Preparation of a novel biodegradable packaging film based on corn starch-chitosan and poloxamers

Advances in biomaterials based food packaging systems: Current status and the way forward

World hunger is getting worse, while one-third of food produced around the globe is wasted and never consumed. It is vital to reduce food waste to promote the sustainability of food systems, and improved food packaging solutions can augment this effort. The utilization of biomaterials in smart food packaging not only enhances food preservation and safety but also aligns with current demands for eco-friendly technologies to mitigate the impacts of climate change. This review provides a comprehensive overview of the developments in the field of food packaging based on the innovative use of biomaterials. It emphasizes the potential use of biomaterials derived from nature including cellulose, chitosan, keratin, etc. for this purpose. Various smart food packaging technologies such as active and intelligent packaging are discussed in detail including scavenging additives, colour-changing environment indicators, sensors, RFID tags, etc. The article also delves into the utilization of edible films and coatings, nanoparticle fillers and 2D materials in food packaging systems. Furthermore, it outlines the challenges and opportunities in this dynamic domain, emphasizing the ongoing need for research and innovation to shape the future of sustainable and smart food packaging solutions to enhance and monitor the shelf-life of food products.

Fabrication of bio-inspired carbon nanodot-corn starch nanocomposite films via extrusion process for sustainable active food packaging applications

In this study, carbon nanodot (CD)-corn starch (CS) nanocomposite films are fabricated for active food packaging applications. First, ginkgo biloba leaves (GBL) were used as a biomass-derived carbon precursor, and a facile hydrothermal method was employed to synthesise environmentally sustainable CDs. The GBL-derived carbon nanodots (gCDs) were then characterised and incorporated into a CS matrix via an extrusion process to fabricate the CS/gCD nanocomposite film. The effects of various gCD concentrations on the physicochemical and functional properties of CS/gCD composite films were systematically investigated. The gCD exhibited non-cytotoxic effect against human colorectal adenocarcinoma cell line (Caco-2) cells when exposed up to 1000 μg/mL. The incorporation of gCDs into the CS film improved its mechanical properties, with the toughness of the CS/gCD2% nanocomposite film exhibiting 198 % superiority compared to the CS film. In addition, the oxygen barrier and UV-blocking properties were significantly improved. Furthermore, the CS/gCD nanocomposite film significantly extended the shelf life of ω-3 oils owing to the superior antioxidant activity of the gCDs, exhibiting only 9 meq/kg during the 15-day storage period. Our results suggest that the developed CS/gCD active composite film is a promising candidate for environmentally sustainable solutions to enhance food shelf life and reduce food waste.

Improving physicomechanical properties of arrowroot starch films incorporated with kappa-carrageenan: Sweet cherry coating application

Arrowroot starch (AS)-based films potential is influenced by its low-cost processing and high transparency packaging material but low tensile strength; hence, AS was blended with kappa-carrageenan (KC) to improve mechanical properties of AS-based films and enhance its potential use in food packaging or coating applications. AS-KC-based films were characterized based on structural, physicomechanical, thermal, pasting properties, and coating application in sweet cherry. The films demonstrated high tensile strength from 3.2 to 29.4 MPa and low elongation properties from 160.3 % to 1.9 %. Moreover, AS/KC films exhibited peak viscosities of 18.7 to 34.8 RVU, and thermal analysis depicted lower weight losses (59-45 %) compared to AS-based films (62 %). In addition, sweet cherry samples coated with AS/KC films and stored at 20 °C for 15 days depicted lower weight losses (26.6 %) compared to non-coated samples (>41 %), which indicated the potential use of the film's coating application in extending the shelf life and quality of fresh fruits.

Metal-phenolic networks spontaneously reinforced carrageenan-based packaging films with antibacterial and antioxidant properties

The burdens of microbial food safety and environmental contamination make it necessary to search sustainable, safe, antibacterial and antioxidant active food packaging materials. This contribution proposed the use of copper-ferulic acid networks (CuFA NWs) as antibacterial substances. By immobilizing CuFA NWs into carrageenan matrix, a CuFA network-reinforced carrageenan-based packaging film (Carr/CuFA) was obtained via spontaneously hydrogen bond and electrostatic interaction indicated by ATR-IR and XPS. Interestingly, the addition of CuFA NWs increased the mechanical strength, surface hydrophobicity, and water vapor barrier properties of the carrageenan-based film, and imparted the film with UV-shielding capacity. Importantly, the Carr/CuFAx film exhibited effective antioxidant activity, and antibacterial performance against four foodborne bacteria. As a result, after confirming the safety of Carr/CuFA3 films by releasing, hemolysis and cell viability experiments, the Carr/CuFA3 film exhibited great potential in the safety control and preservation of fresh fruit by using blueberry and cherry as model fruit. In summary, this work provides a feasible candidate for the preservation and contamination control of fresh fruit.

Effect of clays incorporation on properties of thermoplastic starch/clay composite bio-based polymer blends

In this study, thermoplastic starch (TPS) biofilms were developed using starch isolated from the seeds of Melicoccus bijugatus (huaya) and reinforced with bentonite clays at concentrations of 1%, 3%, and 5% by weight. Novelty of this research lies in utilizing a non-conventional starch source and enhancing properties of TPS through clay reinforcement. FTIR analysis verified bentonite's nature of clays, while SEM analysis provided insights into morphology and agglomeration behavior. Key findings include a notable increase in biofilm thickness and elastic modulus with higher clay content. Specifically, tensile strength of biofilms improved from 2.5 MPa for pure TPS to 5.0 MPa with 5% clay reinforcement. The elastic modulus increased from 25 MPa (TPS) to 60 MPa (5% clay). Thermal stability also showed enhancement, with initial degradation temperature increasing from 110 °C for pure TPS to 130 °C for TPS with 5% clay. Water vapor permeability (WVP) tests demonstrated a decrease in WVP values from 4.11 × 10-10 g m-1 s-1 Pa-1 for pure TPS to 2.09 × 10-10 g m-1 s-1·Pa-1 for TPS with 5% clay, indicating a significant barrier effect due to clay dispersion. These results suggest that biofilms based on huaya starch and reinforced with bentonite clay have considerable potential for sustainable food packaging applications, offering enhanced mechanical and barrier properties.

Potato oxidized hydroxypropyl starch/pectin-based indicator film with Clitoria ternatea anthocyanin and silver nanoparticles for monitoring chilled beef freshness

Potato oxidized hydroxypropyl starch (POHS)/pectin (P) functional and smart beef freshness indicator films were prepared using butterfly pea (Clitoria ternatea) anthocyanin (BA) and silver nanoparticles (AgNPs). BA exhibited significant pH-responsive color changes. BA and AgNPs were evenly distributed within a polymer matrix to create a compatible film with POHS/P. The films containing BA and AgNPs had good UV resistance and maintained strong mechanical strength, barrier properties, and color stability. The color of the indicator film changed from purple to green when exposed to ammonia, with the 1 % POHS/P/BA/AgNPs film showing the most sensitive response. The films also demonstrated strong antibacterial and antioxidant properties. The freshness of beef was monitored using 1 % POHS/P/BA/AgNPs films and was identified as sub-fresh and spoiled on days 4 and 7, respectively. The relationship between the color change of the indicator label and the freshness of chilled beef was established: purple for fresh meat, blue for less fresh meat, and green for spoiled meat. Thus, the new POHS/P/BA/AgNPs film can serve as a smart packaging material to indicate food freshness and extend shelf life. These results suggest that POHS/P/BA/AgNPs films have significant potential as an active and smart food packaging material.

Radish residue carbon dots-based novel starch/chitosan film with high antioxidant, biocompatibility, and antibacterial activities for salmon fillets' active packaging

The corruption of refrigerated marine fish results in global economic losses exceeding 25 billion euros annually. However, conventional preservatives present challenges, including singular functionality, potential toxicity, and high cost. In response, we developed multifunctional, safe, cost-effective, and environmentally friendly carbon dots derived from radish residues (R-CDs) by using the one-pot hydrothermal method. The surface of R-CDs is enriched with hydroxyl groups, conferring broad-spectrum antioxidant and antibacterial characteristics. R-CDs exhibited a notable 72.92 % inhibition rate on lipid peroxidation, surpassing the effectiveness of vitamin C (46 %). Additionally, R-CDs demonstrated impressive scavenging rates of 93.8 % for 2,2-diphenyl-1-picrylhydrazyl free radicals and 99.36 % for 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid-free radicals. In combating spoilage bacteria such as Aeromonas sobria and Hafnia alvei, R-CDs disrupted cell structures and influenced intracellular substance content. Importantly, co-cultivation with R-CDs showed no significant cytotoxicity. Further incorporating R-CDs into films using starch and chitosan (S/CS/R-CDs films) for efficient and convenient use in salmon fillets preservation. S/CS/R-CDs films effectively inhibited the growth of spoilage bacteria, lipid oxidation, and protein decomposition in salmon fillets, thereby extending shelf life by 4 days. This combination of antioxidant and antibacterial properties in R-CDs, along with the functional films, presents a promising approach for enhancing salmon fillet preservation.

Fabrication of a ternary biocomposite film based on polyvinyl alcohol, cellulose nanocrystals, and silver nanoparticles for food packaging

Silver nanoparticles (AgNPs) were loaded on deprotonated cellulose nanocrystals (CNCd) and incorporated into polyvinyl alcohol (PVA) to develop novel active food packaging films. The AgNPs were fabricated using the liquid phase chemical reduction method using the sodium borohydride reductant of AgNO3. The analysis using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Ultraviolet-visible spectroscopy (UV-Vis) showed that the CNCd surface had a homogeneous distribution of AgNPs with a diameter of about 100 nm. Additionally, CNCd/Ag was successfully incorporated into the PVA film. The developed PVA/CNCd/Ag film showed significantly improved mechanical properties, thermal stability, and UV barrier properties compared to a neat PVA film. The PVA/CNCd/Ag composite film could significantly preserve bananas for 14 days, preventing deterioration and allowing extended storage periods. This composite film generally shows promise in food packaging and prolongs food's shelf life.

Characterization of feruloylated arabinoxylan - acorn starch double network gel composite film and its application in postharvest preservation of Agaricus bisporus

To obtain efficient natural food packaging materials, we utilized acorn starch (AS)-based film strengthened by feruloylated arabinoxylan (FAX) gel and additional retrogradation treatment to extend the shelf life of Agaricus bisporus (A. bisporus). Fourier transform infrared spectroscopy (FT-IR), confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM) analyses showed that due to the strong hydrogen bonding between FAX and starch molecules, physical crosslinking occurred between FAX and starch molecules in the composite film, and the microstructure became more compact. Thermogravimetric, tensile strength and swelling degree analyses indicate that the composite film exhibits better thermal stability, mechanical properties, and waterproofing compared to the pure AS film. Consequently, after five days of storage, the moisture content of the A. bisporus packaged with our composite film was 7.53 times and 5.73 times higher than that of the control group and the commercially available PEF group, respectively. Moreover, it delayed the respiration or transpiration of A. bisporus (lower weight loss, relative conductivity, MDA content). This packaging film developed with the objective of eco-friendly and biodegradability has considerable application potential in food and other industries.

Starch-chitosan blends: A comprehensive review on the preparation, physicochemical properties and applications

Starch and chitosan, polysaccharides derived from natural sources, have significant potential across various domains. Starch is extracted from starch-bearing plants, such as potatoes, whereas chitosan is obtained from the exoskeletons of marine animals, fungi and insects. However, the original forms of starch and chitosan have several limitations, such as low solubility and weak mechanical strength. Interestingly, the combined effects of starch and chitosan resulted in the development of starch-chitosan blends with markedly improved functional properties. These blends demonstrated high tensile strength, improved hydrophilicity and increased adsorption capacity. Furthermore, modification of starch-chitosan blends by techniques such as crosslinking and incorporation of other functional materials contributes to diverse characteristics and functionalities. This review addresses a crucial gap in the literature by providing an overview and up-to-date analysis of starch-chitosan blends. The preparation methods and functional properties of these blends in various forms, such as films, beads and hydrogels, have been extensively discussed. Emphasis is placed on the versatile applications of these blends in research, development and industries such as pharmaceuticals, wastewater treatment, agriculture and food technology. This review aims to provide an insightful overview of starch-chitosan blends and stimulate broader interdisciplinary research interests. By providing concluding insights and prospects, this review highlights the potential for further exploration of the impact of starch-chitosan blends on consumers and the environment.

Developing high performance biodegradable film based on crosslinking of cellulose acetate and tannin using caprolactone

The use of metal catalysts during the production process of cellulose acetate (CA) film can have an impact on the environment, due to their toxicity. Diphenyl phosphate (DPP) was used instead of toxic metal catalyst to react with cellulose acetate, tannin (T) and caprolactone (CL) for preparation of cellulose acetate-caprolactone-tannin (CA-CL-T) film. The results show that DPP can produce a cross-linked network structure composed of tannin, caprolactone and cellulose acetate. The maximum molecular weight reached 113,260 Da. The introduction of tannin and caprolactone into cellulose acetate caused the resulting CA-CL-T film acquire excellent strengthening/toughening effect, in which a tensile strength of 23 MPa and elongation at break of 18 % were attained. More importantly, the resistance of the film to UV radiation was significantly improved with the tannin addition, which was corroborated by the CA-CL-T film still exhibiting a tensile strength of 13 MPa and elongation at break around 13 % after continuous exposure to UV radiation for 9 days. On the other hand, the insertion of caprolactone provoked enhancement of the overall moisture resistance. Five days treatment of the films with Penicillium sp. induced gradual drop in quality, indicating the CA-CL-T film show response to biodegradation. In all, the effective crosslinking between the components of the developed material is responsible for the acquired set of these distinct characteristics.

Starch biocomposites preparation by incorporating organosolv lignins from potato crop residues

Plastic wastes accumulated due to food packaging pose environmental threats. This study proposes biopolymeric films containing lignins extracted from potato crop residues (PCR) through organosolv treatment as a green alternative to non-degradable food packaging. The isolation process yielded 43.9 wt% lignins with a recovery rate of 73.5 wt% achieved under optimum conditions at 180 °C with 50 % v/v ethanol. The extracted lignins were then incorporated into a starch matrix to create biocomposite films. ATR-FTIR analysis confirmed interactions between the starch matrix and extracted lignins, and XRD analysis showed the amorphous structure of lignins, reducing film crystallinity. The addition of 1 wt% of extracted lignins resulted in a 87 % reduction in oxygen permeability, a 25 % increase in the thermal stability of the film, and a 78 % enhancement in antioxidant. Furthermore, introducing 3 wt% lignins led to the lowest water vapor transmission rate, measuring 9.3 × 10-7 kg/s·m2. Morphological studies of the films demonstrated a homogeneous and continuous structure on both the surface and cross-sectional areas when the lignins content was below 7 wt%. These findings highlight the potential of using organosolv lignins derived from potato crop residues as a promising additive for developing eco-friendly films designed for sustainable food packaging.

Physicochemical and antioxidant properties of tannic acid crosslinked cationic starch/chitosan based active films for ladyfinger packaging application

In the present study, cationic starch (CS)/chitosan (CH) incorporated with tannic acid (TA)(CSCT) eco-friendly films were prepared by employing an inexpensive solvent casting technique. Influence of TA on the physicochemical and antimicrobial properties of CS/CH polymer matrix were studied. The FTIR findings and homogeneous, dense SEM micrographs confirms the effective interaction of TA with CS/CH polymer matrix. CSCT-3 active film displayed tensile strength of 26.99±1.91 MPa, which is more substantial than commercially available polyethylene (PE) (12-16 MPa) films. The active films exhibited excellent barrier properties against moisture and water, supported by increased water contact angle values (86.97±0.29°). Overall migration rate of active films was found to be below the permitted limit of 10mg/dm2. The active films showed around 56% of degradation in soil within 15 days. Besides, the active films showed concurring impact against food borne pathogens like E. coli, S. aureus and C. albicans. The CSCT-3 active film presented 90.83% of antioxidant capacity, demonstrating the effective prevention of food oxidation related deterioration. Ladyfinger packaging was inspected to examine the ability of active films as packaging material resulted in effectively resisting deterioration and extending shelf life in comparison with traditional PE packaging.

Application of chitosan and other biopolymers based edible coatings containing essential oils as green and innovative strategy for preservation of perishable food products: A review

Deterioration of perishable foods due to fungal contamination and lipid peroxidation are the most threatened concern to food industry. Different chemical preservatives have been used to overcome these constrains; however their repetitive use has been cautioned owing to their negative impact after consumption. Therefore, attention has been paid to essential oils (EOs) because of their natural origin and proven antifungal and antioxidant activities. Many EO-based formulations have been in use but their industrial-scale application is still limited, possibly due to its poor solubility, vulnerability towards oxidation, and aroma effect on treated foods. In this sense, active food packaging using biopolymers could be considered as promising approach. The biopolymers can enhance the stability and effectiveness of EOs through controlled release, thus minimizes the deterioration of foods caused by fungal pathogens and oxidation without compromising their sensory properties. This review gives a concise appraisal on latest advances in active food packaging, particularly developed from natural polymers (chitosan, cellulose, cyclodextrins etc.), characteristics of biopolymers, and current status of EOs. Then, different packaging and their effectiveness against fungal pathogens, lipid-oxidation, and sensory properties with recent previous works has been discussed. Finally, effort was made to highlights their safety and commercialization aspects towards market solutions.

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.

Recent advances in green technology and Industrial Revolution 4.0 for a sustainable future

This review gives concise information on green technology (GT) and Industrial Revolution 4.0 (IR 4.0). Climate change has begun showing its impacts on the environment, and the change is real. The devastating COVID-19 pandemic has negatively affected lives and the world from the deadly consequences at a social, economic, and environmental level. In order to balance this crisis, there is a need to transition toward green, sustainable forms of living and practices. We need green innovative technologies (GTI) and Internet of Things (IoT) technologies to develop green, durable, biodegradable, and eco-friendly products for a sustainable future. GTI encompasses all innovations that contribute to developing significant products, services, or processes that lower environmental harm, impact, and worsening while augmenting natural resource utilization. Sensors are typically used in IoT environmental monitoring applications to aid ecological safety by nursing air or water quality, atmospheric or soil conditions, and even monitoring species' movements and habitats. The industries and the governments are working together, have come up with solutions-the Green New Deal, carbon pricing, use of bio-based products as biopesticides, in biopharmaceuticals, green building materials, bio-based membrane filters for removing pollutants, bioenergy, biofuels and are essential for the green recovery of world economies. Environmental biotechnology, Green Chemical Engineering, more bio-based materials to separate pollutants, and product engineering of advanced materials and environmental economies are discussed here to pave the way toward the Sustainable Development Goals (SDGs) set by the UN and achieve the much-needed IR 4.0 for a greener-balanced environment and a sustainable future.

Morphological, physical, thermal, and mechanical properties with the aspect ratio effects of bio loose-fill packaging from corn stalk

Protective packaging, such as loose-fill material, is commonly used for void filling in packages during transportation and handling. Due to environment concerns about packaging materials, alternative materials derived from agricultural residues, such as corn stalks (CS), are of attention. Dried internodal CS without rind (DCS-R) were prepared as a cylindrical-shaped bio loose-fill packaging pieces (DCS-RP) at three different aspect ratios [length/diameter (L/D) of 0.4, 0.8, and 1.2]. The morphological, physical, and thermal properties of the DCS-RP were investigated and the effect of the L/D ratio of the DCS-RP was examined under compression loading. The DCS-RP exhibited a porous structure with a low density and bulk density, while the packing efficiency at all L/D ratios was less than 1. Different compressive resistance and failure patterns of the DCS-RP were obtained, depending on the direction of compression loading (parallel and perpendicular) to the DCS-RP. In addition, the L/D ratio of bulk DCS-RP also affected the compressive resistance. The results of this study provide important information for future investigations on the protective ability of DCS-RP to the products inside the packages during transportation and handling.

Loquat seed starch - Emerging source of non-conventional starch: Structure, properties, and novel applications

Recently, non-conventional sources of starch have attracted attention due to their potential to provide cost-effective alternatives to traditional starch. Among non-conventional starches, loquat (Eriobotrya japonica) seed starch is an emerging source of starch consisting of the amount of starch (nearly 20 %). Due to its unique structure, functional properties, and novel applications, it could be utilized as a potential ingredient. Interestingly, this starch has similar properties as commercial starches including high amylose content, small granule size, and high viscosity and heat stability, making it an attractive option for various food applications. Therefore, this review mainly covers the fundamental understanding of the valorization of loquat seeds by extracting the starch using different isolation methods, with preferable structural, morphological, and functional properties. Different isolation and modification methods (wet milling, acid, neutral and alkaline) are effectively used to obtain higher amounts of starch are revealed. Moreover, insight into various analytical techniques including scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction used to characterize the molecular structure of the starch are discussed. In addition, the effect of shear rate and temperature on rheological attributes with solubility index, swelling power, and color is revealed. Besides, this starch contains bioactive compounds that have shown a positive impact on the enhancement of the shelf-life of the fruits. Overall, loquat seed starches have the potential to provide sustainable and cost-effective alternatives to traditional starch sources and can lead to novel applications in the food industry. Further research is needed to optimize processing techniques and develop value-added products that can be produced at a large scale. However, there is relatively limited published scientific evidence on the structural and morphological characteristics of loquat seed starch. Thus, in this review, we focused on different isolation techniques of loquat seed starch, its structural and functional characteristics, along with potential applications.

Construction of compostable packaging with antibacterial property and improved performance using sprayed coatings of modified cellulose nanocrystals

Increasing concerns about food safety and the environment have facilitated the development of eco-friendly antibacterial packaging. This study aimed to demonstrate a facile way to fabricate active packaging materials with modified cellulose nanocrystals (CNCs) and compare the effects of different modified CNCs on the performance of compostable materials. Polylactic acid (PLA) film was selected as a model, and CNCs were modified with methacrylamide, cetyltrimethylammonium bromide, and zinc oxide, respectively, and then applied on the surface of PLA films by spray-coating. All modified CNCs showed excellent antibacterial activity against S. aureus and E. coli (>99.999 %). The effects of different CNC modifications on the performance of PLA films were investigated. Compared to neat PLA films, PLA/CNC films exhibited improved mechanical strength with maintained flexibility, lower gas permeability, and faster compost disintegration rate, and extended the shelf life of wrapped pork samples from 3 days to >10 days. Therefore, this work will also facilitate the applications of PLA materials in eco-friendly packaging.

Development of nanocellulose fiber reinforced starch biopolymer composites: a review

In the last few years, there are rising numbers for environmental waste due to factors such as plastic based food packaging that really need to get enough attention in order to prevent the issue from becoming worse and bringing disaster to society. Thus, the uses of plastic composite materials need to be reduced and need to be replaced with materials that are natural and have low degradation to preserve nature. Based on the statistics for the global, the production of plastic has been roughly calculated for passing 400 million metric tons every year and has a high probability of approaching the value of 500 million metric tons at the year of 2025 and this issue needs to be counteracted as soon as possible. Due to that, the increasing number for recent development of natural biopolymer, as an example starch, has been investigated as the substitution for the non-biodegradable biopolymer. Besides, among all biodegradable polymers, starch has been considered as promising substitution polymer due to its renewability, easy availability, and biodegradability. Apart from that, by the reinforcement from the nanocellulose, starch fiber has an increasing in terms of mechanical, barrier and thermal properties. In this review paper, we will be discussing the up-to-date development of nanocellulose fiber reinforced starch biopolymer composites throughout this century.

Construction and application of nano ZnO/eugenol@yam starch/microcrystalline cellulose active antibacterial film

The goal of this study was to develop new biocomposite films that can better protect and prolong the shelf life of food. Here, a ZnO: eugenol@yam starch/microcrystalline cellulose (ZnO:Eu@SC) antibacterial active film was constructed. Because of the advantages of metal oxides and plant essential oils, codoping with these can effectively improve the physicochemical and functional properties of composite films. The addition of an appropriate amount of nano-ZnO improved the compactness and thermostability, reduced the moisture sensitivity, and enhanced the mechanical and barrier properties of the film. ZnO:Eu@SC exhibited good controlled release of nano-ZnO and Eu in food simulants. Nano-ZnO and Eu release was controlled by two mechanisms: diffusion (primary) and swelling (secondary). After loading Eu, the antimicrobial activity of ZnO:Eu@SC was significantly enhanced, resulting in a synergistic antibacterial effect. Z₄:Eu@SC film extended the pork shelf life by 100 % (25 °C). In humus, the ZnO:Eu@SC film was effectively degraded into fragments. Therefore, the ZnO:Eu@SC film has excellent potential in food active packaging.

Improving chitosan performance in the simultaneous adsorption of multiple polycyclic aromatic hydrocarbons by oligo(β-pinene) incorporation

The occurrence of persistent organic pollutants in aquatic bodies, namely polycyclic aromatic hydrocarbons (PAHs), has been increasingly detected. The presence of such contaminants represents a serious threat to human health due to their toxicity. Therefore, aiming to provide a novel and efficient alternative for PAHs' removal from water, the present study assesses the effect of oligo(β-pinene) blended with chitosan for the adsorption of these pollutants. Oligo(β-pinene) with phenyl end-groups was synthesized by organocatalyzed atom transfer radical polymerization (O-ATRP) and incorporated in different concentrations (6, 12, and 18 %) to chitosan films. The oligo(β-pinene) loading in the chitosan matrix impressively improved this polysaccharide adsorption capacity. The formulation containing 12 % of oligomer demonstrated a contaminant removal performance three times higher (298.82 %) than pure chitosan during only 1 h of the decontamination process. Adsorption isotherms showed an improved uptake of PAHs with the increase of the contaminants' concentration in the aqueous media due to the formation of a higher concentration gradient. Additionally, a comprehensive characterization of oligo(β-pinene)/chitosan formulation was performed to provide a better understanding of the interactions between the components of the blends. Overall, it was concluded that oligo(β-pinene)/chitosan blends can be used as a high-performance and sustainable alternative for PAHs removal.

Development and characterization of chitosan/bacterial cellulose/pullulan bilayer film with sustained release curcumin

A natural biopolymer bilayer film based on chitosan and bacterial cellulose with a protective layer of pullulan was developed by a two-step solution casting method. Curcumin was incorporated as an active antioxidant and antibacterial agent into the inner layer. The films with different curcumin concentrations were systematically characterized. Fourier transform infrared spectroscopy and X-ray diffraction analyses showed high compatibility between curcumin and the polysaccharide matrix through intermolecular interactions, which was verified by enhanced mechanical and barrier properties. The curcumin incorporation improved the thermal stability by >35.4 %, along with lower visible and ultraviolet light transmittance (< 8.6 %) and water solubility (< 25.1 %). The film had both antibacterial and antioxidant properties, and the sustained release of curcumin was largest (> 58.8 %) in the fatty food simulant lasting for over 155 h. The results suggested that the film containing 0.2 % curcumin had ideal physical and functional properties, suggesting its potential as a novel packaging material for the preservation of high-fat food.

Structure and properties of flexible starch-based double network composite films induced by dopamine self-polymerization

Starch-based packaging materials are being developed to alleviate environmental pollution and greenhouse gas emissions associated with plastic-based ones. However, the high hydrophilicity and poor mechanical properties of pure-starch films limit their widespread application. In this study, dopamine self-polymerization was used as a strategy to improve the performance of starch-based films. Spectroscopy analysis showed that strong hydrogen bonding occurred between polydopamine (PDA) and starch molecules within the composite films, which significantly altered their internal and surface microstructures. The composite films had a greater water contact angle (> 90°), which indicated that the incorporation of PDA reduced their hydrophilicity. Additionally, the elongation at break of the composite films was 11-fold higher than pure-starch films, indicating that PDA improved film flexibility, while the tensile strength decreased to some extent. The composite films also exhibited excellent UV-shielding performance. These high-performance films may have practical applications in food and other industries as biodegradable packaging materials.

Enhanced Antibacterial Performance of Chitosan/Corn Starch Films Containing TiO2/Graphene for Food Packaging

Chitosan (CTS)/corn starch (CSH)/nano-TiO₂/graphene (Gr) antibacterial active packaging films were prepared by ultrasonic-assisted electrospray deposition and solution-casting methods, and the effects of the TiO₂:Gr mass ratio and ultrasonication power on their morphology and mechanical, optical, thermal, barrier, and antibacterial properties were investigated. The film fabricated at a TiO₂:Gr ratio of 6:4 and an ultrasonication power of 160 W exhibited a uniform distribution of the nanofillers in the CTS/CSH matrix and significantly enhanced the mechanical, barrier, and water-resistance properties. Furthermore, this film demonstrated superior ultraviolet and visible light-shielding characteristics as compared with those of the non-filled CTS/CSH film, while its Escherichia coli and Staphylococcus aureus inhibition efficiencies were equal to 96.67 ± 0.09% and 99.85 ± 0.13%, respectively. Therefore, the film can effectively prevent food spoilage, indicating its potential for food-packaging applications.

Biopolymer-based functional films for packaging applications: A review

Food packaging is a coordinated system comprising food processing, protection from contamination and adulteration, transportation and storage, and distribution and consumption at optimal cost with a minimum environmental impact to the packed food commodity. Active packaging involves deliberate addition of the functional ingredients either in the film or the package headspace to preserve the food quality, improve safety and nutrition aspects, and enhance the shelf-life. In this review, recent advances in the fabrication of biopolymer-based films, their classification (biodegradable-, active-, and intelligent packaging films), advanced fabrication strategies (composite-, multilayer-, and emulsified films), and special functions induced by the biopolymers to the film matrix (mechanical-, water resistance and gas barrier-, and optical properties, and bioactive compounds reservoir) were briefly discussed. A summary of conclusions and future perspectives of biopolymer-based packaging films as advanced biomaterial in preserving the food quality, improving safety and nutrition aspects, and enhancing shelf-life of the products was proposed.

Chitosan based film reinforced with EGCG loaded melanin-like nanocomposite (EGCG@MNPs) for active food packaging

In this study, EGCG loaded melanin-like nanoparticles (EGCG@MNPs) were incorporated into chitosan matrix to prepare an active nanocomposite food packaging film, chitosan-EGCG@MNPs (CH-EM). The influence of EGCG@MNPs on the physical and biological properties of the chitosan film was investigated. The EGCG@MNPs nanoparticles were cross-linked with chitosan through intermolecular hydrogen bonds and uniformly distributed in the matrix. Besides, the incorporation of EGCG@MNPs tremendously improved the solubility, swelling ratio and water vapor barrier properties of the film, and permitted superior ultraviolet rays blocking property. In addition, the mechanical properties, thermal stability and surface hydrophobicity have also been significantly improved. The CH-EM^2.0 nanocomposite films also showed excellent oxidation resistance (58.4 ± 4.4%, DPPH and 92.4 ± 1.3%, ABTS⁺), and strong inhibitory ability against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The experimental results comprehensively showed that the prepared chitosan-EGCG@MNPs nanocomposite film offering excellent potential for eco-friendly active food packaging.

Development of Eggshell-Based Orange Peel Activated Carbon Film for Synergetic Adsorption of Cadmium (II) Ion

Heavy metal contamination has spread around the world, particularly in emerging countries. This study aimed to assess the effectiveness of starch/eggshell/orange peel-activated carbon-based composite films in removing cadmium (II) ions from water samples. X-ray diffraction and scanning electron microscopy were used to characterize the composite films. The effect of Cd²⁺ was studied using a UV-Vis spectrophotometer and atomic absorption spectroscopy. The morphology of the composite film reveals a highly porous and rough surface with more open channels and a non-uniform honeycomb, indicating that the film has a high potential to adsorb Cd²⁺. The diffraction peaks for this film were found to be at 13.74°, 17.45°, 18.4°, and 23.6°, indicating a typical crystalline A-type packing arrangement within the starch granules. The results indicate that crystalline structure was unaffected by the addition of eggshell powder and orange peel-activated carbon. In 0.5 mg L^-1 and 1.0 mg L^-1 Cd²⁺ ions, the composite film removed 100% and 99.7% of the Cd²⁺, respectively, while the maximum removal efficiency for methylene blue was 93.75%. Thus, the current study shows that starch/eggshell/orange peel activated carbon film has a high potential for commercial activated carbon as a low-cost adsorbent.

Fabrication and characterization of pullulan-based composite films incorporated with bacterial cellulose and ferulic acid

Pullulan-based composite films incorporated with bacterial cellulose (BC) and ferulic acid (FA) were prepared by solution casting method. The rheological, morphological, barrier, optical, anti-fogging, and antioxidant properties of pullulan-based composite films doped with BC and FA were investigated. The rheological results showed that all film-forming solution was pseudoplastic fluid and its viscosity increased with the increase of BC content. An appropriate BC (2 %) and FA were uniformly dispersed in pullulan to form uniform and dense composite films. With the increase of BC content, the roughness and opacity of composite films increased while their UV-vis barrier performance was improved by incorporating BC and FA. Fourier transform infrared spectrometer analysis demonstrated that hydrogen bond interactions among pullulan, BC, and FA were found, and incorporating BC could increase the crystallinity of the composite films, thus enhancing their mechanical, barrier, hydrophobic, and thermal stability properties. Pullulan-based composite films incorporated with 2 % BC and FA (P-BC2-FA) showed better mechanical properties, water, oxygen, and carbon dioxide barrier performances, and its water contact angle value also increased compared with control, respectively. P-BC2-FA film showed superior anti-fogging and antioxidant activities. These results indicate that the P-BC2-FA film are expected to be a potential target of bioactive packaging.

Nano-fertilizers: A sustainable technology for improving crop nutrition and food security

Excessive use of synthetic fertilizers cause economic burdens, increasing soil, water and atmospheric pollution. Nano-fertilizers have shown great potential for their sustainable uses in soil fertility, crop production and with minimum or no environmental tradeoffs. Nano-fertilizers are of submicroscopic sizes, have a large surface area to volume ratio, can have nutrient encapsulation, and greater mobility hence they may increase plant nutrient access and crop yield. Due to these properties, nano-fertilizers are regarded as deliverable 'smart system of nutrients'. However, the problems in the agroecosystem are broader than existing developments. For example, nutrient delivery in different physicochemical properties of soils, moisture, and other agro-ecological conditions is still a challenge. In this context, the present review provides an overview of various uses of nanotechnology in agriculture, preference of nano-fertilizers over the conventional fertilizers, nano particles formation, mobility, and role in heterogeneous soils, with special emphasis on the development and use of chitosan-based nano-fertilizers.

Development of Aloe Vera-Green Banana Saba-Curcumin Composite Film for Colorimetric Detection of Ferrum (II)

This study was performed to develop and characterize a bio-film composed of Aloe vera (Aloe barbadensis), green banana Saba (Musa acuminata x balbisiana), and curcumin for the detection of Fe²⁺ ions. Cross-linking interaction between banana starch-aloe vera gel and banana starch-curcumin enhanced l the sensing performance of the composite film towards divalent metal ions of Fe²⁺. The morphological structure of the Aloe vera-banana starch-curcumin composite revealed a smooth and compact surface without cracks and some heterogeneity when observed under Scanning Electron Microscopy (SEM). The thickness, density, color property, opacity, biodegradation, moisture content, water-solubility, water absorption, swelling degree, and water vapor permeability of bio-films were measured. The incorporation of aloe vera gel and curcumin particles onto the banana starch film has successfully improved the film properties. The formation of the curcumin-ferrum (II) complex has triggered the film to transform color from yellow to greenish-brown after interaction with Fe²⁺ ions that exhibit an accuracy of 101.11% within a swift reaction time. Good linearity (R² = 0.9845) of response on colorimetric analysis was also obtained in Fe²⁺ ions concentration that ranges from 0 to 100 ppm, with a limit of detection and quantification found at 27.84 ppm and 92.81 ppm, respectively. In this context, the film was highly selective towards Fe²⁺ ions because no changes of color occur through naked eye observation when films interact with other metal ions, including Fe³⁺, Pb²⁺, Ni²⁺, Cd²⁺, and Cu^2+. Thus, these findings encourage curcumin-based starch films as sensing materials to detect Fe²⁺ ions in the field of food and agriculture.

Evaluation of the Antimicrobial, Thermal, Mechanical, and Barrier Properties of Corn Starch-Chitosan Biodegradable Films Reinforced with Cellulose Nanocrystals

Packaging materials play an essential role in the preservation and marketing of food and other products. To improve their conservation capacity, antimicrobial agents that inhibit bacterial growth are used. Biopolymers such as starch and chitosan are a sustainable alternative for the generation of films for packaging that can also serve as a support for preservatives and antimicrobial agents. These substances can replace packaging of synthetic origin and maintain good functional properties to ensure the quality of food products. Films based on a mixture of corn starch and chitosan were developed by the casting method and the effect of incorporating cellulose nanocrystals (CNC) at different concentrations (0 to 10% w/w) was studied. The effect of the incorporation of CNC on the rheological, mechanical, thermal and barrier properties, as well as the antimicrobial activity of nanocomposite films, was evaluated. A significant modification of the functional and antimicrobial properties of the starch–chitosan films was observed with an increase in the concentration of nanomaterials. The films with CNC in a range of 0.5 to 5% presented the best performance. In line with the physicochemical characteristics which are desired in antimicrobial materials, this study can serve as a guide for the development this type of packaging for food use.

Novel Biodegradable Poly (Lactic Acid)/Wood Leachate Composites: Investigation of Antibacterial, Mechanical, Morphological, and Thermal Properties

This research aimed to investigate the effects of using wood leachate (WL) powder as a cost-effective filler added to novel poly (lactic acid) biocomposites and evaluate their mechanical, thermal, morphological, and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), tensile test, Charpy impact test, Shore hardness, scanning electron microscope (SEM), differential scanning calorimetry (DSC), contact angle, and bacterial growth inhibition tests were employed to characterize the developed biocomposites. The SEM results indicated a proper filler dispersion in the polymer matrix. WL powder improved the hydrophobic nature in the adjusted sample’s contact angle experiment. Markedly, the results showed that the addition of WL filler improved the mechanical properties of the fabricated biocomposites. The thermal analysis determined the development in crystallization behavior and a decline in glass transition temperature (Tg) from 60.1 to 49.3 °C in 7% PLA-WL biocomposites. The PLA-WL biocomposites exhibited an antibacterial activity according to the inhibition zone for Escherichia coli bacteria. The developed novel PLA-WL composites can be effectively utilized in various value-added industrial applications as a sustainable and functional biopolymer material.

Recent Advancements in Smart Biogenic Packaging: Reshaping the Future of the Food Packaging Industry

Due to their complete non-biodegradability, current food packages have resulted in major environmental issues. Today’s smart consumer is looking for alternatives that are environmentally friendly, durable, recyclable, and naturally rather than synthetically derived. It is a well-established fact that complete replacement with environmentally friendly packaging materials is unattainable, and bio-based plastics should be the future of the food packaging industry. Natural biopolymers and nanotechnological interventions allow the creation of new, high-performance, light-weight, and environmentally friendly composite materials, which can replace non-biodegradable plastic packaging materials. This review summarizes the recent advancements in smart biogenic packaging, focusing on the shift from conventional to natural packaging, properties of various biogenic packaging materials, and the amalgamation of technologies, such as nanotechnology and encapsulation; to develop active and intelligent biogenic systems, such as the use of biosensors in food packaging. Lastly, challenges and opportunities in biogenic packaging are described, for their application in sustainable food packing systems.

Effect of Plasticizer Content on Mechanical and Water Vapor Permeability of Maize Starch/PVOH/Chitosan Composite Films

Packaging materials based on biodegradable polymers are a viable alternative to replace conventional plastic packaging from fossil origin. The type of plasticizer used in these materials affects their functionality and performance. The effect of different plasticizers such as glycerol (GLY), sorbitol (SOR), and poly(ethylene glycol) (PEG) in concentrations of 5%, 10%, and 15% (w/w) on the structural features and functional properties of starch/PVOH/chitosan films was evaluated. The incorporation of a plasticizer increased the thickness of the biodegradable composite films. Furthermore, the material plasticized with 30% (w/w) sorbitol had the highest elongation at break, lowest water vapor permeability, and better thermal resistance. The results obtained in this study suggest that maize starch/PVOH/chitosan biodegradable composite films are a promising packaging material, and that sorbitol is the most suitable plasticizer for this formulation.

Starch-based bio-nanocomposites films reinforced with cellulosic nanocrystals extracted from Kudzu (Pueraria montana) vine

In the current study, starch-based active nanocomposite films reinforced with cellulosic nanocrystals (CNCs) of Kudzu were developed as an alternative option to existing biodegradable plastic packaging. Firstly, Kudzu CNCs were prepared by subjecting Kudzu fibers to the processes such as depolymerization followed by bleaching, acid hydrolysis, and mechanical dispersion. Further, nanocomposite films were formulated by blending pearl millet starch (PMS) and glycerol (30%) with different Kudzu CNCs compositions (0-7 wt%) using the solution casting process. The prepared PMS/Kudzu CNCs nanocomposite films were analyzed for their morphological (SEM and TEM), thermal (TGA and DSC), structural (FTIR), mechanical (tensile strength (TS), elongation at break and young modulus), and water barrier properties. The PMS/Kudzu CNCs films possessed improved crystallinity, heat and moisture-barrier properties, TS, and young-modulus after reinforcement. The optimum reinforcer concentration of CNCs was 5%. The Kudzu CNCs reinforced starch film offers a promising candidate for developing biodegradable films.

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.

O-ATRP synthesized poly(β-pinene) blended with chitosan for antimicrobial and antioxidant bio-based films production

Antioxidant and antimicrobial activities are important characteristics of active film packaging designed to extend food preservation. In this study, functional bio-based films were produced using different concentrations of antioxidant poly(β-pinene) bio-oligomer synthesized via organocatalyzed atom transfer radical polymerization (O-ATRP) and blended with chitosan of different molecular weights. The structural, mechanical, thermal, solubility, antioxidant, and antimicrobial properties of the films were investigated. The poly(β-pinene)-chitosan blends presented significant pores and irregularities with the increase of poly(β-pinene) concentration over 30%. Chitosan molecular weight did not show any important influence in the physical properties of the blends. Poly(β-pinene) load decreased the materials' tensile strength and melting temperature, exhibiting a plasticizing effect on chitosan chains. The antioxidant and antimicrobial activities of the films were improved by poly(β-pinene) incorporation and mainly depended on its concentration. Therefore, the incorporation of poly(β-pinene) in chitosan films can be an alternative for active packaging production.