Development of active packaging with chitosan, guar gum and watermelon rind extract: Characterization, application and performance improvement mechanism

Effect of polydimethylsiloxane on the structure and barrier properties of starch/PBAT composite films

This study aimed to investigate the effects of polydimethylsiloxane (PDMS) with a low surface energy on the structure and physicochemical properties of starch/poly (butylene adipate-co-terephthalate) (PBAT) blown films. The film's appearance was not significantly changed after the addition of PDMS. Compared with the films without PDMS, the films with PDMS displayed a smoother surface. A 2% w/w PDMS addition resulted in the maximum mechanical properties (8.10 MPa of strength, 211.00% of modulus) and surface hydrophobicity (87°) of the films. By contrast, the film with 3% w/w PDMS showed the lowest light transmittance, water vapor (2.73 × 10-11 g·cm·cm2·s-1·Pa-1) and oxygen permeability (9.73 × 10-13·cm3·cm·cm-2·s-1·Pa-1), owing to the improved tightness of the matrix, which increased the zigzag path for molecules to pass through. Films with higher PDMS contents effectively extended the shelf life of packaged bananas and shiitake mushrooms, benefiting from the outstanding and appropriate barrier properties, according to principal component analysis results. Findings supported that high-content starch/PBAT films containing PDMS had potential in the preservation of fresh agricultural products.

Development of active film based on collagen and hydroxypropyl methylcellulose incorporating apple polyphenol for food packaging

Collagen (COL)-hydroxypropyl methylcellulose (HPMC) blended films with apple polyphenol (AP) as cross-linking agent and antioxidant compound were developed to produce biodegradable active packaging film. The effects of AP content on the rheological behavior of the blended solution, the structure, physicochemical and functional properties of the blended film were systematically investigated. The incorporation of AP increased the viscosity and reduced the fluidity of COL-HPMC solution. The results of rheological tests and FTIR analysis manifested the formation of hydrogen bonding interactions between collagen, HPMC and AP, which made the structures of COL-HP-AP films more compact. The mechanical strength, UV-blocking ability, water-resistance performance and thermostability were gradually enhanced as increasing AP content. DPPH free radical scavenging experiment showed that a small amount of AP could efficiently improve the antioxidant activity of COL-HP film, and with increasing AP content to 5 wt%, the scavenging rate was as high as 94.23 %. Active film containing 5 wt% AP showed obvious antibacterial effect on E. coli and S. aureus, and it could effectively prevent the oxidation of vitamin C and reduce the accumulation of MDA on green pepper during the storage. COL-HP-AP films have great potential in food packaging field for extending the shelf life of food.

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

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

Properties of modified chitosan-based films and coatings and their application in the preservation of edible mushrooms: A review

Edible mushrooms are prone to deteriorate during storage. A Single chitosan film or coating has limitations in preservation. Therefore, this article focused on the improvement of modified chitosan-based films and coatings on properties related to storage quality of edible mushrooms (e.g.: safety, barrier, mechanical, antioxidant and antibacterial properties). Besides, the application of chitosan-based materials in the preservation of mushrooms was also discussed. The modified chitosan film and coating can slow down the respiration of mushrooms, inhibit the growth of microorganisms, protect antioxidant compositions, and regulate the activity of related enzymes, thus improving the quality and prolonging the shelf life of mushrooms. Meanwhile, the added ingredients improve the water and gas barrier properties of chitosan through volume and group occupation, and reduce the light transmittance of chitosan through light transmission, scattering and absorption. Essential oils and polyphenolic compounds had a better enhancement of antioxidant and antimicrobial properties of chitosan.

Preparation and characterization of biodegradable food packaging films using lemon peel pectin and chitosan incorporated with neem leaf extract and its application on apricot fruit

The present study aims to develop and characterize biodegradable packaging films from lemon peel-derived pectin and chitosan incorporated with a bioactive extract from neem leaves. The films (PCNE) contained varying concentrations of neem leaf extract and were comprehensively assessed for their physical, optical, mechanical, and antimicrobial attributes. The thickness, moisture content, water solubility, and water vapor permeability of the biodegradable packaging films increased with the increasing concentration of neem leaf extract. Comparatively, the tensile strength of the films decreased by 42.05 % compared to the control film. The Scanning Electron Microscopy (SEM) confirmed that the resultant blended pectin-chitosan films showed a uniform structure without cracks. Furthermore, the analysis targeting Staphylococcus aureus and Aspergillus niger indicated that the films had potent antimicrobial activity. Based on these results, the optimum films were selected and subsequently applied on apricot fruits to increase their shelf life at ambient temperature. The findings, after examining factors such as colour, firmness, total soluble solids, shrinkage, weight loss, and appearance, concluded that the apricots coated by PCNE-5 had the most delayed signs of spoilage and increased their shelf life by 50 %. The results showed the potential applicability of lemon peel pectin-chitosan-neem leaf extract blend films in biodegradable food packaging.

Tannic acid crosslinked chitosan-guar gum composite films for packaging application

Chitosan (CH)-guar gum (GG) composite films crosslinked with tannic acid (TnA) were prepared by solution casting method. The films were then immersed in 5 % aqueous NH3 and dried again. They were characterized by IR spectroscopy, wide angle x-ray diffraction and thermogravimetric analysis. All the films were studied for physicochemical properties such as moisture content, swelling, solubility in water, water contact angle, water vapor permeability, opacity, tensile strength and antioxidant activity. The physicochemical and mechanical properties of films changed significantly when compared to CH as reflected by an increase in the amorphous domains of the films, a decrease in moisture content, swelling and solubility in water. The films turned hydrophobic with concomitant decrease in moisture content, swelling, water-solubility and exhibited improved UV absorption as well as mechanical strength, which in turn was dependent on the tannic acid concentration. These results along with enhanced antioxidant properties, UV absorption with no significant change in water vapor permeation compared to CH suggested that the films could find application in packaging applications.

Techno-functional properties of active film based on guar gum-propolis and its application for "Nanguo" pears preservation

Guar gum (GG) composite films, incorporating the ethanolic extract of propolis (EEP), were prepared and subjected to a comprehensive investigation of their functional characteristics. The addition of EEP resulted in a discernible enhancement in the opacity, moisture barrier capacity, and elongation at break. Incorporating EEP led to a noteworthy increase in the total phenolic and total flavonoid content of the films, resulting in superior antioxidant capacity upon GG-EEP films. Remarkably, the addition of 5 % EEP yielded noteworthy outcomes, manifesting in a DPPH radical scavenging rate of 47.60 % and the ABTS radical scavenging rate of 94.87 %, as well as FRAP and cupric reducing power of 331.98 mmol FeSO4-7H2O kg-1 and 56.95 μg TE mg-1, respectively. In addition, GG-EEP films demonstrated antifungal effect against Penicillium expansum and Aspergillus niger, along with a sustained antibacterial effect against Escherichia coli and Staphylococcus aureus. GG-EEP films had superior inhibitory ability against Gram-positive bacteria than Gram-negative bacteria. Crucially, GG-EEP composite films played a pivotal role in reducing both lesion diameter and depth, concurrently mitigating weight loss and firmness decline during the storage period of "Nanguo" pears. Therefore, GG-EEP composite films have the considerable potential to serve as advanced and effective active packaging materials for food preservation.

Intelligent packaging based on chitosan/fucoidan incorporated with coleus grass (Plectranthus scutellarioides) leaves anthocyanins and its application in monitoring the spoilage of salmon (Salmo salar L.)

The innovation of this study was to develop a novel biodegradable intelligent packaging based on chitosan/fucoidan combined with different amounts (1, 3 and 5 wt% on chitosan basis) of coleus grass (Plectranthus scutellarioides) leaves anthocyanins (CGL) to monitor the spoilage of salmon (Salmo salar L.). The addition of fucoidan improved the barrier and mechanical properties of the chitosan films (CS) due to hydrogen bonds and intermolecular electrostatic interactions. Moreover, the addition of CGL not only improved the physical properties but also improved the biological activity of chitosan/fucoidan film (CF). The DPPH and ABTS radical scavenging activity of CF contained 5 wt% CGL was 1.83 and 1.75 times than CF, respectively. The inhibition zone size of CF films containing 5 wt% CGL (CF-5%CGL) was approximately 2.04 (Escherichia coli) and 2.16 (Staphylococcus aureus) times higher than that of CF. Moreover, CF-CGL displayed obvious color changes in different pH environments and is highly sensitive to ammonia gas. The CF-CGL has visible color changes during the monitoring of salmon spoilage and extended the shelf life of salmon. According to our findings, CF-CGL film might be employed as a possible intelligent packaging material for monitoring and preserving salmon in the future.

Recent advances in chitosan-based materials; The synthesis, modifications and biomedical applications

The attention to polymer-based biomaterials, for instance, chitosan and its derivatives, as well as the techniques for using them in numerous scientific domains, is continuously rising. Chitosan is a decomposable naturally occurring polymeric material that is mostly obtained from seafood waste. Because of its special ecofriendly, biocompatible, non- toxic nature as well as antimicrobial properties, chitosan-based materials have received a lot of interest in the field of biomedical applications. The reactivity of chitosan is mainly because of the amino and hydroxyl groups in its composition, which makes it further fascinating for various uses, including biosensing, textile finishing, antimicrobial wound dressing, tissue engineering, bioimaging, gene, DNA and drug delivery and as a coating material for medical implants. This study is an overview of the different types of chitosan-based materials which now a days have been fabricated by applying different techniques and modifications that include etherification, esterification, crosslinking, graft copolymerization and o-acetylation etc. for hydroxyl groups' processes and acetylation, quaternization, Schiff's base reaction, and grafting for amino groups' reactions. Furthermore, this overview summarizes the literature from recent years related to the important applications of chitosan-based materials (i.e., thin films, nanocomposites or nanoparticles, sponges and hydrogels) in different biomedical applications.

Production of PVA-chitosan films using green synthesized ZnO NPs enriched with dragon fruit extract envisaging food packaging applications

In this work, the PVA-chitosan composite packaging films doped with biomass-fabricated zinc oxide nanoparticles (ZnO NPs) and dragon fruit waste extract (DFE) were developed for potential use in food packaging applications. ZnO NPs were synthesized using a sustainable method employing C. sinensis waste extract as a reducing agent. Chitosan and PVA were blended in a specific ratio (1: 1 w/w) to obtain a film-forming solution, into which the ZnO NPs and dragon fruit waste extract were incorporated. The resulting solution was cast into films, which were characterized using various analytical techniques. Mechanical properties, water solubility, and thermal stability of the films were also evaluated. The results demonstrated that the incorporation of green ZnO NPs and dragon fruit waste extract enhanced the mechanical strength and thermal stability of the films while reducing water vapor permeability. Moreover, the films exhibited biocidal and excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging properties, indicating their use in the food packaging sector. The production of these films offers a practical approach to produce bioactive food packaging materials. The use of plant extract and waste material as reducing agents can reduce the overall cost of production while providing added benefits, such as antioxidant and antibacterial properties.

Vanillin Cross-Linked Chitosan Film with Controlled Release of Green Tea Polyphenols for Active Food Packaging

We report a novel cross-linked chitosan composite film containing vanillin, glycerol, and green tea extract. The effects of vanillin-mediated cross-linking and the incorporation of antimicrobial green tea polyphenols were investigated. The cross-linking effect, confirmed by Fourier transform infrared (FTIR) analysis, increased the tensile strength of the biopolymer film to 20.9 ± 3 MPa. The release kinetics of polyphenols from the chitosan-vanillin matrix was studied, and we reported an initial burst release (8 h) followed by controlled release (8 to 400 h). It was found that both vanillin and green tea polyphenols were successful inhibitors of foodborne bacteria, with a minimum inhibitory concentration of the tea polyphenols determined as 0.15 mg/mL (Staphylococcus aureus). These active components also displayed strong antioxidant capacities, with polyphenols quenching >80% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals at all concentrations tested. Degradation results revealed that there was a significant (>85%) mass loss of all samples after being buried in compost for 12 weeks. The biopolymeric films, prepared by solvent casting methods, adhere to green chemistry and waste valorization principles. The one-pot recipe reported may also be applied to other cross-linkers and active compounds with similar chemical functionalities. Based on the obtained results, the presented material provides a promising starting point for the development of a degradable active packaging material.

Development and characterization of active packaging based on chitosan/chitin nanofibers incorporated with scallion flower extract and its preservation in fresh-cut bananas

The aim of this study was to develop a novel active packaging using chitosan (CS) and esterified chitin nanofibers (CF) combined with different contents (1, 2 and 4 wt% on CS basis) of scallion flower extract (SFE) to protect banana samples. The addition of CF significantly improved the barrier and mechanical properties of the CS films (p < 0.05) due to hydrogen bonds and electrostatic interactions. Moreover, the addition of SFE not only improved the physical properties of the CS film but also improved the CS film biological activity. The oxygen barrier property and antibacterial ability of CF-4%SFE were approximately 5.3 and 1.9 times higher than those of the CS film, respectively. In addition, CF-4%SFE had strong DPPH radical scavenging activity (74.8 ± 2.3 %) and ABTS radical scavenging activity (84.06 ± 2.08 %). Fresh-cut bananas stored in CF-4%SFE showed less weight loss, starch loss, color and appearance change than those stored in traditional polyethylene film, which indicated that CF-4%SFE was much better at storing fresh-cut bananas than conventional plastic packaging. For these reasons, CF-SFE films have great potential as a candidate to replace traditional plastic packaging and extend the shelf life of packaged foods.