Advances in sustainable food packaging applications of chitosan/polyvinyl alcohol blend films.

Researchers are addressing environmental concerns related to petroleum-based plastic packaging by exploring biopolymers from natural sources, chemical synthesis, and microbial fermentation. Despite the potential of individual biopolymers, they often exhibit limitations like low water resistance and poor mechanical properties. Blending polymers emerges as a promising strategy to overcome these challenges, creating films with enhanced performance. This review focuses on recent advancements in chitosan/polyvinyl alcohol (PVA) blend food packaging films. It covers molecular structure, properties, strategies for performance improvement, and applications in food preservation. The blend's excellent compatibility and intermolecular interactions make it a promising candidate for biodegradable films. Future research should explore large-scale thermoplastic technologies and investigate the incorporation of additives like natural extracts and nanoparticles to enhance film properties. Chitosan/PVA blend films offer a sustainable alternative to petroleum-based plastic packaging, with potential applications in practical food preservation.

Recent progress in pectin extraction, characterization, and pectin-based films for active food packaging applications: A review.

Pectin is an abundant complex polysaccharide obtained from various plants. Safe, biodegradable, and edible pectin has been extensively utilized in the food industry as a gelling agent, thickener, and colloid stabilizer. Pectin can be extracted in a variety of ways, thus affecting its structure and properties. Pectin's excellent physicochemical properties make it suitable for many applications, including food packaging. Recently, pectin has been spotlighted as a promising biomaterial for manufacturing bio-based sustainable packaging films and coatings. Functional pectin-based composite films and coatings are useful for active food packaging applications. This review discusses pectin and its use in active food packaging applications. First, basic information and characteristics of pectin, such as the source, extraction method, and structural characteristics, were described. Then, various methods of pectin modification were discussed, and the following section briefly described pectin's physicochemical properties and applications in the food sector. Finally, the recent development of pectin-based food packaging films and coatings and their use in food packaging were comprehensively discussed.

Gelatin/poly(vinyl alcohol)-based functional films integrated with spent coffee ground-derived carbon dots and grapefruit seed extract for active packaging application.

Nanoparticles are attractive, functional additives with great potential to be applied in biomaterial and food packaging. However, these particles are not soluble in water, thus limiting their widespread application. Here, we report a facile fabrication of carbon dots (CDs) using the spent coffee ground as the carbon source through a hydrothermal method. The CD was added to the gelatin/poly(vinyl alcohol) (Gel/PVA) film and grapefruit seed extract (GSE) to prepare multifunctional packaging films. The functional films' physiochemical and functional properties and packaging application were investigated. The composite film showed good UV protection properties with a slight decrease in transparency. The composite film containing CD/GSE showed strong antioxidant activity, scavenging >38 % DPPH and 100 % ABTS radicals. The film also exhibited significant antibacterial activity against the foodborne pathogens Listeria monocytogenes and Escherichia coli, completely eradicating the growth of these bacteria within 9 h of exposure. The CD/GSE-incorporated Gel/PVA films were used for pork packaging. The films were able to enhance the pork shelf life by reducing the L. monocytogenes bacterial growth in meat by 2 Log CFU/mL lower than the control wrapping film. The multifunctional Gel/PVA films are expected to be used for the active packaging of meat products.

Grapefruit Seed Extract-Added Functional Films and Coating for Active Packaging Applications: A Review.

Recently, consumers have been increasingly inclined towards natural antimicrobials and antioxidants in food processing and packaging. Several bioactive compounds have originated from natural sources, and among them, grapefruit seed extract (GSE) is widely accepted and generally safe to use in food. GSE is a very commonly used antimicrobial in food; lately, it has also been found very effective as a coating material or in edible packaging films. A lot of recent work reports the use of GSE in food packaging applications to ensure food quality and safety; therefore, this work intended to provide an up-to-date review of GSE-based packaging. This review discusses GSE, its extraction methods, and their use in manufacturing food packaging film/coatings. Various physical and functional properties of GSE-added film were also discussed. This review also provides the food preservation application of GSE-incorporated film and coating. Lastly, the opportunities, challenges, and perspectives in the GSE-added packaging film/coating are also debated.

Fabrication of Antioxidant and Antimicrobial Pullulan/Gelatin Films Integrated with Grape Seed Extract and Sulfur Nanoparticles.

Biopolymer-based functional blend films were prepared using pullulan and gelatin with functional fillers of sulfur nanoparticles (SNPs) and grape seed extract (GSE). A mixture of pullulan/gelatin (1:1) produced a compatible but slightly translucent free-standing film. SNPs capped with enoki mushroom extract and GSE were added as functional fillers to improve the properties (physical and functional) of the pullulan/gelatin-based film. The addition of SNP and GSE significantly (p < 0.05) boosted the UV-light barrier, water vapor barrier, and oxygen barrier properties of the pullulan/gelatin films. The mechanical performance of the pullulan/gelatin-based films was slightly decreased (∼10%), whereas the addition of fillers did not significantly affect the hydrophobicity and thermal stability. The addition of SNP provided the antimicrobial function against foodborne pathogenic bacteria, L. monocytogenes and E. coli, while GSE provided a powerful antioxidant activity to the pullulan/gelatin-based film. Therefore, pullulan/gelatin-based composite films with better UV, water vapor, and oxygen barrier properties and enhanced antioxidant and antibacterial properties are expected to have high utility in active food packaging applications.

Carrageenan/agar-based functional film integrated with zinc sulfide nanoparticles and Pickering emulsion of tea tree essential oil for active packaging applications.

A functional carrageenan/agar-based film was prepared by combining tea tree oil Pickering emulsion (PET) and zinc sulfide nanoparticles (ZnSNP). PET was formulated using tea tree essential oil stabilized with nanocellulose fibers. PET and ZnSNPs were uniformly dispersed in the binary polymer matrix and formed compatible films. The incorporation of ZnSNPs improved the mechanical strength, whereas PET slightly decreased the strength, but the combined addition of ZnSNP and PET maintained the mechanical strength with slightly improved flexibility. The addition of ZnSNP and PET, alone or in combination, slightly improved the water vapor barrier, water resistance, and thermal stability of the film. In addition, the carrageenan/agar-based composite membrane showed distinct antioxidant and antibacterial activity. The ZnSNP and PET incorporated binary composite films with enhanced physical and functional properties are likely to be used in active food packaging applications.

Preparation of pectin/agar-based functional films integrated with zinc sulfide nano petals for active packaging applications.

Here we report on the robust synthesis of zinc sulfide nanoparticles (ZnSNP) using a simple one-pot reaction. The prepared ZnSNP was characterized and confirmed to be a petal-shaped nanoparticle. The ZnSNP was added to fabricate the pectin/agar-based functional composite film. The integration of ZnSNP has greatly improved the physical properties of the film, such as mechanical and UV protection properties, without significantly changing the transparency of the film. The addition of the nanofillers did not affect the film's hydrophobicity, water vapor barrier, and thermal properties. Moreover, the composite film showed intense antibacterial activity against foodborne pathogenic bacteria, E. coli and L. monocytogenes. The functional bio-nanocomposite films based on pectin/agar have high potential in active packaging applications.

Pectin/pullulan blend films for food packaging: Effect of blending ratio.

Edible films were prepared using various pectin and pullulan mixing ratios and evaluated for their properties in food packaging applications. FTIR characterization showed that an intermolecular H-bond was formed between the hydroxyl group of pullulan and the carboxyl group of pectin. As observed by FE-SEM, as the pullulan content increased, the film's surface became smoother and formed a film with a denser structure, leading to an increased water vapor barrier. The blend film with a 50:50 ratio of pullulan and pectin exhibited the highest thermal stability and surface hydrophobicity. Blending also increased strength while maintaining flexibility and stiffness compared to the individual films. Besides, the films with ratios above 50:50 displayed the least water and oil absorption values.

Fabrication of Carboxymethyl Cellulose/Agar-Based Functional Films Hybridized with Alizarin and Grapefruit Seed Extract.

Carboxymethyl cellulose/agar-based functional halochromic films were fabricated by adding alizarin and grapefruit seed extract (GSE). The fillers were evenly dispersed in the polymer matrix to form compatible composite films. The addition of alizarin has improved the film's mechanical strength (20%) and water resistance (40%) with potent antioxidant and excellent color indicating properties. In contrast, GSE has imparted strong antibacterial and antioxidant activities to the film. Also, the addition of alizarin and GSE slightly improved the water vapor barrier properties but did not affect the thermal stability of the film. The composite film also exhibited UV blocking properties with adequate transparency. The composite film showed an excellent pH-dependent color change with color reversibility and color stability and a volatile gas detection function. The film also showed potent antimicrobial activity against foodborne pathogenic bacteria, Escherichia coli and Listeria monocytogenes, and showed an intense antioxidant action.

pH-responsive pectin-based multifunctional films incorporated with curcumin and sulfur nanoparticles.

pH-responsive pectin-based functional films have been prepared by incorporating curcumin and sulfur nanoparticles (SNP). FTIR and SEM results indicated that curcumin and SNP were uniformly dispersed in the pectin to form a well-developed composite film. Addition of curcumin and SNP significantly influenced the surface color and UV-blocking properties of the composite films. The composite films showed a higher water contact angle and thermal stability compared with the neat pectin film, however, the mechanical and water vapor barrier properties did not change significantly. The composite film exhibited antibacterial activity against E. coli and L. monocytogenes, and strong antioxidant activity. When applied to shrimp packaging, the film showed a pH-responsive highly distinctive color change from yellow to orange as the quality of the shrimp changed.

Preparation of multifunctional carboxymethyl cellulose-based films incorporated with chitin nanocrystal and grapefruit seed extract.

Chitin nanocrystals (ChNC) were isolated from shrimp shells powder using acid hydrolysis and ammonium persulfate methods. Multifunctional carboxymethyl cellulose (CMC) composite films were prepared by adding ChNC and grapefruit seed extract (GSE), and their effects on the optical, mechanical, water vapor barrier, and antibacterial properties of CMC film were investigated. The isolated ChNC had a needle-like structure with a length of 340-370 nm and a diameter of 18-20 nm depending on the isolation method. The CMC films prepared with ChNC and GSE were transparent with high UV barrier properties. The addition of GSE reduced the strength (TS) and stiffness (EM) of CMC films by 10.4% and 30.3%, respectively, while the flexibility (EB) increased by 17.7%. However, when the ChNC was added, the TS and EM of CMC film increased by 19.7% and 58.7%, respectively, and the EB remained the same. The addition of ChNC reduced the water vapor permeability (WVP) of the CMC film by 27%. CMC films containing GSE also showed strong antibacterial activity against foodborne pathogenic bacteria, E. coli and L. monocytogenes.

Carrageenan-based functional hydrogel film reinforced with sulfur nanoparticles and grapefruit seed extract for wound healing application.

κ-Carrageenan-based (Carr) functional wound healing hydrogel films were prepared by incorporating chitosan capped sulfur nanoparticles (SNP) and grapefruit seed extract (GSE). In vivo wound healing effect of the hydrogel films was tested using artificially wounded male Sprague-Dawley rats. The hydrogel film (Carr/GSE/SNP) showed higher mechanical strength, swelling ratio and ultraviolet barrier properties than the carrageenan film, but the water vapor permeability and water solubility were decreased. The hydrogel film showed antibacterial activity strong enough to destroy Staphylococcus epidermis and Escherichia coli within 3 h of incubation and showed high biocompatibility against mouse fibroblast (L929 cell lines). The hydrogel film (Carr/GSE/SNP3%) showed excellent wound healing effect (1.3% wound area after 2 weeks) compared to the control group (31% wound area after 2 weeks) through in vivo wound healing test. Histological examination showed the complete appearance of the healed epidermis. The Carr/GSE/SNP hydrogel films are most likely to be used for the treatment of full-thickness wounds.

Preparation of antibacterial poly(lactide)/poly(butylene adipate-co-terephthalate) composite films incorporated with grapefruit seed extract.

Antimicrobial poly(lactide) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend films incorporated with grapefruit seed extract (GSE) were prepared using a solvent casting method. Effect of GSE on the morphological, water vapor barrier, thermostability, color, optical, and antimicrobial properties of PLA/PBAT composite films was investigated. The composite films showed a yellowish tint after incorporation of GSE and exhibited a high UV-light barrier property. Incorporation of GSE increased the flexibility and tensile strength of the composite films. Films incorporated with 7 wt% of GSE exhibited potent antibacterial activity against Listeria monocytogenes, but they showed only bacteriostatic activity against Escherichia coli. The PLA/PBAT-GSE composite film with UV-light barrier and antibacterial properties has a high potential for an active food packaging application.

Alginate-based nanocomposite films reinforced with halloysite nanotubes functionalized by alkali treatment and zinc oxide nanoparticles.

Functionalized halloysite nanotubes were prepared by surface activation of halloysite (Hal) with sodium hydroxide and deposition of zinc oxide nanoparticles (ZnONP). The surface charge of Hal was changed from 0.18 ±â€¯0.6 mV to -35.2 ±â€¯2.8 mV after alkali treatment. The functionalized Hal (AT-Hal/ZnONP) was incorporated into alginate biopolymer as a reinforcing filler with different concentration of AT-Hal/ZnONP (1, 3, 5, and 7 wt% of alginate). Alginate films with AT-Hal/ZnONP exhibited a significant increase in the mechanical, water vapor barrier, and UV light barrier properties. The thermal stability of composite films has not changed after AT-Hal/ZnONP incorporation. The AT-Hal/ZnONP incorporated alginate films demonstrated strong antibacterial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes. The nanocomposite film with 7 wt% of AT-Hal/ZnONP exhibited complete sterilization of E. coli and L. monocytogenes after 3 and 9 h of treatment, respectively.

Antimicrobial wrapping paper coated with a ternary blend of carbohydrates (alginate, carboxymethyl cellulose, carrageenan) and grapefruit seed extract.

A functional biopolymer-coated paper was prepared by coating a ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) for the substitute use of synthetic polymer-coated paper. The microstructure of the surface and cross-section of the coated paper analyzed by field emission scanning electron microscope (FE-SEM) indicated that the biopolymer was compatible with the base paper and filled the pores of the porous fiber to make a smooth-surfaced coating paper. The properties of the biopolymer-coated paper, such as water and oil resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with not only the base paper but also commercially used PE-coated paper. The blended biopolymer coating material exhibited strong antibacterial activity against food-borne pathogenic bacteria, Listeria monocytogenes and Escherichia coli, which were destroyed completely within 3 and 9 h, respectively. The packaging test for a minced fish cake packed with the biopolymer-coated paper showed the complete destruction of surface inoculated bacteria in 6-9 days. The biopolymer-coated paper showed a high potential for disposable food packaging applications to increase the shelf-life of packaged food.

Preparation of pectin/silver nanoparticles composite films with UV-light barrier and properties.

Silver nanoparticles (AgNPs) was synthesized by a green method using an aqueous extract of Caesalpinia mimosoides Lamk (CMLE) as reducing and stabilizing agents, and they were used for the preparation of pectin-based antimicrobial composite films. The AgNPs were spherical in shape with the size in the range of 20-80nm and showed the absorption peak around 500nm. The pectin/AgNPs composite film exhibited characteristic absorption peak of AgNPs at 480nm. The surface color and light transmittance of the pectin films were greatly influenced by the addition of AgNPs. The lightness of the films decreased, however, redness and yellowness of the films increased after incorporation of AgNPs. UV-light barrier property of the pectin film increased significantly with a little decrease in the transparency. Though there were no structural changes in the pectin film by the incorporation of CMLE and AgNPs as indicated by the FTIR results, the film properties such as thermal stability, mechanical strength, and water vapor barrier properties of the pectin films increased. The pectin/AgNPs nanocomposite films exhibited strong antibacterial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes.

Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity.

Development and characterization of carrageenan/grapefruit seed extract composite films for active packaging.

Carrageenan-based antimicrobial films were developed by incorporation of grape fruit seed extract (GSE) at different concentration into the polymer using a solvent casing method and their physical, mechanical, and antimicrobial properties were examined. The carrageenan/GSE composite films appeared yellowish tint due to the polyphenolic compounds in the GSE. SEM analysis showed rough surface with sponge like structures on the cross section of the films. FT-IR results indicated at GSE had good compatibility with carrageenan. The amorphous structure of polymer films was not changed by the incorporation of GSE. But, the addition of GSE increased moisture content, water vapor permeability, and surface hydrophilicity of the films. The tensile strength and elastic modulus decreased with increasing content of GSE, however, the elongation at break increased significantly up to 6.6µg/mL of GSE then decreased thereafter. Thermal stability of the films was not influenced by GSE incorporation. The carrageenan/GSE composite films exhibited great antibacterial activity against food borne pathogens. These results suggest that the carrageenan-based composite films have a high potential for being used as an antimicrobial or active food packaging applications.

Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 µg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food.