Nanoformulated Curcumin for Food Preservation: A Natural Antimicrobial in Active and Smart Packaging Systems

Abstract

Food spoilage and contamination remain pressing global challenges, undermining food security and safety while driving economic losses. Conventional preservation strategies, including thermal treatments, refrigeration, and synthetic additives, often compromise nutritional quality and raise sustainability concerns, thereby necessitating natural, effective alternatives. Curcumin, a polyphenolic compound derived from Curcuma longa, has demonstrated broad-spectrum antimicrobial, antioxidant, and anti-inflammatory activities, making it a promising candidate for food preservation. However, its poor solubility, instability, and low bioavailability limit direct applications in food systems. Advances in nanotechnology have enabled the development of nanoformulated curcumin, enhancing solubility, stability, controlled release, and functional efficacy. This review examines the antimicrobial mechanisms of curcumin and its nanoformulations, including membrane disruption, oxidative stress via reactive oxygen species, quorum sensing inhibition, and biofilm suppression. Applications in active and smart packaging are highlighted, where curcumin nanoformulation not only extends shelf life but also enables freshness monitoring through pH-responsive color changes. Evidence across meats, seafood, fruits, dairy, and beverages shows improved microbial safety, oxidative stability, and sensory quality. Multifunctional systems, such as hybrid composites and stimuli-responsive carriers, represent next-generation tools for sustainable packaging. However, challenges remain with scale-up, migration safety, cytotoxicity, and potential promotion of antimicrobial resistance gene (ARG) transfer. Future research should focus on safety validation, advanced nanocarriers, ARG-aware strategies, and regulatory frameworks. Overall, nanoformulated curcumin offers a natural, versatile, and eco-friendly approach to food preservation that aligns with clean-label consumer demand.

1. Introduction

Food safety and spoilage remain major global challenges, with microbial contamination, chemical degradation, and oxidative processes significantly affecting the quality, shelf life, and safety of food products [1,2]. Foodborne pathogens such as Escherichia coli, Campylobacter, Salmonella spp., and Listeria monocytogenes, along with spoilage-causing microorganisms, contribute to substantial economic losses and pose serious public health risks worldwide [3]. Oxidative deterioration of fats, proteins, and other biomolecules also compromises nutritional value and sensory quality [4,5], further emphasising the need for effective preservation strategies.

Traditional food preservation methods, including thermal processing, refrigeration, and the use of synthetic chemical additives, have been widely applied to control microbial growth and prolong shelf life [6,7]. However, these approaches have limitations. Thermal and chemical treatments can degrade sensitive nutrients and bioactive compounds, alter food texture and flavour, and in some cases, generate potentially harmful by-products [8]. Additionally, the increasing consumer demand for minimally processed, clean-label foods highlights concerns over the safety and sustainability of synthetic preservatives, prompting the search for safer and more natural alternatives [9].

Natural antimicrobials have emerged as promising substitutes for conventional additives. Compounds such as essential oils, plant extracts, and polyphenols demonstrate potent antimicrobial and antioxidant activities while being biocompatible and environmentally friendly [10]. Among these, curcumin, a polyphenolic compound derived from Curcuma longa, has gained attention for its broad-spectrum antimicrobial, antioxidant, and anti-inflammatory properties. However, the practical application of curcumin in food systems is limited by its low water solubility, poor stability, and rapid degradation under light, heat, and alkaline conditions [11].

Nanotechnology offers innovative solutions to these challenges by enabling the development of nanoformulated curcumin with enhanced solubility, stability, and bioavailability [12]. Nanoencapsulation, nanoemulsions, and polymeric nanoparticles (NPs) allow controlled release of curcumin, improving its efficacy as a natural antimicrobial in food packaging systems. Smart packaging technologies, integrating these nanoformulated bioactive compounds, can actively monitor and extend the shelf life of perishable foods while ensuring safety and quality [13].

This review offers a comprehensive examination of nanoformulated curcumin in food safety applications, with particular emphasis on its roles in food preservation as well as active and smart packaging systems. It outlines the fundamental mechanisms underlying its antimicrobial activity, critically evaluates the efficacy of curcumin NPs and nanoformulations within diverse food matrices, and highlights the challenges that hinder large-scale industrial adoption. Furthermore, the review explores prospective strategies and future directions for incorporating curcumin-based nanomaterials into sustainable, effective, and next-generation food packaging solutions.

2. Curcumin: Properties and Antimicrobial Potential in Food Systems

Curcumin is a bright yellow polyphenolic compound extracted from the rhizome of Curcuma longa L., a plant widely used in traditional medicine and culinary applications, especially in South Asia [14]. Chemically known as diferuloylmethane, curcumin has a diketone structure featuring two aromatic ring systems containing o-methoxy phenolic groups connected by a seven-carbon linker with α,β-unsaturated carbonyl groups, as shown in Figure 1 [15].

Its polyphenolic structure enables hydrogen bonding, hydrophobic interactions, and metal ion chelation, which facilitate binding to bacterial proteins, enzymes, and nucleic acids, thereby disrupting vital cellular functions [16,17]. The amphiphilic nature of curcumin allows insertion into lipid bilayers, leading to perturbation of membrane integrity, increased permeability, and ultimately leakage of cellular contents [18]. Furthermore, its ability to undergo keto–enol tautomerism enhances redox activity, enabling curcumin to act as both an antioxidant and a pro-oxidant depending on the environment [19]. Under antimicrobial settings, this redox flexibility supports the generation of reactive oxygen species (ROS) [20], which cause oxidative damage to microbial DNA, proteins, and membranes, amplifying its inhibitory effects.

This unique structure contributes to its broad-spectrum bioactivity, including antioxidant, anti-inflammatory, and antimicrobial effects. These multifunctional bioactivities make curcumin highly valuable in food systems, where it acts as a natural preservative by inhibiting microbial growth and oxidative spoilage, thus enhancing food safety and shelf life [21].

2.1. Antimicrobial Spectrum and Activity of Curcumin in Food Systems

Curcumin has emerged as a promising natural antimicrobial agent for diverse applications in food systems due to its broad-spectrum activity against foodborne pathogens and spoilage microorganisms [22]. Studies have demonstrated its effectiveness against Gram-positive bacteria such as Staphylococcus aureus, L. monocytogenes, and Bacillus cereus, as well as Gram-negative species including E. coli and Salmonella enterica [23,24,25]. Gulel et al. (2024) demonstrated that curcumin significantly reduced Salmonella typhimurium counts in chicken meat in a dose-dependent manner. Treatments with 1–3% curcumin led to reductions of up to 2.84 log CFU by day 6 [26]. In addition to antibacterial properties, curcumin exhibits significant antifungal activity against food spoilage fungi like Aspergillus niger and Candida albicans [27]. These antimicrobial effects are particularly valuable in ensuring microbiological safety and extending the shelf life of food products.

In food systems, curcumin can be applied in various forms, directly as an additive, incorporated into edible coatings, or integrated into active packaging films [28]. Bagale et al. (2022) demonstrated that embedding curcumin nanoemulsion directly into bread significantly inhibited microbial growth, including algae, under both ambient and refrigerated conditions, effectively delaying spoilage for up to 14 days. The increased antioxidant activity (31.59%) further enhanced product stability, emphasising curcumin’s dual functionality in preserving quality and extending shelf life [29]. When incorporated into biodegradable films or coatings, such as those based on starch, chitosan, or proteins, curcumin imparts both antimicrobial and antioxidant protection, preventing microbial proliferation on food surfaces and limiting the oxidation of fats and pigments. Curcumin-infused packaging or coatings have proven effective in extending the freshness of perishable foods, including meats, cheeses, and bakery items, by reducing microbial load and delaying spoilage [29,30,31].

Moreover, curcumin’s antibiofilm properties are particularly relevant to food safety, as biofilm formation on food processing equipment and packaging surfaces is a major source of microbial contamination and cross-infection. By inhibiting microbial adhesion and biofilm development, curcumin reduces microbial persistence in production and storage environments [32]. For example, empirical studies have demonstrated that, at sub-inhibitory concentrations, curcumin significantly reduced biofilm biomass in common uropathogens and foodborne contaminants such as E. coli, Pseudomonas aeruginosa, Proteus mirabilis, and Serratia marcescens. It not only inhibited the formation of early-stage biofilms but also disrupted mature biofilms that had already established their complex extracellular matrix [33].

2.2. Mechanisms of Antimicrobial Action

The antimicrobial efficacy of curcumin is attributed to several mechanisms targeting critical cellular functions in microorganisms. Figure 2 illustrates how curcumin NPs exert their antimicrobial action through multiple mechanisms.

2.2.1. Disruption of Membrane and Cell Wall Integrity

Curcumin exhibits broad-spectrum antimicrobial activity, primarily through disruption of cell wall and bacterial membrane integrity, and increased membrane permeability [34,35,36]. In a study by Morsy et al. (2023), curcumin nanoparticles (NPs) adhered to the bacterial surface, ruptured the cell wall, and penetrated the cytoplasm. Transmission electron microscopy (TEM) images of E. coli, S. aureus, and B. cereus revealed dark, electron-dense curcumin-NP aggregates disrupting the peptidoglycan layer and compromising structural integrity [37]. Similarly, Yadav et al. (2020) reported that a water-soluble form of curcumin exerted potent antibacterial activity against multidrug-resistant strains by inducing membrane depolarisation and loss of integrity. Fluorescent dye assays (FM 4-64 and propidium iodide) and confocal microscopy confirmed extensive membrane damage in E. coli and Bacillus subtilis, with enhanced antibiotic efficacy due to increased intracellular uptake [34]. Other studies have corroborated curcumin’s ability to permeabilize bacterial membranes across both Gram-positive and Gram-negative bacteria. Using PI and calcein-AM assays, curcumin was shown to cause cytoplasmic leakage in S. aureus, Enterococcus faecalis, E. coli, and P. aeruginosa. Scanning electron microscopy revealed morphological distortions and ruptures in bacterial cells, while fluorescence microscopy corroborated extensive membrane damage. These findings suggest that curcumin exerts a broad-spectrum antimicrobial effect, with significant potential for synergistic application in combination therapies [35]. Mechanistically, curcumin integrates into the bacterial lipid bilayer and interacts with phospholipids and peptidoglycans, disrupting membrane structure and increasing porosity [38]. This leads to the efflux of potassium, calcium, ATP, nucleic acids, and proteins, causing osmotic imbalance and cellular collapse. Supporting this, Wray et al. (2021) identified the mechanosensitive channel of large conductance (MscL) as a molecular target of curcumin. Activation of MscL by curcumin induces leakage of osmoprotectants such as potassium and glutamate, disrupts homeostasis, and enhances antibiotic uptake. Moreover, it impairs septation and induces a RecA-dependent apoptosis-like response in E. coli [39]. These findings show that membrane-targeting and MscL activation are central mechanisms in curcumin’s antimicrobial action, supporting its application in combination therapies and food preservation systems.

2.2.2. Reactive Oxygen Species Generation

Curcumin generates reactive oxygen species (ROS) through several mechanisms that contribute to its antimicrobial activity. Some of these include:

i.

Photodynamic Activation

Under light exposure, curcumin absorbs photons and transitions to an excited state. It can then transfer energy to molecular oxygen, generating singlet oxygen (¹O₂) and other ROS such as superoxide anions (O₂⁻), hydrogen peroxide (H₂O₂), and hydroxyl radicals (•OH). This process is particularly effective in antimicrobial photodynamic therapy (aPDT) and in light-activated food packaging systems [40,41]. For instance, aPDT employing curcumin was evaluated for its efficacy against S. aureus, using various curcumin formulations including synthetic curcumin (curcumin-Syn) and heavy-atom derivatives, curcumin-Cl, curcumin-Se, and curcumin-I. Among these, selenium-modified curcumin (curcumin-Se) exhibited the highest antimicrobial activity, achieving complete bacterial inactivation (100% CFU/mL reduction) across all tested concentrations and light energy doses. This enhanced efficacy was attributed to curcumin-Se’s superior photostability and ROS-generating capacity. While curcumin-Syn and curcumin-Cl also significantly reduced bacterial viability, curcumin-I was less effective. Curcumin-Se reached peak bacterial uptake within 20 min and underwent slower photobleaching than curcumin-Syn, enabling prolonged ROS production [42]. Similarly, curcumin-mediated photodynamic treatment effectively inactivated Botrytis cinerea spores, a major fungal pathogen causing grey mould in fruits and vegetables. Using 420 nm blue light and 13 μM curcumin in aqueous ethanol, ROS, mainly O₂•⁻, were generated, leading to a 3.25-log CFU/mL reduction. Treatment induced severe structural damage, including organelle destruction. Electron paramagnetic resonance confirmed ROS formation, reinforcing curcumin’s role as a safe, eco-friendly antimicrobial [43]. These findings highlight curcumin’s potential as a natural photosensitizer for inactivating both bacterial and fungal pathogens through ROS-driven photodynamic mechanisms.

ii.

Disruption of Bacterial Iron Homeostasis:

Curcumin also disrupts bacterial iron metabolism, enhancing ROS-mediated killing. Acting as an iron chelator, it mobilises intracellular iron and increases free ferrous ions (Fe²⁺). These ions participate in Fenton reactions, converting H₂O₂ into highly reactive hydroxyl radicals (•OH). Such radicals, along with other ROS, trigger oxidative stress that damages DNA, proteins, and lipids [44]. Yadav et al. (2020) demonstrated that water-soluble curcumin elevated H₂O₂, •OH, and Fe²⁺ levels in B. subtilis and E. coli, leading to chromatin condensation, DNA fragmentation, and membrane destabilisation. The antimicrobial effect was significantly reduced when ROS scavengers such as thiourea were introduced, confirming the central role of ROS in bacterial killing [34]. Thus, curcumin’s iron-disruptive activity complements its membrane-targeting action, making it a potent therapeutic candidate.

iii.

Autooxidation

Curcumin undergoes spontaneous, free radical-driven autooxidation under physiological or mildly alkaline conditions, where molecular oxygen acts as the initial electron acceptor. This process involves the incorporation of O₂ into the heptadienedione chain, leading to a double cyclisation and the formation of bicyclopentadione as the major stable product [45,46]. During the reaction, ROS are generated.

The ROS produced through these mechanisms exert widespread cellular damage. Lipid peroxidation disrupts membrane integrity, increasing permeability and causing ion leakage, loss of membrane potential, and eventual lysis [47]. Protein oxidation alters structural and enzymatic proteins, impairing essential functions and destabilising cellular processes. DNA damage, including strand breaks, base modifications, and cross-linking, further hampers replication and transcription [48]. The combined damage overwhelms microbial defence systems, leading to oxidative stress-induced cell death. For example, Adeyemi et al. (2020) demonstrated that curcumin exerts antimicrobial effects partly by inducing DNA damage in E. coli and S. aureus, with treatments causing significant DNA fragmentation. This damage was strongly linked to oxidative stress, as curcumin increased lipid peroxidation (elevated malondialdehyde levels) and promoted excessive ROS generation [49]. In fungi, curcumin exhibits potent activity against Aspergillus flavus by suppressing aflatoxin B1 synthesis (via downregulation of aflK, aflO, aflL), inhibiting mycelial growth and sporulation, and disrupting ergosterol biosynthesis, thereby increasing membrane permeability. ROS bursts, including superoxide anions and hydrogen peroxide, mediate these effects, as confirmed by recovery with superoxide dismutase, showing ROS accumulation as a central mechanism of curcumin’s multifaceted antimicrobial activity [50].

2.2.3. Inhibition of Quorum Sensing and Biofilm Formation

Curcumin has been extensively studied for its ability to interfere with microbial cell-to-cell communication, known as quorum sensing (QS). QS allows microorganisms to detect population density and coordinate behaviours such as biofilm formation and virulence factor production, which are essential for survival, pathogenicity, and antimicrobial resistance [51]. By disrupting QS pathways, curcumin decreases microbial virulence and compromises survival strategies, even at sub-minimum inhibitory concentrations (sub-MIC), reducing pathogenicity without exerting strong selective pressure for resistance [51,52].

A key outcome of curcumin treatment is the inhibition of biofilm formation. It disrupts the initial adhesion of microbial cells and prevents biofilm maturation, interfering with the establishment of structured microbial communities embedded in protective extracellular matrices [53]. This anti-biofilm activity has been demonstrated in clinically significant pathogens, reducing microbial persistence and lowering the risk of chronic infections. For instance, Mangoudehi et al. (2020) demonstrated that, in Aeromonas hydrophila, curcumin downregulates the acyl-homoserine lactone synthase gene (ahyI) and its transcriptional regulator gene (ahyR), disrupting the AhyI/AhyR-acyl-homoserine lactone complex, a key system controlling virulence gene expression. This leads to significant reductions in biofilm formation, motility, and pigmentation, with moderate effects on protease activity, while hemolytic activity remains largely unaffected [54]. Similarly, Fernandes et al. (2023) reported that curcumin inhibits the LuxS/autoinducer-2 (AI-2) QS system in B. subtilis and the LasI/LasR system in P. aeruginosa. In vitro, curcumin dose-dependently reduced AI-2 accumulation (33–77%) and 3-oxo-C12-homoserine lactone (3-oxo-C12-HSL) production (21%) without affecting bacterial growth [55]. Additionally, curcumin enhances the susceptibility of biofilm-associated bacteria to conventional antibiotics. By disrupting biofilm architecture, microbial cells become more exposed to antimicrobial agents, overcoming resistance mechanisms associated with restricted drug penetration and altered metabolic activity [56].

Through its combined actions of QS inhibition, biofilm prevention, virulence factor suppression, and enhancement of antibiotic sensitivity, curcumin emerges as a promising natural compound for controlling bacterial infections.

2.2.4. Inhibition of Nucleic Acid Synthesis

Curcumin exerts antimicrobial activity by directly targeting microbial genetic and nucleic acid processes, interfering with DNA and RNA synthesis, and thereby inhibiting replication, transcription, and overall microbial proliferation. Murai et al. (2024) demonstrated that curcumin inhibits Porphyromonas gingivalis through two principal mechanisms. Firstly, it disrupts nucleic acid synthesis by reducing key metabolites in purine and pyrimidine pathways, including high-energy compounds such as ATP and nucleoside/amino sugars, limiting the precursors necessary for RNA and DNA formation and suppressing bacterial growth. Secondly, curcumin downregulates sigma-54 (rpoN) and sigma-70 (rpoD), essential RNA polymerase subunits that regulate transcription and stress responses. This downregulation mimics nutrient starvation, impairing gene expression coordination and metabolic activity [57].

2.2.5. Disruption of Protein Function and Metabolic Pathways

Curcumin compromises microbial viability by targeting proteins and essential metabolic enzymes. Through hydrogen bonding and hydrophobic interactions, it alters enzyme active sites, impairing catalytic activity [58]. In bacteria, curcumin inhibits the FtsZ protein, a tubulin-like GTPase essential for cell division. Normally, FtsZ assembles into GTP-dependent protofilaments that form the division septum and recruit additional division factors. Curcumin disrupts this process by stimulating FtsZ’s GTPase activity, preventing proper filament formation [59]. For instance, in B. subtilis, treatment at the MIC₉₀ caused complete septum dissolution within 15 min and mislocalization of FtsZ-GFP fluorescence to the cytoplasm. Binding studies further confirmed high affinity (dissociation constant ~7 μM), likely mediated by interactions between curcumin’s β-diketone moiety and specific glycine residues in FtsZ from B. subtilis and E. coli [36].

In fungi, curcumin interferes with ergosterol biosynthesis by inhibiting key enzymes, thereby compromising membrane integrity. For instance, curcumin showed potent antifungal activity against Rhizopus oryzae by targeting Cytochrome P450 51B (CYP51B), a crucial enzyme in ergosterol synthesis. In silico analyses revealed strong binding to CYP51B, including stable heme–iron interactions confirmed by molecular docking, MM-GBSA, and molecular dynamics simulations. In vitro, curcumin suppressed R. oryzae growth in a dose-dependent manner, with a MIC of 256 μg/mL, and reduced ergosterol content by up to 86% [60]. Similarly, against Paracoccidioides spp., curcumin inhibits enzymes essential for survival and oxidative stress defence, including superoxide dismutase and catalases, through hydrogen bonding with specific residues. It also targets isocitrate lyase, disrupting the glyoxylate cycle, and glucose-6-phosphate dehydrogenase, reducing NADPH production and redox balance. Collectively, these actions weaken fungal antioxidant defences, elevate ROS, and trigger apoptosis, confirming enzyme inhibition as curcumin’s primary antifungal mechanism [61]. Curcumin disrupts vital microbial enzymes, impairing growth and defences, making it a promising natural broad-spectrum antimicrobial agent.

Curcumin’s activity is not only antimicrobial but also antioxidant and anti-inflammatory, making it an ideal candidate for multifunctional food preservation strategies. Its antioxidant properties help prevent lipid peroxidation and pigment degradation, thus maintaining food quality, flavour, and colour. These roles are especially useful in oil-rich products and fresh produce susceptible to oxidative spoilage [62].

However, despite its potent antimicrobial properties, native curcumin faces limitations in food applications. Its high hydrophobicity restricts dispersion in aqueous food systems, reducing microbial interaction and preservative efficacy. Low bioavailability, due to rapid metabolism and degradation, limits sustained antimicrobial activity. Furthermore, curcumin is unstable under common processing conditions, including light, heat, and alkaline pH, resulting in structural breakdown and loss of potency. These limitations necessitate the use of curcumin nanoformulations or nano-delivery systems to enhance solubility, stability, and controlled release, thereby improving curcumin’s functional application in food preservation and active packaging [63].

3. Antimicrobial Efficacy of Curcumin NPs and Nanoformulations in Food Systems

Curcumin, despite its potent antimicrobial and antioxidant properties, faces significant limitations when applied directly in food systems due to its poor aqueous solubility, low bioavailability, and chemical instability [64]. To address these challenges, nanoformulation strategies have been extensively explored. Encapsulation of curcumin into nanostructures enhances its solubility, protects it from degradation, improves stability, and allows for controlled release while maintaining its biological activity [11].

A variety of curcumin NPs and nanoformulations, including polymeric NPs, lipid-based carriers, inorganic nanomaterials, and hybrid nanostructures (Figure 3), have been investigated for applications in food preservation and active packaging [65].

These nano-systems can be produced using solvent-based, physical, encapsulation, and chemical methods, each promoting NP formation through different mechanisms. In solvent evaporation, curcumin-loaded polymers are dissolved and, upon solvent removal, self-assemble into NPs. Nanoprecipitation relies on dispersing curcumin into a non-solvent, where rapid supersaturation triggers precipitation as nanosized particles. Physical methods like high-pressure homogenization break bulk curcumin into nanostructures under intense shear, while ultrasonication employs sound waves to fragment particles into stable NPs [11]. Encapsulation approaches, including polymer coating or microfluidics, drive controlled self-assembly into uniform nano-systems, improving solubility and stability [66]. Chemical conjugation with polymers or functional molecules produces nano-conjugates, where covalent bonding locks curcumin into nanoscale frameworks, enhancing bioavailability and enabling controlled release [67].

These systems not only amplify the antimicrobial efficacy of curcumin against diverse foodborne pathogens (utilising the same mechanisms of action as bulk curcumin, as discussed in Section 2.2, but with greater efficiency), but also provide additional functional benefits. Specifically, nanoformulated curcumin demonstrates superior antioxidant capacity, more effectively preserves food quality attributes such as colour, texture, and flavour, and prolongs shelf life under both refrigerated and ambient storage conditions compared to its bulk counterpart [37,68]. Curcumin NPs and nanoformulations provide multifunctional benefits rarely achievable with other natural antimicrobials, such as essential oils or chitosan, which are limited by volatility, strong sensory effects, or pH-dependent activity. Nanoformulated curcumin functions simultaneously as an antioxidant, antimicrobial, and food-grade photosensitizer [69]. Its enhanced anti-virulence activity, improved biofilm penetration, and photodynamic antimicrobial potential distinguish curcumin nanoformulations, positioning them as novel, next-generation bioactive agents for safe and effective food preservation and active packaging.

3.1. Antimicrobial Applications of Curcumin Nanoformulations in Food Systems

Table 1. Antimicrobial activity of curcumin NPs and nanoformulations in food preservation.

Curcuminnanoformulation	% (w/w) Curcumin in Nanoformulation	Shape, Size, Zeta Potential	Applied Area	Effect	Ref
Curcumin NPs	-	Spherical, 80 ± 2 nm, zeta potential was 4.5 mV	Preservative in processed chicken fingers	Strong activity against S. aureus, E. coli, and B. cereus; reduces lipid oxidation, stabilises pH, lowers microbial counts, extending shelf life beyond 3 days (compared to 1 day for the control).	[37]
Curcumin NPs in rice starch (RS) films	0.5 to 3	Spherical, 141 ± 7 nm, zeta potential was −30.3 mV	Food packaging films for strawberry preservation	Inhibited B. cinerea, preserved pH and sweetness, reduced weight loss, delayed softening, and extended freshness	[70]
Ferric-curcumin (Fe-Curcumin) NPs	-	65 nm, zeta potential was −67.2 mV	Pork preservation	Enhanced stability, antibacterial efficacy against S. aureus and E. coli, disrupt biofilms and preserve pork freshness in chitosan films (Total Viable Count value of 6.41 at Day 15 compared to 8.06 at Day 10 for the control)	[71]
Curcumin-modified Cu-doped ZnO NPs (Cu-ZnO@Curcumin)	≈ 1	Round, 30 nm	Banana edible coating	Reduced spoilage by reducing banana fruit mass loss by up to 17.58% after seven days of storage, compared to uncoated fruit, delayed ripening, and enhanced antibacterial activity	[72]
Curcumin-AgNPs in pectin/gelatin films	0.3	AgNPs spherical and 20 nm	Shrimp packaging films	Inhibited S. aureus and E. coli, enhanced antioxidant activity, and introduced pH-sensitive colour changes that visually indicated food spoilage.	[73]
Curcumin-loaded mesoporous silica NPs	1.85	Hexagonal, pore size of 6 nm	Food packaging films	Improved film strength, pH-responsive sustained release, prolonged activity against S. aureus and E. coli.	[74]
Curcumin-loaded Prunus armeniaca gum NPs	-	Spherical, 50–100 nm	Edible coating for shrimp during storage	Superior antimicrobial activity against S. aureus and E. coli, effectively extending shrimp shelf life by maintaining low pH, reducing total volatile basic nitrogen and enabling controlled curcumin release.	[75]
Curcumin nanoencapsulated in polyvinylpyrrolidone (PVP) and Tween 80	8.3	Spherical, 12 nm	Food preservation	Curcumin nanoformulation was readily dispersible in water, showing enhanced water solubility, inhibited S. aureus and showed synergistic antibacterial effects when co-encapsulated with nisin	[76]
Curcumin nanoencapsulated in PVP	8.3	Irregular shape, 20 to 250 nm	Orange juice	Enhanced antimicrobial activity against S. aureus (with a 4 log CFU/mL reduction at 125 μg/mL), Salmonella Enteritidis, and Alicyclobacillus acidoterrestris (including spores with 1.04 log CFU/mL compared to 6.31 log CFU/mL for orange juice without the curcumin nanoformulation (control)), reduced cytotoxicity to normal cells, retained antioxidant capacity, and maintained pH and color stability in orange juice.	[77]
Curcumin-integrated chitosan NPs (CTNP@Curcumin) in pullulan/chitosan films	1–4	Spherical, 37 ± 7 nm, zeta potential of 50 mV	Active food packaging	Enhanced UV shielding, mechanical strength, antioxidant capacity, and hydrophobicity. Improved antibacterial activity against E. coli and L. monocytogenes.	[78]
Curcumin-loaded chitosan NPs incorporated into zein/potato starch composite film.	-	Spherical, 218 to 359 nm	Preservation of Schizothorax prenati fillets	Enhanced curcumin stability, release, and antioxidant performance. Composite films inhibited S. prenati spoilage (reaching almost 6 log CFU/g by day 15 while the control group exceeded 6 log CFU/g by day 12), extended shelf life to 15 days, reduced lipid oxidation and microbial growth, and maintained texture, odour, and sensory quality better than polyethene packaging.	[79]
Curcumin-loaded nano Metal–Organic Frameworks (MOFs) integrated with carboxymethylated filter paper (CMFP)	5	-	Pitayas preservation	Delayed pitaya spoilage, reducing the rotten area to <5% by day 6, while controls rotted fully. Strong antibacterial activity against S. aureus and exceptional antioxidant performance.	[80]
Curcumin-nisin-loaded pectin NPs in chitosan/zein bilayer films	1–3	Spherical, 143 nm, ζ-potential of −33.0 mV	Intended for active food packaging	Enhanced mechanical strength, UV blocking, and barrier properties, while significantly boosting antimicrobial (against S. aureus, E. coli) and antioxidant activity. The films also showed controlled release and reduced water sensitivity	[81]
	-	-	Grass Carp fillet preservation	Enhanced barrier, antioxidant, and antimicrobial properties, reducing Pseudomonas and Shewanella growth, lipid oxidation, and biogenic amine formation, while extending shelf life and preserving sensory, pH, and colour stability in refrigerated fish fillets.	[82]
Curcumin-loaded hollow graphitic carbon nitride (HCNS-Curcumin) in chitosan films	7	Spherical	Food packaging films for banana preservation	Improved curcumin’s thermal stability and slow-release behaviour. Sustained antibacterial activity against S. aureus and E. coli, reduced water vapour permeability, and extended banana shelf life by minimising weight loss, softening, and microbial spoilage.	[83]
Curcumin-loaded rice protein NPs	0.79–23	18 to 28 nm	Preservation of freshly cut apples	Improved curcumin’s thermal and photo-stability, enhanced antibacterial activity against E. coli and S. aureus, and preserved freshly cut apples by reducing microbial growth (with 1.46 log CFU/g compared to 6.57 log CFU/g for the control group (without curcumin-loaded rice protein NPs) after 7 days of storage), oxidative browning, and weight loss, while maintaining flavour and antioxidant effectiveness.	[84]
Curcumin NPs in pectin (PE) biodegradable nanocomposite coating with ajowan essential oil nanoemulsion (ANE).	0.2	10 nm	Storage of chilled lamb loins	Enhanced antimicrobial and antioxidant activity, effectively inhibiting L. monocytogenes, S. aureus, E. coli, and S. Typhimurium. When combined with ajowan oil and irradiation, the curcumin NPs PE nanocomposite extended the shelf life of lamb loin to 25 days.	[85]
Curcumin-loaded solid lipid NPs	-	Spherical, 127 ± 1 nm, zeta potential of −30 ± 0.3 mV	Preservation of hamburger patties	Strong antimicrobial activity against S. aureus and E. coli, reducing bacterial growth in hamburger patties during 8-day storage at 4 °C, outperforming free curcumin and enhancing food safety through sustained release.	[86]

-: Not reported.

presents various curcumin-based nanoformulations studied for food preservation. Different carriers, such as biopolymers, metals/inorganics, solid lipids, and proteins, enhance curcumin’s solubility, stability, and antimicrobial activity. The table details each formulation’s composition, particle size, shape, zeta potential, application in food, and preservation effects.

The data presented in Table 1 demonstrates the wide range of nanoformulations of curcumin developed to address specific food preservation challenges. These strategies collectively highlight how nanostructuring improves curcumin’s performance as a preservative agent by enhancing its solubility, bioavailability, and stability, while simultaneously enabling controlled release and multifunctional activity. For instance, simple curcumin NPs (spherical, ~80 nm) presented a hydrophilic surface, rendering them water-dispersible, which facilitated their uniform integration into the food matrix. These were applied successfully in processed chicken fingers, where they exhibited strong antimicrobial activity against S. aureus, E. coli, and B. cereus. Beyond their direct microbial inhibition, these NPs were also shown to reduce lipid oxidation and stabilise pH, effectively extending the shelf life of refrigerated chicken products [37]. Such multifunctionality emphasises the advantage of curcumin NPs not only as antimicrobials but also as antioxidant agents, thereby addressing dual causes of food spoilage: microbial contamination and oxidative degradation. The ability to simultaneously target these deterioration pathways is particularly important in high-protein foods, where lipid oxidation and microbial growth occur concurrently and compromise both safety and quality.

Another significant approach is the integration of curcumin NPs into biopolymer-based films and coatings, including rice starch, chitosan, pectin, or protein matrices. These edible films serve not only as curcumin carriers but also as structural reinforcements and sustainable alternatives to conventional packaging. Curcumin-loaded rice starch films, for example, inhibited B. cinerea in strawberries while preserving sensory qualities such as sweetness, colour, and texture throughout storage [70]. Similarly, curcumin incorporated into pectin or chitosan-based films improved UV shielding, mechanical strength, and barrier properties while providing sustained antimicrobial protection [78,79,81]. These bio-based films serve a dual role: they act as carriers for curcumin delivery and function as sustainable alternatives to synthetic packaging. This aligns well with current industry and regulatory emphasis on biodegradable packaging materials, demonstrating how nanoformulation can simultaneously improve preservation efficacy, sustainability, and market acceptance.

Metal-enhanced curcumin nanoformulations have further expanded the potential applications of curcumin in food systems. For example, ferric-curcumin complexes (Fe-Curcumin NPs) stabilised curcumin, improved its bioactivity under near-infrared light, and successfully preserved pork freshness [71]. Similarly, curcumin-modified Cu-doped ZnO NPs (Cu-ZnO@Curcumin) delayed the ripening and spoilage of bananas through potent antibacterial effects [72]. These findings demonstrate the synergistic potential of combining curcumin with metallic or metal oxide carriers, which not only enhances its antimicrobial stability but also introduces responsiveness to external stimuli such as light. Such systems broaden the functional scope of curcumin nanoformulations and may pave the way for antimicrobial packaging triggered by environmental factors.

An emerging and promising trend involves the use of hybrid nanostructures with multiple functionalities. Curcumin combined with silver NPs in pectin–gelatin films not only inhibited foodborne pathogens but also introduced pH-sensitive colourimetric changes that visually indicated spoilage [73]. This represents a new generation of smart packaging systems, capable of extending shelf life while simultaneously enhancing consumer confidence by providing real-time quality monitoring. Likewise, curcumin-loaded mesoporous silica NPs improved controlled release and film integrity, enabling long-lasting antimicrobial activity [74]. Such multifunctional systems reflect the transition from traditional passive packaging to intelligent packaging technologies, where curcumin contributes both antimicrobial efficacy and structural enhancement. These examples show the synergistic benefits of combining curcumin with metallic or inorganic carriers to achieve both antimicrobial efficacy and intelligent packaging features. However, concerns remain regarding their long-term safety, scalability, and regulatory approval, given the potential for migration of metallic or inorganic residues into foods.

The application of curcumin nanoformulations has also demonstrated versatility across a broad range of food matrices. In meats such as chicken, lamb loins, hamburgers, and pork, curcumin NPs lowered microbial counts, delayed lipid oxidation, and extended shelf life [37,71,85,86]. For instance, lamb loins coated with a pectin nanocomposite containing curcumin NPs and ajowan essential oil nanoemulsion, combined with low-dose gamma irradiation (2 kGy), showed marked microbial reduction and longer shelf-life. Irradiated samples started with lower TMB counts (4.5–5.0 log CFU/g) compared to ~6 log CFU/g in non-irradiated ones, while Enterobacteriaceae fell below detection. During storage, the curcumin NP–PE coating with ajowan oil and irradiation kept the lowest microbial load, with TMB at 5.59 log CFU/g on day 25 (1.41 log CFU/g below the meat safety limit (7 log CFU/g)). This treatment extended shelf-life from 5 to 25 days, demonstrating strong synergistic effects [85].

In seafood products like shrimp and fish fillets, curcumin-based formulations maintained freshness by reducing microbial counts, limiting pH fluctuations, and lowering total volatile nitrogen compounds [73,75,79,82]. For example, shrimp coated with curcumin-loaded P. armeniaca gum NPs exhibited the lowest total volatile basic nitrogen (TVB-N) content (20.39 ± 1.44 mg/100 g) after 10 days, remaining well below the rejection threshold of 30 mg/100 g. In contrast, the control shrimp (without coating) exceeded this limit, reaching 36.14 ± 1.06 mg/100 g by the 10th day. These results demonstrate that the coated shrimp retained their freshness for a longer period [75].

Fruits and vegetables such as bananas, apples, strawberries, and pitayas have also benefited, with curcumin-based coatings slowing ripening, minimizing spoilage, and retaining sensory appeal [70,72,80,83,84]. For instance, curcumin-loaded hollow graphitic carbon nitride (HCNS-Curcumin) incorporated into chitosan (CT) films effectively preserved bananas for up to 10 days. By day 10, bananas packaged with CT-HCNS-Curcumin films retained the best overall appearance, exhibited the least weight loss, and maintained the lowest pH value, demonstrating superior preservation compared to polyethylene (control), CT, and CT-Curcumin films. Bananas stored in CT-HCNS-Curcumin films also showed the highest stiffness on day 10, further confirming their extended freshness [83].

Even beverages have been targeted, as seen with polyvinylpyrrolidone (PVP)-encapsulated curcumin, which exhibited significant antimicrobial activity against A. acidoterrestris spores in orange juice, addressing a critical spoilage issue in the fruit juice industry [77]. These applications highlight curcumin’s broad relevance for both perishable and processed foods, showing its flexibility as a natural preservative.

A central advantage of nanoformulation lies in the controlled and sustained release of curcumin, which ensures prolonged antimicrobial protection. Curcumin-loaded solid lipid NPs and hollow graphitic carbon nitride composites are notable examples that improved stability and provided extended antibacterial activity [83,86]. This extended release is particularly important in real food systems, where microbial contamination and spoilage occur gradually over storage and distribution. By maintaining a continuous antimicrobial effect, such systems can substantially reduce food waste while enhancing food safety.

Curcumin nanoformulations consistently act as both antimicrobial and antioxidant agents. This synergy is especially critical in the preservation of high-fat or protein-rich foods such as meats and seafood, where both microbial activity and lipid oxidation compromise shelf life and consumer acceptability [37]. Many studies reported that curcumin NPs not only reduced microbial counts but also slowed lipid oxidation, thereby protecting flavour, texture, and nutritional quality [79,80,81,82,83,84]. This dual action makes curcumin-based nanostructures particularly competitive against synthetic preservatives, which often address only one spoilage pathway.

The percentage of curcumin incorporated into NP systems (% w/w), as shown in Table 1, varies considerably across studies, ranging from very low levels (0.2% in pectin coatings) to higher amounts exceeding 20% in protein NPs. This variability reflects both the specific requirements of the target food system and the capacity of the carrier matrix to stabilise and effectively deliver curcumin.

The choice of nanocarrier plays a decisive role in stability, release behaviour, and antimicrobial performance. Polymeric carriers such as chitosan, rice starch, zein, and pullulan typically provide high stability and controlled release, making them suitable for long shelf-life foods, although encapsulation efficiency can fluctuate considerably [87] (for example, 0.79–23% for rice protein NPs [84]), with the fluctuation probably due to variations in protein-to-curcumin ratios, pH, particle size, processing conditions, and the degree of interaction between curcumin and the carrier matrix. Solid lipid NPs (SLNPs) offer strong protection against thermal and oxidative degradation, ensuring prolonged antimicrobial action, but their long-term stability may be compromised by lipid polymorphic transitions, which occur when the crystalline structure of the lipid changes over time, causing the encapsulated curcumin to be prematurely released [88]. Nanoemulsions and PVP-based dispersions greatly enhance curcumin’s solubility and dispersibility in aqueous systems, enabling rapid antimicrobial activity in beverages and liquid foods. However, their long-term preservation is limited by burst release, as curcumin is loosely held within the system. Incorporating stabilisers such as proteins or other polymers can enhance stability and enable controlled, sustained release [89]. Inorganic and hybrid carriers, including mesoporous silica, MOFs, Cu-ZnO, and AgNPs, demonstrate high stability and multifunctionality, such as pH responsiveness and spoilage sensing, though broader use depends on addressing safety and cost challenges.

Despite these general patterns, antimicrobial efficacy remains inconsistent across studies. Shelf-life extensions ranged from two to three days, as in chicken fingers [37], to more than 25 days in lamb loins [85]. Such variability can be attributed to differences in NP size, carrier chemistry, and release profiles. Smaller NPs (10–50 nm) typically yield rapid antimicrobial effects due to their higher surface area, while larger ones (200–350 nm) deliver slower but more sustained protection. Biopolymer carriers support controlled release and strong biocompatibility, whereas inorganic carriers achieve fast microbial inactivation but raise toxicity concerns. Burst-release systems like PVP dispersions are most effective in liquids, while sustained-release systems such as SLNPs and chitosan composites are better suited to solid foods like meat and fish. Polymeric NPs and SLNPs appear to strike the most favourable balance between stability, controlled release, and consumer acceptability, making them strong candidates for near-term applications in edible coatings and biodegradable packaging. Nanoemulsions and PVP dispersions are particularly advantageous for beverages and short-shelf-life products requiring rapid antimicrobial activity. In contrast, inorganic and hybrid systems offer advanced multifunctionality and promise for intelligent packaging but face significant challenges in scalability, safety validation, and regulatory approval.

3.2. Safety Assessment of Curcumin NPs and Nanoformulations for Application in Food Systems

While antimicrobial activity is critical for food safety, the cytotoxic potential of curcumin nanoformulations must also be evaluated to ensure biosafety in food-related applications.

Table 2. Cytotoxicity of curcumin NPs and nanoformulations.

NPs	Applied Cell Line	Toxicity Effect	Ref
Curcumin NPs in rice starch (RS) films	Human colorectal adenocarcinoma cells (Caco-2)	RS (control) film was non-cytotoxic across all concentrations. Incorporation of curcumin NPs slightly increased cytotoxicity in RS@Curcumin NP3.0% films; however, cell viability remained >80% at 1000 μg/mL, confirming good biosafety.	[70]
Ferric-curcumin (Fe-Curcumin) NPs	Mouse fibroblast cell line (3T3)	After 24 h exposure at the highest concentration (400 μg/mL), no detrimental effect on 3T3 cell viability was observed.	[71]
Curcumin-AgNPs in pectin/gelatin films	Human embryonic kidney cells	Films containing curcumin (0.3 wt%) and ≤0.5 wt% AgNPs showed good biocompatibility (>80% viability). Higher AgNP concentrations caused significant cytotoxicity.	[73]
Curcumin-loaded mesoporous silica NPs	Breast cancer cell line and human ovarian cancer cell line	Curcumin-loaded NPs were cytotoxic to cancer cell lines, suggesting selective anticancer potential.	[74]
Curcumin nanoencapsulated in PVP	Non-tumour liver primary culture (PLP-2) and the African green monkey non-tumour culture (Vero cells)	Nanoencapsulation reduced curcumin toxicity toward non-tumour PLP-2 and Vero cells.	[77]

shows the cytotoxicity of some of the nanoformulations shown in Table 1.

The cytotoxicity of curcumin NPs and their nanoformulations is strongly influenced by the carrier system, applied concentration, and target cell line. Evidence consistently demonstrates that nanoencapsulation enhances curcumin’s biocompatibility toward non-tumour cells, while in some cases enabling selective toxicity against cancer cells. For instance, rice starch-based curcumin NP films maintained over 80% viability of Caco-2 cells even at high concentrations (1000 μg/mL) [70], suggesting suitability for edible coatings and films. Similarly, Fe–Curcumin NPs exhibited no detrimental effects on 3T3 mouse fibroblasts at concentrations up to 400 μg/mL [71], and PVP-encapsulated curcumin reduced toxicity toward non-tumour PLP-2 liver and Vero cells [77], confirming the protective role of polymeric dispersions.

In metallic nanocomposites, cytotoxicity was concentration-dependent: curcumin–AgNPs incorporated into pectin/gelatin films were biocompatible at ≤0.5 wt% AgNPs but became cytotoxic at higher silver loadings [73]. This shows the importance of fine-tuning metal content to maintain safety while preserving antimicrobial activity. In contrast, curcumin-loaded mesoporous silica NPs exhibited selective cytotoxicity against breast and ovarian cancer cells [74], indicating potential dual functionality as both a food safety tool and a therapeutic platform for oncology.

As shown in Table 2, biopolymer-based carriers and edible film systems demonstrate strong biosafety profiles suitable for food packaging and preservation, whereas metal-containing and inorganic carriers require strict concentration optimization to avoid adverse effects. However, significant uncertainties remain. Current data are largely based on short-term in vitro assays, with limited understanding of long-term toxicity, nanoparticle migration from packaging into food, bioaccumulation, and potential impacts on the gut microbiome. Advanced delivery platforms, such as MOFs, hollow graphitic carbon nitride, and solid lipid NPs, also remain underexplored, with scarce cytotoxicity data.

These findings suggest that curcumin nanoformulations can balance safety and efficacy, but biosafety cannot be generalised across all systems. Carrier selection, dosage optimisation, and adherence to regulatory safety assessments are critical determinants of cytotoxic behaviour and must guide future development of curcumin-based nanoformulations for safe integration into food systems.

4. Applications of Nanoformulated Curcumin in Food Safety and Preservation

4.1. Active Food Packaging

Active food packaging refers to systems that go beyond passive barriers, actively maintaining or enhancing food quality and safety. Such packaging extends shelf life, preserves freshness, and reduces waste [90]. Curcumin NPs, with potent antioxidant, antimicrobial, and anti-inflammatory properties, are increasingly explored in this context. Typically, curcumin is encapsulated in NPs (such as zein, chitosan, or cyclodextrin) to improve solubility, stability, and compatibility with hydrophilic biopolymers, while enabling controlled release and protecting against degradation during processing and storage [78,79,91].

These NPs are further incorporated into biodegradable matrices such as sodium alginate, polyvinyl alcohol (PVA), starch, or pectin to produce functional films. Such films provide robust antimicrobial protection against pathogens and delay lipid oxidation and discolouration in meats, oils, and fruits [85,92,93]. Consequently, they extend the shelf life of perishable products by reducing weight loss, slowing respiration, and preserving visual and sensory quality in foods such as strawberries, grapes, pork, and shrimp. For instance, Liang et al. (2025) demonstrated that curcumin-loaded zein NPs embedded in sodium alginate films significantly improved stability, oxygen barrier properties, and antimicrobial activity against E. coli and S. aureus, effectively extending strawberry and grape freshness [94]. Importantly, these films are biodegradable, edible, and environmentally friendly, offering an eco-sustainable alternative to petroleum-based plastics. Their controlled release systems are particularly advantageous for fatty foods prone to oxidation, making them versatile solutions for next-generation active packaging.

4.2. Smart/Intelligent Packaging Systems

While active packaging primarily focuses on preserving food quality, smart packaging integrates both preservation and real-time spoilage detection [95]. Curcumin, owing to its pH-responsive chromatic properties, is an attractive candidate for such systems. Films containing curcumin undergo distinct colour transitions, from yellow to orange, red, or brown, when exposed to spoilage-induced pH changes, thereby serving as freshness indicators [24]. Figure 4 demonstrates the pH-dependent colour variations in curcumin.

The pH-responsive colour changes in curcumin stem from its structural dynamics, particularly keto–enol tautomerism and the deprotonation of phenolic –OH groups, which modify its electronic configuration. In acidic to neutral media (pH ≤ 7), curcumin predominantly adopts the keto form, appearing bright yellow and relatively stable. Around near-neutral pH, partial deprotonation shifts the equilibrium, giving rise to orange colouration. In alkaline conditions (pH > 8), enolization and complete deprotonation occur, producing red to reddish-brown tones [96]. These transitions are supported by UV–Visible spectra, which show a bathochromic shift in the absorption maximum from ~425–428 nm under acidic conditions to ~470–500 nm at higher pH. At strongly alkaline levels (pH 10–13), curcumin undergoes degradation into ferulic acid derivatives and condensation products, further deepening the colour change from orange-red to brown [97].

Encapsulation into nanoformulations or polymer matrices enhances curcumin’s stability against photodegradation, yielding sharper and more reproducible chromatic responses in aqueous and food-simulating environments. When incorporated into edible films and coatings, curcumin retains its pH sensitivity, although the intensity of colour changes due to keto–enol tautomerism may vary with the carrier matrix. For instance, curcumin–nanocellulose films detect spoilage in fish and meat by changing from yellow to reddish-brown [98], whereas curcumin inclusion complexes in chitosan/polyvinyl alcohol films combine antioxidant and antimicrobial activity with visual spoilage signalling (from light yellow to red) in shrimp and pork [99]. Similarly, curcumin-incorporated cellulose films prepared via in situ growth exhibit pH-sensitive colour changes, transitioning from yellow at neutral pH to brick-red or purple under alkaline conditions [100]. During food spoilage, volatile basic nitrogen compounds increase the local pH, inducing structural changes in curcumin that shift film colour from yellow in acidic or neutral environments to red in alkaline conditions [101]. In addition to their sensing capabilities, these films demonstrate enhanced mechanical strength, thermal stability, and bioactivity, offering a sustainable, multifunctional alternative to conventional plastics [102].

Taken together, curcumin’s structural tautomerism, reproducible spectral shifts, and preserved responsiveness in polymeric matrices show its dual functionality in intelligent packaging: as a bioactive preservative and as a real-time visual freshness indicator.

4.3. Antimicrobial Food Preservatives

Nanoformulated curcumin has emerged as a promising natural food preservative owing to its enhanced physicochemical and biological properties compared to free curcumin [94]. Retaining the multi-target antimicrobial mechanisms of its bulk form (Section 2.2), curcumin NPs exhibit greater efficacy due to reduced particle size, higher surface area, and improved bioavailability [103]. These features enable strong activity against a broad spectrum of microorganisms, including E. coli, Salmonella enterica, L. monocytogenes, fungi, and yeasts [70,79,85]. As a generally recognised as safe (GRAS) compound, curcumin NPs align with clean-label preferences for natural, non-synthetic additives and offer versatile applications in food preservation [9]. Apart from its application in active and smart packaging films, curcumin NPs can be incorporated into marinades for meats and poultry, added to dairy products, formulated as nanoemulsions in beverages, and embedded in edible coatings for fresh produce [77,84,104,105] as illustrated in Figure 5.

These examples reflect their broader relevance to agricultural products, including meats, fruits and vegetables, dairy, seafood, and cereal grains, which are highly perishable and prone to microbial spoilage, lipid oxidation, and enzymatic deterioration. Such vulnerabilities not only compromise food safety and quality but also drive significant postharvest losses [106]. By enhancing antimicrobial activity, antioxidant protection, and physicochemical stability, nanoformulated curcumin offers a versatile strategy to preserve quality, extend shelf life, and reduce waste across these commodities. The following subsections outline their applications in major agricultural product groups.

4.3.1. Edible Coatings and Marinades for Meats and Poultry

Curcumin nanoformulations have shown significant potential in edible coatings and marinades for meats and poultry by combining antimicrobial and antioxidant functionalities with improved stability and bioavailability [37,71,85]. When incorporated into edible coatings, nanoformulated curcumin forms a protective barrier on the product surface, suppressing microbial growth, delaying lipid oxidation, and maintaining sensory attributes such as flavour, colour, and texture during storage [28,105]. In marinades, nanoformulated curcumin penetrates effectively into the meat matrix, ensuring uniform antimicrobial activity while enhancing oxidative stability and reducing contamination risks from pathogens [107]. These applications extend shelf life and improve overall food safety and quality.

4.3.2. Edible Coatings for Fresh Produce

Biopolymer-based coatings enriched with nanoformulated curcumin form protective barriers around fruits and vegetables, reducing respiration rates, slowing enzymatic browning, and providing antimicrobial activity at the surface where contamination risk is highest [108]. Nanoencapsulation ensures controlled and sustained release, prolonging effectiveness throughout storage. For example, curcumin-loaded protein NPs preserved freshly cut apples by inhibiting microbial growth, oxidative browning, and weight loss, thereby extending shelf life while maintaining flavour, antioxidant activity, safety, and visual appeal [84].

4.3.3. Dairy Safety Applications

Milk and dairy products are prone to spoilage; however, curcumin NPs offer dual antimicrobial and antioxidant benefits without compromising sensory qualities. In NP form, curcumin disperses uniformly in aqueous systems, enhancing interaction with microbial cell walls while remaining compatible with dairy matrices [109,110,111]. This functionality inhibits pathogens and spoilage organisms while preserving taste, colour, and nutritional value. For instance, curcumin nanoemulsions incorporated into refrigerated Egyptian Kareish cheese to enhance shelf life, improved antibacterial activity against S. aureus and B. cereus, increased antioxidant capacity, and maintained physicochemical and sensory properties, demonstrating effective quality preservation without compromising taste or texture [111].

4.3.4. Aquaculture and Seafood Preservation

Seafood quality deteriorates rapidly due to lipid oxidation and microbial contamination. Curcumin NPs incorporated into packaging films or edible coatings deliver antimicrobial and antioxidant protection, with controlled release ensuring prolonged efficacy during cold storage and transport. This preserves critical sensory attributes such as texture, odour, and colour [11,75,79,82]. For instance, chitosan/zein bilayer films with curcumin/nisin-loaded pectin NPs extend the shelf life of refrigerated fish fillets by reducing yellowing, off-odours, softening, lipid oxidation, biogenic amine formation, and microbial growth (including Pseudomonas and Shewanella). Their water and oxygen barriers, combined with sustained release of active compounds (curcumin and nisin), preserve overall quality [82].

4.3.5. Grain and Cereal Protection

Curcumin NPs provide a natural antifungal strategy for grains and cereals by enhancing stability, bioactivity, and penetration into fungal cells [112,113]. This reduces mould growth and mycotoxin production, lowering reliance on synthetic fungicides. Curcumin-mediated aPDT completely inactivated Fusarium graminearum mycelia and spores, suppressed zearalenone production, and preserved maize quality, thereby enhancing grain safety and extending shelf life [114]. Similarly, it effectively reduced A. flavus spores, prolonging the shelf life of peanuts [115]. Curcumin NPs are expected to offer superior antifungal activity and stronger mycotoxin control than bulk curcumin, showing their potential as a natural and sustainable strategy to protect grains and legumes from fungal contamination and spoilage.

Although curcumin is classified as GRAS, dosage remains a critical consideration. Excessive intake, even of GRAS compounds, may lead to undesirable effects such as gastrointestinal discomfort. In nanoformulated form, the enhanced bioavailability of curcumin indicates the need for careful regulation of concentrations used in food applications to balance efficacy with safety. Furthermore, long-term toxicological evaluations are necessary to assess NP release, accumulation, and biodegradation within food matrices.

Nanoformulated curcumin demonstrates strong potential as an eco-sustainable, multifunctional food preservation strategy. By integrating antimicrobial, antioxidant, and intelligent sensing functions, it can improve food quality, extend shelf life, minimise postharvest losses, and contribute to global food security.

5. Limitations and Future Perspectives

While nanoformulated curcumin shows promise as a natural antimicrobial in active, smart packaging and food preservation, emerging evidence highlights potential unintended consequences, particularly regarding antimicrobial resistance. Wang et al. (2026) experimentally demonstrated that curcumin can accelerate plasmid-mediated transfer of resistance genes, including bla_NDM, mcr-1, and tet(X4), through multiple mechanisms. These include increased bacterial membrane permeability and cell-wall damage, induction of oxidative stress and activation of the DNA-repair SOS response, enhanced energy metabolism via electron-transport chain stimulation and proton-motive force, modulation of conjugation-related genes, and intracellular arginine accumulation mediated by arginine transporter genes (artJ, artI, argT). Collectively, these effects may facilitate horizontal gene transfer in food-associated microbiomes and along the farm-to-fork continuum [116]. Consequently, careful deployment of curcumin in foods and packaging materials is essential, with strategies aimed at maintaining antimicrobial efficacy while minimising the risk of resistance gene dissemination.

Stability under processing and storage remains a significant limitation. Curcumin is prone to photodegradation, autoxidation, and pH- and temperature-dependent isomerisation [45,46]. Although nanoencapsulation can enhance stability, processing steps such as thermal treatment, high-pressure processing, UV exposure, and storage factors like light, oxygen, and humidity can destabilise carriers, including chitosan, proteins, lipids, lignin, and cyclodextrins, altering release profiles [117]. Interactions with food matrix components may further reduce bioactivity, affect partitioning, or modify sensory properties [118]. Industrial processing, such as extrusion or drying, can disrupt particle size and crystallinity, while scale-up may increase polydispersity and batch-to-batch variability, compromising antimicrobial performance.

Migration and toxicity are additional concerns requiring thorough evaluation. Active release is critical for antimicrobial action but may lead to migration into food, necessitating robust testing under worst-case conditions, including different food simulants, repeated use, and storage scenarios [119,120]. Despite many carriers being biobased and generally recognised as safe, nano-specific hazards, including cellular uptake, gastrointestinal translocation, microbiome perturbation, and oxidative stress, require verification through in vitro and in vivo studies. Importantly, curcumin’s potential to enhance ARG transfer highlights the need to assess impacts on the resistome in both food and the human gut. Furthermore, NP accumulation within tissues or ecosystems may pose long-term risks, since even biodegradable carriers may not fully degrade under certain environmental or physiological conditions, leading to persistent residues. Allergenicity and sensory changes due to curcumin’s intense color also warrant careful consideration.

Environmental impacts and biodegradability must be addressed. Carriers may degrade faster than curcumin, leaving behind residues, and if curcumin promotes conjugation, post-consumer residues could influence environmental resistomes in soils, wastewater, or compost. Life-cycle assessments should capture nano-scale production processes and compare curcumin-based systems with alternative interventions. Integration of curcumin with other antimicrobials or biosensors may reduce effective doses and limit resistance selection, but co-formulants could also modulate mechanisms that favor horizontal gene transfer. Synergies with natural antimicrobials such as essential oils, peptides, or bacteriocins are particularly attractive, as these combinations may broaden antimicrobial spectra, improve efficacy through multi-target modes of action, and reduce the concentration of each agent needed, thereby potentially lowering toxicity and resistance risks. Smart, stimuli-responsive packaging, releasing curcumin only upon spoilage signals, offers a strategy to minimise chronic exposure, NP accumulation, and ARG dissemination.

Future research should prioritise ARG-aware design rules, including mapping particle size, charge, carrier type, and curcumin load against conjugation rates, SOS activation, and metabolic stimulation to define safe operating windows. Equally important is systematic modelling of release kinetics under both food simulant and real-food matrices, since diffusion, partitioning, and interactions with fats, proteins, and water activity strongly influence antimicrobial performance. Immobilisation or surface tethering of curcumin could retain antimicrobial activity while reducing free curcumin that may trigger ARG transfer. Co-formulation with conjugation inhibitors, ROS modulators, or SOS-pathway dampeners may further mitigate unintended effects.

Advanced carriers such as lignin NPs, MOFs, COFs, and hybrid biopolymer–inorganic scaffolds can enhance photostability, controlled release, and edibility. Besides functional benefits, industrial feasibility must be considered: production costs, scalability, and regulatory compliance are critical factors. For instance, lignin NPs are cost-effective and biomass-derived, while MOFs and COFs may face higher synthesis costs and regulatory scrutiny for food or pharmaceutical use. Hybrid scaffolds offer tunable properties but require careful scale-up to maintain reproducibility and safety standards.

Finally, regulatory frameworks and labelling requirements represent a critical frontier. Current food safety regulations often lack nano-specific provisions, yet consumers and regulators demand transparency regarding the presence of engineered nanomaterials in packaging and foods. Mandatory labelling of nano-enabled curcumin systems could increase trust but may also influence consumer acceptance. This highlights the need for consumer acceptance studies, including sensory neutrality assessments, to ensure that nanoformulated curcumin systems do not negatively impact taste, odour, or appearance. Standardised testing of ARG transfer, migration, NP accumulation, release kinetics, and shelf-life under real-food conditions is urgently needed to ensure translational robustness. Engagement with regulators to define permissible active loads, nano-specific safety thresholds, and risk-based decision trees will be essential.

Nanoformulated curcumin thus emerges as a promising food-grade antimicrobial, but its potential to accelerate plasmid-mediated ARG transfer reframes its application. Advancing its use requires ARG-conscious formulations, controlled release systems validated through kinetic modelling, synergistic combinations with other natural antimicrobials, rigorous toxicity and accumulation assessments, clear labelling strategies, and environmentally responsible end-of-life management. Future research should establish optimal dosage, validate long-term safety, and co-develop regulatory frameworks to safeguard antimicrobial benefits while maintaining consumer trust and minimising ecological and resistance risks.

6. Conclusions

Nanoformulated curcumin has emerged as a multifunctional natural antimicrobial with strong potential to transform food preservation strategies. Through nanoencapsulation, curcumin overcomes its intrinsic physicochemical limitations, enabling improved solubility, stability, and bioavailability, while providing sustained release and compatibility with biodegradable matrices. Evidence supports its efficacy across a wide spectrum of food products, where it simultaneously inhibits microbial growth, delays lipid oxidation, and preserves sensory quality. Moreover, integration into active and smart packaging introduces innovative functionalities, including controlled release and real-time spoilage detection. However, challenges persist regarding scalability, migration into food matrices, potential sensory alterations, and the risk of promoting antimicrobial resistance gene transfer. To ensure safe and effective application, future research should prioritise advanced nanocarriers such as lignin NPs, MOFs, and COFs; explore stimuli-responsive release mechanisms; and conduct standardised biosafety and life-cycle assessments. Regulatory clarity and consumer acceptance will be equally crucial in translating laboratory advances into commercial practice. By balancing innovation with safety, sustainability, and affordability, nanoformulated curcumin holds promise as a next-generation, eco-friendly solution to food preservation and packaging.