Sustainable soft materials for food packaging: quality preservation and environmental impact

1 Introduction

The desire for convenience foods has increased due to urban lifestyles, which leads to sharp increase in packaged food consumption. Because conventional packaging materials contribute to pollution, resource depletion, and ecosystem deterioration, the negative environmental implications of their production and disposal have garnered a lot of attention. The main materials used for packaging in the food business include paper, glass, metal, and plastic. Different combinations of materials result in unique packaging solutions (Hemachandra et al., 2024).

Food packaging assists in developing more sustainable food value chains and reduces food waste by protecting and preserving the product’s quality and sensory attributes (Nilsen-Nygaard et al., 2021a). Due to its affordability, ease of processing, and lightweight nature, plastics were originally hailed as one of the most revolutionary inventions of the 20th century, enabling fast industrial growth and international trade. But there is a cost to the environment associated with this convenience. The annual production of plastics is over 359 million tons worldwide each year, of which an estimated 14 million tons end up in aquatic environments. Only 6%–26% of plastic trash is recycled; the other material ends up in landfills or the environment, with 74% of it being single-use plastic used mostly for packaging. Food pack aging is a major contributor to plastic pollution among packaging materials, especially because it is multilayered, non-recyclable, and prone to contamination. A rising concern about toxic plasticizers like phthalates—it is a class of synthetic chemical compounds—leaching into the food chain and possibly endangering human health are exacerbating these problems (Kumar et al., 2025).

Soft matter is a class of materials with mechanical properties that fall somewhere between ordinary solids and liquids, distinguished by its capacity to undergo substantial, reversible deformations in reaction to relatively small external forces. Sustainable soft materials for food packaging include bio-based polymers, hydrogels, edible films, elastomeric biopolymers, and nanocomposite systems that act according to fundamental soft matter principles. These principles include viscoelasticity, which determines mechanical flexibility and durability; glass transition behavior, which influences thermal stability and gas permeability; interfacial tension, which affects adhesion, coating performance, and multilayer film formation; and self-assembly, which allows for the formation of hierarchical nanostructures with improved barrier and functional properties. Understanding these soft matter properties is critical for developing sustainable packaging materials with increased mechanical performance, regulated mass transport, extended shelf life, and environmentally friendly characteristics. As a result, this analysis uses a soft matter viewpoint to critically investigate the structure-property-function linkages that support the development and deployment of sustainable food packaging materials (Ayari et al., 2024).

1.1 Comparative evaluation of sustainable packaging materials

Despite significant advances in producing sustainable packaging materials, no single material simultaneously meets the barrier, mechanical, economicand sustainability demands of food packaging (Nilsen-Nygaard et al., 2021b; Sharma et al., 2021). Excellent oxygen barrier qualities, biodegradability, renewability, and good film-forming ability are exhibited by polysaccharide-based materials such as starch, cellulose, alginate, pectin, and chitosan; however, their hydrophilic nature results in high water vapor permeability and relatively poor mechanical strength, limiting their use in high-moisture foods unless reinforced by cross-linking, nanofillers, or multilayer structures (Wani et al., 2021; Sharma et al., 2021). Gelatin, whey protein, soy protein, and zein are examples of protein-based films that have good film-forming qualities together with superior oxygen and aroma barrier qualities. However, broader industrial uses are still limited by their moisture sensitivity, comparatively low water resistance, and greater production costs (Ramos et al., 2012; Galus and Kadzińska, 2015).

Because they are hydrophobic, lipid-based coatings, like beeswax, carnauba wax, and formulations based on essential oils, effectively minimize moisture loss. However, rather than being used as stand-alone packaging materials, their brittleness, low mechanical strength, and limited gas barrier qualities typically necessitate their integration into composite films (Galus and Kadzińska, 2015; Han, 2014). Similar to various petroleum-based plastics, biodegradable polymers like polylactic acid (PLA) and polyhydroxyalkanoates (PHAs) can be manufactured using standard thermoplastic techniques. But their brittleness, comparatively high production costs, and reliance on industrial composting facilities continue to be major obstacles to commercialization (Auras et al., 2010; Niaounakis, 2015).

Due to their renewability, recyclability, and established recycling infrastructure, paper and fiber-based materials continue to be among the most economically successful sustainable packaging solutions. However, because of their porous nature, they are less resistant to gasses, moisture, and grease, requiring barrier coatings that could make recycling more difficult (Nilsen-Nygaard et al., 2021b). Similarly, incorrect disposal within traditional recycling streams may decrease recycling effectiveness, and compostable bioplastics often need industrial composting conditions for effective biodegradation (European Bioplastics, 2024; Ayari et al., 2024).

1.2 Nanomaterials and biodegradable polymers

For biodegradable polymers, nanomaterials have shown remarkable potential as reinforcing agents. By enhancing polymer–filler interactions and raising diffusion tortuosity, nanofillers such cellulose nanocrystals, nanoclays, graphene derivatives, and metal oxide nanoparticles enhance tensile strength, thermal stability, oxygen barrier performance, and antibacterial activity (Rhim et al., 2013; Ashfaq et al., 2022; Taghiyeva et al., 2024). However, large-scale commercialization is still hampered by issues with nanoparticle dispersion, migration, toxicological safety, regulatory approval, customer acceptance, and production costs (European Food Safety Authority (EFSA), 2021). As a result, choosing sustainable packaging materials should be application-specific, taking into account factors such as food attributes, shelf-life needs, processing circumstances, economic viability, regulatory compliance, and end-of-life management. Table 1 Summarizes the sustainable packaging materials, highlighting their advantages, limitations, and practical applications in food packaging.

TABLE 1. Types of sustainable packaging materials.

The majority of packaging material based on petroleum is non-biodegradable, its costs are unstable, and disposal issues that contaminate water and ecosystems are becoming more pressing. Plastics break down over time into micro and nanoplastics, which are currently found in more than 15 human tissues and fluids, such as meconium, blood, breastmilk, and placenta (Pulikkalparambil et al., 2023). Thus, it is much needed to develop bio-based, biodegradable food packaging materials has been prompted by customer push for greater sustainability (Nilsen-Nygaard et al., 2021b; Panou and Karabagias, 2023).

The term “sustainable food packaging materials” refers to the materials used in different packaging to provide safe, healthful, economical, and market-efficient packaging solutions by incorporating the idea of sustainability into the production process (Hussain et al., 2024). Biopolymers being non-toxic, eco-friendly, biodegradable and biocompatible, their application in food packaging is promising. These organic biopolymers contain thin protective film layers and superior cohesive structures that form films. Polysaccharides, proteins, starch, cellulose, and PLA are typical examples of substances that aid in food preservation by reducing the transmission of moisture, gas, aromatic compounds, and lipids. Their poor moisture resistance and inadequate mechanical strength are their primary disadvantages. These can be improved by adding strengthening agents like nanofillers, plasticizers, and natural additions like essential oils (Perera et al., 2023; Akhundzada et al., 2026).

In food packaging, edible films and coatings contain flavors, antimicrobials, or antioxidants, increase safety, strength, and shelf life, reduce waste, and withstand moisture, scent, solvents, and oxidation. Lipids give superior moisture/oxygen barriers and hydrophobicity, while proteins and polysaccharides offer acceptable mechanical and oxygen barriers but low moisture resistance because of hydrophilicity. Due to intrinsic restrictions, packaging composed of a single material sometimes falls short of ideal packaging standards. Consequently, creating composites is a tactic to enhance the qualities of food packing (Devi et al., 2024).

A new paradigm that goes beyond containment is smart packaging, which offers intelligent, active characteristics that interact with food and its surroundings (Park and Kwon, 2026). Time-temperature indicators (TTIs), freshness sensors, and colorimetric labels are examples of sensors and indicators used in intelligent packaging to track food quality in real time. Enhanced by developments in materials science, nanotech, and digital tools, it promotes circular food systems when combined with bio-based or biodegradable materials (Park and Kwon, 2026).

Biofilms based on starch and alginates are inexpensive, abundant, nontoxic, renewable, and biodegradable. While alginate gives mechanical strength, chemical stability, water barriers, flavor preservation, and control over fat oxidation, starch offers transparency, strong lipid/oxygen/UV barriers, and the capacity to create films. Alginate exhibits brittleness, low moisture barriers, high WVTR, and hydrophilicity, while starch has poor processability, water/thermal resistance, and hydrophilicity. Similar to this, pectins have superior oil, gas, and aroma barriers as well as mechanical and rheological qualities; however, they are not efficient against moisture and have poor mechanical and thermal stability, brittleness, high solubility, and no antibacterial activity (Perera et al., 2023). This review paper focus on sustainable packaging materials, their mechanical, barrier and thermal properties, mechanical reinforcement, material interactions and safety in detail.

1.3 Structure–property relationships, molecular interactions, and dynamics

The interaction between molecular structure and functional characteristics controls the performance of sustainable soft materials used in food packaging. Mechanical strength, flexibility, permeability, thermal stability, and biodegradability are determined by polymer chain architecture, crystallinity, molecular orientation, cross-linking density, and phase morphology (Auras et al., 2010; Rhim et al., 2013; Ayari et al., 2024). Because amorphous domains improve chain mobility and enable moisture and gas movement while crystalline portions inhibit molecular diffusion, semi-crystalline polymers, such polylactic acid (PLA), often have lower gas permeability and greater stiffness than amorphous polymers (Auras et al., 2010; Siracusa, 2012). Similarly, adding nanofillers or reinforcing fibers alters the microstructure of the polymer, increasing mechanical and barrier qualities, decreasing free volume, and improving stress transfer (Rhim et al., 2013; Ashfaq et al., 2022).

Intermolecular interactions such as hydrogen bonding, electrostatic attraction, van der Waals forces, hydrophobic interactions, and covalent cross-linking also control these materials’ activity. Water sensitivity, film cohesiveness, polymer compatibility, and deformation resistance are all impacted by these interactions (Nilsen-Nygaard et al., 2021a). While hydrophobic interactions enhance the moisture resistance of lipid-based coatings, hydrogen bonding fortifies films based on proteins and polysaccharides (Galus and Kadzińska, 2015). Strong polymer–nanofiller interfacial adhesion enhances gas barrier performance, thermal stability, and reinforcing effectiveness in polymer nanocomposites (Rhim et al., 2013).

Biodegradable packaging materials display viscoelastic behavior that is dependent on glass transition temperature (Tg), molecular relaxation, and chain mobility, just like normal soft matter systems. Increased chain mobility improves flexibility above Tg, but it also speeds up additive migration and gas permeation. On the other hand, below Tg, decreased molecular mobility increases brittleness while enhancing dimensional stability and barrier performance (Fang and Vitrac, 2015). Therefore, creating sustainable food packaging materials with enhanced performance, safety, and durability requires an understanding of how molecular structure, intermolecular interactions, and material dynamics interact.

2 Classification of soft materials

The food packaging industry has long employed conventional packaging materials made from petroleum and its byproducts. Among them are polystyrene (PS), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and linear low-density polyethylene (LLDPE). Only 21% of them are recycled and burned, while 79% are rejected, endangering the environment. Plastics that end up in landfills and the ocean can contaminate the ecosystem (Panou and Karabagias, 2023). The timely development of sustainable and ecologically suitable substitutes for conventional plastic food packaging materials would be extremely beneficial to the earth and its people (Jahangiri et al., 2024). The different types of soft packaging materials used in food industry has been summarized in Figure 1.

2.1 Bio-based and biodegradable polymers

These substances come from renewable sources, such as microorganisms or plants, and undergo biological breakdown to produce non-toxic byproducts. They are divided into two groups: those that come from biomass, such PHAs and PLA, and those that come from natural sources, like proteins and polysaccharides.

2.1.1 Naturally sourced polymers

They are inexpensive, renewable, biodegradable, and edible, naturally generated biopolymers made from plants, animals, algae, and microbes show promise as sustainable substitutes for polymers derived from fossil fuels in food and beverage packaging. Caseins and whey proteins, collagen and gelatin, chitin and chitosan, keratin, gluten, soy, starch and zein, cellulose, pectin, alginate, pullulan, and kefiran are examples of biopolymers that are appropriate for biodegradable, bio-based packaging materials (Stoica et al., 2024; Mustafazade et al., 2025).

2.1.2 Polymers synthesized from biomass

These biopolymers, like polylactic acid (PLA) and polyhydroxyalkanoates (PHAs), are produced by microorganisms using renewable resources or by fermentation and chemical processes from lactic acid and agricultural waste (such as corn, beets, rice, and potatoes), providing sustainable substitutes for plastics derived from fossil fuels that perform similarly. PHAs are biodegradable polyesters with strong mechanical and UV resistance (Stoica et al., 2024).

2.2 Edible and water-solublefilms

Polysaccharides, lipids, and proteins from both plant and animal sources are used to make these edible and biodegradable films and coatings. A solubilizing medium (such as water or ethanol), plasticizers, and film-forming biopolymers (such as proteins and carbohydrates) are the primary constituents; optional additions (such as cross linkers, colorants, surfactants, or lipid-based compounds) interact to improve film qualities. Improved moisture resistance, water solubility, gelling behavior, mechanical and thermal performance, antibacterial activity, heat-based sealing, flexibility, and colorless appearance are some of the main benefits (Chhikara & Kumar, 2021; Akhundzada et al., 2026).

2.2.1 Polysaccharide-based films

Long carbohydrate chains joined by glycosidic linkages make up polysaccharides, which are the most prevalent natural macromolecules and are frequently utilized in edible packaging. They originate from marine (alginate), animal (chitin, chitosan), plant (cellulose, starch, pectin), and microbial (xanthan gum, pullulan). Oil-free, tasteless, colorless, chemically stable, and simple to process, polysaccharide-based films and coatings can prolong the shelf life of fruits, vegetables, meat, and seafood by reducing oxidative rancidity, dehydration, and surface darkening. Owing to their selective permeability, they function as efficient barriers to CO₂ and O₂ at low to medium humidity, limiting gas exchange and respiration in fresh cut produce (Nair et al., 2023; Mustafazade et al., 2025).

2.2.2 Protein-based films

Edible packaging uses both the fibrous (water insoluble) and globular (water soluble) forms of proteins, which are intricate polymers of amino acids joined by peptide bonds. Collagen, gelatin, casein, whey, soy, bean, wheat gluten, and peanut proteins are common examples. These proteins have weak water resistance but strong mechanical strength and effective barriers to _CO2, O₂, lipids, and aromas (Nair et al., 2023).

2.2.3 Lipid-based films

Natural waxes, acetylated monoglycerides, and resins are examples of lipids, which are hydrophobic polymers derived from plants, animals, or insects that are frequently utilized in food packaging. They are efficient moisture barriers in composite films and coatings, particularly wax coatings, which significantly minimize water migration, but they are unable to create stand-alone films. Animal (such as beeswax) and plant (such as carnauba, candelilla, and rice bran) waxes are esters of long-chain alcohols and fatty acids that are frequently employed to restrict moisture and increase fruit shelf life. Essential oils are added to lipid systems to provide antibacterial and antioxidant action, delaying lipid oxidation and extending shelf life. Natural and synthetic waxes, such as paraffin, are applied either alone or in combination with other ingredients (Nair et al., 2023).

2.3 Paper and fibre-based flexible substrates

Flexible packaging materials offer food products a long shelf life and ease of transportation due to their non-rigid nature, high mechanical strength, and compatibility. Paper, paper board, laminates, aluminum foil, and other flexible packaging materials are crucial for the packaging of both fresh and processed foods (Saha et al., 2022).

2.3.1 Paper and paperboard

Paper-based food packaging materials are biodegradable, renewable, and widely utilized. Paper’s porous porosity makes it ineffective as a barrier against grease, water vapor, water, and volatile chemical compounds (Kopacic et al., 2018). In order to enhance the functional and protective qualities of paper used as primary packaging, it is nearly always treated, coated, laminated, or lacquered with substances like waxes, resins, or lacquers (Sarkar and Kuna, 2022). Kraft paper, bleached paper, wrapping tissue paper, greased proof paper, glassine paper, vegetable parchment paper, waxed paper, and other types of paper are used in the food business.

Grammage is the primary distinction between paper and paperboard, with paperboard having a grammage more than 250 gms (grams per meter square). Paper boards are often thicker than paper and consist of several layers (Deshwal et al., 2019). Secondary or tertiary packages, such as boxes, cartons, and trays, are frequently made with it. It hardly ever comes into contact with food (Sarkar and Kuna, 2022). Linerboard, chipboard, food board, folding boxboard, whiteboard, solid board, and other forms of paperboard materials are also utilized (Deshwal et al., 2019).

2.3.2 Aluminium foil

Packaging made of aluminum is widely used to transport and store both wet and dry food items at various temperatures. Its pliability, inertness (nontoxic), hygiene (sterile), and barrier qualities against light, moisture, and aroma, aluminum foil is used in packaging. Aluminum can be recycled without losing quality, it is both affordable and completely sustainable. Thin, pure aluminum foil crumbles easily and has poor strength. Fiber reinforcement can enhance these characteristics of aluminum foil.

2.3.3 Fibre based flexible substrates

Natural fibers are lightweight, biodegradable, CO₂-neutral, renewable, and improves the ecological disposal of polymer matrices, therefore, are frequently utilized as reinforcements in composites. However, in humid environments, their significant hydrophilicity results in poor mechanical qualities, which presents packing issues. By origin, natural fibers can be classified into three groups: plant-based, mineral-based, and animal-based. Natural fibers derived from plants, such as hemp, kenaf, sisal, bamboo, jute, banana plant, pineapple, corn, agave, and cotton, are lignocellulosic in origin and consist of lignin, hemicellulose, and cellulose. Proteins make up the majority of animal-based fibers, such as wool and silk. Asbestos and basalt are examples of mineral-based fibers that are created by geological processes (Pulikkalparambil et al., 2023).

2.4 Compostable bioplastics

Bioplastics are bio-based, biodegradable, or both, grouped into:

• bio-based non-biodegradable (e.g., bio-PE, bio-PP, bio-PVC, bio-PET)
• bio-based biodegradable (e.g., PHA, PLA)
• fossil-based biodegradable (e.g., PBAT, PBSA, PCL, PVOH) (Piergiovanni and Limbo, 2015).

Although bioplastics have the potential to be used in sustainable packaging, they have disadvantages such as temperature-sensitive biodegradation that might contaminate landfills, high costs, and poor mechanical and barrier qualities that need to be improved with sophisticated technology (Varghese et al., 2023).

3 Nanocomposites and nanomaterial reinforcement

To stop deterioration and nutrient loss, food packaging uses nanomaterials such as nanofibers, nanoparticles, nanocomposites, and nanoplatelets. Antibacterial, self-cleaning, mechanical, thermal, barrier, and water-resistant qualities are all improved by nanofillers. NPs improve antimicrobial preservation by focusing on humidity, smells, ethylene, CO₂, and O₂. For secure, useful packaging, sustainable designs include organic, inorganic, and hybrid nanoparticles into polymer matrices (Ghosh et al., 2025).

By enhancing physicochemical characteristics, quality protection, shelf life, and freshness, inorganic nanoparticles (ZnO, Au, CuO, Ag, TiO-NPs), nanoclays, and carbonaceous nanostructures (CNTs, graphene) improve food packaging (Taghiyeva et al., 2024). Metal-based nanocomposites are functionalized for better performance by combining nanofillers such as ZnO, Au, TiO, CuO, and Ag-NPs with plasticizers and antimicrobials. They are perfect for biopolymer matrices because of their large surface area and innate antibacterial qualities, acting as both structural and active elements (Ghosh et al., 2025).

Flexibility, biocompatibility, and conductivity are provided by organic nanomaterials, which are mainly carbon-based or biologically generated. In addition to biopolymers including alginate, cellulose nanocrystals (CNC), and nanofibers (CNF) from plants and animals, it contains starch, cellulose, chitosan, proteins, clay, and carbon nanotubes (CNTs) (Ghosh et al., 2025).

Hybrid nanomaterials merge the strengths of inorganic and organic components for specific applications such as electronics, packaging, nanomedicine, and catalysis. Both metal-organic and organic-inorganic varieties are included; hybrid nanocomposite films including AgNPs and ZnO NPs provide antibacterial activity, a compact microstructure, tensile strength, thermal stability, barrier qualities, and sustainability (Ghosh et al., 2025). The Application of soft packaging materials along with nanomaterials used has been depicted in Table 2.

TABLE 2. Application of soft packaging materials in food industry.

3.1 Mechanisms of mechanical reinforcement

As stress-transfer agents, nanofillers greatly increase Young’s modulus and tensile strength (Yang and Skirtach, 2025; Peng et al., 2025). This is accomplished by the fillers wasting energy under mechanical load and limiting the mobility of polymer chains. For instance, hardness and stiffness are significantly increased when cellulose nanocrystals are added to a k-carrageenan matrix (Yang and Skirtach, 2025). While exfoliated systems (individual layers dispersed) increase contact area and reinforcement, intercalated structures offer fewer notable advantages; the dispersion state is crucial (Honarvar et al., 2016). Reinforcement efficiency usually peaks at modest concentrations (generally less than five weight percent); going above this threshold causes nanoparticle aggregation, which results in structural flaws (Peng et al., 2025).

3.1.1 Factors influencing mechanical reinforcement in nanocomposite packaging

By enabling effective stress transfer between the polymer matrix and the reinforcing phase, nanoscale reinforcements can greatly improve the mechanical performance of sustainable soft packaging materials by increasing tensile strength, Young’s modulus, toughness, and dimensional stability (Rhim et al., 2013; Honarvar et al., 2016). In addition to nanoparticle concentration, other factors that affect reinforcement efficacy include aspect ratio, particle shape, surface chemistry, dispersion quality, and interfacial adhesion. These factors all affect load transmission and fracture propagation within the polymer matrix (Dufresne, 2013; Honarvar et al., 2016).

3.1.2 Influence of nanofiller morphology and aspect ratio on reinforcement efficiency

Because they have a larger interfacial area than spherical nanoparticles, high-aspect-ratio nanofillers like carbon nanotubes, cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), layered nanoclays, and graphene nanoplatelets enable stronger polymer–filler interactions and significant improvements in stiffness, tensile strength, and gas barrier properties at comparatively low filler contents (Rhim et al., 2013; Dufresne, 2013). Conversely, because they offer less interfacial contact and are less successful in creating continuous reinforcing networks, spherical nanoparticles, such as ZnO, TiO, and Ag nanoparticles, typically require larger loading levels (Ashfaq et al., 2022).

3.1.3 Surface functionalization and nanoparticle dispersion strategies

Because surface chemistry determines the compatibility of nanoparticles with the polymer matrix, it also plays a critical role in reinforcing. By improving interfacial adhesion and facilitating effective stress transmission, surface functionalization via silanization, acetylation, or graft polymerization increases mechanical strength, thermal stability, and moisture resistance (Dufresne, 2013; Rhim et al., 2013). Because agglomeration at greater filler concentrations produces stress concentration spots that lower tensile strength and elongation at break, uniform nanoparticle dispersion is equally crucial (Honarvar et al., 2016). Therefore, producing repeatable nanocomposites with excellent performance requires adjusting filler loading and using appropriate processing methods such solvent casting, melt blending, and ultrasonication.

3.1.4 Reinforcement mechanisms of different nanofillers in biodegradable polymers

Through various processes, biodegradable polymers are reinforced by different nanofillers. While cellulose nanocrystals strengthen polymers due to their high crystallinity and large hydrogen-bonding networks, layered silicate nanoclays enhance stiffness and barrier characteristics by enhancing the tortuosity of diffusion channels (Rhim et al., 2013; Dufresne, 2013). Because of their inherent mechanical strength and high aspect ratio, carbon nanotubes and graphene derivatives show remarkable reinforcing capability; however, efficient dispersion is necessary to prevent aggregation (Ashfaq et al., 2022). In addition to their antibacterial and UV-protective properties, metal oxide nanoparticles like ZnO and TiO often have a lower reinforcing capability than anisotropic nanofillers (Honarvar et al., 2016). Therefore, choosing the right nanoparticle type, shape, surface properties, and dispersion method is essential to creating food packaging materials that are both mechanically stable and environmentally friendly.

3.2 Barrier enhancement through tortuosity

Reducing permeability to gases (O₂, CO₂) and water vapor is one of the main objectives of reinforcement (Honarvar et al., 2016). This is explained by the “tortuous pathway” paradigm, which states that high-aspect-ratio nanofillers, such as clay platelets, decrease the diffusion rate of gas molecules by creating a zigzag path for them to follow (Nilsen-Nygaard et al., 2021b). This reinforcement is essential for keeping fresh fruit from losing moisture and protecting foods high in lipids from oxidation. Layer-by-layer (LbL) assembly is one advanced technology that can produce “nanobrick wall” constructions with almost undetectable oxygen transmission rates (Ashfaq et al., 2022).

3.3 Synthesis and processing challenges

Both top-down (such as mechanical milling and electrospinning) and bottom-up (such as sol-gel, ionic gelation, and chemical vapor deposition) techniques are used to create reinforced nanocomposites (Ashfaq et al., 2022). It is still very difficult to achieve interfacial compatibility between hydrophilic fillers and hydrophobic matrices, which frequently calls for surface modifications like acetylation or silane grafting (Nilsen-Nygaard et al., 2021a).

3.4 Safety, migration, and future perspectives

The main issue with reinforced packaging is the migration of nanoparticles into food matrices, which is affected by temperature, contact time, and particle size (Honarvar et al., 2016). Although migration is frequently negligible and falls within legal bounds, careful risk assessments are necessary due to the possibility of cytotoxicity (Silva et al., 2020). In order to ensure food safety and advance a circular economy, future trends will focus on green nanotechnology, giving priority to the use of recycled and renewable nanomaterials (Barage et al., 2022).

4 Functional performance and quality preservation

Conventional petroleum-based polymers with high gas and moisture permeability include polyethylene (PE) and polypropylene (PP). This disadvantage reduces shelf life of packed food items as it encourages oxidation, microbial growth, and texture or flavor degradation. The food sector has therefore requires the development of packaging materials with enhanced barrier qualities on top priority. Researchers have looked into biopolymers as sustainable substitutes to lessen these difficulties. Compared to conventional plastics, biopolymer such as polylactic acid (PLA), starch-based film coatings, and polyhydroxyalkanoates (PHA)—offers renewability as well as biodegradability, ensuring them to be more environmental friendly. However, these materials frequently exhibit less mechanical strength with high gas permeability, which limits their use in food packaging. Incorporating nanoparticles into polymer matrices has become a promising strategy to overcome these limitations. To surmount these constraints, incorporating nanomaterials into polymer matrices has emerged as a viable approach. Nanomaterials such as nanoclays, metal oxide nanoparticles, and carbon-based nanomaterials enhance the mechanical strength and flexibility of packaging films. These nanomaterial-reinforced films are lightweight, durable, and cost-effective, minimizing material usage, shipping costs, and the need for multi-layer structures. Moreover, biodegradable and bio-based nanomaterials offer sustainable alternatives with comparable or superior barrier properties, being compostable or recyclable in line with environmental initiatives (Edo et al., 2025). The incorporation of other polymers, crosslinking agents, and nanofillers along with biopolymer has shown enhanced the thermal stability.

4.1 Mechanical and barrier properties of packaging material

Mechanical properties of packaging systems protect food during storage, handling, and processing. The polymer matrix architecture governs these properties, primarily assessed via tensile strength, elongation at break, and elastic modulus (Perera et al., 2023). Tensile strength (MPa) is the maximum uniaxial stress a film withstands before fracture. In food packaging, it ensures resistance to handling and distribution damage alongside barrier properties (OTR/WVTR). It depends on polymer chemistry (molecular weight, stereochemistry/branching), crystallinity/orientation, additives (plasticizers, fillers), processing history, and conditioning (thickness, temperature, RH) (Kumar et al., 2025). The percentage increase in a film’s gauge length at fracture compared to its initial length in typical tensile tests is measured by elongation at break (EAB, %). Materials can be strong but brittle (low EAB) or moderately strong and very ductile (high EAB), depending on their ductility and stretchability. Benchmarking biodegradable matrices and mixes is a common usage for it (Kumar et al., 2025). Young’s modulus (E or Y, GPa) is a measurement of material stiffness that connects mechanical attributes and film flexibility to the composition of chemicals (Shah et al., 2023).

The biodegradable polymers have less mechanical strength than the petroleum-based equivalents. For practical use, investigations concentrate on enhanced reinforcement and structure-property handling. Cellulose provides structural support with strength of 30–50 MPa, whereas starch is brittle and needs plasticizers such as glycerol to reduce tensile strength (Abdulsalam et al., 2025). Protein-based materials (soy, gelatin or whey) form dense hydrogen-bonded networks that can reach high tensile strengths (up to 55 MPa for whey), but these materials are hydrophilic and thus their mechanical robustness drastically deteriorates under extreme humidity conditions (Kumar et al., 2025).

Similarly, flexible wraps for fresh fruit made from biodegradable starch-based nanocomposites have shown promise in reducing the need for plastics derived from petroleum. A further notable advancement involves chitosan-based antimicrobial films, which are now commercially employed in meat and dairy packaging to suppress bacterial growth and bolster food safety (Motelica et al., 2020). Studies have reported that chitosan-based nanocomposites enhance water resistance and improves food shelf life (Liu et al., 2023; Mustafazade et al., 2025).

The mechanical attributes of soy protein isolate (SPI) film had poor mechanical properties and was brittle and hard to handle. The incorporation of SPI and gelatin for the composite films, significantly improved the TS and EAB (Cao et al., 2007). The mechanical parameters, including TS, EAB, and YM of the films, increased with increasing the concentration of SPI. At an SPI concentration of 10% and 6%, the maximum and minimum tensile strengths were found to be 3.5 MPa and 1.6 MPa, respectively (Nandane and Jain, 2015).

Zein, a hydrophobic prolamin protein from corn, is widely used for edible films owing to its superior film-forming and barrier properties, making it ideal for food packaging (Argüello-García et al., 2014). Torun and Ozdemir (2022) showed that zein films outperform milk protein-based films in tensile strength (TS) and elongation at break (EAB). Combining zein with biopolymers like chitosan enhances film elasticity and barrier performance, particularly with increasing zein concentration (Escamilla-García et al., 2013; Shah et al., 2023).

To strengthen biodegradable polymers and enhance stress transfer, researchers employ nanocomposites (metal oxides, nanoclays, nanocellulose). The incorporation of nanoparticles frequently improves mechanical attributes: gallic acid-ZnO in chitosan increased TS/EB by 7×/5× via hydrogen bonding; TiO/ZnO/Ag composites show 30%–50% TS gains from strong matrix-filler interactions (Peng et al., 2025). During transportation, snack bar wrappings composed of cellulose nanofibers and graphene derivatives had superior tensile strength and barrier qualities. Improved moisture and oxygen barrier qualities were demonstrated by edible food coatings made of biopolymers loaded with nanoclay and plant extracts. Similarly, improved moisture resistance and biodegradability were reported in cheese packaging films made of starch-based bioplastics and silver-doped nanopolymers (Edo et al., 2025). Cherry and tomatoes treated with polylactic acid containing nano-zinc oxide (ZnONPs) and pomegranate peel extract showed improved UV barrier, water vapor permeability, elongation at break, and increased antibacterial and antioxidant activity (Dai et al., 2022).

4.2 Thermal, antioxidant and antimicrobial properties

For edible films to maintain their structural integrity at elevated temperatures, thermal stability is essential (Bhatia et al., 2023). Innovative packaging requires an evaluation of this attribute during film development. Commonly employed methods include differential scanning calorimetry (DSC), thermomechanical analysis (TMA), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). Key thermo-physical parameters such as thermal conductivity, diffusivity, glass transition, crystallization and melting temperatures, decomposition temperature, heat deformation temperature and expansion rate determine the stability of the packing material. Nano-reinforcements like nanocellulose, nanostarch, and nanochitosan enhance the heat resistance of edible films prepared from biopolymers. For example, nanocomposites based on gelatin matrices and cellulose nanocrystals from bacterial cellulose (made by Gluconacetobacter xylinus) have improved thermal characteristics. Similarly, crosslinking enhances stability by restricting the rotational and vibrational motion of molecules under heat stress. This is possible to obtain utilizing natural acids (tannic, gallic, caffeic, ferulic) or synthetic agents (formaldehyde, glutaraldehyde, carbodiimides, polyepoxy compounds, acylazides) (Shah et al., 2024). The addition of cinnamon essential oil to sodium alginate (SA) and acacia gum (AG) composite edible films led to an increase in thickness and elongation at break (EAB), but a decrease in transparency, tensile strength (TS), water vapor permeability (WVP) and moisture content (MC). Furthermore, it increased the antioxidant capabilities of the hydrogel based films.

Even while natural bioactive substances including essential oils, plant polyphenols, flavonoids, and antimicrobial peptides have garnered a lot of interest for the development of active food packaging, a number of physicochemical and technological constraints still limit their practical application. During manufacturing and storage, essential oils can undergo oxidation, evaporation, hydrolysis, and photodegradation due to their high volatility and chemical instability. Major bioactive components, such as thymol, carvacrol, eugenol, cinnamonaldehyde, and limonene, degrade more quickly when exposed to oxygen, UV light, high temperatures, and humidity. This reduces their antioxidant and antimicrobial efficacy long before the packaged food reaches its intended shelf life (Ribeiro-Santos et al., 2017; Ju et al., 2019; Han, 2014). As a result, long-term performance during commercial storage and distribution may not be effectively represented by the initial antimicrobial activity that is commonly reported under laboratory settings.

The release kinetics of bioactive substances from the polymer matrix are another crucial factor. Antimicrobial efficacy is dependent on both the concentration of active ingredients and their continuous and regulated release into the food-package interface. While excessive retention within the polymer restricts the active ingredient’s availability for microbial suppression, rapid diffusion may lead to an initial burst release that causes premature depletion of the molecule. Thus, careful regulation of polymer composition, cross-linking density, matrix crystallinity, diffusion paths, and interactions between the active chemicals and the packaging material is necessary to achieve an ideal release profile (Nilsen-Nygaard et al., 2021a; Realini and Marcos, 2014; Donsì and Ferrari, 2016). Cyclodextrins, liposomes, nanoemulsions, nanofibers, and mesoporous nanoparticles are examples of encapsulation techniques that have shown significant promise for safeguarding volatile substances and permitting continuous release during storage.

Furthermore, the absence of defined testing methodologies makes assessing the long-term performance of active packaging difficult. Few studies examine the stability of bioactive compounds under realistic food storage conditions, such as temperature fluctuations, humidity, light exposure, and extended storage times. The majority of published studies use short-term in vitro assays to evaluate antimicrobial and antioxidant performance immediately following film preparation. In addition to making direct comparisons between research more difficult, differences in microbial strains, food simulants, analytical techniques, and storage conditions also restrict the implementation of laboratory results in commercial settings (Ashfaq et al., 2022; Ribeiro-Santos et al., 2017; Ju et al., 2019). Therefore, in order to evaluate active packaging solutions objectively and support regulatory approval, internationally standardized testing procedures that include release kinetics, accelerated aging studies, real-food storage experiments, and long-term antimicrobial performance are crucial.

In order to enhance the stability, controlled release, and durability of naturally occurring bioactive substances, future research should focus on developing safe-by-design delivery methods that integrate encapsulating technologies with biodegradable polymer matrices. Incorporating migration studies, real-time shelf-life evaluations, and predictive diffusion models will enable the successful commercialization of active packaging in sustainable food packaging applications while offering a more thorough understanding of its long-term functionality.

Chitosan/beeswax films are environmentally friendly and may successfully control pathogenic germs while maintaining food quality. Chitosan films properties can be further improved when combined with plant-derived non-toxic extracts such as honeysuckle flower and citrus extracts (for antimicrobial activity), clove eugenol and maqui berry extracts (for antioxidant capacity), thyme extract (for barrier performance), tannic acid (for mechanical strength), young apple polyphenols (for thermal stability), and carvacrol (for color stability). Synthetic mixes such as chitosan/poly (lactic acid), chitosan/salicylic acid, chitosan/fumaric acid and chitosan/low density polyethylene sheets also increase packaging performance. Improved tensile and thermal characteristics of chitosan nanocomposites with lactic acid oligomer grafted as nanofillers (Hussain et al., 2024).

Starch nanoparticles/starch nanocrystals improves biodegradability, water and thermal impermeability, flexibility, barrier and strength properties of composites (Dularia et al., 2019; Campelo et al., 2020). Condensed tannins (CTs), abundant natural phenolic polymers, serve as multifunctional additives in food packaging. They reinforce polymer matrices, improving mechanical properties, UV and thermal stability, and gas barrier performance. Additionally, CTs extend food shelf life by mitigating deterioration, while their antioxidant properties protect common packaging materials, like polyolefins and polylactic acid—from thermal and photo-oxidation (Hussain et al., 2024).

5 Food packaging material interactions with food and safety aspects

The safety, quality and shelf life of food are greatly impacted by the interactions between food products and packaging materials. The above interaction involves complicated physical, chemical, and biological processes and hence demands thorough examination. It involves mass transfer, which takes place when substances pass through the packaging material to the food by migration, permeation/sorption mechanisms, either independently or concurrently. Fick’s and Henry’s equations of diffusion govern the transfer of mass, which describe the transport of substances through materials due to concentration gradients (Gupta et al., 2024).

5.1 Migration behaviour in sustainable soft packaging materials

Migration is defined as the absorption of chemicals in packaging material by food (or vice versa) via a particular method. Migration from food packaging material involves the transfer of chemical compounds from the packaging material to food, and it is a key concern in ensuring food safety. Temperature, contact time, and food composition all exert an impact on the migration rates, with fatty and acidic food products usually showing higher rates (Seref and Cufaoglu, 2025). Low molecular weight compounds can migrate from polymeric packaging into food matrices, these chemicals include residual monomers, additives (antioxidants, plasticizers) and oligomers. This migration might lead to risk of toxicological concerns (Souza et al., 2024). This chemical migration can occur at varied concentrations, based on the nature of the packaging material and the nature of the product (Fang and Vitrac, 2015).

The migration mechanism, which is triggered by techniques such as partitioning, diffusion and penetration, comprises variety of compounds, which includes antioxidants, stabilizers and plasticizers, that are integrated into materials of packaging in order to improve their functionality as well as reliability (Akhundzada et al., 2026). Diffusion is the macroscopic action of molecules that occurs when chemical compounds shift from a higher concentration to a lower concentration. Additives, residue monomers, and harmful substances migrate naturally via the packing medium and then into food items because of the concentration variations. This process continues until the system is in equilibrium. This movement is assessed by Fick’s and Henry’s diffusion laws that determine the rate of substance transfer on the basis of gradient and material characteristics. Environmental and physical factors have a major impact on the rate of diffusion. For example, higher temperatures increase chemical mobility and diffusion rates, which facilitate migration. On the other hand, diffusion rate is inversely related to thickness of the packaging material, exhibiting that thick barrier may decrease movement of migrants.

The actual distribution of a migrant between the two contact phases—the food and the polymer (packing)—after thermodynamic equilibrium is reached is referred to as partition. The partition coefficient (K), which indicates the ratio of the migrant’s concentration in the packaging material to its concentration in the food in equilibrium, is used to assess this interaction.

K = C p C f

One crucial indicator of food safety is the value of K. The migrant’s preference to stay inside the packing material is indicated by a high K value, which restricts migration into the meal. On the other hand, a low K value suggests that more of the migrant is absorbed by the food phase, increasing the risk of chemical contamination. Partitioning is highly impacted by chemical solubility and polymer-food compatibility. Lipophilic (fat-soluble) chemicals, such as plasticizers, have a major preference for fatty foods, which results in lower partition coefficients and higher migration levels into the food supply (Gupta et al., 2024).

The physicochemical properties of the polymer matrix, in particular glass transition temperature (Tg), crystallinity, free volume, and polymer chain mobility, which together control the diffusivity of migrating substances, have a significant impact on migration behavior in sustainable soft packaging materials. Biodegradable polymers like polylactic acid (PLA), starch, cellulose, chitosan, and protein-based films have diverse microstructures with crystalline and amorphous regions with distinct diffusion characteristics, in contrast to traditional petroleum-based plastics (Auras et al., 2010; Fang and Vitrac, 2015). Because of their dense molecular packing, crystalline domains limit molecular transport, while amorphous portions are the principal channels for the diffusion of additives, residual monomers, and other low-molecular-weight compounds because they have more free volume and improved chain mobility (Auras et al., 2010; Siracusa, 2012).

One of the most crucial elements influencing migration is the glass transition temperature (Tg). Polymer chains stay in a stiff, glassy form below Tg, which lowers migration and diffusion coefficients. Increased chain mobility increases free volume and promotes molecular diffusion into food when the storage temperature gets close to or higher than Tg (Fang and Vitrac, 2015). Migration is also influenced by the degree of crystallinity since highly crystalline polymers often have lower permeability than polymers with higher amorphous fractions (Auras et al., 2010).

Through polymer plasticization, environmental factors-specifically, temperature and relative humidity—further alter migration behavior. In hydrophilic biopolymers including starch, cellulose, gelatin, and chitosan, water molecules function as plasticizers by enhancing chain mobility and weakening hydrogen bonds, which speeds up diffusion and lowers barrier performance (Nilsen-Nygaard et al., 2021b; Siracusa, 2012). As a result, compared to hydrophobic polymers like polyethylene and polypropylene, biodegradable polymers frequently show higher sensitivity to environmental conditions.

These traits have significant effects on the safety of food contact. The behavior of biodegradable soft materials under actual storage circumstances may not be sufficiently predicted by traditional migration studies based only on Fickian diffusion. Therefore, to enhance consumer risk assessment and regulatory review, migration assessment should incorporate polymer-specific diffusion models, environmental plasticization, accelerated aging, and actual food storage circumstances (EFSA, 2021; Fang and Vitrac, 2015).

5.1.1 Migration pathways

Chemicals penetrate food networks via several different pathways, which are addressed below:

Contact migration is a major challenge in food a packaging system which is defined as the transfer of chemical compounds from packing materials to food via direct physical contact. Compounds included in packaging materials such as additives, residual monomers, plasticizers, stabilizers, dyes, adhesives and by-products generated during manufacture or processing may leach into the food matrix over time. This migration usually happens due to the transfer of molecules from regions of high concentration in the packing material to regions of lower concentration in the food product.

The extent of migration relies on parameters such as nature of the packaging material, temperature, storage period, type of food, surface area of contact and climatic conditions. There is a greater likelihood of chemical migration in fatty, acidic and high moisture diets. Excessive migration of dangerous compounds can negatively impact food quality, safety, sensory attributes, and consumer health. Thus, the study of migration behavior is crucial for the development of safe and sustainable food packaging materials (Yenido˘gan et al., 2023).

5.1.1.1 Gas phase migration

Gas phase migration refers to the process by which volatile chemicals transfer from packaging materials to the ambient atmosphere and subsequently into the food product. Unlike contact migration, characterized by direct interaction between packaging material and food, gas phase migration occurs when volatile chemicals are emitted and disperse into the air, potentially interacting with the food (Aydemir and Özsoy, 2020). Packaging materials may be utilized for aromatic or flavored items in environments susceptible to off-flavors and in the presence of chemical compounds or poisons. Volatile chemicals originating from mineral oil and solvents in printing inks may migrate from porous packaging materials to food through the gas phase.

5.1.1.2 Diffusion (penetration) migration

Penetration migration in food packaging occurs when chemicals or harmful substances from packaging materials permeate through the packaging structure into food upon contact: toxic substances, including heavy metals, residual chemicals plasticizers, and, inks that dissolve in water, fats, or other solvents (Yenido˘gan et al., 2023). Key factors influencing migration include packaging permeability, chemical composition of packaging materials, and food attributes (fat content, moisture). Health risks involve exposure to endocrine disruptors, heavy metals, and toxic residues. Prevention techniques encompass the utilization of barrier materials, the selection of safer packaging alternatives, and compliance with safety regulations to successfully restrict penetration migration (Naziruddin et al., 2023).

Set-off migration denotes the transference of chemical substances, including coatings, varnishes, or printing inks, from the external non-food-contact surface of packing materials via the substrate to the internal food-contact surface. This phenomenon frequently arises when printed packaging materials are layered, facilitating movement that may occur either visually or invisibly. Upon reaching the food-contact interface, these chemicals may contaminate food via gas-phase diffusion or direct contact transfer (Rzayev et al., 2021).

Numerous substances included in plastic packaging materials, such as monomer residues, oligomers, additives, reaction by-products, adhesive constituents, and printing inks, may migrate from external packaging layers into food products, especially in stacked packaging systems or vending machine cups. Various factors affect migration behavior, including pressure, temperature, the chemical characteristics of inks or coatings, and the solubility of ink components in food matrices, whether hydrophilic or lipophilic. Residual chemicals, heavy metals, and other pollutants leaching from packing materials may jeopardize food quality and customer safety. Preventive measures encompass the utilization of food-grade printing substances, suitable packaging design, and enough drying or curing of inks to reduce direct ink-food interaction and guarantee food safety.

5.2 Permeation

Permeation is one of the most significant process in this field of food packaging that involves transfer of gases (such as carbon dioxide and oxygen), light, moisture, flavor, aroma, and volatile chemicals coming from packaging substances into the food or vice versa (Caner, 2018). This transport of gases may affect food safety due to variations in gas composition within the packing material (Garba, 2023). As an example, the penetration of oxygen may induce oxidative reactions in high-fat foods like olive oil (Devi et al., 2024).

5.3 Adsorption

Also known as “Scalping” refers to the phenomenon wherein packaging materials adsorb or absorb essential sensory components in food, including flavors, aromas, lipids, and moisture (Garba, 2023). This correlation may diminish the quality of packaged food, especially in products where flavor and aroma are paramount. Adsorption transpires when components adhere to the surface of the packing, while absorption occurs when they infiltrate the substance. Sorption can compromise the structural integrity of packaging materials, such as low-density polyethylene (LDPE), by enhancing their permeability to oxygen, hence accelerating food deterioration (Caner, 2018). The extent of sorption is influenced by the characteristics of the packaging material, the food content, and environmental factors such as temperature and humidity. Fick’s law of diffusion, which elucidates the movement of molecules in relation to concentration gradients, regulates sorption similarly to migration (Gupta et al., 2024; Rzayev et al., 2021).

5.4 Nanomaterial safety, toxicological concerns, and food-contact regulations

The mechanical strength, barrier qualities, antibacterial activity, and shelf-life extension of sustainable food packaging have all been greatly enhanced by the addition of engineered nanomaterials. However, their use has sparked worries about long-term toxicological safety, consumer exposure, and nanoparticle migration. Particle size, morphology, surface chemistry, concentration, polymer–nanoparticle interactions, food content, storage conditions, temperature, and relative humidity are some of the variables that affect migration (EFSA, 2021; Bott et al., 2014). Smaller nanoparticles have more surface area and reactivity, which increases the possibility of migration, especially in matrices of biodegradable polymers where temperature and moisture may plasticize the polymer and improve molecular mobility.

Oxidative stress, inflammation, cytotoxicity, genotoxicity, and bioaccumulation after extended dietary exposure are among the possible toxicological consequences linked to migrating nanoparticles. Even while nanoparticles like ZnO, TiO, Ag, and CuO have strong antibacterial properties, too much migration can change the intestinal microbiota, cause reactive oxygen species (ROS), and interfere with cellular homeostasis. There are currently few long-term exposure studies and systematic toxicological evaluations, especially for biodegradable nanocomposites and multifunctional nanomaterials, however evidence indicates that migration typically stays below regulatory limits under typical food-contact circumstances (EFSA, 2021; Chaudhry et al., 2008).

The European Food Safety Authority (EFSA), the U.S. Food and Drug Administration (FDA), and Commission Regulation (EU) No. 10/2011 have established frameworks for regulating food-contact nanomaterials that mandate thorough migration testing, toxicological evaluation, and risk assessment prior to commercialization. Safe-by-design methods incorporating migration modeling, polymer physics, chronic toxicity assessment, life-cycle analysis, and post-market surveillance should be used in future regulatory initiatives. To enhance the assessment of nanoparticle migration, environmental fate, and human health hazards related to sustainable food packaging materials, harmonized international testing methodologies are also required.

6 Industrial translation and commercial viability of sustainable soft materials for food packaging

The transition from laboratory research to industrial-scale production is critical for sustainable soft food packaging materials. Despite advances in biodegradable polymers, bio-based films, edible coatings, and compostable laminates, large-scale commercialization faces technical, economic, regulatory, and infrastructural challenges (Kumar et al., 2025). Successful industrial adoption requires functional properties, consistent performance, regulatory compliance, cost competitiveness, and integration with existing packaging systems (Zhou and Liu, 2026). Standardization frameworks ensure sustainability claims are reliable and comparable across markets (Mia et al., 2025). This data has been summarized in Table 3.

TABLE 3. Industrial translation and commercial viability framework for sustainable soft packaging.

6.1 Scale-up challenges and process compatibility

Scaling polymer production from laboratory to industrial levels requires maintaining consistent material properties, performance, and safety standards (Sitompul et al., 2014). Bio-based polymers (PLA, PHAs, starch-based blends, protein-derived films) developed in small batches face challenges at industrial scale due to variations in biomass feedstock, fermentation efficiency, and molecular weight distribution, affecting mechanical strength and barrier properties (Stoica et al., 2024; Meyer, 2002). Defined feedstock specifications and quality-control systems maintain consistency across batches, preventing variability that complicates high-speed processing (Saha et al., 2026).

Sustainable materials must work with existing converting equipment (extrusion, blown-film, lamination, thermoforming) optimized for conventional plastics (PE, PP) to avoid costly equipment changes. Many biodegradable polymers have narrower thermal ranges, lower melt strength, or higher brittleness (Gonzalez-Lopez et al., 2023). Materials should function as ‘drop-in’ alternatives with minimal equipment modification. Researchers use reactive extrusion, polymer blending, and compatibilizers to improve processing. Standardized benchmarks for seal strength, machinability, puncture resistance, and printability enable comparison with conventional plastics.

6.2 Economic feasibility and and supply-chain stability

Cost competitiveness is crucial for commercial adoption. Conventional petrochemical plastics benefit from established infrastructure and large-scale manufacturing, enabling low costs. Bio-based polymers manufactured in smaller facilities with fermentation-based processes have higher production costs (Menglei, 2022). Costs are expected to decrease with expanded manufacturing capacity and biorefinery technology development (economies of scale). Policy measures like carbon pricing, plastic taxes, or recycled content requirements may help address environmental external costs of conventional plastics.

Commercial adoption depends on reliable supply chains and feedstock availability. Agricultural resources are susceptible to crop yield variations, climate conditions, and food production competition. Manufacturers seek diverse biomass sources; agricultural residues and organic waste streams are increasingly considered alternative feedstocks to improve supply stability (Versino et al., 2023). Clear sustainability standards for biomass sourcing (land-use change, water use, greenhouse gas emissions) support industrial investment and reduce regulatory uncertainty.

The substantial potential of agricultural waste valorization for creating sustainable food packaging materials has been demonstrated by recent data. High-value nanomaterials, such as nanocellulose, cellulose nanocrystals (CNCs), lignin nanoparticles, and biochar, which function as efficient reinforcing agents in biodegradable polymer matrices, can be produced from agricultural residues like pea hulls, pineapple peels, walnut shells, rice husks, and sugarcane bagasse. While lowering reliance on virgin resources and minimizing agricultural waste, these waste-derived nanocomposites improve tensile strength, thermal stability, oxygen and water vapor barrier qualities, and antibacterial efficacy. Additionally, by converting low-value biomass into packaging materials with additional value, this strategy promotes the concepts of the circular bioeconomy. Commercialization is still hampered by issues with biomass variability, nanoparticle extraction, large-scale processing, standardization, and economic viability, underscoring the need for scalable green technologies and standardized quality-control procedures (Mehdizadeh et al., 2026).

6.3 Food contact regulations and compost ability certification

All food packaging materials must meet strict food-contact safety regulations. Bio-based and biodegradable polymers require migration testing for monomers, additives, degradation products, or nanoparticles transferring to food (Stoica et al., 2024). Testing methods and regulatory requirements vary across regions, creating challenges for global manufacturers. Standardized migration testing procedures considering food simulants, storage durations, and temperature conditions are needed. Greater regulatory harmonization would reduce repeated testing and support international trade (Seref and Cufaoglu, 2025).

Industrial adoption depends on certification per EN 13432 (Europe) and ASTM D6400 (USA), establishing requirements for disintegration, biodegradation rates, ecotoxicity, and heavy metal limits (ASTM International, 2023). These standards target industrial composting and may not represent everyday waste management (International Organization for Standardization, 2012). Clear certification and labeling indicating appropriate end-of-life options help consumers and waste operators. Expanding frameworks to include home composting, anaerobic digestion, and mechanical recycling could improve effectiveness (de Jong et al., 2025; Moon et al., 2026).

6.4 Recycling, composting and waste management

Soft packaging poses mechanical recycling difficulties due to multilayer structures and food contamination. Sustainable alternatives must be compatible with existing recycling systems or supported by separate collection routes. Mono-material bio-based films recyclable with conventional plastics are one approach (Menglei, 2022). Standardized identification methods (resin codes, digital watermarks) improve automated sorting. Cooperation between manufacturers and recycling facilities ensures new materials do not interfere with existing processes (Rumetshofer and Fischer, 2025; Fialkowska-Filipek et al., 2026).

Compostable packaging success depends on waste management infrastructure availability. Limited industrial composting facilities in many areas mean compostable packaging is often landfilled or incinerated, reducing environmental advantages (Raźniewska, 2022). Standardization should address waste management system readiness. Greater coordination between policymakers, waste authorities, and industry is needed to expand organic waste treatment facilities, aligning infrastructure investments with packaging development (Versino et al., 2023; Nazareth et al., 2022).

6.5 Life-cycle assessment (LCA) harmonization and greenwashing prevention

Life-cycle assessment (LCA) examines carbon emissions, water consumption, and resource use. However, LCA results vary based on system boundary definitions, impact allocation, and end-of-life accounting, making comparisons difficult (Menglei, 2022). Standardized LCA approaches for soft food packaging would enable reliable comparisons. International alignment in reporting strengthens environmental claim credibility and supports informed manufacturer decisions (Hjellvik and Kirkels, 2025; Blackstone et al., 2025).

Sustainability claims like ‘eco-friendly,’ ‘green,’ and ‘biodegradable’ often lack clear definitions. Unsupported claims mislead consumers and create unfair competition (greenwashing). Labeling should link to recognized certification standards. Clear, regulated labeling ensures accurate, comparable claims (Stoica et al., 2024). Digital traceability tools (QR codes) providing certification records, LCA summaries, and disposal instructions improve transparency and informed purchasing decisions.

Sustainable soft packaging materials have made great strides, but economic, infrastructure, and regulatory obstacles still prevent their widespread commercialization. The kind of polymer, manufacturing scale, feedstock, and geographic location all have a significant impact on the cost of producing bioplastics. Bio-based polymers like polylactic acid (PLA) and polyhydroxyalkanoates (PHAs) are often more costly than traditional polyolefins, which restricts their broad use in cost-sensitive food packaging applications even if production costs have decreased with technological advancements (European Bioplastics, 2024; Niaounakis, 2015). Due to its compatibility with traditional polymer-processing technologies, NatureWorks^TMIngeo PLA has proved commercial success and is frequently used for thermoformed food trays, beverage cups, and fresh-produce packaging (Vink and Davies, 2015). On the other hand, starch-based materials still struggle with moisture sensitivity and poor mechanical durability in humid storage environments (Nilsen-Nygaard et al., 2021). Additionally, certification standards like EN 13432, ASTM D6400, and ISO 17088 assess compostability in controlled industrial composting settings and do not ensure biodegradation in soil, freshwater, marine, or home composting (ASTM International, 2023). As a result, consumers frequently misunderstand the term “biodegradable,” highlighting the need for uniform labeling, better waste management infrastructure, and more public knowledge to support commercialization and circular economy goals (European Bioplastics, 2024; European Commission, 2011).

6.6 Commercialization, industrial scalability, and circular economy perspectives

Technical performance, economic viability, regulatory compliance, and environmental sustainability must all be balanced for sustainable soft packaging materials to be successfully commercialized. Despite the promising laboratory performance of biodegradable polymers like polylactic acid (PLA), polyhydroxyalkanoates (PHAs), starch-based blends, and cellulose composites, their widespread adoption is still hampered by increased production costs, feedstock variability, processing constraints, and insufficient end-of-life infrastructure (European Bioplastics, 2024; Niaounakis, 2015). Reliable biomass supply chains, established production procedures, compatibility with current extrusion and thermoforming technologies, and constant product quality are all necessary for industrial scaling. It is anticipated that improvements in biorefinery technology, renewable feedstocks, and process optimization will lower manufacturing costs and increase production efficiency (Niaounakis, 2015).

Commercialization also requires regulatory compliance. The European Food Safety Authority (EFSA), the U.S. Food and Drug Administration (FDA), and internationally recognized standards like EN 13432, ASTM D6400, and ISO 17088, which outline requirements for migration limits, compostability, biodegradation, and product safety, must all be met by food-contact materials (European Commission, 2011; EFSA, 2021). The need for more precise labeling and consumer awareness is highlighted by the fact that these criteria mainly evaluate industrial compostability and do not always reflect biodegradation in home composting, soil, freshwater, or marine conditions.

From raw material extraction to end-of-life management, life-cycle assessment (LCA) offers a thorough framework for assessing the environmental effects of packaging materials. Comparisons of greenhouse gas emissions, energy use, water consumption, and waste generation between conventional plastics and bio-based alternatives are made possible by standardized life cycle assessment (LCA) procedures based on ISO 14040 and ISO 14044 (International Organization for Standardization, 2006). Packaging development can increase resource efficiency and lessen environmental effects by incorporating circular economy techniques, such as biomass valorization, mono-material design, recycling, industrial composting, and extended producer responsibility (EPR). Therefore, to expedite the adoption of high-performance, ecologically conscious food packaging, future commercialization should incorporate materials science, industrial biotechnology, regulatory science, and sustainable waste-management systems.

7 Current challenges, research gaps, and standardization needs

Sustainable soft materials for food packaging—including films, pouches, coatings, and flexible laminates made from bio-based or biodegradable polymers—are increasingly viewed as crucial for reducing plastic pollution while maintaining food safety and shelf life. Significant progress has been made developing materials like polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polysaccharide or protein-derived films. However, wider adoption remains limited due to performance trade-offs, regulatory and certification differences, end-of-life management uncertainties, and insufficient evidence on health and system impacts (Stoica et al., 2024; Versino et al., 2023). The current challenges and gaps have been well exhibited in Figure 2 and Table 4.

TABLE 4. Current challenges, research gaps, and standardization needs framework.

Current technical challenges include material performance limitations. Soft packaging must provide low oxygen and moisture permeability, puncture resistance, flexibility, and reliable heat sealing. Many biodegradable polymers like starch, gelatin, and polysaccharide-based films show weaker barrier performance against water vapor and oxygen compared to conventional multilayer polyolefin or metallized films. While PLA and certain PHAs offer improved mechanical strength, they exhibit brittleness, low elongation at break, or insufficient heat resistance for hot filling or retort sterilization (González-López et al., 2023). Strategies like polymer blending, nanocomposites, and protective coatings enhance properties but complicate recycling and large-scale processing.

Food safety concerns persist as long-term toxicological data and migration studies under realistic storage and heating conditions remain limited for newly developed biopolymers. Some starch-based formulations may release unwanted compounds or micro/nano-sized particles under specific conditions, emphasizing the need for standardized migration testing (Stoica et al., 2024). Safety varies based on raw materials, processing additives, and degradation products, so bio-based materials cannot be assumed automatically safe without comprehensive assessment.

End-of-life complexity presents major challenges. Terms like “biodegradable” and “compostable” have different meanings depending on environmental conditions (industrial composting, home composting, anaerobic digestion, recycling, or natural environments). Laboratory testing conditions often differ from actual agricultural or municipal waste streams, creating misleading degradation expectations. Limited collection and processing infrastructure means compostable packaging often enters recycling systems or becomes litter, disrupting circular waste management (Fakhrizada and Dahman, 2025).

Scalability and cost remain barriers. Many materials performing well in pilot studies encounter difficulties at industrial scale due to feedstock availability, inconsistent polymer quality, and inability to achieve economies of scale. High-performance biopolymers remain more expensive than petrochemical polymers and may require processing equipment adjustments. Cost differences and cautious industry purchasing practices slow adoption, as companies prioritize solutions meeting regulatory requirements with proven shelf-life performance (Castro-Dominguez et al., 2025).

Priority research gaps include realistic barrier and shelf-life studies under commercial conditions, migration and toxicology assessments including micro/particle release, systems research on collection infrastructure and contamination dynamics, harmonized lifecycle assessments incorporating social and economic metrics, and process engineering for industrial converting (El Bilali et al., 2021; Teltemann and Schunck, 2020; Salem et al., 2023; Nitkiewicz et al., 2020).

Standardization needs include clarifying definitions and harmonizing terminology for “biodegradable,” “compostable,” “bio-based,” and “oxo-degradable” across regulations and markets. While standards like ISO 17088 and EN 13432 exist, interpretation differences among countries create confusion and enable greenwashing. Aligning terminology across major economies would improve transparency and consumer confidence. Robust, context-aware certification regimes should distinguish between industrial composting, home composting, and anaerobic digestion, ensuring claimed performance aligns with available regional waste management infrastructure.

8 Future perspectives and emerging trends

Despite the fact that sustainable soft materials have shown a great deal of promise to replace traditional petroleum-based food packaging, a number of scientific and technological obstacles still prevent their widespread adoption. A significant obstacle is striking a balance between biodegradability and mechanical performance. Tensile strength, thermal stability, and barrier qualities can be enhanced by techniques such polymer blending, copolymerization, and nanofiller integration. However, increasing cross-linking or crystallinity frequently slows biodegradation and decreases polymer chain mobility, resulting in a trade-off between environmental performance and material longevity (Auras et al., 2010; Rhim et al., 2013).

The industrial scalability of sophisticated processing technologies is another significant issue. Despite the promising laboratory-scale performance of electrospinning, reactive extrusion, multilayer processing, and nanocomposite fabrication, their industrial application is still restricted due to high processing costs, energy requirements, and challenges in maintaining consistent product quality (Ashfaq et al., 2022; Niaounakis, 2015). Furthermore, production repeatability is still impacted by non-uniform nanofiller dispersion and biomass feedstock variability.

There are still issues with the functionality and long-term safety of nanocomposite packaging. In biodegradable polymer matrices, where environmental plasticization increases molecular mobility, nanoparticle migration may increase with increased temperature, humidity, or extended storage (EFSA, 2021; Bott et al., 2014). Similarly, volatilization, oxidation, and uncontrolled release during storage frequently cause natural antimicrobial compounds like essential oils to lose their efficacy, underscoring the need for better encapsulation technologies and standardized techniques for assessing long-term antimicrobial performance (Ribeiro-Santos et al., 2017).

Thus, safe-by-design nanocomposites, scalable green manufacturing processes, predictive structure-property modeling, standardized migration and biodegradation protocols, and thorough life-cycle and toxicity evaluations should be the main areas of future research. Transforming sustainable soft materials from lab inventions into commercially feasible and ecologically responsible food-packaging solutions will require integrating polymer science, nanotechnology, food safety, regulatory science, and circular economy principles. Table 5 describes the future perspectives and emerging trends in sustainable food packaging, highlighting technological innovations, research priorities, policy directions, and their potential impacts on sustainability and circular economy development.

TABLE 5. Future perspectives and emerging trends framework.

9 Conclusion

Although significant progress has been made in the development of bio-based polymers, nanocomposites, edible coatings, and active packaging systems capable of improving food quality and extending shelf life, a number of significant obstacles still stand in the way of their widespread commercialization. These obstacles include limitations in mechanical strength, moisture resistance, thermal stability, long-term barrier performance, and nanomaterial safety; additionally, the lack of harmonized testing protocols, long-term toxicological effects, and polymer degradation under realistic environmental conditions. Future studies should concentrate on creating safe-by-design biodegradable nanocomposites with enhanced recyclability, regulated release of bioactive chemicals, optimal structure–property relationships, and predictable biodegradation behavior. To help with material optimization and regulatory approval, more focus should be given to biomass valorization, enhanced life-cycle assessment, standardized migration and biodegradation testing, scalable green manufacturing methods, and predictive modeling. Addressing current scientific and technological barriers will require integrating polymer science, nanotechnology, toxicity, food engineering, and environmental assessment. From an industrial standpoint, successful commercialization will depend not just on enhanced material performance but also on economic viability, regulatory compliance, dependable biomass supply chains, compatibility with current processing infrastructure, and efficient end-of-life management. To provide uniform standards, boost consumer confidence, and support circular economy initiatives, strong cooperation between academia, business, legislators, and regulatory bodies will be essential. By tackling these interdisciplinary issues, sustainable soft packaging materials will move more quickly from laboratory-scale innovations to commercially feasible, safe, and ecologically friendly solutions that support long-term environmental sustainability, global food security, and decreased plastic pollution.

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Glossary

AG Acacia Gum Ag Silver AgNPs Silver Nanoparticles ASTM American Society for Testing and Materials Au Gold CNC Cellulose Nanocrystals CNF Cellulose Nanofibers CNTs Carbon Nanotubes CO _**2** Carbon Dioxide CuO Copper Oxide DSC Differential Scanning Calorimetry DMA Dynamic Mechanical Analysis E Young’s Modulus EAB Elongation at Break EN European Norm HDPE High-Density Polyethylene ISO International Organization for Standardization LbL Layer-by-Layer LCA Life Cycle Assessment LDPE Low-Density Polyethylene LLDPE Linear Low-Density Polyethylene MAP Modified Atmosphere Packaging MC Moisture Content NFC Near Field Communication NPs Nanoparticles O _**2** Oxygen OTR Oxygen Transmission Rate PBAT Polybutylene Adipate Terephthalate PBSA Polybutylene Succinate Adipate PCL Polycaprolactone PE Polyethylene PET Polyethylene Terephthalate PHA Polyhydroxyalkanoates PHAs Polyhydroxyalkanoates PLA Polylactic Acid PP Polypropylene PS Polystyrene PVC Polyvinyl Chloride PVOH Polyvinyl Alcohol QR Quick Response RH Relative Humidity SA Sodium Alginate SPI Soy Protein Isolate TGA Thermogravimetric Analysis TiO _**2** Titanium Dioxide TMA Thermomechanical Analysis TS Tensile Strength TTIs Time–Temperature Indicators UV Ultraviolet WVP Water Vapor Permeability WVTR Water Vapor Transmission Rate YM Young’s Modulus ZnO Zinc Oxide ZnONPs Zinc Oxide Nanoparticles

Footnotes

Edited by: Carlos M. Costa, University of Minho, Portugal

Reviewed by: Mohammad Mehdizadeh, University of Mohaghegh Ardabili, Iran

Haji Vahid Akhundzada, Azerbaijan National Academy of Sciences, Azerbaijan