the epidermis/dermis thickness and enhancement in collagen I deposition. Thus, these formulations are promising biomaterials for wound care and tissue repairing.

Composite films based on carboxy methyl cellulose and sodium alginate incorporated Thymus vulgaris purified leaves extract for food application: Assessment, antimicrobial and antioxidant properties

The current study was conducted to develop biodegradable films with matrix composed from carboxymethyl cellulose (CMC), sodium alginate (SA) and different concentrations from Thymus vulgaris purified leaves extract (TVE). The color properties, physical properties, shape of surface, manners of crystallinity, mechanical properties and thermal properties of produced films were investigated. The continuous addition of TVE up to 1.6 % inside films matrix imparted the yellow color of extract that increased opacity to 2.98 and reduced moisture, swelling, solubility and water vapor permeability (WVP) of films up to 10.31 %, 30.17 %, 20.18 % and (1.12× 10^-10 g.m^-1 s^-1 pa^-1), respectively. Furthermore, the surface micrographs showed smoother surface after using small concentrations of TVE and turned to irregular with rough surface at higher concentrations. The FT-IR analysis indicated typically bands that demonstrated physical interaction between TVE extract and CMC/SA matrix. The fabricated films showed suitable thermal stability with decreasing trend by incorporation of TVE inside CMC/SA films. Furthermore, the developed CMC/SA/TVE2 showed significant effects on preserving the levels of moisture content, titrable acidity, force to puncture and sensory properties of cheddar cheese during cold storage days compared with commercial packaging materials.

Development and Characterization of Films with Propolis to Inhibit Mold Contamination in the Dairy Industry

Due to the number of polyphenols with multiple biological activities, propolis has high potential to be used as an active agent in food protective films. Therefore, this study aimed to develop and characterize a sodium alginate film with ethanolic extract of propolis (EEP) for its potential use as protective active packaging against filamentous fungi in ripened cheese. Three different concentrations of EEP were analyzed: 0, 5 and 10% w/v. The films obtained were characterized, assessing thermal and physicochemical properties, as well as the concentration of polyphenols in the EEP and antifungal activity of the active films. The incorporation of EEP in the films generated thermal stability with respect to the loss of mass. Total color values (ΔE) of the films were affected by the incorporation of the different concentrations of EEP, showing a decrease in luminosity (L*) of the films, while the chromatic parameters a* and b* increased in direct proportion to the EEP concentration. Antifungal activity was observed with a fungistatic mode of action, stopping the growth of the fungus in cheeses without development of filamentous molds, thus increasing the shelf life of the ripened cheese under the analytical conditions, over 30 days at room temperature. Overall, EEP can be used to prevent growth and proliferation of spoilage microorganisms in cheese.

Correlation between Mechanical and Morphological Properties of Polyphenol-Laden Xanthan Gum/Poly(vinyl alcohol) Composite Cryogels

This study aimed to evaluate the effect of the synthesis parameters and the incorporation of natural polyphenolic extract within hydrogel networks on the mechanical and morphological properties of physically cross-linked xanthan gum/poly(vinyl alcohol) (XG/PVA) composite hydrogels prepared by multiple cryo-structuration steps. In this context, the toughness, compressive strength, and viscoelasticity of polyphenol-loaded XG/PVA composite hydrogels in comparison with those of the neat polymer networks were investigated by uniaxial compression tests and steady and oscillatory measurements under small deformation conditions. The swelling behavior, the contact angle values, and the morphological features revealed by SEM and AFM analyses were well correlated with the uniaxial compression and rheological results. The compressive tests revealed an enhancement of the network rigidity by increasing the number of cryogenic cycles. On the other hand, tough and flexible polyphenol-loaded composite films were obtained for a weight ratio between XG and PVA of 1:1 and 10 v/v% polyphenol. The gel behavior was confirmed for all composite hydrogels, as the elastic modulus (G') was significantly greater than the viscous modulus (G″) for the entire frequency range.

Antioxidant and ammonia-sensitive films based on starch, κ-carrageenan and Oxalis triangularis extract as visual indicator of beef meat spoilage

In this study, we first investigated the rheological property of sweet potato starch (SPS), κ-carrageenan (KC) and Oxalis triangularis extract (OTE) blends and found that the blends exhibited high apparent viscosity with an apparent shear thinning behavior. And then films based on SPS, KC and OTE were developed and their structural and functional properties were studied. The physico-chemical test results showed that OTE exhibited different colors in solutions with different pH values and the incorporation with OTE and KC could significantly increase the thickness, water vapor permeability, light barrier ability, tensile strength and elongation at break as well as the pH- and ammonia-sensitive properties of the SPS film. The structural property test results showed that some intermolecular interactions between OTE and SPS/KC occurred in SPS-KC-OTE films. Finally, the functional properties of SPS-KC-OTE films were examined and SPS-KC-OTE films showed significant DPPH radical scavenging activity as well as a visible color change in response to changes in beef meat freshness. Our results suggested that the SPS-KC-OTE films could be used as an active and intelligent food packaging material in food industry.

Valorization of Amaranth (Amaranthus cruentus) Grain Extracts for the Development of Alginate-Based Active Films

This research work investigates the development of alginate-based films incorporating phenolic compounds extracted from Amaranthus cruentus grain using different solvents. Alginate, glycerol, and amaranth grain phenolic compounds at various concentrations were used to produce the films. An experimental Central Composite Rotatable Design (CCRD) was used to evaluate the effect of these variables on different film’s properties, i.e., water vapor permeability, hydrophobicity, moisture content, solubility, thermal, mechanical, and optical properties. This study demonstrated that high phenolic compound content and antioxidant capacity were obtained from amaranth grain using ethanol as the extraction solvent. Alginate films incorporating amaranth phenolic compounds were successfully manufactured, and this study can be used to tailor the formulation of alginate films containing amaranth phenolic compounds, depending on their final food application. For example, less flexible but more resistant and water-soluble films can be produced by increasing the alginate concentration, which was confirmed by a Principal Component Analysis (PCA) and Partial Least Squares (PLS) analysis. This study showed that active alginate films with amaranth phenolic compounds can be tailored to be used as food packaging material with potential antioxidant activity.

The effect of incorporation of gambier filtrate and rosella flower petals extract on mechanical properties and antioxidant activity of canna starch based active edible film

The research objective was to analyse the incorporation effect of gambier filtrate and rosella flower petals extract on mechanical properties and antioxidant activity of canna starch-based active edible film. This research used an experimental method consisting of two treatments, namely gambier filtrate (A): A1 = 3, A2 = 4, and A3 = 5 (% v/v), as well as rosella flower petals extract (B): B1 = 2, B2 = 4 and B3 = 6 (% v/v) and each treatment was replicated three times. The results showed that the two treatment interactions significantly influenced elongation percentage, water vapour transmission rate, and antioxidant activity. The edible film’s thickness, tensile strength, and water vapour transmission rate were 0.096-0.124 mm, 1.89-3.38 MPa, and 12.99-17.04 g.m-2.d-1, respectively. The edible film contains an antioxidant compound of the strong category with IC50 values of 34.53 to 48.02 ppm. Treatment of A3B2 [gambier filtrate 5% (v/v) and rosella flower petals extract 4% (v)] was the best treatment. This edible film is generally suitable for application as a packaging material for food having high lipid content to inhibit the oxidation process of that food.

Antimicrobial, antioxidant, and pH-sensitive polyvinyl alcohol/chitosan-based composite films with aronia extract, cellulose nanocrystals, and grapefruit seed extract

Aronia or black chokeberry (Aronia melanocarpa), cellulose nanocrystals (CNCs), and grapefruit seed extract (GSE) were used for the preparation of multifunctional polyvinyl alcohol/chitosan (PVA/CS) composite films with pH-sensitivity, antimicrobial, antioxidant, and UV-barrier properties. Aronia extract showed total phenolic content of 297 ± 0.5 μg GAE/mg aronia extract, potent antioxidant activity, and high color-response efficiency. Isolated CNCs showed a needle-like structure with a length of 470 nm and a width of 35 nm. The tensile strength of the PVA/CS composite film increased by 74% after the incorporation of CNCs, whereas the film flexibility was enhanced by 75% after adding GSE. The PVA/CS-A (aronia extract) composite film showed a significant color change at different pHs and potent antioxidant activity. At the same time, the PVA/CS-G (GSE) showed the highest antimicrobial activity against Escherichia coli (Gram-negative) and Listeria monocytogenes (Gram-positive) bacteria. The PVA/CS-CGA composite film, reinforced with CNCs/GSE/Aronia extract, showed the highest UV-barrier (95.5%), highest antioxidant activity (95%), potent antimicrobial activity, pH-sensitivity, lowest water vapor permeability (WVP), and desirable mechanical properties. The multifunctional properties of the produced composite films encourage their use as active and intelligent food packaging films to extend shelf life and monitor food quality.

Characterization of Natural Anthocyanin Indicator Based on Cellulose Bio-Composite Film for Monitoring the Freshness of Chicken Tenderloin

Intelligent packaging with indicators that provide information about the quality of food products can inform the consumer regarding food safety and reduce food waste. A solid material for a pH-responsive indicator was developed from hydroxypropyl methylcellulose (HPMC) composited with microcrystalline cellulose (MCC). MCC at 5%, 10%, 20%, and 30% w/w was introduced into the HPMC matrix and the physical, barrier, thermal, and optical properties of the HPMC/MCC bio-composite (HMB) films were analyzed. At 5, 10, and 20% MCC, improved mechanical, transparency, and barrier properties were observed, where HMB with 20% of MCC (H20MB) showed the best performance. Therefore, H20MB was selected as the biodegradable solid material for fabricating Roselle anthocyanins (RA) pH sensing indicators. The performance of the RA-H20MB indicator was evaluated by monitoring its response to ammonia vapor and tracking freshness status of chicken tenderloin. The RA-H20MB showed a clear color change with respect to ammonia exposure and quality change of chicken tenderloin; the color changed from red to magenta, purple and green, respectively. These results indicated that RA-H20MB can be used as a biodegradable pH sensing indicator to determine food quality and freshness.

Characterisation and Antibacterial Properties of Novel Biodegradable Films Based on Alginate and Roselle (Hibiscus sabdariffa L.) Extract

Composite films were prepared with alginate and roselle extract (HE) at different concentrations (1%, 3%, and 5% w/v) via solvent casting technique and analyzed in terms of physical, mechanical, and antibacterial properties. The incorporation of HE into alginate films resulted in rough and heterogeneous surface characteristics with increasing concentrations of HE. The thickness and water vapor permeability of alginate-HE composite films were significantly higher (p < 0.05) compared to pure alginate films. Moreover, water content, solubility, swelling, tensile strength, and elongation at break value of the composite films decreased (p < 0.05) with increasing concentrations of the extract. FTIR spectra revealed shifts and intensity variations in the composite films and the formation of new peaks suggesting a possible interaction between alginate and HE. Alginate-HE films exhibited good antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The antibacterial effect of the films, more pronounced against Gram-positive bacteria, increased with higher amounts of HE. The resulting films may be utilised as new biodegradable, antibacterial films in the food packaging industry to prolong shelf life and preserve food safety.

Graphical Abstract

Supplementary Information

The online version of this article (10.1007/s12649-022-01710-3) contains supplementary material, which is available to authorized users.

In vivo anti-inflammatory and antinociceptive effects, and in vitro antioxidant, antiglycant and anti-neuroinflammatory actions of Syzygium malaccense

Syzygium malaccense is popularly used to treat inflammation and pain-related ailments. The species was assessed regarding its antioxidant, antiglycant, anti-inflammatory, including anti-neuroinflammatory, and antinociceptive activities. Different models were employed to measure S. malaccense extract (ESM) antioxidant activity. The antiglycant activity was determined using the glucose-induced protein glycation model. LPS-induced neuroinflammation on murine BV-2 microglial cell line was used for anti-neuroinflammatory activity evaluation. The croton oil-induced ear edema test was accomplished to evaluate the in vivo anti-inflammatory activity. Acetic acid-induced writhing together with formalin-induced paw licking assays were performed to evaluate the antinociceptive potential. Finally, the chemical characterization was accomplished by a UHPLC-MS analysis. ESM presented relevant antioxidant and antiglycant activity. NO production by BV-2 cells was reduced, indicating the relevant neuroprotective activity. ESM significantly decreased the mice ear edema induced by croton oil and the nociceptive stimulus induced by acetic acid and formalin by central and peripheral mechanisms. The flavonoids myricitrin, myricetin and quercetin were identified and, as far as we know, the alkaloid reserpine was reported in the species for the first time. The antioxidant and antiglycant potential of ESM, may be related to the in vivo anti-inflammatory and antinociceptive effects, and to the in vitro neuroinflammation inhibition.

Development of multifunctional food packaging films based on waste Garlic peel extract and Chitosan

A sustainable multifunctional food packaging composite film containing waste garlic peel extract (GPE) and Chitosan (CH) was prepared. This film exhibited antimicrobial potential towards Staphylococcus aureus and Klebsiella pneumoniae. GPE/CH films' morphological, physical, and functional properties were compared to those of CH film. Fourier transform infrared showed the interactions through hydrogen bonding between CH and GPE in the blends that improved the polymers' compatibility. Furthermore, X-ray diffraction analysis validated the compatibility between GPE and CH. GPE/CH films exhibited higher thickness and moisture content than the CH film. Remarkably, GPE/CH films showed lower water vapor barrier properties and higher ultra-violet protection and mechanical strength than CH film. Compact surfaces of the GPE infused CH films were unveiled through Scanning electron microscopy. GPE/CH film showed improved thermal stability after the addition of GPE. MTT method's cytotoxicity study manifested that the GPE/CH films are antioxidant and non-cytotoxic, implicating their biocompatibility and non-toxicity. The results suggest that GPE/CH films can find widespread commercial applications like food packaging materials, replacing the commonly used petrochemical plastics.

Preparation and characterization of Zein-sulfated Cardamine hupingshanensis polysaccharide composite films

Cardamine hupingshanensis polysaccharide (CHP) was modified by the sulfur trioxide-pyridine method to obtain the sulfated C. hupingshanensis polysaccharide (SCHP) with a substitution degree of 0.72. The spectral results revealed that the sulfate group was successfully introduced to CHP. In the in vitro antioxidant assay, SCHP showed the highest scavenging rate of hydroxyl radicals, ABTS, and DPPH. Different concentrations of SCHP were chosen to form a compound with Zein to prepare novel bioactive films successfully. The functional and characterization studies of the films were also conducted. The scavenging ability of the films for hydroxyl radicals, ABTS, and DPPH was improved by adding different concentrations of SCHP. Although the films showed a decrease in transparency with the addition of 4 mg/ml SCHP, there was an improvement in tensile strength compared to films without the addition of SCHP. These findings indicate that Zein-SCHP films can be used as a functional food packaging material with antioxidant properties.

Developing multifunctional edible coatings based on alginate for active food packaging

The applications of edible coatings stemmed exclusively from alginate in food packaging are restricted due to their inherent deficient antimicrobial, barrier, and UV-barrier properties. In this work, we aimed to design smart alginate-based coatings for active food packaging through the addition of both aloe vera (AV) and garlic oil (GO). The interactions between the film components were verified by FTIR and XRD. Thermal and mechanical properties were improved by the presence of AV and GO. The presence of AV and GO did not significantly influence the transparency of alginate films. The films exhibited a significant UV-shielding to all UV regions. Water vapor permeability was significantly (p < 0.05) reduced either through the incorporation of AV or GO. The antimicrobial properties of the prepared films were considerably improved by the presence of AV and GO. The shelf-life of tomatoes (Solanum lycopersicum L.) was extended when coated with the alginate film incorporated with AV and GO. Owing to the outstanding UV-shielding, mechanical, thermal, and antimicrobial properties, the alginate/AV/GO active coatings could potentially be implemented in the food packaging industry.

Edible packaging: Sustainable solutions and novel trends in food packaging

Novel food packaging techniques are an important area of research to promote food quality and safety. There is a trend towards environmentally sustainable and edible forms of packaging. Edible packaging typically uses sustainable, biodegradable material that is applied as a consumable wrapping or coating around the food, which generates no waste. Numerous studies have recently investigated the importance of edible materials as an added value to packaged foods. Nanotechnology has emerged as a promising method to provide use of bioactives, antimicrobials, vitamins, antioxidants and nutrients to potentially increase the functionality of edible packaging. It can act as edible dispensers of food ingredients as encapsulants, nanofibers, nanoparticles and nanoemulsions. In this way, edible packaging serves as an active form of packaging. It plays an important role in packaged foods by desirably interacting with the food and providing technological functions such as releasing scavenging compounds (antimicrobials and antioxidants), and removing harmful gasses such as oxygen and water vapour which all can decrease products quality and shelf life. Active packaging can also contribute to maintaining the nutritive profile of packaged foods. In this review, authors present the latest information on new technological advances in edible food packaging, their novel applications and provide examples of recent studies where edible packaging possesses also an active role.

The potential of anthocyanins in smart, active, and bioactive eco-friendly polymer-based films: A review

Among the bioactive compounds that are considered important for the food industry, anthocyanins, which are flavonoid compounds presenting antioxidant activity and are responsible for beneficial health effects, have received researchers' attention in the last decades. In addition, anthocyanins are highly reactive and can be used as indicators of foodstuff quality conditions, particularly as a packaging ingredient. Considering this line of work, the eco-friendly film is a novel packaging technology that arose from the concern to reduce non-renewable resources and their impact on the environment. These films can be vehicles for loading bioactive compounds such as anthocyanins. Among the contribution of films in the food industry, we can highlight several potential applications: i) smart film: assess food quality and safety, transmitting food information to consumers and increasing the reliability of their consumption without breaking the packaging; ii) active film: use to preserve food quality through the release of active agents; and iii) bioactive film: carry substances in desired concentrations until their controlled or rapid diffusion within the gastrointestinal tract so that they can promote its benefit to human health. Thus, this review presents anthocyanin extract's potential as a powerful tool to improve the development of eco-friendly films, directing its purpose to the application as smart, active, and bioactive films.

Investigation of Ultrasonic Treatment on Physicochemical, Structural and Morphological Properties of Sodium Alginate/AgNPs/Apple Polyphenol Films and Its Preservation Effect on Strawberry

An antibacterial and anti-oxidation composite film was prepared by a casting method using sodium alginate (SA) and apple polyphenols (APPs) as the base material and glycerol as the plasticizer. Silver nanoparticles (AgNPs) were deposited by ultrasonic-assisted electrospray method. The degree of influence of the addition ratio of SA and AgNPs and different ultrasonic time on the mechanical properties, barrier properties, optical properties, and hydrophilicity of the composite film was explored. The composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the SA: AgNPs ratio of 7:3 and the ultrasonic time for 30 min have the best comprehensive performance, and SA/AgNPs/APP films showed the lowest water vapor permeability value of 0.75 × 10⁻¹¹ g/m·s·Pa. The composite film has good strength and softness, with tensile strength (TS) and elongation at break (E) at 23.94 MPa and 29.18%, respectively. SEM images showed that the surface of the composite film was smooth and the AgNPs’ distribution was uniform. The composite film showed broad antibacterial activity, and the antibacterial activity of Escherichia coli (92.01%) was higher than that of Staphylococcus aureus (91.26%). However, due to the addition of APP, its antioxidant activity can reach 98.39%, which has a synergistic effect on antibacterial activity. For strawberry as a model, the results showed that this composite film can prolong the shelf life of strawberries for about 8 days at 4 °C, effectively maintaining their storage quality. Compared with the commonly used PE(Polyethylene film) film on the market, it has a greater fresh-keeping effect and can be used as an active food packaging material.