Chitosan/acetylated starch composite films incorporated with essential oils: Physiochemical and antimicrobial properties

Preparation, characterization, and antibacterial properties of a soybean protein isolate/gelatin composite film containing rosemary-modified bentonite and application of fresh lemon slices

To address the rapid deterioration of fruit slices, soy protein isolate (SPI) and gelatin (GEL) composite films were optimized for food packaging using rosemary-modified bentonite (RB) as an active ingredient and glycerol as a plasticizer to enhance flexibility. Composite films with RB demonstrated superior ultraviolet-visible (UV-Vis) light barrier properties, increased opacity, and enhanced mechanical performance, achieving a tensile strength of 2.27 MPa. Barrier properties were significantly improved, with reduced water vapor transmission rate (1.85 × 10-3 g·m-2·s-1) and oxygen permeability (6.69 × 10-3 g·m-2·s-1), alongside elevated hydrophobicity, antibacterial activity, and antioxidant capacity (DPPH scavenging activity: 54.74 %; ABTS scavenging activity: 53.89 %). In preservation trials with fresh lemon slices, RB/SPI/GEL-2 films reduced weight loss to 37.89 %, maintained firmness at 0.99 N, stabilized pH at 3.14, and extended freshness lifetime by delaying mold formation. These results confirm that RB/SPI/GEL films effectively preserve freshness and minimize nutritional loss in lemon slices, demonstrating their feasibility for fruit preservation applications.

Active biodegradable bacterial cellulose films with potential to minimize the plastic pollution: Preparation, antibacterial application, and mechanism

Petroleum-based films have triggered a serious global pollution crisis because they are difficult to recycle, degrade, and reuse. Developing alternative sustainable active films represents a powerful strategy to address these issues. Here, a multifunctional biodegradable bacterial cellulose (BC) film incorporated with guanidine-based polymer (PHGH)/gallic acid (GA) was constructed (termed OBC-PHGH/GA). The resulting OBC-PHGH/GA film exhibited a highly interweaved nanofiber network structure with excellent tensile strength and ductility. The OBC-PHGH/GA film showed an excellent antibacterial effect against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with inhibition efficiencies of ∼99.99 % compared with the OBC film. Moreover, the as-prepared film showed excellent UV-shielding, antioxidant, and antifungal activities, showing great potential in food packaging. More importantly, the OBC-PHGH/GA film can be degraded into safe and reusable sugars, demonstrating outstanding environmental friendliness and sustainability. This work provides a promising and unique strategy for designing and fabricating green active packaging materials.

Recent progress in the source, extraction, activity mechanism and encapsulation of bioactive essential oils

There is growing concern about the potential risks posed by synthetic additives in industrial products, such as foods, cosmetics, agrochemicals, and personal care products. Many plant-derived essential oils (EOs) have been shown to exhibit excellent antibacterial, antifungal, antiviral, and antioxidant activities, and may therefore be used as natural preservatives in these applications. However, most EOs have relatively low water solubility and are prone to chemical degradation during storage. The degradation products of EOs can be toxic and may not be able to fully exert their biological activity, which limits their application. Typically, these challenges can be overcome by encapsulating the essential oil in an appropriate colloid delivery system. This article begins by reviewing the sources, extraction, and activity mechanisms of EOs, and then highlights plant-based encapsulation technologies that can be used to enhance their efficacy. Finally, the potential applications of plant essential oil encapsulation system are discussed.

Influence of pomelo pericarp essential oil on the structural characteristics of gelatin-arrowroot tuber flour-based edible films

The present study examined the comprehensive effects of incorporating pomelo pericarp essential oil (PEO) at varying concentrations (0.5, 1.0, 1.5, and 2.0%) into gelatin-arrowroot tuber flour (GEL-ATF) based edible films and evaluated the influence on various structural properties. ATF was prepared from Maranta arundinacea L. tubers using a carefully controlled method to ensure its quality and suitability as a polysaccharide base in film formulations. The results indicated that adding PEO to the GEL-ATF films decreased L, a, and b color values and increased opacity values, especially at higher PEO concentrations. Furthermore, the appearance of both GEL-ATF and GEL-ATF-PEO films exhibited similar characteristics. Incorporating PEO significantly reduced moisture content and water vapor permeability (WVP), indicating enhanced barrier properties against moisture. Additionally, an increase in PEO concentration resulted in decreased film solubility. A decrease in tensile strength (TS) but an increase in elongation at break (EAB) was observed in the GEL-ATF films with higher PEO concentrations (>1% PEO). Slight variations in thermal degradation patterns with increased PEO addition in GEL-ATF were noticed, while X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR) results of the tested films provided insights into structural and chemical modifications, indicating changes in crystallinity and molecular interactions upon increased PEO concentration in the film compositions. The microstructural observations confirmed that PEO incorporation led to smoother film surfaces, suggesting a more uniform matrix, which could enhance the film's barrier and mechanical properties. Furthermore, applying PEO into GLE-ATF films exhibited strong antimicrobial activity against Bacillus cereus ATCC 11778. Overall, the present study found that the higher PEO (>1%) concentrations significantly influenced the physical and mechanical properties of GEL-ATF-based edible films. This newly developed edible film could be an effective alternative to inedible polymers for sustainable food packaging solutions.

Chitosan, gelatin and pectin based bionanocomposite films with rosemary essential oil as an active ingredient for future foods

Bionanocomposite films of three biopolymers including chitosan, gelatin, and pectin incorporated with rosemary essential oil (REO) were developed and characterized in terms of their physical, structural, mechanical, morphological, antioxidant, and antimicrobial properties. Incorporation of REO showed an increased hydrophobic nature thus, improved water vapor transmission rate (WVTR), tensile strength (TS), elongation-at-break (EAB), and thermal stability significantly (P ≤ 0.05) as compared to the control films. The addition of REO leads to more opaque films with relatively increased microstructural heterogeneity, resulting in an increase in film opacity. Fourier transform infrared spectroscopy (FTIR) and particle size revealed that REO incorporation exhibits high physicochemical stability in chitosan, gelatin, and pectin bionanocomposite films. Incorporation of REO exhibited the highest inhibitory activity against the tested pathogenic strains (Bacillus subtilis and Escherichia coli). Furthermore, the addition of REO increased the inhibitory activity of films against ABTS and DPPH free radicals. Therefore, chitosan, gelatin, and pectin-based bionanocomposite films containing REO as food packaging could act as a potential barrier to extending food shelf life.

Extension of Quality and Shelf Life of Tomatoes Using Chitosan Coating Incorporated with Cinnamon Oil

This study examined the effects of 2% chitosan (CS) coatings incorporated with varying concentrations of cinnamon oil (CO) (0%, 0.5%, 1.0%, and 1.5%) on the extension of the quality and shelf-life of tomatoes stored under ambient conditions. Control samples were untreated and coated with distilled water. All samples were stored for 14 days at 25 ± 1 °C, with quality assessments conducted every two days. The application of CS-CO treatments was notably effective in controlling weight loss (3.91-5.26%) and firmness loss (10.81-16.51 N), sustaining the color index score (11.98-16.78), and stabilizing the total soluble solids (4.64-4.71 brix), titratable acidity (0.374-0.383%), total phenolic content (75.89-81.54 mg/100 g), ascorbic acid concentration (21.64-33.69 mg/100 g), total antioxidant capacity (85.89-91.54%) and pigment levels, particularly chlorophyll (52.80-63.18 mg/100 g), compared to control samples (p < 0.05). Higher CO concentrations (1.0% and 1.5%) in the CS coating maintained a significant level of phytochemicals in the samples compared to the control group, while CS-CO at 0.5% performed similarly in preserving the other physicochemical qualities. Both CS and CS-CO treatments extended the shelf life of the tomatoes up to 14 days (<6.78 log10 CFU/mL), whereas control samples were only viable for storage for 6 days due to higher microbial growth (>7.8 log10 CFU/mL) (p < 0.05). Overall, CS-CO-treated tomatoes demonstrated superior quality preservation and shelf-life enhancement, with a notable improvement in overall qualities as compared to the CS and control samples.

Pulp waste extracted reinforced powder incorporated biodegradable chitosan composite film for enhancing red grape shelf-life

Chitosan (CS) is widely used as a natural biopolymer due to its semi-crystalline structure, good film-forming properties, and easy availability. CS-based composite films are widely used in industry, particularly in the food sector as active food packaging. Despite all of these advantages, their wide range of applications are constrained by poor mechanical properties. Therefore, this work introduced refined bamboo cellulose powder (RBCP), a reinforcing material that is extracted from waste bamboo pulp and applied to CS composite films to enhance their mechanical and physicochemical properties. The chemical composition and crystallinity properties of CS composite films with RBCP addition were observed by ATR-FTIR and XRD. The homogeneous and heterogeneous surfaces of the RBCP incorporated films before biodegradation and after biodegradation (20 days) were observed by scanning electron microscopy (SEM). The increase in reinforcing RBCP materials from 0.00 to 5.00 % resulted in an increase in tensile strength for CS/RBCP films from 2.9 to 8.3 MPa. The application of the CS/RBCP/5 composite film as red grapefruit storage was also investigated, which performed much better than commercial plastic and control CS films with 92.8 and 88.6 % viability of S. aureus and E. coli bacteria. Overall achieved properties demonstrated strong potential for usage as active packaging materials to preserve and lengthen the shelf life of red grapefruits.

Characterization of Nano-SiO2/Zein Film Prepared Using Ultrasonic Treatment and the Ability of the Prepared Film to Resist Different Storage Environments

This study has developed, ultrasound-assisted, a novel food packaging film (U-zein/SiO2) for food packaging applications. Incorporating an optimal concentration of 18 mg/mL of nano-SiO2 and subjecting the film to 10 min of ultrasonic treatment resulted in a remarkable increase of 32.89% in elongation at break and 55.86% in tensile strength. In addition, the incorporation of nano-SiO2 effectively reduces the water content and solubility of the composite film, resulting in improved water/oxygen barrier properties. These physiochemical properties were further improved with the application of ultrasound. The analysis of attenuated total reflectance-Fourier transform infrared, X-ray diffraction, differential scanning calorimetry, and scanning electronic microscope demonstrated that the ultrasound treatment improved the hydrogen bonds, improved thermal stability, molecular arrangement, structure stability, and intermolecular compatibility of the composite film, resulting in enhanced physio-mechanical properties of the film. In addition, the ultrasound treatment led to a smoother film surface and reduced the pores on the film's cross-section. Moreover, the U-zein/SiO2 film exhibited excellent mechanical and water/oxygen barrier properties in different storage environments over a period of 30 days. These results offer sound theoretical support for the practical application of the prepared preservative film.

Preparation and Characterization of a Novel Artemisia Oil Packaging Film and Its Application in Mango Preservation

In this work, a new food packaging film was synthesized via blending Artemisia oil (AO) into soybean protein isolate (SPI) and gelatin (Gel) for the postharvest storage of mango. The morphological architecture and mechanical properties of the films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and other technologies. The results show that the prepared films had relatively flat surfaces with good mechanical properties. AO enhanced the light-blocking ability of the film, increased the hydrophobicity, and affected the moisture content and water solubility of the film to a certain extent. Furthermore, the antioxidant performance and antifungal (Colletotrichum gloeosporioides) capacity of the films increased with higher AO concentration due to the presence of the active components contained in AO. During mango storage applications, the films showed good freshness retention properties. The above results indicate that SPI-Gel films containing AO have excellent physicochemical and application properties and have great potential in the field of food packaging.

Chitosan/esterified chitin nanofibers nanocomposite films incorporated with rose essential oil: Structure, physicochemical characterization, antioxidant and antibacterial properties

Active films were developed based on chitosan, esterified chitin nanofibers and rose essential oil (REO). The joint effects of chitin nanofibers and REO on structure and physicochemical properties of chitosan film were investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy showed that the chitin nanofibers and REO had significant effects on the morphology and chemical structure of chitosan composite films. The negatively charged esterified chitin nanofibers formed a compact network structure through intermolecular hydrogen bonding and electrostatic interactions with the positively charged chitosan matrix. Chitin nanofibers and REO synergistically enhanced the water resistance, mechanical properties and UV resistance of chitosan-based films, but the addition of REO increased the oxygen permeability. Furthermore, the addition of REO enhanced the inhibition of ABTS and DPPH free radicals and microorganisms by chitosan-based film. Therefore, chitosan/chitin nanofiber-based active films containing REO as food packaging materials can potentially provide protection to extend food shelf life.

Chitosan Based Materials in Cosmetic Applications: A Review

This review provides a report on the properties and recent advances in the application of chitosan and chitosan-based materials in cosmetics. Chitosan is a polysaccharide that can be obtained from chitin via the deacetylation process. Chitin most commonly is extracted from cell walls in fungi and the exoskeletons of arthropods, such as crustaceans and insects. Chitosan has attracted significant academic interest, as well as the attention of the cosmetic industry, due to its interesting properties, which include being a natural humectant and moisturizer for the skin and a rheology modifier. This review paper covers the structure of chitosan, the sources of chitosan used in the cosmetic industry, and the role played by this polysaccharide in cosmetics. Future aspects regarding applications of chitosan-based materials in cosmetics are also mentioned.

Preparation of zein/chitosan/eugenol/curcumin active films for blueberry preservation

This study aimed to develop zein/chitosan-based films formulated with curcumin and eugenol to improve the quality of postharvest blueberries. First, the film-forming solutions were characterized (rheological property and water distribution), and the mechanical, structural properties and bioactivity of active films fabricated by casting were evaluated. Further, the active film was coated with blueberry stored at 4 °C, and physicochemical properties (weight loss, hardness, microbial counts, and appearance changes) were measured. The film-forming solutions exhibited non-Newtonian behavior. The incorporation of curcumin and eugenol improved the tensile strength and elongation at the break of films, reaching 17.86 MPa and 92.80 %, respectively. The antioxidant capacity was enhanced, and DPPH and ABTS radical scavenging rates were up to 90.60 ± 0.06 % and 86.34 ± 0.39 %, respectively. Meanwhile, the prepared active films possessed good anti-UV and sensitive pH-response color-shifting ability. Compared to the uncoated blueberry, blueberry coated with zein/chitosan/curcumin/eugenol showed lower weight loss and higher hardness, indicating that the prepared active films played a vital role in delaying the deterioration of blueberry and extending its shelf life. Overall, the zein-chitosan incorporated with curcumin and eugenol films could be a promising candidate to prolong the shelf life of food products due to their excellent bioactive capacity.

Fabrication and Evaluation of Basil Essential Oil-Loaded Halloysite Nanotubes in Chitosan Nanocomposite Film and Its Application in Food Packaging

Increasing health concerns regarding the use of plasticware have led to the development of ecofriendly biodegradable packaging film from natural polymer and food additives. In the present study, basil essential oil (BEO) loaded halloysite nanotubes (HNTs) composite films were synthesized using a solution casting method. The effects of BEO and nanotube concentration on the mechanical, physical, structural, barrier, and antioxidant properties of films were evaluated. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) demonstrated well-dispersed HNTs and BEO in tailored composite films. The addition of BEO in Chitosan (Ch) film caused darkening of the film color; furthermore, the incorporation of HNTs in varied concentrations increased opaqueness in Ch/BEO film. The Ch/BEO film, upon adding HNTs 5-30 wt%, exhibited a corresponding increase in the film thickness (0.108-0.135 mm) when compared with the Ch/BEO film alone (0.081 mm). The BEO-loaded HNTs composite films displayed reduced moisture content and characteristic barrier and UV properties. The Ch/BEO film with 15 wt% HNTs was found to have enhanced antioxidant activity. The Ch/BEO/HNTs composite also managed to prevent broccoli florets from losing weight and firmness during storage. The enhanced barrier and antioxidant qualities of the nanocomposite film suggest its potential application in the food processing and packaging sector. This is the first ever report on the fabrication of nanocomposite film using BEO and HNTs for food packaging. The low production cost and ecofriendly approach make the film acceptable for further research and commercialization thereafter.

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

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

Acetylated polysaccharides: Synthesis, physicochemical properties, bioactivities, and food applications

Polysaccharides are biomacromolecular widely applied in the food industry, as gelling agents, thickeners and health supplements. As hydrophobic groups, acetyls provide amphiphilicity to polysaccharides with numerous hydroxyl groups, which greatly expand the presence of polysaccharides in organic organisms and various chemical environments. Acetylation could result in diverseness and promotion of the structure of polysaccharides, which improve the physicochemical properties and biological activities. High efficient and environmentally friendly access to acetylated derivatives of different polysaccharides is being explored. This review discusses and summarizes acetylated polysaccharides in terms of synthetic methods, physicochemical properties and biological activities and emphasizes the structure-effect relationships introduced by acetyl groups to reveal the potential mechanism of acetylated polysaccharides. Acetyls with different contents and substitution sites could change the molecular weight, monosaccharide composition and spatial architecture of polysaccharides, resulting in differences among properties such as water solubility, emulsification and crystallinity. Coupled with acetyls, polysaccharides have increased antioxidant, immunomodulatory, antitumor, and pro-prebiotic capacities. In addition, their possible applications have also been discussed in green food materials, bioactive ingredient carriers and functional food products, indicating that acetylated polysaccharides hold a clear vision in food health and industrial development.

Chitin, Chitosan, and Nanochitin: Extraction, Synthesis, and Applications

Crustacean shells are a sustainable source of chitin. Extracting chitin from crustacean shells is ongoing research, much of which is devoted to devising a sustainable process that yields high-quality chitin with minimal waste. Chemical and biological methods have been used extensively for this purpose; more recently, methods based on ionic liquids and deep eutectic solvents have been explored. Extracted chitin can be converted into chitosan or nanochitin. Once chitin is obtained and modified into the desired form, it can be used in a wide array of applications, including as a filler material, in adsorbents, and as a component in biomaterials, among others. Describing the extraction of chitin, synthesis of chitosan and nanochitin, and applications of these materials is the aim of this review. The first section of this review summarizes and compares common chitin extraction methods, highlighting the benefits and shortcomings of each, followed by descriptions of methods to convert chitin into chitosan and nanochitin. The second section of this review discusses some of the wide range of applications of chitin and its derivatives.

Highly effective and sustainable antibacterial membranes synthesized using biodegradable polymers

In order to reduce foodborne diseases caused by bacterial infections, antibacterial membranes have received increasing research interests in recent years. In this study, highly effective antibacterial membranes were prepared using biodegradable polymers, including polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and carboxymethyl cellulose (CMC). The cation exchange property of CMC was utilized to introduce silver to prepare antibacterial materials. The presence of silver in the membranes was confirmed by EDS mapping, and the reduction of silver ions to metallic silver was confirmed by the Ag3d XPS spectrum which displayed peaks at 374.46 eV and 368.45 eV, revealing that the oxidation state of silver changed to zero. Two common pathogenic bacteria, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), were used to investigate the antibacterial performance of the prepared membranes. Zone of inhibition and bacteria-killing tests revealed that the antibacterial membranes were efficient in inhibiting the growth of bacteria (diameters of inhibition zone ranged from 16 mm to 19 mm for fresh membranes) and capable of killing 100% of bacteria under suitable conditions. Furthermore, after 6 cycles of continuous zone of inhibition tests, the membranes still showed noticeable antibacterial activities, which disclosed the sustainable antibacterial properties of the membranes.

Preparation and Physicochemical Properties of Modified Corn Starch-Chitosan Biodegradable Films

Starch is a biopolymer with enormous potential for generating new biodegradable packages due to its easy availability and low cost. However, due to its weak functional properties, limitation of its interaction with some hydroxyl groups and evaluation of blends with other polymers are necessary in order to improve its performance. Glycerol-plasticized acetylated corn starch films were developed using the casting method, and the impact of incorporating chitosan (TPS:CH) in various proportions (75:25, 50:50, and 25:75 v/v) was studied in the present research. The effect of chitosan ratios on the physical, mechanical, water-vapor barrier, and thermal properties of the film was studied. Chitosan-protonated amino groups promoted the formation of intermolecular bonds, improving tensile strength, thermal stability, hydrophobicity, water adsorption capacity, and the gas barrier of starch films. The results show that the film composed of TPS25-CH75 proved to be the best barrier to water vapor; thus, these composite films are excellent choices for developing biodegradable packaging for the food industry.