Alginate-Based Edible Films and Coatings for Food Packaging Applications

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

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

Bioprinted Hormone-Responsive Bilayer Model of Human Endometrium for Embryo Implantation Studies

Implantation failure is a major challenge in reproductive medicine, with two-thirds of cases attributed to poor uterine receptivity. Current models have limited utility in capturing the complexities of the endometrium. This study introduces a novel bioprinted endometrial model with epithelial and stromal cells in a bilayer structure, designed to replicate the hormone-regulated endometrial environment and support embryo implantation studies. Alginate-based bioink formulations, cross-linked with calcium chloride or calcium gluconate, were optimized for 3D cell bioprinting, based on key parameters: reduced spreading ratio, lower printed line width standard deviation (SD), slower degradation rates, and enhanced cell viability. Human endometrial epithelial (RL95-2) and stromal (T HESCs) cell lines were encapsulated in the bioink and bioprinted in a bilayer structure: Clear stratification mimicking the layered architecture of native endometrium was confirmed using fluorescent microscopy. Sequential hormonal treatments with estradiol (proliferative phase), followed by estradiol and progesterone (secretory phase) highlighted the model's hormone-responsiveness. Estradiol significantly enhanced cell viability by day 2, while progesterone reduced cell viability by day 5, consistent with adaptation to the proliferative and secretory phases. Hormone-treated constructs displayed significantly lower E-cadherin expression, higher mRNA expression of various integrins and of vascular endothelial growth factor (VEGF), and reduced metalloproteinase (MMP)-2 secretion after 5 days, mirroring in vivo endometrial remodeling under progesterone influence. JAR spheroids, representing human blastocyst cells, adhered to and infiltrated the epithelial layer of the hormone-treated, bilayered model, effectively simulating embryo implantation. This bioprinted bilayer endometrial model represents a significant advancement in reproductive biology. It offers a platform for studying in vitro endometrial receptivity and implantation and paves the way for personalized treatment approaches in recurrent implantation failure.

Production of polysaccharide and protein edible films: Challenges and strategies to scale-up

Polymeric films are among the main packaging materials used by food industry, and they can be produced using petrochemical-based polymers and biopolymers. Although the use of petrochemical-based polymers for food packaging is associated with a harmful impact on the environment, and human health through direct contact with food, the food industry cannot avoid their use due to the lack of fully viable alternatives. Therefore, there is an imperative need for potential food packaging alternatives made from natural, bio-based polymers that should be safe and biodegradable. In this group, edible polysaccharides and proteins present several advantages, making them green and safe alternatives. Therefore, several pilot and semi-commercial attempts have been made to commercialize the production of edible packaging materials. However, their industrial-scale production still presents big challenges. These challenges are related to the properties of edible biopolymers, such as low elasticity and high hygroscopicity, and, others are associated with the commercial-scale manufacturing technologies, which causes a slower implementation of edible films at the industrial level. This study aims to discuss edible films' main properties and limitations and propose possibilities for their industrial-scale production, focusing on maintaining their natural and ecofriendly food packaging with evolved functionalities.

Optimization and evaluation of a simplified green biorefinery for alginate extraction from sugar kelp (Saccharina latissima)

A simplified two-stage ultrasound-assisted biorefinery process for sodium alginate extraction from sugar kelp (Saccharina latissima) was developed using green solvents. The process yielded three distinct fractions: fucoidan/laminarin (S1), sodium alginate (S2), and cellulose (P2). The results were analyzed with response surface methodology. Key parameters, including sonication amplitude, time, and pH, were evaluated, and sonication energy was introduced as a predictive factor to improve model accuracy. Mathematical optimization of the response surface model identified an optimal sodium alginate yield of 76.4 % at pH 2 and 432.2 kJ of sonication energy. Fourier-transform infrared spectroscopy (FTIR) confirmed effective sodium alginate fractionation, and molecular weight analysis correlated viscosity with alginate quality. Inductively coupled plasma mass spectrometry (ICP-MS) showed reduced heavy metal content in both fucoidan/laminarin and alginate, indicating an improved safety profile for potential food and nutritional applications. This scalable and eco-friendly biorefinery highlights an environmentally sustainable approach for sodium alginate production, maximizing biomass valorization and ensuring product safety.

Eco-friendly carboxymethyl cellulose films incorporated with phenolic compounds from hydrodistillation wastewater of rosemary essential oil

The food packaging industry seeks innovative materials that enhance food preservation while promoting sustainability. This study investigated the development of carboxymethyl cellulose (CMC) films incorporating both rosemary essential oil (EO) and phenolic compounds extracted from the hydrodistillation wastewater of rosemary. The aqueous extract (AE), rich in rosmarinic acid, caffeic acid, chlorogenic acid, vanillic acid, luteolin, rosmanol, and carnosic acid, was used to improve the bioactive properties of the films. Four formulations were produced: CMC (control), CMC/EO (with essential oil), CMC/AE (with aqueous extract), and CMC/EO/AE (with both EO and AE). The incorporation of EO and AE increased the film thickness and altered microstructural properties, with EO-containing films exhibiting larger voids due to oil droplet coalescence. Films with AE showed a significantly higher yellowing index and superior UV barrier properties, which could protect light-sensitive foods. FTIR and XRD analyses confirmed successful incorporation of bioactive compounds, while solubility tests revealed that EO-containing films were fully soluble, whereas AE-containing films exhibited reduced solubility (∼50 %), enhancing their potential for moisture-sensitive food applications. EO increased film flexibility, whereas AE-containing films demonstrated improved antioxidant activity, with FRAP and TEAC values approximately 300 % and 700 % higher, respectively, compared to the control. These films have potential for food packaging applications, particularly for lipid-rich foods prone to oxidative degradation (e.g., nuts, dairy, processed meats) and fresh produce susceptible to photodegradation. By utilizing a by-product of the essential oil industry, this study contributes to the development of sustainable and functional food packaging solutions.

A host-pathogen metabolic synchrony that facilitates disease tolerance

Disease tolerance mitigates organ damage from non-resolving inflammation during persistent infections, yet its underlying mechanisms remain unclear. Here we show, in a Pseudomonas aeruginosa pneumonia mouse model, that disease tolerance depends on the mitochondrial metabolite itaconate, which mediates cooperative host-pathogen interactions. In P. aeruginosa, itaconate modifies key cysteine residues in TCA cycle enzymes critical for succinate metabolism, inducing bioenergetic stress and promoting the formation biofilms that are less immunostimulatory and allow the bacteria to integrate into the local microbiome. Itaconate incorporates into the central metabolism of the biofilm, driving exopolysaccharide production-particularly alginate-which amplifies airway itaconate signaling. This itaconate-alginate interplay limits host immunopathology by enabling pulmonary glutamine assimilation, activating glutaminolysis, and thereby restrain detrimental inflammation caused by the inflammasome. Clinical sample analysis reveals that P. aeruginosa adapts to this metabolic environment through compensatory mutations in the anti-sigma-factor mucA, which restore the succinate-driven bioenergetics and disrupt the metabolic synchrony essential for sustaining disease tolerance.

Enhancing circular bioeconomy: Alginate-cellulose nanofibre films/coatings functionalized with encapsulated pomegranate peel extract for postharvest preservation of pomegranate arils

This study investigated the properties of alginate-cellulose nanofiber (AL-CNF) bio-composite coatings functionalized with pomegranate peel extract powder (PPEP) at 0.1, 0.3, and 0.5 % (w/v) and their effects on the postharvest shelf life of pomegranate arils stored at 5 °C and 95 ± 2 % RH for 15 days. The results demonstrated that PPEP incorporation enhanced the physical, functional, and antioxidant properties of the coatings while reducing their mechanical strength. Microstructural analysis revealed that CNF contributed to a rougher surface, whereas PPEP addition improved homogeneity and smoothness. The 0.5 % PPEP concentration exhibited the highest thickness, antioxidant activity, and phenolic content. Application of AL-CNF bio-composite coatings significantly (p < 0.05) reduced weight loss, delayed respiration, and maintained firmness compared to the control. PPEP incorporation increased total soluble solids (TSS) and preserved the visual quality of arils. Additionally, 0.5 % PPEP retained higher phenolic content, anthocyanin levels, and DPPH activity while reducing microbial growth. These findings suggest that AL-CNF nanocomposite coatings enriched with PPEP (0.1-0.5 %) effectively preserve quality and extend the shelf life of minimally processed pomegranate arils, offering a sustainable postharvest preservation strategy.

Recent developments in conductive polysaccharide adsorbent formulations for environmental remediation: A review

Environmental remediation is crucial for human life and ecosystems, involving the cleanup of contaminated water to protect health and restore ecological balance. However, rapid industrialization and population growth have worsened pollution, particularly in water bodies, making effective wastewater treatment a key challenge in ensuring clean drinking water, and the adsorption of toxic gases for air treatment are the main strategies for environmental remediation. Among the various treatment methods, adsorption stands out for its high selectivity, low energy and chemical use, ease of operation, and cost-effectiveness. To date, innovative, highly efficient, non-toxic, engineered adsorbent materials have received potential interest from scientific and governmental communities. Conducting polymer-modified polysaccharide formulations are crucial in wastewater treatment due to their high surface area, adsorption efficiency, excellent stability, and eco-friendly, biodegradable properties. This review offers an extensive overview of recent progress in synthesizing conducting polymer-modified polysaccharide formulations (hydrogels, aerogels, nanofibers, and nanocomposites) for capturing toxic heavy metal ions, organic dyes, pharmaceuticals, phenols as well as adsorbing different toxic gases using various adsorption mechanisms. It also emphasizes the integration of different nanofillers, including carbon-based materials, Mxenes, nanoclay, metal/metal oxides, and hybrid nanomaterials, into conductive polysaccharide chains to improve their physicochemical properties and adsorption efficiency. The reported data showed that these engineered adsorbent materials based on conductive polysaccharide formulations have immense potential for wastewater treatment applications, offering more effective and sustainable solutions.

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.

Strictly G-Specific Alginate Lyase Aly7Sa for Efficient Preparation of Unsaturated Guluronate Oligosaccharides

Alginate is a commercially valuable polysaccharide consisting of β-d-mannuronate (M) and its C5 epimer, α-l-guluronate (G). Alginate lyases are efficient tools for the degradation of alginate and the preparation of oligosaccharides. In this research, an endolytic alginate lyase Aly7Sa with strict G specificity was expressed and characterized with the optimum reaction conditions at 30 °C and pH 6.5. The main degradation products of Aly7Sa for alginate were trisaccharide to octasaccharide, and those of PolyG were disaccharide to heptasaccharide. By utilizing HPAEC-PAD/MS and NMR methods, we identified the structure of products obtained from alginate. Interestingly, the trisaccharide to hexasaccharide products of Aly7Sa contained only unsaturated guluronate oligosaccharides, which were different from all of the characterized G-specific alginate lyases. The absence of oligosaccharide products with M residues demonstrated the strict G specificity of Aly7Sa. The targeted preparation was carried out based on the regular oligosaccharide pattern of Aly7Sa. By single-step purification employing gel-permeation chromatography, 4.8 mg of ΔGG, 6.8 mg of ΔGGG, and 3.7 mg of ΔGGGG were obtained with 100 mg of alginate as substrate. The strictly G-specific alginate lyase Aly7Sa provided an efficient tool for the preparation of unsaturated guluronate oligosaccharides, and the unique substrate specificity of the enzyme could also serve the research and development of alginate.

Next-Generation Edible Packaging: Development of Water-Soluble, Oil-Resistant, and Antioxidant-Loaded Pouches for Use in Noodle Sauces

The development of sustainable biodegradable packaging materials is essential for enhancing food quality and shelf life while reducing plastic waste. This study explored polymer-based monolayer, composite, and bilayer films to produce water-soluble, oil-proof pouches. Single-serving seasoning oil pouches were prepared from bilayer films with polyvinyl alcohol (PVA) as the inner and sodium alginate (SA) as the outer layer. The PVA/SA films exhibited excellent UV protection, low oil permeability (0.18 × 10-6 g·mm/mm2·day), hydrophilic surface (water contact angle < 90°), and rapid solubility in hot water (87 ± 2 °C). Incorporating curcumin, a natural antioxidant, into PVA/SA films (Cur-PVA/SA) improved thermal stability, reduced light transmittance, and decreased water vapor permeability (0.28 × 10-10 g/m·Pa·s). Curcumin release followed a biphasic diffusion model, with 94.8% released at 96 h (diffusion coefficient: 1.30 × 10-11 m2/s), ensuring prolonged antioxidant activity. The Cur-PVA/SA pouches delayed lipid oxidation more effectively, with peroxide values of 6.48 and 10.35 meq/kg after 45 days at 35 °C, respectively. The Q10 model, which is commonly used to predict the shelf life of oils based on temperature-dependent oxidation rates, estimated that the oil packaged in Cur-PVA/SA pouches would remain stable for 12 months at 23 °C. This represents a 37% longer shelf life compared to oil packaged in PVA/SA pouches without curcumin. Cur-PVA/SA pouches also reduced noodle moisture migration, limiting weight loss to 2.73% over 14 days compared to 5.80% in controls. These findings highlight their potential as eco-friendly active packaging solutions.

Influence of alginate extraction conditions from the brown seaweed Dictyota mertensii on the functional properties of a novel glycerol plasticized alginate film

Alginate films were prepared from the brown seaweed Dictyota mertensii using glycerol as a plasticizer. The effects of extraction conditions-time, temperature, and Na2CO3 concentration-on the optical, barrier, and mechanical properties of the films were investigated using a central composite design (CCD). ANOVA and F tests confirmed the models' statistical significance at p ≤ 0.05, 95 % CI. Na2CO3 concentration significantly influenced moisture absorption, water vapor permeability, solubility, opacity, L*, b*, and elongation at break. Temperature mainly affected the color parameter a* and tensile strength, while time was more relevant for the modulus of elasticity. The properties of alginate from Dictyota mertensii were correlated to the film properties. Optimization through numerical desirability function yielded a global desirability index of 0.767, with optimal conditions at 1.390 h, 54.927 °C, and 0.361 mol.L-1 Na2CO3. Under these conditions, the films showed low moisture content (0.277 %), moderate WVP (31.278 g.mm/kPa.m2.h), low solubility (18.825 %), appropriate color parameters (Opacity: 12.411 AU.nm/mm, L*: 49.655, a*: 17.680, b*: 44.657), and balanced mechanical properties (TS: 13.270 MPa, EB: 20.638 %, and E: 64.592 MPa). These findings emphasize the potential of alginate films from Dictyota mertensii and promote sustainable use of marine resources.

Recent developments in alginate-based nanocomposite coatings and films for biodegradable food packaging applications

Packaging made of plastic harms the environment. Thus, polysaccharide edible films are becoming a popular food packaging solution. Alginate is a biopolymer derived from seaweed that has the potential to create food packaging materials that are environmentally friendly and biodegradable. This article explores the potential use of nanocomposite coatings and films made from alginate as an alternative to petroleum-based polymers in the food industry. Alginate is desirable for food packaging due to its low cost, high nutritional value, renewability, low oxygen permeability, biodegradability, and biocompatibility. This article delves into alginate's history and extraction processes and covers techniques for modifying its physical and chemical properties using blended polymers and additives. Alginate-based coatings and films have been found to improve the mechanical properties and sensory characteristics of various food items and prolong the shelf life of perishable items by regulating oxygen and moisture levels and as a barrier against microbial growth. Further investigation is necessary to maximize the performance of alginate-based polymers in various food industry applications. Future prospects call on advancements in their physicochemical and functional characteristics to increase the acceptability of alginate-based nanocomposite coatings and films for biodegradable food packaging applications.

Polymeric Nanofibers via Green Electrospinning for Safe Food Engineering

Electrospun functional nanofibers enable controlled release of the loaded active ingredient and an adjustable dissolution rate. However, the widespread use of toxic organic solvents in electrospinning poses risks to human health and the environment whereas increasing production costs and complexity. This article examines the application of eco-friendly electrospinning technologies in food engineering, with a focus on water-based and melt electrospinning methods. It provides a detailed analysis of water-soluble biopolymers and synthetic polymers, highlighting their current applications and challenges in food engineering. Water-based electrospinning is proposed as a sustainable alternative, offering scalability and reduced environmental impact. This transition is essential for advancing food engineering toward more sustainable and environmentally responsible practices.

Edible Coatings for Ready-to-Eat Products: Critical Review of Recent Studies, Sustainable Packaging Perspectives, Challenges and Emerging Trends

If edible coatings are proven to control deterioration reactions by preventing chemical reactions, why aren't they more widely used in industry applications, especially in the ready-to-eat food sector? This sector is a growing and emerging market and is interesting to diverse consumer groups. The potential of edible coatings as an innovative approach for more eco-friendly packaging systems should be further investigated. This article reviews the state-of-the-art developments of edible coatings for chilled RTE (ready-to-eat) food products as an area of growing interest and innovation, with a focus on sustainability, functionality, and costs. It discusses challenges associated with the use of edible coatings as eco-friendly packaging system in RTE food sector, including compatibility with food products, processing, shelf-life, storage conditions, cost, and regulatory requirements, and emerging trends, including biodegradable and eco-friendly coatings, shelf-life extension, active and intelligent coatings, and customization and personalization opportunities. Overall, while edible coatings offer many potential benefits in the RTE food sector, there are several challenges that must be addressed to ensure their successful implementation. Research and development efforts are needed to optimize the performance and stability of coatings while ensuring compliance with regulatory requirements and addressing cost concerns. The potential of edible coatings as eco-friendly packaging system should be further studied to highlight the full potential of edible coatings.

Edible Alginate-Fungal Chitosan Coatings as Carriers for Lacticaseibacillus casei LC03 and Their Impact on Quality Parameters of Strawberries During Cold Storage

This study investigated the efficacy of an innovative edible coating, composed of fungal chitosan and alginate, functionalized with Lacticaseibacillus casei LC03, in both free and microencapsulated forms, to extend the shelf life and enhance the nutritional value of strawberries. L. casei LC03 cells were successfully encapsulated in alginate microparticles (MAL) and further coated with chitosan (MALC), resulting in enhanced protection (cell reduction below 1.4 CFU/mL), viability (8.02 log CFU/mL), and encapsulation efficiencies exceeding 90%. The edible coating with L. casei microencapsulated in alginate and coated with fungal chitosan (CACLM) significantly improved strawberry preservation by maintaining pH (3.16 ± 0.41), titratable acidity (0.94 ± 0.20), moisture (90.74 ± 0.27), and microbial quality, and delayed the decrease in total phenolic compounds (below 40%) during the storage time of strawberries. While coatings with free L. casei (CALF) slightly reduced color parameters (L* value 29.13 ± 2.05), those with chitosan (CACLM) demonstrated lower weight loss (below 6%). Overall, the alginate-chitosan coating, particularly when combined with microencapsulated L. casei, proved effective in maintaining the quality, safety, and nutritional value of strawberries during refrigerated storage, highlighting its potential for developing functional, eco-friendly packaging solutions. This research contributes to the development of sustainable food preservation strategies and functional foods.

Prolonging Shelf Life and Meat Quality of Rainbow Trout (Oncorhynchus mykiss) by Immersing in Pine Nut (Pinus gerardiana) Extract During Cold Storage

Rainbow trout (Oncorhynchus mykiss) is a freshwater fish susceptible to chemical and microbial spoilage, limiting its shelf life. This study aimed to enhance and extend the rainbow trout fillets' shelf life stored at 4°C ± 1°C through an immersion treatment using ultrasound-assisted, defatted pine nut (Pinus gerardiana Wallich) extracts at concentrations of 1% and 2% (w/v), compared to the control group (0% pine nut). Evaluations were conducted at storage intervals of 0, 4, 8, 12, 16, and 20 days. The methodology assessed antioxidant activity through 2,2-diphenyl 1-picrylhydrazyl radical scavenging, which showed a linear increase with pine nut extract concentration, reaching 59.24% at 2%. Chemical indicators, such as peroxide values, thiobarbituric acid values, free fatty acids, and total volatile basic nitrogen, decreased significantly (p ≤ 0.05) with higher concentrations of pine nut extract, with the lowest values recorded at 2% across all storage days. Microbial analysis showed a significant reduction (p ≤ 0.05) in the total viable count, psychrotrophic bacteria count, lactic acid bacteria, Enterobacteriaceae, and H₂S-producing bacteria with increasing pine nut concentrations, with the 2% treatment yielding the lowest microbial loads throughout storage. Sensory evaluation indicated that higher pine nut concentrations improved the acceptability of color, odor, and taste (p ≤ 0.05). However, significant degradation (p ≤ 0.05) in chemical, microbial, and sensory parameters occurred with prolonged storage duration. In conclusion, the 2% pine nut extract was the most effective immersion treatment for extending the shelf life of rainbow trout fillets for up to 12 days.

A novel edible biocomposite coating based on alginate from the brown seaweed Dictyota mertensii loaded with beeswax nanoparticles extends the shelf life of yellow passion fruit

In this study, an edible biocomposite coating of alginate extracted from the brown seaweed Dictyota mertensii was loaded with beeswax nanoparticles (BDMAB) to extend the shelf life of yellow passion fruit (Passiflora edulis f. flavicarpa). The films were characterized by morphology, moisture content, contact angle, water vapor permeability, solubility, and optical and mechanical properties. Using a 4 × 6 factorial design, coated fruit was evaluated during six storage intervals (0, 2, 4, 6, 8, 10 days) at 22.5 ± 0.5 °C and 65 ± 5 % RH, focusing on respiration rate, weight loss, peel thickness and color, pulp yield and color, soluble solids, titratable acidity, ascorbic acid, phenolics, antioxidant capacity, and sensory acceptance. The BDMAB coating, composed of 67.9 % (w/w) ADM (bleached), 5 % (w/w) glycerol, 8.5 % (w/w) beeswax, and 18.6 % (w/w) Tween 80, significantly (p < 0.05) reduced the respiration rate, minimized weight loss, and preserved quality attributes, such as acidity, ascorbic acid, phenols, and antioxidant capacity. A 3-day extension in shelf life was inferred based on the climacteric peak delay of BDMAB-coated fruits compared with the control. Sensory analysis confirmed the acceptance of BDMAB coating. Therefore, BDMAB biocomposite coatings have great potential for preserving yellow passion fruit and promoting sustainability and conservation.

Natural biopolymers in the fabrication and coating of ureteral stent: An overview

Ureteral stents are indwelling medical devices that are most commonly used in treating different urinary tract complications like ureteral obstruction, kidney stones, and strictures, and allow normal urine flow from the kidney to the bladder. Tremendous work has been done in ureteral stent technology to meet the clinical demands, however, till-date a gold standard material for ureteral stents has not yet been developed. Many materials such as metal, and synthetic polymers have been published, however, the role of natural biopolymers has not yet been summarized and discussed. There is no detailed review published to explain the role of natural biopolymers in ureteral stent technology. This is the first review that explains and summarizes the role of natural polymer in ureter stent technology. In this review alginate and chitosan polymers are discussed in detail in the fabrications and coating of ureteral stents. It was summarized that alginate polymer alone or in combination with other polymers have been successfully used by many researchers for the manufacturing of ureteral stents with satisfactory results in vitro, in vivo, and clinical trials. However, alginate is rarely used to coat the surface of ureteral stent. On the other hand, only two reports are available on chitosan polymers for the manufacturing of ureteral stents, however, chitosan is largely used to coat the existing ureteral stents owing to their good antibacterial characteristics. Coating procedures can inhibit encrustation and biofilm formation. Nevertheless, the lack of antibacterial efficiency and inadequate coating limit their applications, however, natural biopolymers like chitosan showed significant promises in coating. Overall, the renewable nature, abundant, biocompatible, and biodegradable potential of natural polymer can be established with significant aspects as the ideal ureteral stent. To fully utilize the potential of the natural biopolymers in the ureteral stent design or coatings, an in-depth study is required to understand and identify their performance both in vitro and in vivo in the urinary tract.

Edible Alginate-Lecithin Films Enriched with Different Coffee Bean Extracts: Formulation, Non-Cytotoxic, Anti-Inflammatory and Antimicrobial Properties

The aim of this study was to analyze the functional properties of newly obtained films based on sodium alginate and lecithin with the addition of antioxidant-rich coffee extracts and to verify their potential as safe edible food packaging materials. In our study, we developed alginate-lecithin films enriched with green or roasted coffee bean extracts. The roasting process of coffee beans had a significant impact on the total phenolic content (TPC) in the studied extracts. The highest value of TPC (2697.2 mg GAE/dm3), as well as antioxidant activity (AA) (17.6 mM T/dm3), was observed for the extract of light-roasted coffee beans. Films with the addition of medium-roasted coffee extracts and baseline films had the highest tensile strength (21.21 ± 0.73 N). The addition of coffee extract improved the barrier properties of the films against UV light with a decrease in the transmittance values (200-400 nm), regardless of the type of extract added. Studies on Caco-2, HepG2 and BJ cells showed that digestated films were non-cytotoxic materials (100-0.1 μg/cm3) and had no negative effect on cell viability; an increase was noted for all cell lines, the highest after 48 h in a dose of 1 μg/cm3 for a film with medium-roasted coffee (194.43 ± 38.30) for Caco-2. The tested films at 20% digestate concentrations demonstrated the ability to reduce nitric oxide (NO) production in the RAW264.7 cell line by 25 to 60% compared to the control. Each of the tested films with coffee extracts had growth inhibitory properties towards selected species of bacteria.

Preservation of freshly-cut lemon slices using alginate-based coating functionalized with antioxidant enzymatically hydrolyzed rice straw-hemicellulose

Food coatings are efficient preservative measures, a crucially needed approach to meet hunger growth as well as food management. In the current study, the construction of an efficient coating using alginate polymer fortified with antioxidant rice straw-hemicellulose hydrolysate was examined. Rice straw hemicellulose fraction was extracted under thermal alkaline conditions with a recovery percentage of 15.8%. The extracted hemicellulose fraction was enzymatically hydrolyzed with microbial xylanase with hydrolysis percentage of 53.8%. Characterization of the produced hydrolysate was performed with the aid of thin layer chromatographic analysis (TLC), high-performance liquid chromatographic analysis (HPLC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The reported data showed that xylobiose (240.68 mg/g) in addition to coumaric (383.33 µg/g) and ferulic acid (298.77 µg/g) as the main constituents of the carbohydrate and the polyphenolic contents, respectively. The hydrolysate possessed antioxidant capacity that significantly increased in a direct correlation with the concentration of the hydrolysate. Finally, the prepared coating solution effectiveness in the preservation of lemon slices against fungal growth was monitored up to 20 days with a significant concentration dependent decrease in weight loss and an increase in its antioxidant activity. The combination of xylooligosaccharide-rich rice straw hydrolysate with alginate-based coating not only improved the storage shelf-life of fresh fruits and vegetables but also provided microbial safety and potential benefits for human health.

Eco-friendly methylcellulose/zinc alginate film with multi-function properties: thermal stability, flame retardancy and antibacterial activities

The purpose of this study was to synthesize crosslinked films from methylcellulose (MC) and sodium alginate (SA) using a straightforward ion exchange technique in a ZnCl2 coagulation bath. The resulting MC/ZA blend films exhibited significant improvements in thermal stability, with a measured increase of 191 °C in degradation temperature compared to MC film. The introduction of zinc ion (Zn2+) enhanced the flame retardancy of MC/ZA film, achieving a 92.4 % reduction in flammability. The microstructure of the MC/ZA blend film displayed a relatively smooth surface, indicating better biocompatibility between MC and ZA. Additionally, the barrier property of the MC/ZA film was improved, with a 35 % reduction in permeability to water vapor, and the mechanical properties were strengthened, showing a slightly reduction of 5 % in tensile strength. Furthermore, the MC/ZA blend film demonstrated enhanced antibacterial effectiveness, with a 99.99 % of S. aureus and E. coli, implying their suitability for packaging applications involving high oil content foods.

Preparation and characterization of polyvinyl alcohol/pullulan/ZnO-Nps composite film and its effect on the postharvest quality of Allium mongolicum Regel

Allium mongolicum Regel is prone to rapid senescence and quality deterioration during postharvest storage. Herein, polyvinyl alcohol/pullulan/ZnO nanoparticles (PVA/PUL/ZnO-Nps) composite films were prepared via solution casting and studied to analyze the effects of ZnO-Nps on the PVA/PUL film matrix. Results revealed that the incorporation of suitable ZnO-Nps effectively reduced the light transmittance, improved water contact angle, water vapor permeability, and mechanical properties of the composite films, as well as enhanced their antimicrobial activity. The composite films were used for the postharvest preservation of A. mongolicum Regel. Results revealed that the PVA/PUL/ZnO-Nps film effectively reduced malondialdehyde accumulation content, superoxide radical generation rate, hydrogen peroxide content, improve the activity of related enzymes, and extend the storage time compared with that of polyethylene films. Therefore, the PVA/PUL/ZnO-Nps film can be used as a novel packaging material for the postharvest preservation of A. mongolicum Regel.

Zwitterionic MOF-embedded alginate beads with polydopamine surface functionalization for efficient doxycycline removal: Optimization and mechanistic study

The adsorptive removal of amphoteric antibiotics like doxycycline (DOX) is a difficult task because of the electrostatic repulsion between these amphoteric molecules and adsorbents. For this purpose, a zwitter adsorbent was fabricated by incorporating zwitter ZIF-67/MIL-88A binary MOF into the matrix of alginate (Alg); in addition, the surface of the beads was modified by polydopamine (PDA). The batch experiments implied the super-high adsorption efficacy of ZIF-67/MIL-88A@Alg@PDA toward DOX attained 384.61 ± 5.08 mg/g at a neutral pH medium, 25 °C, and using 0.02 g. The isotherm analysis implied the physisorption of DOX onto ZIF-67/MIL-88A@Alg@PDA, while the kinetic analysis denoted the chemisorption of DOX. The results of XPS, Zeta potential, and Lab experiments identified the types of physical and chemical interactions between ZIF-67/MIL-88A@Alg@PDA and DOX. The durability of the ZIF-67/MIL-88A@Alg@PDA beads was inspected by the recycling test, clarifying that the DOX adsorption aptitude declined by 12.22 mg/g. In addition, the measured leaching concentrations of cobalt and iron from the leaching test were 0.008 and 0.098 mg/L. The ionic strength of ZIF-67/MIL-88A@Alg@PDA, implying an enhancement in the DOX removal (%) from 83.51 to 93.50 % by raising the NaCl concentration from 0.2 to 1.0 mol/L. Therefore, our study could provide a simple procedure to overcome the electrostatic repulsion that retard the adsorption process of the amphoteric drugs onto charged adsorbents with positive or negative charges. Additionally, this procedure could also generate an electrostatic interaction between the zwitter adsorbents and the amphoteric drugs at specific pH media when they are in a zwitterionic nature.

Valorization of the performance of novel and natural sodium alginate/pectin/Portulaca oleracea L. ternary composites in the adsorption of toxic methylene blue dye from the aquatic environment

This research introduces the development of a novel, sustainable, cost-effective, and eco-friendly sodium alginate (SA)-pectin (P) ternary composite, enhanced with Portulaca oleracea L. (PO) additive, which has been thoroughly investigated for its efficacy in removing hazardous methylene blue (MB) dye from wastewater. The selectivity studies using various cationic and anionic dyes were conducted. The composite microbeads that were generated underwent characterization using FTIR-ATR, SEM, XRD, zeta potential, and pHpzc analysis. Subsequently, the most favorable parameters for adsorption, including initial pH (2-12), contact time (0-180 min), adsorbent dosage (0.01-0.20 g), and temperature (298-318 K), were identified. The effect of monovalent and divalent salt concentrations on adsorption process was evaluated. The adsorption data were utilized in several isotherm (Langmuir, Freundlich, D-R, and Temkin) and kinetic (pseudo-first-order and pseudo-second-order) models. According to the Langmuir isotherm model was calculated the adsorption capacity at 298 K is 709.22 mg/g for SA/P/PO30 composite microbeads. The process of adsorption was seen to conform to a pseudo-second-order kinetic model. The results revealed that the process was both exothermic (∆Ho=-10.42kJ/mol) and spontaneous (∆Go=-26.04kJ/molat298K). Moreover, reusability analyses demonstrated that the composite microbeads that were created may be utilized several times, even after the 5th cycle. The results indicate that the developed composite microbeads have the potential to serve as an effective and inexpensive adsorbent for eliminating cationic contaminants from a wastewater.

Advances in Electrospun Nanofiber Membranes for Dermatological Applications: A Review

In recent years, a wide variety of high-performance and versatile nanofiber membranes have been successfully created using different electrospinning methods. As vehicles for medication, they have been receiving more attention because of their exceptional antibacterial characteristics and ability to heal wounds, resulting in improved drug delivery and release. This quality makes them an appealing choice for treating various skin conditions like wounds, fungal infections, skin discoloration disorders, dermatitis, and skin cancer. This article offers comprehensive information on the electrospinning procedure, the categorization of nanofiber membranes, and their use in dermatology. Additionally, it delves into successful case studies, showcasing the utilization of nanofiber membranes in the field of skin diseases to promote their substantial advancement.

Natural Food Components as Biocompatible Carriers: A Novel Approach to Glioblastoma Drug Delivery

Efficient drug delivery methods are crucial in modern pharmacotherapy to enhance treatment efficacy, minimize adverse effects, and improve patient compliance. Particularly in the context of glioblastoma treatment, there has been a recent surge in interest in using natural dietary components as innovative carriers for drug delivery. These food-derived carriers, known for their safety, biocompatibility, and multifunctional properties, offer significant potential in overcoming the limitations of conventional drug delivery systems. This article thoroughly overviews numerous natural dietary components, such as polysaccharides, proteins, and lipids, used as drug carriers. Their mechanisms of action, applications in different drug delivery systems, and specific benefits in targeting glioblastoma are examined. Additionally, the safety, biocompatibility, and regulatory considerations of employing food components in drug formulations are discussed, highlighting their viability and future prospects in the pharmaceutical field.

Alginate composite films incorporated with Zn-based inorganic antimicrobials for food packaging: Effects of morphology

Biopolymers-based food packaging materials have drawn attention as potential candidates for substitution of petroleum-based materials. In this study, composite alginate films were developed by incorporating Zn-based antimicrobials to overcome the intrinsic disadvantages of alginates that hinder their wide applications. Antimicrobials with different morphologies (nanoplatelets, nanorods, and nanospheres) were employed to investigate the effects of antimicrobials' morphology on antibacterial, thermal, mechanical, and barrier performance of composite alginate films. Meanwhile, morphological and structural characterizations were carried out to explore the interactions between antimicrobials and alginate matrix. Results indicated that films with nanospheres exhibited superior antibacterial property, while those with one-dimensional nanorods possessed better mechanical and barrier performance. Besides, preliminary test on fresh-cut potatoes and chicken breasts indicated that the composite films showed potential in extending shelf life of foods. By incorporating antimicrobials with three different morphologies, this study provides particular insights into improving properties of composite packaging materials.

Lycopene extract as an antibrowning agent for edible coating of fresh cut apples

Edible coatings have been utilized for fresh fruit and vegetable preservation to ensure their safety and freshness. The present study reported the effect of edible coatings incorporated with Lycopene extract and Ascorbic Acid on fresh cut Apple slices (Red Delicious) during storage at refrigeration temperature for 12 days. The dipping treatments include Lycopene extract (LC-100 mg), Ascorbic acid (AAC-100 mg) and a combination of both LC + AAC (100 mg lycopene extract and 100 mg Ascorbic acid). Quality parameters (color, physicochemical and enzymatic activities) were studied up to 12 days at refrigeration temperature. Dipping treatments of LC and LC + AAC significantly showed lowest enzymatic activity than AAC treatment. However, color was not preserved in LC + AAC treatments due to high concentration of olive oil in these treatments. Furthermore, physicochemical quality was better preserved in LC + AAC treatments.

Eco-Friendly Design of Chitosan-Based Films with Biodegradable Properties as an Alternative to Low-Density Polyethylene Packaging

Biopolymer-based films are a promising alternative for the food packaging industry, in which petrochemical-based polymers like low-density polyethylene (LDPE) are commanding attention because of their high pollution levels. In this research, a biopolymer-based film made of chitosan (CS), gelatin (GEL), and glycerol (GLY) was designed. A Response Surface Methodology (RSM) analysis was performed to determine the chitosan, gelatin, and glycerol content that improved the mechanical properties selected as response variables (thickness, tensile strength (TS), and elongation at break (EAB). The content of CS (1.1% w/v), GEL (1.1% w/v), and GLY (0.4% w/v) in the film-forming solution guarantees an optimized film (OPT-F) with a 0.046 ± 0.003 mm thickness, 11.48 ± 1.42 mPa TS, and 2.6 ± 0.3% EAB. The OPT-F was characterized in terms of thermal, optical, and biodegradability properties compared to LDPE films. Thermogravimetric analysis (TGA) revealed that the OPT-F was thermally stable at temperatures below 300 °C, which is relevant to thermal processes in the food industry of packaging. The reduced water solubility (WS) (24.34 ± 2.47%) and the improved biodegradability properties (7.1%) compared with LDPE suggests that the biopolymer-based film obtained has potential applications in the food industry as a novel packaging material and can serve as a basis for the design of bioactive packaging.

Alginate beads loaded with rambutan extract: characterization and stability during in vitro gastrointestinal digestion

BACKGROUND

Fallen young rambutan fruit is an underrated agricultural waste which may contain several bioactive compounds. In this study, fallen young rambutan fruit was assessed regarding its phenolic contents and antioxidant activities. In order to expand its utilization, rambutan extract-loaded hydrogel beads were developed by a basic spherification technique using sodium alginate. The effect of ratios of polymer and extract and different calcium sources were evaluated. The recovery of bioactive compounds from the hydrogel beads was determined using in vitro gastrointestinal digestion models.

RESULTS

Use of 50% (v/v) ethanol yielded rambutan extract with good chemical properties. The production of hydrogel beads using a ratio of 1:3 with calcium lactate provided the highest production yield of 122.94%. The hydrogel beads developed using the ratio of 1:3 with a combination of calcium lactate and calcium chloride showed high recovery of phenolic compounds and antioxidant activity after simulated intestinal digestion, which were greater compared to unencapsulated extract.

CONCLUSION

The findings demonstrate that the ratio of wall material to rambutan extract and the calcium source influence the physical properties, chemical properties and in vitro gastrointestinal digestion stability of alginate beads. The obtained hydrogel beads may have potential for application in the food or pharmaceutical industries. © 2024 Society of Chemical Industry.

The dual function of calcium ion in fruit edible coating: Regulating polymer internal crosslinking state and improving fruit postharvest quality

The edible coating is proved to be a convenient approach for fruit preservation. Among these published explorations, naturally sourced macromolecules and green crosslinking strategies gain attention. This work centers on edible coatings containing Ca2+ as crosslinker for the first time, delving into crosslinking mechanisms, include alginate, chitosan, Aloe vera gel, gums, etc. Additionally, the crucial functions of Ca2+ in fruit's quality control are also elaborated in-depth, involving cell wall, calmodulin, antioxidant, etc. Through a comprehensive review, it becomes evident that Ca2+ plays a dual role in fruit edible coating. Specifically, Ca2+ constructs a three-dimensional dense network structure with polymers through ionic bonding. Moreover, Ca2+ acts directly with cell wall to maintain fruit firmness and serve as a second messenger to participate secondary physiological metabolism. In brief, coatings containing Ca2+ present remarkable effects in preserving fruit and this work may provide guidance for Ca2+ related fruit preservation coatings.

Influence of Different Deep Eutectic Solvents and Plant Extracts on Antioxidant, Mechanical, and Color Properties of Alginate Film

Eco-friendly functional alginate films with plant extracts (chokeberry pomace (ChP) or lemon balm (LB) herb) were obtained. Moreover, deep eutectic solvents (DESs) based on choline chloride, glucose, and betaine were used to acquire the active substances from plant materials. The films were tested regarding the antioxidant, mechanical, and color properties. The results revealed that the films' antioxidant capacities (AC) depended on the extract type and DES used, namely AC values for alginate films with LB were higher than those with ChP. Moreover, the results of the films' mechanical properties depended only on the DES, which acted as a plasticizer in most cases. Furthermore, the color analysis of the studied films showed a dependence on the type of extract and DES. The lightness (L*) was influenced only by the DES type, while the solvent and extract type affected the a* and b* values. Our results show that the films can be applied as active packaging for food products.

Effect of alginate coating activated by solid lipid nanoparticles containing Zataria multiflora essential oil on chicken fillet's preservation

The current study aimed to assess the chemical, microbial, and sensory properties of Solid Lipid Nanoparticles (SLNs) in chicken fillets stored at 4 ± 1 °C for 12 days. As a result, the optimized ZEO-SLNS sample exhibited a spherical morphology with a droplet size of 251.51 ± 1.11 nm and a PDI of 0.34 ± 0.01 under transmission electron microscopy (TEM). The encapsulation efficiency (EE) and zeta potential were approximately 55.4 % and -20.87 ± 1.39 mV, respectively. Furthermore, encapsulating ZEO in SLNS enhanced antibacterial and antioxidant activity compared to pure ZEO. As a result, the application of alginate-loaded ZEO-SLNS extended the storage time of fresh chicken fillets. Thus, the application of this edible coating showcased a remarkable ability to substantially decelerate both microbial and chemical changes in chicken fillets during cold storage conditions. This finding underscores the potential of the edible coating as an effective means to enhance the safety and quality of chicken products.

Application of Natural Functional Additives for Improving Bioactivity and Structure of Biopolymer-Based Films for Food Packaging: A Review

The global trend towards conscious consumption plays an important role in consumer preferences regarding both the composition and quality of food and packaging materials, including sustainable ones. The development of biodegradable active packaging materials could reduce both the negative impact on the environment due to a decrease in the use of oil-based plastics and the amount of synthetic preservatives. This review discusses relevant functional additives for improving the bioactivity of biopolymer-based films. Addition of plant, microbial, animal and organic nanoparticles into bio-based films is discussed. Changes in mechanical, transparency, water and oxygen barrier properties are reviewed. Since microbial and oxidative deterioration are the main causes of food spoilage, antimicrobial and antioxidant properties of natural additives are discussed, including perspective ones for the development of biodegradable active packaging.

Valorization of Seafood Waste for Food Packaging Development

Packaging plays a crucial role in protecting food by providing excellent mechanical properties as well as effectively blocking water vapor, oxygen, oil, and other contaminants. The low degradation of widely used petroleum-based plastics leads to environmental pollution and poses health risks. This has drawn interest in renewable biopolymers as sustainable alternatives. The seafood industry generates significant waste that is rich in bioactive substances like chitin, chitosan, gelatins, and alginate, which can replace synthetic polymers in food packaging. Although biopolymers offer biodegradability, biocompatibility, and non-toxicity, their films often lack mechanical and barrier properties compared with synthetic polymer films. This comprehensive review discusses the chemical structure, characteristics, and extraction methods of biopolymers derived from seafood waste and their usage in the packaging area as reinforcement or base materials to guide researchers toward successful plastics replacement and commercialization. Our review highlights recent advancements in improving the thermal durability, mechanical strength, and barrier properties of seafood waste-derived packaging, explores the mechanisms behind these improvements, and briefly mentions the antimicrobial activities and mechanisms gained from these biopolymers. In addition, the remaining challenges and future directions for using seafood waste-derived biopolymers for packaging are discussed. This review aims to guide ongoing efforts to develop seafood waste-derived biopolymer films that can ultimately replace traditional plastic packaging.

Insights into chemistry, extraction and industrial application of lemon grass essential oil -A review of recent advances

Lemongrass essential oil (LEO), extracted from high-oil lemongrass, gains prominence as a versatile natural product due to growing demand for safe health solutions. LEO comprises beneficial compounds like citral, isoneral, geraniol, and citronellal, offering diverse pharmacological benefits such as antioxidant, antifungal, antibacterial, antiviral, and anticancer effects. LEO finds applications in food preservation, cosmetics, and pharmaceuticals, enhancing profitability across these sectors. The review focuses on the extraction of LEO, emphasizing the need for cost-effective methods. Ultrasound and supercritical fluid extraction are effective in reducing extraction time, increasing yields, and enhancing oil quality. LEO shows promise as a valuable natural resource across industries, with applications in packaging, coating, and film development. LEO's ability to extend the shelf life of food items and impart natural flavors positions it as a valuable asset. Overall, the review emphasizes LEO's therapeutic, antimicrobial, and antioxidant properties, strengthening its potential in the food, pharmaceutical, and cosmetic sectors.

Seaweed as Basis of Eco-Sustainable Plastic Materials: Focus on Alginate

Seaweed, a diverse and abundant marine resource, holds promise as a renewable feedstock for bioplastics due to its polysaccharide-rich composition. This review explores different methods for extracting and processing seaweed polysaccharides, focusing on the production of alginate plastic materials. Seaweed emerges as a promising solution, due to its abundance, minimal environmental impact, and diverse industrial applications, such as feed and food, plant and soil nutrition, nutraceutical hydrocolloids, personal care, and bioplastics. Various manufacturing techniques, such as solvent casting, injection moulding, and extrusion, are discussed for producing seaweed-based bioplastics. Alginate, obtained mainly from brown seaweed, is particularly known for its gel-forming properties and presents versatile applications in many sectors (food, pharmaceutical, agriculture). This review further examines the current state of the bioplastics market, highlighting the growing demand for sustainable alternatives to conventional plastics. The integration of seaweed-derived bioplastics into mainstream markets presents opportunities for reducing plastic pollution and promoting sustainability in material production.

Antimicrobial Packaging for Plum Tomatoes Based on ZnO Modified Low-Density Polyethylene

Food safety and quality are major concerns in the food industry. Despite numerous studies, polyethylene remains one of the most used materials for packaging due to industry reluctance to invest in new technologies and equipment. Therefore, modifications to the current materials are easier to implement than adopting whole new solutions. Antibacterial activity can be induced in low-density polyethylene films only by adding antimicrobial agents. ZnO nanoparticles are well known for their strong antimicrobial activity, coupled with low toxicity and UV shielding capability. These characteristics recommend ZnO for the food industry. By incorporating such safe and dependable antimicrobial agents in the polyethylene matrix, we have obtained composite films able to inhibit microorganisms' growth that can be used as packaging materials. Here we report the obtaining of highly homogenous composite films with up to 5% ZnO by a melt mixing process at 150 °C for 10 min. The composite films present good transparency in the visible domain, permitting consumers to visualize the food, but have good UV barrier properties. The composite films exhibit good antimicrobial and antibiofilm activity from the lowest ZnO composition (1%), against both Gram-positive and Gram-negative bacterial strains. The homogenous dispersion of ZnO nanoparticles into the polyethylene matrix was assessed by Fourier transform infrared microscopy and scanning electron microscopy. The optimal mechanical barrier properties were obtained for composition with 3% ZnO. The thermal analysis indicates that the addition of ZnO nanoparticles has increased thermal stability by more than 100 °C. The UV-Vis spectra indicate a low transmittance in the UV domain, lower than 5%, making the films suitable for blocking photo-oxidation processes. The obtained films proved to be efficient packaging films, successfully preserving plum (Rome) tomatoes for up to 14 days.

Microbiological and Physicochemical Evaluation of Hydroxypropyl Methylcellulose (HPMC) and Propolis Film Coatings for Cheese Preservation

Dairy products are highly susceptible to contamination from microorganisms. This study aimed to evaluate the efficacy of hydroxypropyl methylcellulose (HPMC) and propolis film as protective coatings for cheese. For this, microbiological analyses were carried out over the cheese' ripening period, focusing on total mesophilic bacteria, yeasts and moulds, lactic acid bacteria, total coliforms, Escherichia coli, and Enterobacteriaceae. Physicochemical parameters (pH, water activity, colour, phenolic compounds content) were also evaluated. The statistical analysis (conducted using ANOVA and PERMANOVA) showed a significant interaction term between the HPMC film and propolis (factor 1) and storage days (factor 2) with regard to the dependent variables: microbiological and physicochemical parameters. A high level of microbial contamination was identified at the baseline. However, the propolis films were able to reduce the microbial count. Physicochemical parameters also varied with storage time, with no significant differences found for propolis-containing films. Overall, the addition of propolis to the film influenced the cheeses' colour and the quantification of phenolic compounds. Regarding phenolic compounds, their loss was verified during storage, and was more pronounced in films with a higher percentage of propolis. The study also showed that, of the three groups of phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), hydroxycinnamic acids showed the most significant losses. Overall, this study reveals the potential of using HPMC/propolis films as a coating for cheese in terms of microbiological control and the preservation of physicochemical properties.

Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films

The use of processed limestone sludge as a crosslinking agent for films based on Na-alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbitol concentrations of 0.0, 0.5 and 1.0 wt%. The limestone sludge waste obtained from the processing of quarried limestone was converted into an aqueous solution of Ca2+ by dissolution with mineral acid. This solution was then diluted in water and used to induce gel crosslinking. The necessity of using sorbitol as a component of the crosslinking solution was also assessed. The resulting films were characterized regarding their dimensional stability, microstructure, chemical structure, mechanical performance and antifungal properties. Alginate/sorbitol films displayed poor dimensional stability and were deemed not viable. Carrageenan/alginate/sorbitol films exhibited higher dimensional stability and smooth and flat surfaces, especially in compositions with 0.5 wt% sorbitol. However, an increasing amount of plasticizer appears to result in severe surface cracking, the development of a segregation phenomenon affecting carrageenan and an overall decrease in films' mechanical resistance. Although further studies regarding film composition-including plasticizer fraction, film optimal thickness and film/mold material interaction-are mandatory, the attained results show the potential of the reported ɩ-carrageenan/alginate/sorbitol films to be used towards the development of viable films derived from algal polysaccharides.

Anionic species from multivalent metal salts are differentially retained during aqueous ionic gelation of sodium alginate and could fine-tune the hydrogel properties

The role of anionic counterions of divalent metal salts in alginate gelation and hydrogel properties has been thoroughly investigated. Three anions were selected from the Hofmeister series, namely sulphate, acetate and chloride, paired in all permutations and combinations with divalent metal cations like calcium, zinc and copper. Spectroscopic analysis revealed the presence of anions and their interaction with the respective metal cations in the hydrogel. The data showed that the gelation time and other hydrogel properties were largely controlled by cations. However, subtle yet significant variations in viscoelasticity, water uptake, drug release and cytocompatibility properties were anion dependent in each cationic group. Computational modelling based study showed that metal-anion-alginate configurations were energetically more stable than the metal-alginate models. The in vitro and in silico studies concluded that acetate anions preceded chlorides in the drug release, swelling and cytocompatibility fronts, followed by sulphate anions in each cationic group. Overall, the data confirmed that anions are an integral part of the metal-alginate complex. Furthermore, anions offer a novel option to further fine-tune the properties of alginate hydrogels for myriads of applications. In addition, full exploration of this novel avenue would enhance the usability of alginate polymers in the pharmaceutical, environmental, biomedical and food industries.

Application of Plant Oils as Functional Additives in Edible Films and Coatings for Food Packaging: A Review

Increasing environmental concerns over using petroleum-based packaging materials in the food industry have encouraged researchers to produce edible food packaging materials from renewable sources. Biopolymer-based edible films and coatings can be implemented as bio-based packaging materials for prolonging the shelf life of food products. However, poor mechanical characteristics and high permeability for water vapor limit their practical applications. In this regard, plant oils (POs) as natural additives have a high potential to overcome certain shortcomings related to the functionality of edible packaging materials. In this paper, a summary of the effects of Pos as natural additives on different properties of edible films and coatings is presented. Moreover, the application of edible films and coatings containing POs for the preservation of different food products is also discussed. It has been found that incorporation of POs could result in improvements in packaging's barrier, antioxidant, and antimicrobial properties. Furthermore, the incorporation of POs could significantly improve the performance of edible packaging materials in preserving the quality attributes of various food products. Overall, the current review highlights the potential of POs as natural additives for application in edible food packaging materials.

Lipid incorporated biopolymer based edible films and coatings in food packaging: A review

In the evolving landscape of food packaging, lipid-based edible films and coatings are emerging as a sustainable and effective solution for enhancing food quality and prolonging shelf life. This critical review aims to offer a comprehensive overview of the functional properties, roles, and fabrication techniques associated with lipid-based materials in food packaging. It explores the unique advantages of lipids, including waxes, resins, and fatty acids, in providing effective water vapor, gas, and microbial barriers. When integrated with other biopolymers, such as proteins and polysaccharides, lipid-based composite films demonstrate superior thermal, mechanical, and barrier properties. The review also covers the application of these innovative coatings in preserving a wide range of fruits and vegetables, highlighting their role in reducing moisture loss, controlling respiration rates, and maintaining firmness. Furthermore, the safety aspects of lipid-based coatings are discussed to address consumer and regulatory concerns.

An Edible Antibacterial Coating Integrating Lytic Bacteriophage Particles for the Potential Biocontrol of Salmonella enterica in Ripened Cheese

The goal of this research was to create an antibacterial biopolymeric coating integrating lytic bacteriophages against Salmonella enterica for use in ripened cheese. Salmonella enterica is the main pathogen that contaminates food products and the food industry. The food sector still uses costly and non-selective decontamination and disease control methods. Therefore, it is necessary to look for novel pathogen biocontrol technologies. Bacteriophage-based biocontrol seems like a viable option in this situation. The results obtained show promise for food applications since the edible packaging developed (EdiPhage) was successful in maintaining lytic phage viability while preventing the contamination of foodstuff with the aforementioned bacterial pathogen.

Natural polysaccharides and proteins-based films for potential food packaging and mulch applications: A review

Conventional nondegradable packaging and mulch films, after reaching the end of their use, become a major source of waste and are primarily disposed of in landfills. Accumulation of non-degradable film residues in the soil leads to diminished soil fertility, reduced crop yield, and can potentially affect humans. Application of degradable films is still limited due to the high cost, poor mechanical, and gas barrier properties of current biobased synthetic polymers. In this respect, natural polysaccharides and proteins can offer potential solutions. Having versatile functional groups, three-dimensional network structures, biodegradability, ease of processing, and the potential for surface modifications make polysaccharides and proteins excellent candidates for quality films. Besides, their low-cost availability as industrial waste/byproducts makes them cost-effective alternatives. This review paper covers the performance properties, cost assessment, and in-depth analysis of macromolecular structures of some natural polysaccharides and proteins-based films that have great potential for packaging and mulch applications. Proper dissolution of biopolymers to improve molecular interactions and entanglement, and establishment of crosslinkages to form an ordered and cohesive polymeric structure can help to obtain films with good properties. Simple aqueous-based film formulation techniques and utilization of waste/byproducts can stimulate the adoption of affordable biobased films on a large-scale.

Undenatured type II collagen nanofibrils with sodium alginate coating: Structural characterization, physicochemical properties and capability to load curcumin

In this study, the structural design and physicochemical property enhancement of undenatured type II collagen (UC-II) nanofibrils with sodium alginate (SA) coating induced by calcium ions (Ca2+) were investigated. The research aimed to elucidate the impact of Ca2+ concentration on the morphology, thermal stability, and digestive resistance, as well as to assess the potential of UC-II/SA nanofibrils as a delivery system for curcumin (Cur). A series of Ca2+ concentrations (1-9 mM) were methodically applied to optimize the condition that maintains the triple-helical structure of UC-II, thereby enhancing its functional properties. It was found that the Ca2+ level up to 5 mM effectively preserved the structural integrity and improved thermal stability of UC-II, with the added benefit of ensuring the substantial delivery of active fragment to small intestine (70.7 %), which was 3.43 times greater than that of uncoated UC-II. Moreover, incorporating Cur into the UC-II/SA nanofibrils resulted in a 300 times increase in Cur solubility and showcased the superior dispersion stability, antioxidant activity, and sustained release profile during simulated digestion. These findings underscored the dual functionality of the UC-II/SA system as both a stabilizing agent for UC-II nanofibrils and an efficient carrier for Cur delivery.

Limosilactobacillus fermentum Strains as Novel Probiotic Candidates to Promote Host Health Benefits and Development of Biotherapeutics: A Comprehensive Review

Fruits and their processing by-products are sources of potentially probiotic strains. Limosilactobacillus (L.) fermentum strains isolated from fruit processing by-products have shown probiotic-related properties. This review presents and discusses the results of the available studies that evaluated the probiotic properties of L. fermentum in promoting host health benefits, their application by the food industry, and the development of biotherapeutics. The results showed that administration of L. fermentum for 4 to 8 weeks promoted host health benefits in rats, including the modulation of gut microbiota, improvement of metabolic parameters, and antihypertensive, antioxidant, and anti-inflammatory effects. The results also showed the relevance of L. fermentum strains for application in the food industry and for the formulation of novel biotherapeutics, especially nutraceuticals. This review provides evidence that L. fermentum strains isolated from fruit processing by-products have great potential for promoting host health and indicate the need for a translational approach to confirm their effects in humans using randomized, double-blind, placebo-controlled trials.

Smart and UV-Resistant Edible Coating and Films Based on Alginate, Whey Protein, and Curcumin

In this work, smart edible coating and films with excellent UV barrier properties were prepared from alginate, whey protein isolate, and curcumin. The primary focus of this investigation centered on assessing the impact of whey protein and curcumin on the physical and functional properties of the alginate films. Whey protein reduced the film transparency while simultaneously enhancing the hydrophobicity and antioxidant properties of the alginate film. Curcumin imparted a yellow hue to the film, consequently decreasing the transparency of the film. It also substantially improved hydrophobicity, antioxidant activity, and UV-blocking efficiency within the films. Remarkably, curcumin demonstrated a significant reduction in the water vapor transmission rate of the film. For the preservation of apples, a higher concentration of curcumin was required, which effectively suppressed the respiration rate and moisture loss post-harvest, resulting in an extended shelf-life for the apples. As a result, the coated apples exhibited significantly reduced enzymatic browning and weight loss in comparison to their uncoated counterparts. Furthermore, these curcumin-containing films underwent a reversible color change from orange to red when exposed to ammonia vapor. This attribute highlights the potential of the developed coating and film as a smart, active food packaging solution, particularly for light-sensitive food products.