Zinc oxide nano particle integrated biodegradable film in foodquality monitoring

Introduction

Various preservation methods have been used to extend the shelf of food products and the use of ZnO NP in the food industry serve as an effective agent in extending the shelf life and maintaining the quality of food products. In food industry these particles serve as effective agent in extending the shelf life and maintaining the quality of food products. Due to their antimicrobial properties, these nano particles especially in food packaging are capable of preventing the penetration of contaminants and pathogens into the packaging and prevent the transmission of foodborne diseases to humans. The ZnO has beneficial properties like good transparency, antimicrobial agents, high electron mobility, wide band gap, high thermal and mechanical stability (Zhou et al., 2023) [1] . Physical methods such as laser absorption, high energy ball milling and thermal evaporation whereas chemical methods uses solgel, solvothermal, hydrothermal, microemulsion and coprecipitation methods the other method used is the biological methods which includes green synthesis, plant extracts, bacteria and fungi have been used with advantages and disadvantages the most commonly used method is chemical method the Sol-gel, Solvothermal, co-precipitation, micro-emulsion, hydrothermal processes and other processes are some of the ways ZnO NP can be made. The method that is most frequently used among these is sol gel synthesis. Solvothermal method: Widely used technique that usually uses non-aqueous solvents under controlled temperature and pressure higher that atmospheric pressure. (Li et al., 2016) [2] . The films used for the infusion of ZnO NP such as Chitosan, starch, cellulose, soy protein isolate, carboxymethyl chitosan, polylactic acid, gelatin, chitosanpolyvinyl alcohol, cellulose nano fibres, sodim caseinate, carboxycellulose-starch, Alginate. The amount of ZnO NPs generally incorporated in biopolymers is in the range between 0.1 and 10%. (Yadav et al., 2021; Alizadeh-Sani, et al., 2022) [3,32] . The infusion of ZnO NP films by Solvent Casting, also known as solution mixing, is a process in which the nanoparticles in a polymer are vigorously stirred or ultrasonicated before casting into a mold and then the solvent is evaporated. The solvents which are used generally includes water and ethyl alcohol (Soumili Banerjee et al., 2024) [4] . Solution casting is the most commonly used method for producing ZnO-infused biopolymer films, primarily due to its cost-effectiveness and ease of preparation (Kim, et al.,2022 ; Luo 2021) [5,6] . This method involves preparing a film-forming solution by directly incorporating 0.5-5.0 % (w/w) ZnO, along with a plasticizer into a biopolymer solution, followed by thorough homogenisation.

Synthesis of zinc oxide nano particles

Zinc oxide nanoparticles (ZnO NPs) can be synthesized using two main approaches: the bottom-up (Fig1) and top-down (Fig2) methods. In the bottom-up approach, nanoparticles are formed by building up from atoms or molecules, and this can be achieved through physical (Fig3), chemical (Fig4), and biological (Fig5) methods. In contrast, the top-down approach involves breaking down bulk materials into nanoparticles using techniques such as sputtering, etching, mechanical milling, and electro-explosion methods. (Dey et al., 2025) [7] [7] Laser ablation was carried out using pulse energies of 70, 90, and 130 mJ to investigate their effect on nanoparticle formation.

The laser beam was focused onto a small spot (~70 µm in diameter) using a convex lens, producing fluences of 18.2, 23.3, and 33.7 J/mm² for pulse energies of 70, 90, and 130 mJ, respectively. The ablation process was performed on the target surface for 30 minutes.

To prevent laser beam trapping within cavities formed during target ablation, the glass beaker was mounted on a rotating stage. Additionally, a magnetic stirrer was used to maintain continuous circulation and homogenization of the colloidal solution, ensuring effective interaction between the laser beam and the metal target. The synthesis of ZnO nanoparticles (ZnO NPs) at different laser ablation energies was systematically investigated. The pulse energy significantly influences both particle size and concentration; increasing the laser energy results in smaller particle sizes and higher nanoparticle concentrations. The average particle sizes obtained were 12.2, 9.7, and 8.7 nm at pulse energies of 70, 90, and 130 mJ, respectively. The lattice parameter c was calculated as 5.12 Å at 70 mJ and 5.08 Å at both 90 and 130 mJ, showing a slight decrease with reduction in particle size. The morphology and structural characteristics were analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). UV-visible absorption spectra revealed a blue shift in the band gap at higher laser energies, attributed to quantum confinement effects and reduced structural defects. The zeta potential values indicate that the synthesized nanoparticles are physically stable. Furthermore, the formation of ZnO NPs was confirmed by the characteristic Zn-O stretching vibration observed at 450-500 cm ¹ in the FTIR spectra. ⁻ (Flemban et al., 2023) [8] 1. High-energy ball milling (HEBM): is a top-down technique used for the synthesis of fine metal nanoparticles, where bulk materials are mechanically ground using zirconia balls in a high-energy shaker mill. A major advantage of this method is its ability to produce large quantities of nanoparticles in a single process. In this study, the samples were milled for durations of 2, 10, 20, and 50 hours using a horizontal oscillatory mill operating at 25 Hz. The results indicate that particle size decreases with increasing milling time, demonstrating that prolonged milling leads to finer nanoparticles. (Dey et al., 2025) [7] 2. Process: In high energy ball milling, metal powders are ground in a ball mill to reduce particle size and induce nano particle formation as shown in Fig 8 ( Dey et al., 2025) [7] .

Results:

The milled sample consists of approximately 30 nm spherical ZnO nanoparticles, as estimated from SEM analysis, while TEM measurements indicate an average particle size of about 22 nm. An increase in the lattice parameter c from 5.204 to 5.216862 Å is associated with new photoluminescence (PL) emission band around 365 nm. Prior to milling, the micro sized material exhibited a single intense emission peak at 384 nm; however, after 2 hours of milling, an additional emission band appeared near 365 nm. (Salah and Habib et al., 2011) [9] Chemical method: Sol-gel, Solvothermal, co-precipitation, micro-emulsion, hydrothermal processes and other processes are some of the ways ZnO NP can be made. The method that is mot frequently used among these is sol gel synthesis.

• Solvothermal method: Widely used technique that usually uses non-aqueous solvents under controlled temperature and pressure higher that atmospheric pressure (Li et al., 2016) [2] . Two different solvothermal synthesis methods using conventional heating have been reported for the preparation of ZnO nanostructures with distinct properties and applications. In the first method, zinc salt, dimethyl sulfone, and KOH were used as precursors. The reaction was carried out at 60 ^ °C for 3 and 12 hours, followed by drying at 65 °C for 12 hours. The synthesized ZnO particles exhibited a spherical morphology with crystallite sizes of 4 nm and 10 nm, which was consistent with the particle size observed through TEM analysis. These nanoparticles demonstrated effective antibacterial activity. In the second method, Zₙ (Ac)₂ • 2H₂O •ethanol, NaOH, CTAB, wood samples, and FAS-17 were employed as reactants. The reaction was initially conducted at room temperature for 2 hours, followed by autoclaving at 90 °C for 4 hours and drying at 45 °C for 24 hours. This process resulted in the formation of rod-like ZnO structures with particle dimensions of approximately 85 nm in diameter and 1.5 μm in length. These nanostructures were found to possess UV-resistant properties, making them suitable for protective applications.

Hydrothermal process

This process involves the synthesis of ZnO nanoparticles under high temperature (100-1000 °C) and pressure (1-10,000 atm) conditions in an autoclave, using water or other solvents such as ethanol or polyols. Heating can be achieved either by conventional or microwave methods. Conventional heating relies on conduction and convection within the reaction medium, which may result in non-uniform temperature distribution. In contrast, microwave heating provides uniform and rapid heating, leading to improved purity and homogeneity of the synthesized nanoparticles. (Droepenu et al., 2022) [17] Advantages: Produces highly crystalline nano particles with controlled size and shape. It is cost effective and environmentally friendly. ( Dey et al., 2025) [7] with a surface area of 18.9 m²/g. This material demonstrated effective photocatalytic activity against E. coli, indicating its potential application in antimicrobial and water treatment systems (Gupta et al. 2017) [18] .

Green synthesis of Zinc oxide nano particles

From plants: Phytochemicals found in plants are used in the green synthesis process as a reducing agent to convert metal ions or metal oxides into metal nanoparticles. These include things like polyphenolic substances, proteins, alkaloid compounds, terpenoids, and polysaccharides.

Green synthesis from different plant species is written in the table: Several studies have reported the green synthesis of ZnO nanoparticles using various plant sources, highlighting their diverse properties and applications. Grewia flavescens (Malvaceae) leaf extract has been utilized with zinc nitrate hexahydrate as a precursor to produce spherical nanoparticles of 20-30 nm, which exhibited antibacterial activity, drug delivery potential, and cytotoxic effects (Sana et al., 2023) [19] . Similarly, aerial parts of Lupinus albus and Lupinus pilosus (Fabaceae) were used to synthesize crystalline ZnO nanoparticles ranging from 19-26 nm, demonstrating antibacterial and photocatalytic applications (Mirza et al., 2023) [20] . In another study, Cassia sieberiana (Fabaceae) methanolic root bark extract with zinc acetate yielded spherical nanoparticles of 12.9±3.1 nm, showing anti-inflammatory, antioxidant, antimicrobial properties, and suitability for drug delivery (Kyene et al., 2023) [21] . Leaf extract of Moringa oleifera (Moringaceae), when combined with zinc acetate dihydrate, produced agglomerated spherical nanoparticles with a size of 119±36 nm, which were explored for anticancer and biomedical applications (Rafique et al., 2023) [22] . Additionally, Brassica oleracea (Brassicaceae) leaf extract facilitated the formation of flower-like ZnO nanoparticles of approximately 52 nm, exhibiting photocatalytic dye degradation, antimicrobial, and larvicidal activities (Manojkumar et al., 2023) [23] . Furthermore, Azadirachta indica (Neem) leaf extract with 0.1 M zinc nitrate resulted in quasispherical nanoparticles of 20-40 nm, demonstrating antibacterial, antioxidant, and cytotoxic properties (Gupta et al., 2025) [24] .

Synthesis by bacteria

The employment of bacteria to synthesize NPs has several drawbacks, such as the requirement for monitoring the culture medium and the size and form of the NPs, as well as the cost of the medium in which the bacteria are grown. [10] Pseudomonadaceae Aeromonas hydrophila Centrifugation, washing, lyophilization and storage at 0 °C Round, oval 57.72 (AFM), and 42-64 (XRD) Fakhar et al. 2022 [45] Staphylococcaceae Staphylococcus aureus Centrifugation, washing, lyophilization and storage at 0 °C Acicular (10-50 nm) Rauf et al., 2017 [11] Different bacterial families have been explored for the biosynthesis of nanostructured materials, with variations in purification methods, morphology, and size. Members of the Bacillaceae family, such as Bacillus licheniformis, have been reported to produce nanoflower-like structures following drying at 120 °C and annealing at 700 °C for 5 hours. These structures exhibited dimensions of approximately 200 nm, with lengths of about 400 nm and widths of 40 nm as observed through TEM analysis (Alghuthaymi et al., 2022) [10] . In the case of the Pseudomonadaceae family, Aeromonas hydrophila was used for nanoparticle synthesis, followed by purification steps including centrifugation, washing, lyophilization, and storage at 0 °C. The resulting particles were round to oval in shape, with sizes of approximately 57.72 nm measured by AFM and 42-64 nm determined by XRD (Fakhar et al., 2022). Similarly, Staphylococcus aureus from the Staphylococcaceae family produced acicular (needle-like) nanoparticles with sizes ranging from 10-50 nm, using comparable purification techniques involving centrifugation, washing, lyophilization, and cold storage (Rauf et al., 2017) [11] . [12] Trichocomaceae Aspergillus strain Zinc sulfate Spherical forming aggregates 50-120(SEM). Parveen et al., 2016 [13] Fungal strains have also been widely investigated for the biosynthesis of ZnO nanoparticles, offering controlled morphology and size distribution. For instance, a member of the Saccharomycetaceae family, Candida albicans, has been utilized with zinc oxide as a precursor to synthesize nanoparticles exhibiting a hexagonal wurtzite structure with a morphology resembling spherical particles. The particle size was reported to be in the range of 15-25 nm as observed by SEM, approximately 25 nm by XRD, and around 20 nm by TEM analysis (Ilkhechi et al., 2021) [12] . Similarly, fungi from the Trichocomaceae family, particularly Aspergillus strains, have been employed using zinc sulfate as a precursor to produce spherical nanoparticles forming aggregates, with sizes ranging from 50-120 nm as determined by SEM (Parveen et al., 2016) [13] .

Synthesis using fungi

Comparison of physical/chemical synthesis and green synthesis

Costly and inefficient production

Cost-effective due to the accessibility of plant materials and the capping and lowering effects of active bio-components. Production of nanoparticles on a large scale. Require inert environment, high or low temperature, and pressure.

At normal temperature and pressure, nanoparticles can be synthesized. A Significant amount of energy is consumed during synthesis process need no complicated energy system for synthesis A highly restricted laboratory environment is required. Nanoparticle production doesn't need to be done under controlled circumstances or in a well-equipped lab. When toxic chemicals are utilised in chemical processes to create or stabilise nanoparticles, the resultant product may be contaminated or have a faulty surface because the toxic compounds can absorb on the surface of the nanoparticles.

Because natural secondary metabolites of plants are used, the finished product is often secure and stable.

Methods of infusion of zinc oxide nano particles into biodegradable film:

• Solvent/solution casting method • Spray coating and dipping • Electrospinning method • Melt extrusion method 1. Solvent casting, also known as solution mixing, is a technique in which nanoparticles are dispersed in a polymer solution through vigorous stirring or ultrasonication. The homogeneous mixture is then cast into a mold, followed by solvent evaporation to form a solid film. Commonly used solvents include water and ethanol (Banerjee et al., 2024) [4] . Solution casting is the most widely used method for fabricating ZnO-incorporated biopolymer films, owing to its simplicity, low cost, and ease of processing (Kim, et al., 2022 ; Luo 2021) [5,6] . Flow chart of synthesis through solvent casting method is shown in Fig 9 and Fig 10) In this method, a film-forming solution is prepared by incorporating 0.5-5.0% (w/w) ZnO nanoparticles and a suitable plasticizer into a biopolymer matrix, followed by thorough homogenization. The resulting mixture is cast onto Petri dishes and dried under controlled temperature conditions to allow solvent evaporation. After drying, the formed film is carefully peeled from the casting surface. However, this method presents certain limitations, including the loss of volatile compounds during drying and the tendency of ZnO nanoparticles to agglomerate, which can affect film uniformity and functional properties. These challenges can be mitigated by encapsulating volatile or bioactive compounds using nanotechnology to reduce evaporation losses, and by employing stabilizers or dispersing agents to minimize nanoparticle aggregation and ensure a more homogeneous film structure. ( Luo 2022 and Wang et al., 2019) [25,26] .

Coating has become a crucial active packaging technique

for preserving quality and extending the shelf life of fresh food products. Among the most widely used methods, spray coating and dipping are employed to form protective layers on food surfaces. Spray coating (Fig11) involves the uniform application of a treatment solution using an aerosol sprayer, whereas dipping involves immersing the food product in a pre-formulated solution, typically containing ZnO-infused micro/nanocomposites along with antioxidant agents and plasticizers to enhance functionality. After dipping, excess solution is removed, and the samples are dried under controlled temperature and humidity conditions. The dipping method is particularly favored due to its simplicity and effectiveness in producing active packaging without the need for specialized equipment (Bai Qu et al., 2025) [27] . Nanotechnology has advanced the use of ZnO nanoparticles in beverage packaging coatings, enhancing both antimicrobial protection and overall packaging functionality. ZnO-infused nanocomposite films offer antimicrobial protection and enhance the overall functionality of packaging (Bu et al., 2023) [28] .

Electrospinning (Fig 12) is a cutting-edge technique used

to produce nanofibers containing nanoparticles by applying a high-voltage electric field. It is widely employed in the fabrication of nanomaterial films, allowing precise control over the properties of nanobased packaging materials. This method utilizes electrostatic forces to achieve effective encapsulation of nanomaterials within the fibers. Results have shown that the resulting membrane can achieve a porosity exceeding 70%, and when the polyaniline mass fraction is 5%, the antibacterial activity reaches 75.2% against Staphylococcus aureus and 80.08% against Escherichia coli. (Zhou et al., 2024).

The application of electrospinning for the production of nanoparticle (NP) films offers several advantages, including simplicity of operation, strong controllability, and relatively low cost. Films produced by this method exhibit a large surface area, high loading capacity, and high porosity, thereby enhancing the overall performance of packaging materials. However, this method also presents certain challenges, such as high equipment cost and the complexity of parameter settings.

(Sameen et al., 2022) [29] .

ZnO NP incorporated Biodegradable film: The amount of ZnO nanoparticles (ZnO NPs) incorporated into biopolymers typically ranges from 0.1% to 10%. biopolymers used for this purpose include chitosan, starch, cellulose, soy protein isolate, carboxymethyl chitosan, polylactic acid, gelatin, chitosan-polyvinyl alcohol blends, cellulose nanofibers, sodium caseinate, carboxymethyl cellulose-starch composites, and alginate. Cellulose ZnO NP loaded with cellulose 100-200 nm Solution casting Antibacterial Xie (2022) [31] Sodium caseinate Commercial ZnO 10-30 nm Solution casting Antibacterial Alizadeh-Sani, et al., (2022) [32] Cellulose nano fibrils Commercial ZnO <100 nm Solution casting Antioxidant and antibaterial activity Wu et al., (2021) [33] Various types of biopolymer-based packaging materials incorporated with ZnO nanoparticles have been developed to enhance bio functional properties such as antioxidant and antibacterial activity. Chitosan-based films loaded with ZnO nanoparticles and gallic acid, with particle sizes ranging from 15-30 nm, have been prepared using the solution casting method and demonstrated both antioxidant and antibacterial properties (Yadav et al., 2021) [3] . Similarly, soy protein isolate films incorporated with commercially available ZnO nanoparticles of size 30±10 nm, also prepared via solution casting, exhibited enhanced antioxidant and antibacterial activity (Huang et al., 2021) [30] . In another study, cellulosebased films containing ZnO nanoparticles of 100-200 nm synthesized through solution casting showed significant antibacterial properties (Xie, 2022) [31] . Sodium caseinate films with commercial ZnO nanoparticles of 10-30 nm also displayed antibacterial activity when prepared using the same method (Alizadeh-Sani et al., 2022) [32] . Furthermore, cellulose nanofibrilbased films incorporated with ZnO nanoparticles of size less than 100 nm demonstrated both antioxidant and antibacterial activities, highlighting their potential application in active food packaging systems (Wu et al., 2021) [33] . Barrier properties: Resistance to oxygen, moisture, and UV radiation: When ZnO nanoparticles are uniformly dispersed within a polymer matrix, their high surface-to-volume ratio enables them to act as absorbents, attracting polymer chains to their surface. This interaction reduces the entropy of the polymer chains, while adsorption interactions lead to a decrease in enthalpy. Consequently, the free volume is reduced, and the mobility of the polymer chains is restricted. Additionally, due

Role of Zinc oxide NP in food packaging

to the relatively hydrophobic nature of ZnO, moisture absorption by the polymer matrix is decreased, thereby minimizing the adverse effects of moisture. (Mohammed et al., 2022) [35] . Uniformly dispersed ZnO nanoparticles create tortuous pathways that hinder the diffusion of gases such as oxygen. This characteristic enhances the barrier properties of the nanocomposite against moisture and oxidizing gases. Furthermore, due to its crystalline structure, ZnO is capable of absorbing UV radiation. When UV rays strike ZnO, the energy is absorbed and converted into heat, preventing the radiation from reaching the underlying surface. In this way, ZnO effectively provides both scattering and absorption of UV rays. (Channa et al., 2022) [36] . Additionally, their ability to absorb UV radiation can prevent the degradation of food products caused by UV exposure, providing an extra layer of protection for perishable items. (Ezati et al., 2023) [37] .

Photocatalytic activity: ZnO nanoparticles have attracted significant attention due to their photocatalytic properties, making them highly effective in the degradation of environmental contaminants. Upon exposure to UV light, ZnO nanoparticles generate electron-hole pairs, which initiate redox reactions capable of breaking down organic pollutants in water and air. (Zeid et al., 2024) [38] . The photocatalytic activity of ZnO is attributed to its wide bandgap, which allows it to absorb UV radiation and create highly reactive species, such as hydroxyl radicals and superoxide anions. (Baibara et al.,2021) [39] . ZnO's high surface area, combined with its low toxicity and stability, enhances its performance as a photocatalyst. (Lu et al., 2008) [40] . In food packaging, the photocatalytic properties of ZnO nanoparticles can be utilized to improve the safety and shelf-life of packaged goods. By degrading harmful microorganisms and contaminants that may affect the food, ZnO helps maintain food quality and extend its freshness. (Ezati et al., 2023) [37] .

Antioxidant property:

The antioxidant activity of the films was evaluated by measuring the free radical scavenging activity of compounds using the DPPH method (Huang et al., 2021) [30] . ZnO NPs exhibit antioxidant properties primarily through their ability to scavenge reactive oxygen species (ROS), thereby reducing oxidative stress in cells. The particles can interact with free radicals, neutralizing them before they cause cellular damage (Mohammad et al., 2023) [41] . Additionally, ZnO NPs are known to influence various cellular antioxidant defence mechanisms, such as enhancing the activity of antioxidant enzymes like superoxide dismutase (SOD) and catalase (Khan et al., 2021) [42] . Antimicrobial activity of Zinc oxide NP incorporated biopolymers: Biopolymers such as chitosan, starch, cellulose, gelatin, and alginate have been widely studied using different microbial strains. Chitosan-based films incorporated with nano zinc oxide, tested against Bacillus subtilis and Escherichia coli, exhibited stronger bactericidal activity compared to pure chitosan films (Priyadarshi et al., 2017) [14] . Starch-based films evaluated against Staphylococcus aureus and E. coli also demonstrated notable antimicrobial properties.

Cellulose-based films tested against E. coli and Listeria monocytogenes showed higher antibacterial activity specifically against E. coli (Roy et al., 2020) [15] . Similarly, gelatin films studied against Streptococcus pneumoniae, B. subtilis, and E. coli exhibited an increased zone of inhibition against E. coli and B. subtilis (Yadav et al., 2020) [16] .

In contrast, alginate-based films tested against B. subtilis and E. coli did not demonstrate any significant antibacterial activity against the tested microorganisms (Salama et al., 2019) [43] . (Priyadarshi, et al., 2017) [14] . The bactericidal activity of cellulose-based films against E. coli is higher (Roy et al., 2020) [15] . The gelatin film showed an increased zone of inhibition against E. coli and B.

subtilis (Yadav et al., 2020) [16] The alginate-based film did not demonstrate any antibacterial activity against the tested bacteria Salama et al., 2019) [43] .

Migration and safety:

The migration of ZnO from polypropylene food containers into different food-simulating solutions under varying storage time and temperature conditions was quantified using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and migration was observed.

Results revealed significant migration of nano-sized zinc oxide into oily, acidic, and aqueous simulants. The amount of zinc oxide migrated increased with storage time and temperature; however, overall, ZnO exhibited a relatively low tendency to migrate into food simulants. The Zn² ions were quantified by ICP-MS, with migration levels ranging from 0.15 to 0.56 μg L ¹.⁺ ⁻ Compared to aqueous simulants, higher migration levels of zinc oxide were observed in 4% acetic acid and hexane simulants. (Liu et al., 2016) [44] . The CEF panel (European food safety authority panel) recommended that SML (safety migration limit) for zinc is 25mg/kg (EFSA, 2016).

Conclusion

Zinc oxide (ZnO) nanoparticles exhibit significant potential for enhancing food packaging materials due to their unique functional properties, including antibacterial activity, antioxidant capacity, and resistance to ultraviolet (UV) radiation. These characteristics contribute to improved physical and chemical properties of packaging films, thereby extending the shelf life of food products and reducing microbial contamination. Moreover, the incorporation of ZnO nanoparticles into packaging systems offers a sustainable and environmentally friendly approach to food preservation. Despite these advantages, further research is necessary to evaluate the scalability, long-term safety, and regulatory aspects of their application in industrial food systems. Future developments may focus on combining ZnO nanoparticles with other advanced materials to create intelligent and highly efficient packaging solutions. Such innovations hold great promise for widespread application across the food industry, ultimately ensuring improved food quality, safety, and shelf-life extension.

References

1. Zhou XQ, Hayat Z, Zhang DD, Li MY, Hu S, Wu Q, et al. Zinc oxide nanoparticles: synthesis, characterization, modifications, applications in food and agriculture. Processes. 2023;11(4):1193.https://doi.org/10.3390/pr11041193
2. Lin H, Qin LZ, Hong H, Li Q. Preparation of Starch Nanoparticles via High-Energy Ball Milling. Journal of Nano Research. 2016;40:174-
3. Yadav S, Mehrotra GK, Dutta PK. Chitosan-based ZnO nanoparticle-loaded gallic acid films for active food packaging. Food Chem. 2021;334:127605.
4. Banerjee S, Bera K, Das M, Majhi A, Roy S, Mukherjee S, et al. Nanoparticles in packaging films: processing technologies and future trends. Int J Mater Sci. 2024;5(1):22-24.
5. Kim I, Vishwanathan K, Kasi G, Thanakkasaranee S. ZnO nanostructures in active antibacterial food packaging: preparation methods, antimicrobial mechanisms, safety issues, future prospects, and challenges. Food Rev Int. 2022;38(4):537-565.
6. Qu B, Luo Y. A review on the preparation and characterization of chitosan-clay nanocomposite films and coatings for food packaging applications. Carbohydr Polym Technol Appl. 2021;2:100102-100111.
7. Dey S, Mohanty DL, Divya N, Bakshi V, Mohanty A, Rath D, et al. A critical review on zinc oxide nanoparticles: synthesis, properties and biomedical applications. Intell Pharm. 2025;3(1):53-70.
8. Flemban TH. Synthesis, characterization, and analysis of zinc oxide nanoparticles using varying pulsed laser ablation energies in liquid. J Exp Nanosci. 2023;18(1):2175817.
9. Salah N, Habib SS, Khan ZH, Memic A, Azam A, Alarfaj E, et al. Highenergy ball milling technique for ZnO nanoparticles as antibacterial material. J Exp Nanosci. 2011;6:863-869.
10. Alghuthaymi MA, Abd-Elsalam KA, AboDalam HM, et al. Trichoderma: an eco-friendly source of nanomaterials for sustainable agroecosystems. J Fungi (Basel). 2022;8(4):367.
11. Rauf MA, Owais M, Rajpoot R, Ahmad F, Khan N, Zubair S. Biomimetically synthesized ZnO nanoparticles attain potent antibacterial activity against less susceptible Staphylococcus aureus skin infection in experimental animals. RSC Adv. 2017;7:36361-36373.
12. Ilkhechi NN, Mozammel M, Khosroushahi AY. Antifungal effects of ZnO, TiO and ZnO-₂ TiO nanostructures on ₂ Aspergillus flavus. J Aust Ceram Soc. 2021;57:793-802.
13. Parveen K, Banse V, Ledwani L. Green synthesis of nanoparticles: their advantages and disadvantages. AIP Conf Proc. 2016;1721(1):020048.
14. Priyadarshi R, Negi YS. Effect of varying filler concentration on zinc oxide nanoparticleembedded chitosan films as potential food packaging material. J Polym Environ. 2017;25:1087-1098.
15. Roy S, Rhim JW. Carboxymethyl cellulose-based antioxidant and antimicrobial active packaging film incorporated with curcumin and zinc oxide nanoparticles. Int J Biol Macromol. 2020;148:666-676.
16. Yadav S, Mehrotra GK, Bhartiya P, Singh A, Dutta PK. Preparation, physicochemical and biological evaluation of quercetin-based chitosan-gelatin film for food packaging. Carbohydr Polym. 2020;227:115348-115356.
17. Droepenu EK, Jackson NAN, Kyene MO, Ayertey F, Brew-Daniels H, Mensah T, et al. Synthesis and Characterization of Chrysophyllum albidum (African Star Apple) Plant-Mediated Zinc Oxide Nanostructures and Evaluation of Their Antioxidant, Anti-Inflammatory, and Antimicrobial Activity. Journal of Nanomaterials. 2022;2022(1).https://doi.org/10.1155/2022/5508224
18. Gupta J, Mishra P. Antimicrobial Screening of Some Newly Synthesized Triazoles. Journal of Pure and Applied Microbiology. 2017;11(2):10671077.https://doi.org/10.22207/jpam.11.2.50
19. Sana SS, Vadde R, Kumar R, Arla SK, Somala AR, Krishna Rao KSV, et al. Eco-friendly and facile production of antibacterial zinc oxide nanoparticles from Grewia flavescens leaf extract for biomedical applications. J Drug Deliv Sci Technol. 2023;80:104186.
20. Mirza S, Hussaini AA, Öztürk G, Turgut M, Öztürk T, Tugay O, et al. Photocatalytic and antibacterial activities of ZnO nanoparticles synthesized from Lupinus albus and Lupinus pilosus plant extracts via green synthesis approach. Inorg Chem Commun. 2023;155:111124.
21. Kyene MO, Droepenu EK, Ayertey F, Yeboah GN, Archer MA, Kumadoh D, et al. Synthesis and characterization of ZnO nanomaterial from Cassia sieberiana and determination of its anti-inflammatory, antioxidant and antimicrobial activities. Sci Afr. 2023;19:e01452.
22. Rafique S, Bashir S, Akram R, Jawaid S, Bashir M, Aftab A, et al. In vitro anticancer activity and comparative green synthesis of ZnO/Ag nanoparticles by Moringa oleifera, Mentha piperita, and Citrus limon. Ceram Int. 2023;49(4):5613-5620.
23. Manojkumar U, Kaliannan D, Srinivasan V, Balasubramanian B, Kamyab H, Mussa ZH, et al. Green synthesis of zinc oxide nanoparticles using Brassica oleracea var. botrytis leaf extract: photocatalytic, antimicrobial and larvicidal activity. Chemosphere. 2023;323:138263.
24. Gupta SJ, Singh S. Review on green synthesis of zinc oxide nanoparticles: characterization and evaluation of biological activities. Int J Curr Sci. 2025;15(2):241-245.
25. Qu B, Luo Y. Preparation and characterization of carboxymethyl cellulose-capped zinc oxide nanoparticles: a proof-of-concept study. Food Chem. 2022;389:133001.
26. Wang L, Xue J, Zhang Y. Preparation and characterization of curcumin-loaded caseinate/zein nanocomposite film using a pH-driven method. Ind Crops Prod. 2019;130:7180.
27. Bai L, Yang C, Feng X, Meng X, Yi H, Lu Y, et al. Development of metal-organic frameworks and HPβCD/erythritol inclusion complexes loaded onto efficient nanometer fiber membranes for active food packaging. Food Chemistry. 2025;490:145110.https://doi.org/10.1016/j.foodchem.2025 .145110
28. Bu N, Wang L, Zhang D, Xiao H, Xiao H, et al. Highly hydrophobic gelatin nanocomposite film assisted by nanoZnO/(3-aminopropyl)triethoxysilane/stearic acid coating for liquid food packaging. ACS Appl Mater Interfaces. 2023;15(44):51713-51726.
29. Sameen A, Sahar A, Khan S, Tariq T, Ishfaq B. Shelf Life of Foods through Nanosensors Application. Nanotechnology Interventions in Food Packaging and Shelf Life. 2022:173202.https://doi.org/10.1201/9781003207641-11
30. Huang X, Zhou X, Dai Q, Qin Z. Antibacterial, antioxidant, UV-blocking, and biodegradable soy protein isolate food packaging film with mangosteen peel extract and ZnO nanoparticles. Nanomaterials (Basel). 2021;11(12):33373352.https://doi.org/10.3390/nano11123337
31. Xie Y, Chen N, Hua G, Xiao Y. Methodology selecting packaging materials combined multi-sensory experience and fuzzy three-stage network DEA model. Packaging Technology and Science. 2022;36(2):125134.https://doi.org/10.1002/pts.2698
32. Alizadeh Sani M, Khezerlou A, Tavassoli M, Mohammadi K, Hassani S, Ehsani A, et al. Bionanocomposite Active Packaging Material Based on Soy Protein Isolate/Persian Gum/Silver Nanoparticles; Fabrication and Characteristics. Colloids and Interfaces. 2022;6(4):57.https://doi.org/10.3390/colloids6040057
33. Wu M, Zhou Z, Yang J, Zhang M, Cai F, Lu P. ZnO nanoparticles stabilized oregano essential oil Pickering emulsion for functional cellulose nanofibril packaging films with antimicrobial and antioxidant activity. Int J Biol Macromol. 2021;190:430-440.
34. Jin SE, Jin HE. Antimicrobial activity of zinc oxide nano/microparticles and their combinations against pathogenic microorganisms for biomedical applications: from physicochemical characteristics to pharmacological aspects. Nanomaterials (Basel). 2021;11(2):263.
35. Mohammed M, Rahman R, Mohammed AM, Adam T, Betar BO, Osman AF, et al. Surface treatment to improve water repellence and compatibility of natural fiber with polymer matrix: recent advancement. Polym Test. 2022;115:107707.
36. Channa IA, Ashfaq J, Gilani SJ, Shah AA, Chandio AD, Jumah MN. UV blocking and oxygen barrier coatings based on polyvinyl alcohol and zinc oxide nanoparticles for packaging applications. Coatings. 2022;12(7):897.https://doi.org/10.3390/coatings12070897
37. Ezati P, Khan A, Priyadarshi R, Bhattacharya T, Tammina SK, Rhim JW. Biopolymerbased UV protection functional films for food packaging. Food Hydrocoll. 2023;142:108771.
38. Abou Zeid S, Leprince-Wang Y. Advancements in ZnObased photocatalysts for water treatment: a comprehensive review. Crystals (Basel). 2024;14(7):611.https://doi.org/10.3390/cryst14070611
39. Baibara O, Radchenko M, Karpyna V, Ievtushenko A. A review of some aspects for the development of ZnO-based photocatalysts for a variety of applications. Phys Chem Solid State. 2021;22(3):585-594.
40. Lu F, Cai W, Zhang Y. ZnO hierarchical micro/nanoarchitectures: solvothermal synthesis and structurally enhanced photocatalytic performance. Adv Funct Mater. 2008;18(7):1047-1056.
41. Mohammad F, Bwatanglang IB, Al-Lohedan HA, Shaik JP, Al-Tilasi HH, Soleiman AA. Influence of surface coating towards the controlled toxicity of ZnO nanoparticles in vitro. Coatings. 2023;13(1):172.
42. Khan MJ, Ahmad A, Khan MA, Siddiqui S. Zinc oxide nanoparticles induce apoptosis in human epidermoid carcinoma cells through reactive oxygen species and DNA degradation. Biol Trace Elem Res. 2021;199:2172-2181.
43. Salama HE, Aziz MSA, Alsehli M. Carboxymethyl cellulose/sodium alginate/chitosan biguanidine hydrochloride ternary system for edible coatings. Int J Biol Macromol. 2019;139:614-620.
44. Liu J, Hu J. Migration and characterization of nano-zinc oxide from polypropylene food containers. Am J Food Technol. 2016;11(4):159-164.
45. Fakhar A, Gul B, Gurmani AR, et al. Heavy metal remediation and resistance mechanism of Aeromonas, Bacillus, and Pseudomonas: a review. Crit Rev Environ Sci Technol. 2020;1-28.
46. Zhao Z, Zhang B, Huang N, Sun Y, Huai X, Miao J, et al. Types of nanomaterials commonly used in food packaging, film formation techniques, and recent advances in their applications. Int J Food Sci Technol. 2025;60(1):vvae036.
47. Sameen DE, Ahmed S, Lu R, Li R, Dai J, Qin W, et al. Electrospun nanofibers for food packaging: trends and applications in food systems. Crit Rev Food Sci Nutr. 2021;62(22):6238-6251.
48. Jahani A, Biglari N. Zinc oxide nanoparticles: synthesis, properties and their applications in food packaging. Mater Chem Horiz. 2025;3(4):1076.
49. Alizadeh-Sani M, Moghaddas Kia E, Ghasempour Z, Ehsani A. Preparation of active nanocomposite film consisting of sodium caseinate, zinc oxide nanoparticles and rosemary essential oil for food packaging applications. J Polym Environ. 2021;29:588-598.
50. Kim I, et al. ZnO nanostructures in active antibacterial food packaging: preparation methods, antimicrobial mechanisms, safety issues, future prospects, and challenges. Food Rev Int. 2022;38(4):537-565.
51. Qu B, Xiao Z, Luo Y. Sustainable nanotechnology for food preservation: synthesis, mechanisms, and applications of zinc oxide nanoparticles. J Agric Food Res. 2025;19:101743-101751.
52. Perumal MKK, Rajasekaran MBS, et al. Zinc oxide nanoparticles and their nanocomposites as an imperative coating for smart food packaging. Appl Food Res. 2025;5(1):100849.
53. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF). Safety assessment of the substance zinc oxide, nanoparticle, for use in food contact materials. EFSA J. 2016;14(3):1-8.