Curcumin and its uses in active and smart food packaging applications - a comprehensive review

Optically pH-Sensing in smart wound dressings towards real-time monitoring of wound states: A review

BACKGROUND

Over the recent years, the investigations on wound dressings have been undergoing significant evolution, and now smart dressings with the function of the real-time monitoring of the wound states have been recognized as one of the most advanced treatment modalities. Among a variety of wound-related biomarkers, pH represents a promising candidate for in situ supervising the wound healing status. In this regard, a variety of optically pH sensing agents have been widely incorporated into different types of wound dressings.

RESULTS

Herein, we first presented an overview of the advanced wound dressings, especially those commonly used in wound pH sensing. Then, a comprehensive summary of the optical pH sensing agents that could be incorporated into the wound dressings for detecting the pH alteration on the wound bed was described in detail. These materials were classified into colorimetric dyes (i.e., synthetic and plant-based dyes) and fluorescent probes (i.e., small-molecular fluorescein and fluorescent nanomaterials). Each type of pH sensing agent was fully discussed with advantages and limitations for monitoring the wound pH alteration, as well as typical examples of practical applications. To well interpret messages produced by the color-coding dressings, the approaches for defining and communicating color were also summarized, and a proof-of-concept, the smartphone-based remote supervision was particularly highlighted.

SIGNIFICANCE

This review provides a comprehensive overview of the utilization of optically pH sensing in advanced wound dressings for the real-time monitoring of the wound states. It was expected to be an informative source for the exploitation of novel diagnostic dressings for wound management, and also a reference the for application of these materials in the biosensing of other physiological or pathological fluids.

Edible rice starch films incorporated with curcumin nanoparticles exerting anti-microbial properties for strawberry preservation

Pure starch film presents poor barrier properties and lacks anti-microbial properties. Herein, curcumin nanoparticles (cNPs) were prepared by the reassembly of food proteins and were utilized to reinforce the starch-based film. Herein, the reassembly of rice proteins and casein encapsulated curcumin upon pH adjustment to produce water-dispersible cNPs with a diameter of 140.9 ± 6.8 nm and curcumin loading capacity of 276.0 μg/mg. The cNPs showed a good dispersibility in gelatinized rice starch (RS) solutions as well and resultant composites films (RS@cNPs) had greater light barrier property than the pure RS film. The incorporation of cNPs tended to decrease the water solubility and water vapor permeability of RS@cNPs films, and increasing curcumin content gradually enhanced the hydrophobicity of RS@cNPs films. With a curcumin content of 3.0 %, the tensile strength of RS@cNPs was three times higher than the pure starch film. Besides, the RS@cNPs films coating prevented the growth of microorganism in the strawberries with a storage period of 3 days, and the pH value and soluble solids contents of strawberries in RS@cNPs group remained stable over storage period, suggesting that the RS@cNPs films coating preserved the freshness of strawberries and highlighted the preparation of novel starch-based films for food preservation.

Curcumin - a natural colorant-based pH indicator for molecular diagnostics

Loop-mediated isothermal amplification (LAMP) provides highly selective and sensitive DNA amplification and generates hydrogen ions as a byproduct under weakly buffered conditions, causing the solutions' pH to decrease from the initial basic to an acidic environment. This distinctive feature allows the color of the amplified DNA solution to change readily when suitable pH indicators are employed. In this study, curcumin, a biodegradable, non-toxic, and natural colorant, was used as a pH indicator to visually identify LAMP-amplified Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae). Curcumin (10 mM) displayed a unique color difference between negative (red) and positive (yellow) samples, and the detection process was completed within 30 s, demonstrating the effectiveness of using curcumin for on-site diagnostics. Under optimum conditions, curcumin enabled S. aureus and S. pneumoniae detection as low as 10 fg μL-1 and 1 pg μL-1, respectively, due to its unique halochromic properties. Owing to its adaptability, ease of use, and rapid visual detection, the introduced colorimetric pH-based LAMP method can be employed as a practical alternative to conventional colorimetry for infectious pathogen identification in both laboratory and field settings.

Development of pH-responsive active intelligent chitosan film incorporated with pomegranate cellulose nanocrystals and curcumin nanoparticles

Casein Sodium coated curcumin nanocapsules (Cas@Cur) were fabricated by a pH shift method, which improved the water solubility of curcumin (Cur). Hydrogen bonds and hydrophobic interactions were the main forces for the formation of Cas@Cur. Chitosan films (CS) reinforced with pomegranate cellulose nanocrystals (PCNCs), Cas@Cur, PCNC/Cas@Cur, and PCNC/Cur were developed and named CP, CS-Cas@Cur, CP-Cas@Cur and CP-Cur, respectively. The addition of Cas@Cur decreased the moisture content, crystallinity and water contact angle of chitosan film, and increased its water solubility and light barrier property. The CP-Cur film presented the roughest cross-sectional SEM image owing to the hydrophobicity of Cur. CP-Cas@Cur film exhibited the excellent cumulative release of Cur, and was 1.60 and 3.70 times of that of CP-Cur in the semi-fatty and fatty food simulation systems at 2 h, respectively, owing to the controlled-release function of PCNCs and great water solubility of Cas@Cur. Furthermore, the CP-Cas@Cur film displayed excellent antioxidant property, antibacterial activity and sensitive color responsiveness to pH and NH3. Interestingly, the CP-Cas@Cur films exhibited a visible color change at pH 3-7. The application of CP-Cas@Cur film in the preservation of milk and shrimp indicated its potential for the visual monitoring of food freshness.

Potential of curcumin and its derivatives, modern insights on the anticancer properties: a comprehensive overview

Globally, cancer is the top cause of mortality, placing a heavy load on the medical system. One of the first known secondary metabolites is curcumin, a bioactive substance. This study aims to emphasize the chemopreventive and chemotherapeutic properties of curcumin and its derivatives, therefore, offering important insights for the possible creation of certain supplemental medications for the treatment of different cancers. Electronic Google databases, including Google scholar, ResearchGate, PubMed/Medline, and ScienceDirect, were searched to gather pertinent data about the chemopreventive and chemotherapeutic effects of curcumin and its derivatives. Various studies have revealed a diverse array of significant biological effects. The majority of investigations pertaining to the potential anticancer effects and associated processes are currently in the experimental preclinical stage and lack sufficient clinical trial data to validate their findings. Clinical research is further needed to clarify the molecular processes and specific targeted action of curcumin and its derivatives, as well as their potential for toxicity and side effects in humans, in order to open up new therapeutic avenues for treating cancer.

Next-Generation Edible Packaging: Development of Water-Soluble, Oil-Resistant, and Antioxidant-Loaded Pouches for Use in Noodle Sauces

The development of sustainable biodegradable packaging materials is essential for enhancing food quality and shelf life while reducing plastic waste. This study explored polymer-based monolayer, composite, and bilayer films to produce water-soluble, oil-proof pouches. Single-serving seasoning oil pouches were prepared from bilayer films with polyvinyl alcohol (PVA) as the inner and sodium alginate (SA) as the outer layer. The PVA/SA films exhibited excellent UV protection, low oil permeability (0.18 × 10-6 g·mm/mm2·day), hydrophilic surface (water contact angle < 90°), and rapid solubility in hot water (87 ± 2 °C). Incorporating curcumin, a natural antioxidant, into PVA/SA films (Cur-PVA/SA) improved thermal stability, reduced light transmittance, and decreased water vapor permeability (0.28 × 10-10 g/m·Pa·s). Curcumin release followed a biphasic diffusion model, with 94.8% released at 96 h (diffusion coefficient: 1.30 × 10-11 m2/s), ensuring prolonged antioxidant activity. The Cur-PVA/SA pouches delayed lipid oxidation more effectively, with peroxide values of 6.48 and 10.35 meq/kg after 45 days at 35 °C, respectively. The Q10 model, which is commonly used to predict the shelf life of oils based on temperature-dependent oxidation rates, estimated that the oil packaged in Cur-PVA/SA pouches would remain stable for 12 months at 23 °C. This represents a 37% longer shelf life compared to oil packaged in PVA/SA pouches without curcumin. Cur-PVA/SA pouches also reduced noodle moisture migration, limiting weight loss to 2.73% over 14 days compared to 5.80% in controls. These findings highlight their potential as eco-friendly active packaging solutions.

Curcumin Electroanalysis at a Disposable Graphite Electrode

Curcumin (CU, turmeric), a polyphenolic phytochemical that is largely used as a food spice, has benefits for human health, which have led to increased interest in its therapeutic applications and its analysis from different matrices. The two guaiacol moieties of CU are responsible for its antioxidant properties and allow for its voltammetric quantification. Cyclic and differential pulse voltammetry (DPV) investigations at a single-use pencil graphite electrode (PGE) emphasized complex pH-dependent electrode processes, involving an equal number of protons and electrons. Theoretical calculations predicted a folded geometry for the β-diketone CU conformers, which interact with the PGE surface, exposing the electroactive moieties of only one aromatic ring. The Gibbs energy variations of the structures involved in CU electro-oxidation and the theoretical electrochemical potential values were calculated. CU's DPV cathodic peak intensity recorded at an HB-type PGE in 0.05 mol × L-1 H2SO4 varied linearly in the range 5.00 × 10-8-5.00 × 10-6 mol × L-1 CU. The method's detection and quantification limits were 2.12 × 10-8 mol × L-1 and 6.42 × 10-8 mol × L-1, respectively. The practical applicability of the developed method, successfully tested by CU assessment in dietary supplements, provided a recovery of 99.28 ± 2.04%.

Highly fluorescent nitrogen doped carbon dots as analytical probe for sensitive detection of curcumin through smartphone integrated 3D-printed platform: A new horizon in food safety

COVID-19 pandemic has significantly influenced the dietary habits of humans, emphasizing the incorporation of natural ingredients to enhance immunity towards viral and bacterial infections. Curcumin (Cur), a widely used traditional medicine in various Asian countries and a natural coloring agent, has gained popularity, leading to surge in its usage specially in post COVID-19 era. This surge has led to increased scrutiny of the potential side effects of excessive Cur use, with recent reports suggesting it may result in inactivation of DNA and reduce adenosine triphosphate levels, leading to health risks. In this work, we synthesized highly fluorescent nitrogen-doped carbon dots with a photoluminescence quantum yield of 72.9 % for the sensitive and selective detection of Cur. The developed fluorescent probe exhibits excellent sensory response towards Cur within a concentration range of 0.081-51.45 µM, achieving an ultra-low detection limit of 15.91 nM. The sensor was successfully tested on real food samples like ginger powder, turmeric powder, and curry powder, demonstrating good recovery rates. To assess the practicality of the sensor system, we developed a 3D-printed smartphone-integrated device platform for curcumin detection through fluorescence image analysis. This developed platform exhibited promising results, achieving a limit of detection (LoD) of 132.28 nM across a curcumin concentration range of 0.13-54.00 µM. This device platform holds significant potential for the development of efficient sensors for real-time detection of Cur in food samples.

Smart pH-sensitive indicators based on rice starch/pectin/alginate loading Lambrusco pomace extract and curcumin to track the freshness of pink shrimps

This research is focused on the formulation and testing of green visual pH-sensitive indicators based on natural extracts from Curcuma Longa (CUR) and Lambrusco wine pomace (LAM), an Italian wine variety, incorporated into rice starch/pectin/alginate matrixes for non-destructively detecting shrimps freshness in real-time. The effect of the mixed indicators and their synergic combination on the properties and performances of indicators was investigated. Both the extracts and their combination showed pronounced pH responsiveness. Films were widely characterized in terms of morphological, barrier, spectroscopic, thermal and mechanical properties. The presence of extracts slightly reduced the transparency of the films while the film with both the extracts exhibited the highest Young's modulus (14.17 MPa), lowest moisture content (27.67 %) and a WVP value (0.79 g m m-2 s-1 Pa-1) intermediate between the Lambrusco extract loaded film and the curcumin based one. Moreover, the pH-sensitive systems showed a noticeable antioxidant activity (96 % for LAM/CUR film) and enhanced antibacterial activity toward E. coli and S. aureus compared to pristine films. Besides, the mixed indicator-based film showed high sensitivity to ammonia (68 %) determining an ΔE value easily detectable by the human eye. Finally, the films were applied as cheap visual indicators for monitoring the freshness of packaged fresh shrimps over time stored at T = 4 °C and T = 25 °C through the colourimetric variation induced by pH changes. The TVB-N value, which was correlated to the microbial count for shrimps over time, reached the rejection limit at 33 h for T = 25 °C and 54 h for T = 4 °C. The colour changes were recorded simultaneously and the turning to deeper colours indicated the decomposition of proteins to organic amines and the spoilage of food. Results show that the produced films provide easily detectable colour changes during food spoilage proving that, being fabricated from natural sources, they represent novel and sustainable tools for multi-purpose intelligent food packaging applications.

Development of cellulose-based self-healing hydrogel smart packaging for fish preservation and freshness indication

Biomass-based composite packaging materials loaded with functional fillers have good application prospects in food preservation and freshness detection. Self-healing hydrogel packaging films based on nanocellulose (CNF), polyvinyl alcohol (PVA), and ZIF-8 embedded with curcumin (Cur@ZIF-8) were developed in this study. The synthesis of Cur@ZIF-8 was demonstrated by characterization experiments. The addition of Cur@ZIF-8 enhanced the water vapor barrier property, tensile strength, and elongation at break of hydrogel films by 49.2 %, 193.5 %, and 172.9 %, respectively, and endowed them with excellent antimicrobial, antioxidant, and ammonia sensitivity. In packaging tests with fish, hydrogel films loaded with Cur@ZIF-8 inhibited spoilage and microbial growth to extend the shelf life of fish to 9 days, and the color change of hydrogel films allowed for real-time monitoring of fish freshness. This study provided a new solution for smart packaging materials with dual functions of preservation and freshness indication.

Green Extraction of Bioactives from Curcuma longa Using Natural Deep Eutectic Solvents: Unlocking Antioxidative, Antimicrobial, Antidiabetic, and Skin Depigmentation Potentials

This study evaluates the efficiency of 20 Natural Deep Eutectic Solvents (NADES) formulations for extracting curcuminoids and other bioactive compounds from turmeric and emphasize their ability to preserve and enhance antioxidant, antimicrobial, antidiabetic, and skin depigmentation effects. The NADES formulations, prepared using choline chloride (ChCl) combined with sugars, carboxylic acids, glycerol, amino acids, urea, polyols, and betaine, were assessed for their extraction efficiency based on the total phenolic content and curcumin concentration. Fourier transform infrared spectroscopy was employed to characterize the synthesized NADES and confirm their chemical composition. Bioactivity evaluations included antioxidant assays (ABTS and DPPH), antidiabetic tests (α-amylase inhibition), antimicrobial assays, and skin depigmentation (tyrosinase inhibition). The results demonstrated that NADES significantly enhanced the extraction efficiency and bioactive properties of turmeric extracts compared to water as a conventional green solvent. NADES 18 (ChCl/1,2-propanediol/water 1:1:1) and NADES 19 (glycerol/betaine/water 1:1:3) exhibited the highest extraction yields, with curcumin concentrations of 30.73 ± 1.96 mg/g and 31.70 ± 2.02 mg/g, respectively, outperforming water (26.91 ± 1.72 mg/g), while NADES 17 (ChCl/1,2-propanediol/water 0.5:3:0.5:5) and NADES 20 (glycerol/lysine/water 1:1:3) exhibited the most potent antioxidant activity. Furthermore, NADES 14 (ChCl/lactic acid/water 1:2:5) demonstrated the strongest tyrosinase inhibition (98.7%), supporting its potential for skin-brightening applications, including notable α-amylase inhibition exceeding 90%. This study aligns with the principles of green chemistry, as NADES are effective and sustainable solvents for natural product extraction. The presenting benefits of improved extraction efficiency and enhanced bioactivities position NADES as a promising and eco-friendly approach for developing efficient bioactive compound extraction methodologies.

Edible Coating Combining Liquid Smoke from Oil Palm Empty Fruit Bunches and Turmeric Extract to Prolong the Shelf Life of Mackerel

This research aimed to evaluate the use of edible coating from a combination of liquid smoke and turmeric extract as a preservative for mackerel at room temperature. Liquid smoke was obtained from the pyrolysis of oil palm empty fruit bunches (OPEFB) at a temperature of 380 °C and purified by distillation at 190 °C. Liquid smoke with a concentration of 3% was combined with turmeric extract at a ratio of 2, 4, 6, and 8 g/L (CLS 2:1, CLS 4:1, CLS 6:1 and CLS 8:1). TVB-N testing showed that the mixture of liquid smoke and turmeric at a ratio of CLS 6: 1 and CLS 8: 1 maintains the freshness of fish for 48 h. Meanwhile, organoleptic testing reports that the best mixture was CLS 8:1. The number of colonies in the CLS 2:1, CLS 4:1, CLS 6:1, and CLS 8:1 mixtures were 4.92, 4.92, 4.16, and 4 × 10⁵ colonies/g after 44 h of soaking. The MPN test result at 48 h of soaking is 1.1 × 103 MPN/g. Generally, mackerel preserved with a mixture of turmeric extract and liquid smoke with a ratio of 8:1 can be consumed up to a shelf life of 48 h at room temperature storage.

Recent advances in the development and application of curcumin-loaded micro/nanocarriers in food research

The application of curcumin in food science is challenged by its poor water solubility, easy degradation under processing and within the gastrointestinal tract, and poor bioavailability. Micro/nanocarrier is an emerging and efficient platform to overcome these drawbacks. This review focuses on the recent advances in the development and application of curcumin-loaded micro/nanocarriers in food research. The recent development advances of curcumin-loaded micro/nanocarriers could be classified into ten basic systems: emulsions, micelles, dendrimers, hydrogel polymeric particles, polymer nanofibers, polymer inclusion complexes, liposomes, solid lipid particles, structured lipid carriers, and extracellular vesicles. The application advances of curcumin-loaded micro/nanocarriers for food research could be classified into four types: coloring agents, functional active agents, preservation agents, and quality sensors. This review demonstrated that micro/nanocarriers were excellent carriers for the fat-soluble curcumin and the obtained curcumin-loaded micro/nanocarriers had promising application prospects in the field of food science.

Antimicrobial Carboxymethyl Cellulose-Bacterial Cellulose Composites Loaded with Green Synthesized ZnO and Ag Nanoparticles for Food Packaging

Bacterial cellulose (BC) has earned a well-defined place among biopolymers due to its unique physicochemical properties. Unfortunately, native BC lacks antimicrobial and antioxidant properties. To address this limitation, many BC-based nanocomposites with antimicrobial properties have been developed, primarily for applications in the biomedical field, but also for use in food packaging. Many nanoparticles can be incorporated into BC membranes, often in combination with other bioactive molecules. Among the available methods for nanoparticle synthesis, green synthesis has emerged as promising, as it avoids the use of hazardous chemicals. The aim of this paper is to develop and characterize antimicrobial composite materials fabricated using carboxymethyl cellulose (CMC) and bacterial cellulose fibrils loaded with zinc oxide and silver nanoparticles (NPs) obtained using turmeric extract by green synthesis. NP-loaded CMC-BC composites were characterized using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, Grazing incidence X-ray diffraction (GI-XRD), and thermal analysis (TA). The antibacterial potential of such composites was tested against Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), and Candida albicans (C. albicans).

Fabrication of curcumin-incorporated human amniotic membrane extracellular matrix-derived scaffold to enhance full-thickness wound healing in diabetic rats

The multifactorial nature of diabetic wounds necessitates a mixed approach for successful treatment. Compensation of degenerated wound tissue extracellular matrix (ECM) and application of anti-inflammatory and antioxidant agents have been shown to be promising. Here, an attempt was made to fabricate a biocompatible wound dressing from curcumin-incorporated human amniotic membrane (HAM) ECM-derived scaffold to accelerate diabetic wound healing in rats. Therefore, after inducing diabetes, an excisional ischemic wound was created on rat skin, then treatments were administered for a period of 21 days. The main groups were the diabetic animals that received an engraftment of HAM scaffold (HAMS group) and the curcumin-incorporated HAMS (HAMS/β/C group). Evaluation at post-wounding days 7, 14, and 21 indicated that the parameters related to regeneration, including wound closure, volume of new epidermis and dermis, proliferating cells, fibroblasts, blood vessels, collagen deposition, and tensile strength, as well as transcripts of Vegf, bFgf, and Tgf-β genes of the healed wound in both HAMS and HAMS/β/C groups were considerably greater than those of the diabetic group. Conversely, the presence of inflammatory cells, i.e., neutrophils and macrophages, and the transcripts of Tnf-α and Il-1β showed a dramatic decrease in the treated groups relative to the diabetic group. Finally, compared to the HAMS group, considerable differences were found with the HAMS/β/C group in almost all evaluated parameters. Overall, these results suggest that using the complementary or synergistic effects of curcumin and HAMS could be a promising approach to improve diabetic wound healing.

Recent Advances of Cellulose-Based Hydrogels Combined with Natural Colorants in Smart Food Packaging

Due to the frequent occurrence of food safety problems in recent years, healthy diets are gradually receiving worldwide attention. Chemical pigments are used in smart food packaging because of their bright colors and high visibility. However, due to shortcomings such as carcinogenicity, people are gradually looking for natural pigments to be applied in the field of smart food packaging. In traditional smart food packaging, the indicator and the packaging bag substrate have different degrees of toxicity. Smart food packaging that combines natural colorants and cellulose-based hydrogels is becoming more and more popular with consumers for being natural, non-toxic, environmentally friendly, and renewable. This paper reviews the synthesis methods and characteristics of cellulose-based hydrogels, as well as the common types and characteristics of natural pigments, and discusses the application of natural colorants and cellulose-based hydrogels in food packaging, demonstrating their great potential in smart food packaging.

In situ growth of curcumin-loaded cellulose composite film for real-time monitoring of food freshness in smart packaging

Visual pH-responsive packaging material is particularly important in food supply chain safety monitoring due to their non-destructive monitoring method and intuitive result. However, it has always been limited by the instability performance of pH-response components and carriers, which further hinders its wide food safety application. To address these challenges, we selected cellulose with remarkable biocompatibility and mechanical properties as the carrier, and high pH-responsive curcumin to develop a smart packaging material (RC/GC composite film) with real-time food safety monitoring. Compared with pure cellulose film, the RC/GC composite film exhibited excellent mechanical properties (4-fold enhancement) and thermal stability (100 °C increasing). Meanwhile, based on the first reported strategy of curcumin in-situ growth during cellulose film formation, the RC/GC composite film exhibited exceptional antioxidant activity (89.2 %), antimicrobial property (91.6 %), and significant pH-responsive sensitivity (within 15 s). This innovative approach offers a new strategy for easy-to-use and effective monitoring of food spoilage in packaging materials.

Assessing Partial Inhibition of Ribonuclease A Activity by Curcumin through Fluorescence Spectroscopy and Theoretical Studies

Molecular interactions and controlled expression of enzymatic activities are fundamental to all cellular functions in an organism. The active polyphenol in turmeric known as curcumin (CCM) is known to exhibit diverse pharmacological activities. Ribonucleases (RNases) are the hydrolytic enzymes that plays important role in ribonucleic acid (RNA) metabolism. Uncontrolled and unwanted cleavage of RNA by RNases may be the cause of cell death leading to disease states. The protein ribonuclease A (RNase A) in the superfamily of RNases cleaves the RNA besides its role in different diseases like autoimmune diseases, and pancreatic disorders. Interaction of CCM with RNase A have been reported along with the possible role of CCM to inhibit the RNase A enzymatic activity. The interaction strength was found to be 104 M-1 order from spectroscopic results. Quenching of RNase A fluorescence by CCM was 104 M-1 order. Non-radiative energy transfer from RNase A (donor) to CCM (acceptor) suggested a distance of 2.42 nm between the donor-acceptor pair. Circular dichroism studies revealed no structural changes in RNase A after binding. Binding-induced conformational variation in protein was observed from synchronous fluorescence studies. Agarose gel electrophoresis revealed a partial inhibition of the RNase A activity by CCM though not significant. Molecular docking and molecular dynamics studies suggested the residues of RNase A involved in the interaction with supporting the experimental finding for the partial inhibition of the enzyme activity. This study may help in designing new CCM analogues or related structures to understand their differential inhibition of the RNase A activity.

Recent and emerging food packaging alternatives: Chemical safety risks, current regulations, and analytical challenges

Food contact materials should not release their constituent substances into food at levels harmful to human health nor change the food composition, taste, or odor unacceptably. The historical evolution of food packaging shows that the use of plastics has increased dramatically, because of its convenience, lightweight, and cost effectiveness, but carries a significant environmental impact. Influenced by trends such as growing awareness of the environmental footprint and stricter safety requirements, conventional packaging is now progressively evolving toward new alternatives. All stakeholders in the agrifood system are involved in the journey to transform food packaging to more sustainable alternatives, while maintaining the important functionalities of suitable food packaging. The current most promising food packaging alternatives are presented in this review with their benefits, limitations, and associated potential safety hazards, with a focus on chemical hazards. Although some potential hazards are common to conventional packaging, others are specific to the new alternatives. Identification of potential chemical hazards associated with these new packaging alternatives is important to anticipate any risks posed to consumer safety. With much diversity in packaging types and rules aimed at ensuring safety drastically varying between jurisdictions, it is not always easy to determine the best way to assess the safety of food packaging. International guidance on principles for safe food packaging could help drive global harmonization and would play a crucial role in ensuring a consistent and science-based framework for the safety and compliance of new and emerging food packaging.

Eco-friendly, pH-sensitive curcumin-loaded sodium alginate/hydroxyapatite/quaternary ammonium chitosan microspheres with enhanced antibacterial and antioxidant activities for fruit preservation

The development of intelligent responsive reactive packaging materials with natural polymers shows excellent potential in food preservation. In this study, eco-friendly, pH-sensitive sodium alginate (SA)/hydroxyapatite (HA)/quaternary ammonium chitosan (HACC) composite microspheres loading curcumin (CUR) with excellent antibacterial and antioxidant activities were successfully synthesized. Scanning electron microscopy (SEM) and nitrogen adsorption/desorption tests indicated that the doping of HA substantially increased the specific surface area and pore volume of the microspheres. The loading experiments showed that the efficiency of the microspheres was significantly increased by 49.47 % and 55.10 %, respectively, when HA and HACC were incorporated into the SA network. The release test results suggested that the release rate of SA/HA/HACC microspheres loading CUR (SA/HA/HACC@CUR) increased as the pH decreased, demonstrating notable pH-responsive release characteristics. DPPH free radical scavenging experiments demonstrated that the SA/HA/HACC@CUR had excellent and long-lasting antioxidant capacity. The antibacterial experiments revealed that the SA/HA/HACC@CUR had excellent antibacterial properties, with inhibition rates of 88.73 % and 92.52 % against E. coli and S. aureus, respectively. Making coatings out of microspheres could effectively slow down the rotting and deterioration of cherry tomatoes during storage, suggesting that microspheres with intelligent responses have a broad application prospect in fruit preservation.

Hemicellulose-Based Sensors: When Sustainability Meets Complexity

Hemicelluloses (HCs) are promising sustainable biopolymers with a great natural abundance, excellent biocompatibility, and biodegradability. Yet, their potential sensing applications remain limited due to intrinsic challenges in their heterogeneous chemical composition, structure, and physicochemical properties. Herein, recent advances in the development of HC-based sensors for different chemical analytes and physical stimuli using different transduction mechanisms are reviewed and discussed. HCs can be utilized as carbonaceous precursors, reducing, capping, and stabilizing agents, binders, and active components for sensing applications. In addition, different strategies to develop and improve the sensing capacity of HC-based sensors are also highlighted.

Green and sustainable smart wooden system integrated with cellulose nanowhiskers-supported polyvinyl alcohol and anthocyanin biomolecules to monitor food freshness

Smart packaging materials have been used to protect human health from environmental hazards by sending real-time colorimetric signals for changes in the food packaging environment. However, the colorimetric material sensors use synthetic sensor dyes, which are toxic, expensive, non-biodegradable, and difficult to prepare. Herein, a simple strategy is presented for the development of an environmentally-friendly halochromic wood able to change color upon exposure to spoilage of food. A combination of anthocyanin (Ac)/aluminum (Al) mordant (Ac/Al) nanoparticles and cellulose nanowhiskers (CNW)-reinforced polyvinyl alcohol (PVA) was infiltrated into a delignified wood to produce a translucent wood with halochromic properties. CNW were employed as reinforcement agent to improve the mechanical performance of PVA. Additionally, CNW function as a dispersing agent to prevent agglomeration of Ac/Al nanoparticles. The diameters of CNW are in the range of 12-19 nm, whereas Ac/Al particles showed diameters of 9-22 nm. The smart wood changed color from purplish to colorless when exposed to food spoilage. A hypsochromic change from 539 nm to 370 nm was shown by the anthocyanin receptor when the spoilage level of food increased. This could be attributed to the pH-driven molecular switching of anthocyanin, leading to charge delocalization.

Double layer packaging based on active black chickpea protein isolate electrospun nanofibers and intelligent salep film containing black chickpea peel anthocyanins for seafood products

In this study, a double-layer active and intelligent packaging system was developed based on two main natural macromolecules i.e. protein and carbohydrate with green perspective. Firstly, the salep-based films containing different concentrations (0-8 % w/w) of the inclusion complex of β-cyclodextrin/black chickpea anthocyanins (βCD/BCPA) were produced. The salep film containing 8 % of βCD/BCPA complex was specified as the optimized film sample based on its performance as a color indicator. The electrospinning of black chickpea protein isolate nanofibers (BCPI NFs) containing citral nanoliposomes (NLPs) was done on the optimized salep film. The cross-sectional field emission scanning electron microscopy approved the creation of double-layer structure of the developed film. The study of chemical and crystalline structure, as well as the thermal properties of the film exhibited the physical attachment of BCPI electrospun NFs on salep film. The effectiveness of the developed system was studied in detection of spoilage and increasing the shelf life of seafood products, including shrimp and fish fillet. The performance of the intelligent layer in detection of freshness/spoilage was acceptable for both seafood products. In addition, the active layer of the film controlled the changes of pH, total volatile basic nitrogen, oxidation, and microbial load in samples during storage time.

Development and characterization of polyvinyl alcohol/chitosan crosslinked malic acid composite films with curcumin encapsulated in β-cyclodextrin for food packaging application

Considering that fruits are vulnerable to damage and waste during stockpiling, transport and marketing. Given this, an innovative curcumin inclusion compound (Cur@β-CD) was devised in this study to introduce oil-soluble curcumin (Cur) into water-soluble polyvinyl alcohol (PVA) materials, thereby fabricating food packaging films endowed with excellent properties. DPPH test manifested that the oxidation resistance for PCOMC-Cur@β-CD film was 95 % above PVA material. It was ascribed to the fact that the Cur@β-CD elevated the water solubility of Cur while the increase of water solubility heightened the antioxidant effect for Cur in the film. Additionally, the chitosan (CS) was crosslinked with malic acid (MA), which elevated the barrier property of the film, reduced the amount of oxygen transmission and further retarded the oxidation reaction of the fruits for packaging. The antibacterial test demonstrated that the antibacterial rates of PCOMC-Cur@β-CD film against E. coli and S. aureus reached 92 % and 95 %, respectively, which was attributed to the slow release of Cur when Cur@β-CD was dissolved in PVA material and the Schiff base reaction between Cur and amino groups on CS. These findings indicate that the PCOMC-Cur@β-CD film developed in this work can provide certain insights into the field of food packaging.

The potential of using curcumin in dairy and milk-based products-A review

This review examines the potential of curcumin as a technological and functional food additive in dairy and milk-based products. The advantages of incorporating curcumin in these products include its antimicrobial properties, support for the activity of lactic acid bacteria, improvement in sensory characteristics, and shelf-life extension. Curcumin notably enhances antioxidant activity and acts as a natural preservative in cheese, cheese-like products, and butter. In ice cream and dairy desserts, curcumin contributes to attractive color formation and offers functional benefits such as antioxidant activity, photostability, and increased nutritional value. However, the use of turmeric extract, a common source of curcumin, presents challenges including low bioavailability, color instability, and the formation of insoluble precipitates. The application of specialized curcumin formulations with enhanced water dispersion, purity, and bioavailability can mitigate these issues, improve the product's technological properties, and ensure compliance with local regulations. This review highlights the importance of continued research and development to optimize the use of curcumin in dairy and milk-based products, offering valuable insights for scientists and food industry professionals.

A review on the role of pH-sensitive natural pigments in biopolymers based intelligent food packaging films

As food packaging evolves, consumer interests are shifting from traditional to intelligent food packaging systems. Intelligent packaging includes active components that display changes in a visual or interactive form perceivable by consumers. This offers real-time monitoring of the quality and shelf life of the packaged food and enhances transparency. For example, pH-sensitive natural pigment-based films change color in response to variations in pH levels, enabling the film/labels to reflect alterations in the acidity or basicity of the food inside the package. Natural pigments like anthocyanins, curcumin, betalains, chlorophyll, and carotenoids have been comprehensively reported for developing biodegradable pH-sensitive films of starch, protein, chitosan, and cellulose. Natural pigments offer great compatibility with these biopolymers and improve the other performance parameters of the films. However, these films still lack the strength and versatility of petroleum-based synthetic plastic films. But these films can be used as an indicator and combined with primary packaging to monitor freshness, time-temperature, and leak for muscle foods, dairy products, fruits and vegetables, and bakery products. Therefore, this review provides a detailed overview of pH-sensitive pigments, their compatibility with natural polymers, their role in film performance in monitoring, and their food packaging applications.

Amine response smartphone-based portable and intelligent polyvinyl alcohol films for real-time detection of shrimp freshness

Food freshness monitoring is an important component in ensuring food safety for consumers and the food industry. Therefore, there is an urgent need for a portable, low-cost, and efficient detection method to determine the freshness. In this study, polyvinyl alcohol (PVA) was used as polymer carrier to prepare electrospinning film containing curcumin (Cur) and gardenia blue (GB) as intelligent indicator label on food packaging for real-time nondestructive detection of freshness of shrimp. The detection limit of ammonia response is less than or equal to 20 ppm, and the detection time is about 1 min, indicating that it has a sensitive response effect. At the same time, a smartphone application that can identify amines in response to color changes has been developed, and consumers can understand freshness by scanning the label. This study demonstrates the huge potential of smart indicator labels for food freshness monitoring.

Preparation and characterization of zein-caseinate-pectin complex nanoparticles for encapsulation of curcumin: pectin extracted by high-speed shearing from passion fruit (Passiflora edulis f. flavicarpa) peel

BACKGROUND

Pectin extracted by high-speed shearing from passion fruit peel (HSSP) is a potentially excellent wall material for encapsulating curcumin, which has multiple advantages over pectin prepared by heated water extraction. HSSP was used to fabricate complex nanoparticles of zein-sodium caseinate-pectin for encapsulation of curcumin in this study. The influence of heating on the physicochemical properties of the composite nanoparticles was also investigated, as well as the effect of composite nanoparticles on the encapsulation efficiency, antioxidant activity and release characteristics of curcumin.

RESULTS

The nanoparticles were formed through electrostatic interactions, hydrogen bonds and hydrophobic interactions between the proteins and HSSP. A temperature of 50 °C was more favorable for generating compact and small-sized nanoparticles, which could effectively improve the encapsulation efficiency and functional properties. Moreover, compared to other pectin used in the study, the nanoparticles prepared with HSSP showed the best functionality with a particle size of 234.28 ± 0.85 nm, encapsulation rate of 90.22 ± 0.54%, free radical scavenging rate of 78.97% and strongest protective capacity in simulated gastric fluid and intestinal release effect.

CONCLUSION

Zein-sodium caseinate-HSSP is effective for encapsulating and delivering hydrophobic bioactive substances such as curcumin, which has potential applications in the functional food and pharmaceutical industries. © 2024 Society of Chemical Industry.

Hybrid Ethylcellulose Polymeric Films: Ag(I)-Based Components and Curcumin as Reinforcing Ingredients for Enhanced Food Packaging Properties

Bio-active ethylcellulose (EC) polymeric films have been obtained by incorporating curcumin (curc) and Ag(I)-based compounds, known for their antioxidant and antimicrobial activity, respectively, within the polymeric matrix. The recently reported Ag(I) coordination polymer, in both its structural forms (α-[(bpy)Ag(OTf)]∞ and β-{[(bpy)Ag][OTf]}∞), and the [(bpy)Ag(OTf)]∞-curc polymeric co-crystal (bpy=2,2'-bipyridine; OTf=trifluoromethanesulfonate) have been selected as Ag(I) species. The hybrid composite films have been prepared through the simple solvent casting method and characterized through Powder X-Ray Diffraction (PXRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscope (SEM), UV-vis spectroscopy. The deep investigation of the film samples highlighted the non-inert behaviour of EC towards these specific active ingredients. Antimicrobial tests showed that EC films embedding the Ag(I)-based compounds present good antimicrobial performance, in particular against Staphylococcus aureus, used as a model of Gram-positive bacteria. In addition, Silver migration tests, performed on the Ag(I)-incorporating EC films, evidenced low values of silver release particularly in the case of the EC films incorporating [(bpy)Ag(OTf)]∞-curc.

Preparation and stability investigation of ultrasound-assisted W/O/W multiple nanoemulsions co-loaded with hydrophobic curcumin and hydrophilic arbutin for tyrosinase inhibition

In the present, whitening products are most popular in the cosmetics market, and nanoemulsions are effective drug delivery systems through the skin. The objective of this study was to investigate multiple nanoemulsion formulations for lightning skin effects. The method of this study was the selection of active compounds based on synergistic tyrosinase inhibition activity, formulation preparation by low and high energy methods, physicochemical property determination, stability test, cell toxicity, and anti-melanogenesis in cell culture. From the results, it was found that tyrosinase inhibition with substrate l-tyrosine from the mixture of curcumin and alpha-arbutin gave the highest activity with an IC50 of 63.58 ± 4.99 μM, showed a synergistic effect at a CI value of 0.99, and selected these compounds to develop formulations by the low energy method. However, the most formulations prepared by this method were unstable and phase separated, while the high energy method gave the most formulations with good properties, which were selected for further investigation. The best formulation was 2DS which showed internal droplet morphology in the range of nanometers under a TEM microscope. For 3 months stability test, the formulations had no phase separation and gave the slightly changed values of particle size, polydispersity index (PDI), zeta potentials, and pH values. In addition, multiple nanoemulsions also enhanced the stability of active compounds, with the highest percentage of remaining content of curcumin and arbutin at 94.69 and 90.45 %, respectively at 4 °C for 3 months. In a cell culture test on B16F10, 2DS at 0.05 g/ml gave no cell cytotoxicity and anti-melanogenesis at 57.75 ± 5.74 %, the same potency as kojic acid at a concentration of 20 μg/ml. Therefore, this study will be useful to prepare multiple nanoemulsions for further development into novel health care products.

Smart nano-inks based on natural food colorant for screen-printing of dynamic shelf life of shrimp

Intelligent packaging embedded with food freshness indicators can monitor food quality and be deployed for food safety and cutting food waste. The innovative nano-inks for dynamic shelf-life printing based on natural food colorant with application in real-time monitoring of shrimp freshness were prepared. Co-assembly of saffron petal anthocyanin (SPA) with hydrophobic curcumin (Cur) into chitin nano-scaffold (particle sizes around 26 ± 8 nm) could deliver hindering SPA leaching, confirmed by FT-IR, FE-SEM, AFM, and color stability test. The best response to pH-sensitivity was found in a ratio of (1:4) Cur/SPA (30% (v/w) in ChNFs that was correlated with the chemical and microbial changes of shrimp during shrimp freshness. However, smart screen-printed inks signified higher responsiveness to pH changes than FFI films. Therefore, smart-printed indicators introduced the excellent potential for a short response time, easy, cost-effective, eco-friendly, co-assembly, great color stabilities, and lifetime for nondestructively freshness monitoring foods and supplements.

Advances of nanoparticle derived from food in the control of α-dicarbonyl compounds-A review

α-Dicarbonyl compounds (α-DCs) are predominantly generated through the thermal processing of carbohydrate and protein-rich food. They are pivotal precursors to hazard formation, such as advanced glycation end products (AGEs), acrylamide, and furan. Their accumulation within the body will be genotoxicity and neurotoxicity. Recently, significant advancements have been made in nanotechnology, leading to the widespread utilization of nanomaterials as functional components in addressing the detrimental impact of α-DCs. This review focuses on the control of α-DCs through the utilization of nanoparticle-based functional factors, which were prepared by using edible components as resources. Four emerging nanoparticles are introduced including phenolic compounds-derived nanoparticle, plant-derived nanoparticle, active peptides-derived nanoparticle, and functional minerals-derived nanoparticle. The general control mechanisms as well as the recent evidence pertaining to the aforementioned aspects were also discussed, hoping to valuable helpful references for the development of innovative α-DCs scavengers and identifying the further scope of research.

Preparation of edible antibacterial films based on corn starch /carbon nanodots for bioactive food packaging

Packaging plays an important role in protecting food from environmental impacts. However, traditional petroleum-based packaging has difficulty in meeting the antimicrobial and antioxidant requirements of prepared foods. This study introduced carbon dots (CDs), prepared by using carrot as a precursor, into corn starch (CS) to construct a bio-friendly composite film with high freshness retention properties. The scavenging of DPPH radicals reached 92.77 % at a CDs concentration of 512 µg/mL, and the antimicrobial activity of CS/5% CDs against Escherichia coli and Staphylococcus aureus was increased to 99.9 %. Notably, the homogeneous doping of CDs creates a dense surface and high carbon content inside the film, which promotes the elasticity and thermal stability of the composite film. Finally, we encapsulated deep-fried meatballs in CS-CDs films. The results showed that the CS-CDs films effectively protected the quality of deep-fried meatballs, and have excellent potential for application in food preservation.

Engineered Robust Hydrophobic/Hydrophilic Nanofibrous Scaffolds with Drug-Eluting, Antioxidant, and Antimicrobial Capacity

Multifunctional nanofibrous architectures have attracted extensive attention for biomedical applications due to their adjustable and versatile properties. Electrospun fabrics stand out as key building blocks for these structures, yet improving their mechanobiological and physicochemical performance is a challenge. Here, we introduce biodegradable engineered hydrophobic/hydrophilic scaffolds consisting of electrospun polylactide nanofibers coated with drug-eluting synthetic (poly(vinyl alcohol)) and natural (starch) polymers. The microstructure of these composite scaffolds was tailored for an increased hydrophilicity, optimized permeability, water retention capacity of up to 5.1 g/g, and enhanced mechanical properties under both dry and wet conditions. Regarding the latter, normalized tensile strengths of up to 32.4 MPa were achieved thanks to the improved fiber interactions and fiber-coating stress transfer. Curcumin was employed as a model drug, and its sustained release in a pure aqueous medium was investigated for 35 days. An in-depth study of the release kinetics revealed the outstanding water solubility and bioavailability of curcumin, owing to its complexation with the hydrophilic polymers and further delineated the role of the hydrophobic nanofibrous network in regulating its release rate. The modified curcumin endowed the composites with antioxidant activities up to 5.7 times higher than that of free curcumin as well as promising anti-inflammatory and bacteriostatic activities. The cytocompatibility and cell proliferation capability on human dermal fibroblasts also evidenced the safe use of the constructs. Finally, the fabrics present pH-responsive color-changing behavior easily distinguishable within the pH range of 5-9. Thus, these designs offer a facile and cost-effective roadmap for the fabrication of smart multifunctional biomaterials, especially for chronic wound healing.

Hybrid Metal Oxide (Ag-ZnO) Impregnated Biocomposite in the Development of an Eco-Friendly Sustainable Film

Nanotechnology offers an innovative application as an eco-friendly food packaging film fabricated along with a degradable active mixture (AM). The AM is an assortment of alloyed metal oxide nanoparticles (Ag-ZnO), citron powder (AA), and Curcuma peel powder (CPP). Alloyed nanoparticles (NPs) were observed to exhibit a hexagonal structure from the experimental X-ray diffraction. Compositional and morphological study of the NPs (22.69 nm) and AM (32 nm) was done using energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and ζ- potential was observed to be -14.7 mV, indicating the stability of NPs. The prepared film was observed to be more effective with antibacterial analysis against Escherichia coli, exhibiting 72% of inhibition and antioxidant activity with IC50: 51.56% using the 2,2 diphenyl-1-picrylhydrazyl (DPPH) assay. Film 1, Film 2, Film 3, and Film 4 were fabricated with the AM and observed to be perfectly encapsulated by PVA using XRD. FESEM images of the film exhibit the aggregation of NPs with biocomposites in perfect distribution. The mechanical properties such as Young's modulus, elongation at break, tensile strength, and ultimate tensile strength (UTS- 5.37 MPa) were experimented for the films. The degradation rate was observed to be 6.12% for film 1 using the soil burial method. The study emphasizes that NPs along with biocomposite upgrade the sustainability of the packaging film with improved mechanical and physicochemical properties. The synthesized film with biomaterials could be used as a "green" food package to store fruits, vegetables, and sweets in the food industry.

Recent advances in modifications of exudate gums: Functional properties and applications

Gums are high-molecular-weight compounds with hydrophobic or hydrophilic characteristics, which are mainly comprised of complex carbohydrates called polysaccharides, often associated with proteins and minerals. Various innovative modification techniques are utilized, including ultrasound-assisted and microwave-assisted techniques, enzymatic alterations, electrospinning, irradiation, and amalgamation process. These methods advance the process, reducing processing times and energy consumption while maintaining the quality of the modified gums. Enzymes like xanthan lyases, xanthanase, and cellulase can selectively modify exudate gums, altering their structure to enhance their properties. This precise enzymatic approach allows for the use of exudate gums for specific applications. Exudate gums have been employed in nanotechnology applications through techniques like electrospinning. This enables the production of nanoparticles and nanofibers with improved properties, making them suitable for the drug delivery system, tissue engineering, active and intelligient food packaging. The resulting modified exudate gums exhibit improved rheological, emulsifying, gelling, and other functional properties, which expand their potential applications. This paper discusses novel applications of these modified gums in the pharmaceutical, food, and industrial sectors. The ever-evolving field presents diverse opportunities for sustainable innovation across these sectors.

Medical properties, market potential, and microbial production of golden polyketide curcumin for food, biomedical, and cosmetic applications

Curcumin, a potent plant polyketide in turmeric, has gained recognition for its outstanding health benefits, including anti-inflammatory, antioxidant, and anticancer effects. Classical turmeric farming, which is widely used to produce curcumin, is linked to deforestation, soil degradation, excessive water use, and reduced biodiversity. In recent years, the microbial synthesis of curcumin has been achieved and optimized through novel strategies, offering increased safety, improved sustainability, and the potential to revolutionize production. Here, we discuss recent breakthroughs in microbial engineering and fermentation techniques, as well as their capacity to increase the yield, purity, and cost-effectiveness of curcumin production. The utilization of microbial systems not only addresses supply chain limitations but also helps meet the growing demand for curcumin in various industries, including pharmaceuticals, foods, and cosmetics.

A novel acid-responsive polymer coating with antibacterial and antifouling properties for the prevention of biofilm-associated infections

Chronic infections caused by the pathogenic biofilms on implantable medical devices pose an increasing challenge. To combat long-term biofilm-associated infections, we developed a novel dual-functional polymer coating with antibacterial and antifouling properties. The coating consists of N-vinylpyrrolidone (NVP) and 3-(acrylamido)phenylboronic acid (APBA) copolymer brushes, which bind to curcumin (Cur) as antibacterial molecules through acid-responsive boronate ester bonds. In this surface design, the hydrophilic poly (N-vinylpyrrolidone) (PVP) component improved antifouling performance and effectively prevented bacterial adhesion and aggregation during the initial phases. The poly (3-(acrylamido) phenylboronic acid) (PAPBA, abbreviated PB) component provided binding sites for Cur by forming acid-responsive boronate ester bonds. When fewer bacteria overcame the anti-adhesion barrier and colonized, the surface responded to the decreased microenvironmental pH by breaking the boronate ester bonds and releasing curcumin. This responsive mechanism enabled Cur to interfere with biofilm formation and provide a multilayer anti-biofilm protection system. The coating showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, preventing biofilm formation for up to 7 days. The coating also inhibited protein adsorption and platelet adhesion significantly. This coating also exhibited high biocompatibility with animal erythrocytes and pre-osteoblasts. This research offers a promising approach for developing novel smart anti-biofilm coating materials.

Current progress in functionalization of cellulose nanofibers (CNFs) for active food packaging

There is a growing interest in utilizing renewable biomass resources to manufacture environmentally friendly active food packaging, against the petroleum-based polymers. Cellulose nanofibers (CNFs) have received significant attention recently due to their sustainability, biodegradability, and widely available sources. CNFs are generally obtained through chemical or physical treatment, wherein the original surface chemistry and interfacial interactions can be changed if the functionalization process is applied. This review focuses on promising and sustainable methods of functionalization to broaden the potential uses of CNFs in active food packaging. Novel aspects, including functionalization before, during and after cellulose isolation, and functionalization during and after material processing are addressed. The CNF-involved structural construction including films, membranes, hydrogels, aerogels, foams, and microcapsules, is illustrated, which enables to explore the correlations between structure and performance in active food packaging. Additionally, the enhancement of CNFs on multiple properties of active food packaging are discussed, in which the interaction between active packaging systems and encapsulated food or the internal environment are highlighted. This review emphasizes novel approaches and emerging trends that have the potential to revolutionize the field, paving the way for advancements in the properties and applications of CNF-involved active food packaging.

Curcumin and silver nanoparticles loaded antibacterial multifunctional pectin/gelatin films for food packaging applications

Renewable biomass-based materials have a huge potential to replace petroleum-based products in food packaging. Herein, pectin/gelatin films loaded with curcumin and silver nanoparticles (AgNPs) are prepared by solution-pouring technology to serve as antimicrobial multifunctional food packaging films. AgNPs and curcumin are found to equally distribute in the films. Fourier transform infrared spectroscopy (FT-IR) reveal the hydrogen bonding and electrostatic interaction among curcumin, AgNPs, pectin and gelatin. The composite films show good antioxidant activity, mechanical performance, hydrophobicity and antibacterial ability. The films of P-GCA 0.5 showed 99.57 ± 0.16 % and 100 % inhibition against E. coli and S. aureus, respectively. The films also demonstrate excellent water vapor barrier qualities. In addition, the composite films possess pH-responsive color change behaviors from yellow (pH 3-8) to light red (pH 8-9) to dark red (pH 11-12), which is suitable for monitoring the freshness of shrimp packaging based on pH changes during deterioration process. As sustainable biomass-based materials, the multifunctional composite films are promising in intelligent food packaging applications.

Photostabilities and anti-tumor effects of curcumin and curcumin-loaded polydopamine nanoparticles

Currently, the photostability of photosensitizer curcumin is the main bottleneck limiting their application, reducing the bioavailability of curcumin. Studying the effect of different light sources on the photostabilities of curcumin and loading it onto polydopamine nanocarriers with better biocompatibility will help improve its light utilization efficiency. In this study, we investigated the photostabilities of curcumin and a polydopamine-based nanoparticle (polydopamine-curcumin composite nanoparticles, PDA-Cur NPs) loaded with curcumin through in vitro and in vivo experiments to achieve better antitumor effects. The results demonstrated that curcumin has good photostability in dark, but with significant photodegradation rates in both red and blue light. Blue light has a faster effect on the photodegradation of curcumin, with a degradation rate of 42.1% after 10 minutes, which is about 1.7 times that of the red light. Our study successfully synthesized PDA-Cur NPs, demonstrating its ability to stably load and release curcumin, with a loading percentage of 65.7% after 2 hours and 41.9% release in 8 hours (pH 6.0). Compared with single curcumin treatments, the photodegradation rates of PDA-Cur NPs in red and blue light treatments were reduced by 46% and 50%, respectively. Meanwhile, PDA-Cur NPs exhibited remarkable antitumor efficacy due to PDT and promote apoptosis in cancer cells, which both better than that of single curcumin treatments. Moreover, in MCF-7 tumor-bearing mice, the PDA-Cur NPs led to significant tumor growth inhibition effects, without causing evident systemic damage in vivo. The findings highlight the potential of PDA-Cur NPs as anticancer photosensitizer with greatly increased utilization of curcumin in PDT.

Unlocking the future of smart food packaging: biosensors, IoT, and nano materials

This review examines how biosensors, the Internet of Things (IoT), and nano materials can revolutionize food packaging. It highlights the limitations of traditional packaging, particularly concerning barrier properties and food quality monitoring. The paper aims to provide specific insights into the potential of these technologies. Biosensors enable real-time monitoring and spoilage detection, ensuring safer products, while IoT enhances traceability and transparency in the supply chain, leading to reduced material waste, energy waste, and operational inefficiencies, ultimately improving efficiency. Nano materials offer improved barrier capabilities, strength, and antimicrobial properties, enhancing product quality and sustainability. The review paper also discusses the promising future of smart food packaging, driven by technological advancements and consumer demand for safer and eco-friendly products. However, it acknowledges the challenges related to regulations, sustainability, and consumer acceptance that need to be addressed for widespread adoption. In conclusion, this paper demonstrates how smart food packaging with biosensors, IoT, and nano materials can transform the food industry by overcoming traditional limitations and meeting evolving consumer needs, providing improved food safety, quality, and sustainability.

Development of Intelligent Indicators Based on Cellulose and Prunus domestica Extracted Anthocyanins for Monitoring the Freshness of Packaged Chicken

Meat is a widely consumed food globally; however, variations in storage conditions along its supply chain can pose a potential food safety risk for consumers. Addressing this concern, we have developed freshness indicators designed to monitor the condition of packaged chicken. In this study, anthocyanins were infused with cellulose paper measuring 2 × 2 cm, and subsequent analysis focused on examining color changes concerning deteriorating chicken stored at 30°C for 48 h, with varying sample sizes being considered. The rise in total volatile nitrogen (TVB-N) compounds from an initial value of 3.64 ± 0.39 mg/100 g to 28.17 ± 1.46 mg/100 g acted as the stimulus for the color change in the indicator, simultaneously influencing the pH from the initial 7.03 ± 0.16 to 8.12 ± 0.39. The microbial load (aerobic plate count) of the chicken samples was also significantly increased. This collective shift in various parameters strongly suggests the occurrence of spoilage in chicken meat. The pH indicators exhibited a dark pink to red color for fresh chicken. As the chicken meat turned towards spoilage, the indicators changed to a dark blue and then a pale green color. FTIR spectroscopy results confirmed the presence of cellulose and anthocyanins. The FTIR analysis also validated the immobilization of plum anthocyanins within the cellulose paper and assessed their stability after 8 months of storage. Notably, the indicators demonstrated rapid sensitivity, showing a 20.5% response within one minute of ammonia exposure, which further increased to 29.5% after 3 min of exposure. The total color difference (ΔE) steadily rose in all the examined samples and also under various storage conditions. Overall, the indicators developed in this study exhibited a highly pronounced color transition, capable of distinguishing between fresh and spoiled chicken samples depending on the extent of spoilage and the specific day of observation.

Irreversible colorimetric bio-based curcumin bilayer membranes for smart food packaging temperature control applications

Research into innovative food safety technologies has led to the development of smart packaging with embedded chemical sensors that can monitor food quality throughout the supply chain. Thermochromic materials (TM), which are able to dynamically change colour in response to temperature fluctuations, have proven to be reliable indicators of food quality in certain environments. Natural colourants such as curcumin are becoming increasingly popular for smart packaging due to their low toxicity, environmental friendliness and ability to change colour. The innovation in this research lies in the production of a bio-based bilayer membrane specifically designed for irreversible temperature monitoring. Membrane A was prepared by dissolving cellulose acetate and curcumin in acetone at room temperature, with glycerol serving as a plasticiser. At the same time, membrane B was carefully formulated by dissolving cellulose acetate and triethanolamine in acetone, with sorbitol as plasticiser. The preparation of these different membranes revealed a remarkable event: a gradual and irreversible colour transition from an initial yellow to a brick-red hue after 24 hours of storage at 25 °C. The chemical structure and morphological analyses of the membranes were performed using several techniques, including FTIR, DSC and SEM. The membrane labels were adhered to aluminium cans and their colorimetric response was observed over a period of 10 days. Minimal colour variations were observed, confirming the reproducibility and stability of the curcumin-based membranes as temperature sensors.

Development of films based on chitosan, gelatin and collagen extracted from bocachico scales (Prochilodus magdalenae)

Biodegradable biopolymers from species of the animal kingdom or their byproducts are sustainable as ecological materials due to their abundant supply and compatibility with the environment. The research aims to obtain a biodegradable active material from chitosan, gelatin, and collagen from bocachico scales (Prochilodus magdalenae). Regarding the methodology, films were developed from gelatin, chitosan, and collagen from bocachico scales (Prochilodus magdalenae) at different concentrations using glycerol as a plasticizer and citric acid as a cross-linker. The films were obtained with the hydrated mass processed by compression molding and characterized according to humidity, water solubility, contact angle, mechanical properties, and structural properties. The results of the films showed a hydrophobic characteristic. First, the chitosan-collagen (CS/CO) films showed a yellowish color, while the gelatin-collagen (Gel/CO) films were transparent and less soluble than the gelatin-collagen (Gel/CO) films. Concerning mechanical properties, gelatin films showed higher stiffness and tensile strength than chitosan films. Furthermore, in the morphological analysis, more homogeneous chitosan films were obtained by increasing the concentration of citric acid. In general, chitosan, gelatin, and collagen extracted from the scales of the bocachico (Prochilodus magdalenae) are an alternative in the application of films in the food industry.

Methylcellulose/chitosan nanofiber-based composites doped with lactoferrin-loaded Ag-MOF nanoparticles for the preservation of fresh apple

Increasing demand for high-quality fresh fruits and vegetables has led to the development of innovative active packaging materials that exhibit controlled release of antimicrobial/antioxidant agents. In this study, composite biopolymer films consisting of methylcellulose (MC) and chitosan nanofibers (ChNF) were fabricated, which contained lactoferrin (LAC)-loaded silver-metal organic framework (Ag-MOF) nanoparticles. The results indicated that the nanoparticles were uniformly distributed throughout the biopolymer films, which led to improvements in tensile strength (56.1 ± 3.2 MPa), thermal stability, water solubility, swelling index, water vapor barrier properties (from 2.2 ± 2.1 to 1.9 ± 1.9 × 10-11 g. m/m2. s. Pa), and UV-shielding effects. The Ag-MOF-LAC2% films also exhibited strong and long-lasting antibacterial activity against E. coli (19.8 ± 5.2 mm) and S. aureus (20.1 ± 3.2 mm), which was attributed to the slow release of antimicrobial LAC from the films. The composite films were shown to maintain the fresh appearance of apples for at least seven days, which was attributed to their antimicrobial and antioxidant activities. Consequently, these composite films have the potential in the assembly of innovative active packaging materials for protecting fresh fruits and vegetables. However, further work is required to ensure their safety and economic viability.

Fluorescence and pectinase double-triggered chitosan/pectin/calcium propionate/curcumin-β-cyclodextrin complex film for pork freshness monitoring and maintenance

An intelligent and active food packaging film based on chitosan (CS), pectin (P), calcium propionate (CP), and curcumin-β-cyclodextrin complex (Cur-β-CD) was prepared. The CS/P/CP/Cur-β-CD film exhibited improved hydrophobicity (74.78 ± 0.53°), water vapor (4.55 ± 0.16 × 10-11 g·(m·s·Pa)-1), and oxygen (1.50 ± 0.06 × 10-12 g·(m·s·Pa)-1) barrier properties, as well as antioxidant (72.34 ± 3.79 % for DPPH and 86.05 ± 0.14 % for ABTS) and antibacterial (79.41 ± 2.89 % for E. coli and 83.82 ± 3.96 % for S. aureus) activities. The release of CP and Cur could be triggered by pectinase, with their cumulative release reaching 92.62 ± 1.20 % and 42.24 ± 1.15 %, respectively. The CS/P/CP/Cur-β-CD film showed delayed alterations in surface color, pH value, total volatile bases nitrogen, total viable counts, thiobarbituric acid reactive substance, hardness, and springiness of pork. Additionally, the fluorescence intensity of the film gradually decreased. In conclusion, we have developed a pH-responsive film with pectinase-triggered release function, providing a new concept for the design of multi-signal responsive intelligent food packaging.

Biodegradable cellulose/curcumin films with Janus structure for food packaging and freshness monitoring

The development of renewable, hydrophobic, and biodegradable intelligent packaging materials as an alternative to petroleum-based plastic products has become a new research focus in recent years, but remains a challenge. Herein, regenerated cellulose/curcumin composite films were fabricated by dispersing hydrophobic curcumin uniformly in a hydrophilic cellulose matrix using an aqueous alkali/urea solvent based on the pH-driven principle of curcumin. In addition, a unilateral hydrophobic modification was carried out using chemical vapor deposition of methyltrichlorosilane to obtain Janus structure. The composite films exhibited high transparency in the visible light spectrum, excellent antioxidation, thermal stability, mechanical strength, gas barrier properties, and antibacterial activity. Furthermore, the films demonstrated the capability to lower the overall levels of volatile basic nitrogen in stored fish. The color of the films shifted from a pale yellow to a reddish-brown over time during storage. The composite films can be completely degraded after approximately 98 days in soil with an average environmental temperature of 29 °C. This work provided a facile strategy to prepare biodegradable cellulose/curcumin films with Janus structure as packaging materials which could preserve the freshness of food products while offering visual monitor of their freshness in real-time.

Preparation of sodium alginate/Cur-PLA hydrogel beads for curcumin encapsulation

The low bioavailability of hydrophobic compounds, however, limits their medicinal use. Hydrogel beads made of biopolymers can be employed as controlled delivery systems and as a carrier to carry curcumin molecules. In this study, encapsulation of curcumin is done within the hydrogel by using Polylactic acid. The prepared SA/Cur-PLA and SA/Cur beads were examined using FTIR, SEM, TGA, NMR, and, XRD to study the interaction between drug and polymer. The developed bead's curcumin encapsulation efficiency was found to be 81.47 % in SA/Cur-PLA. Curcumin's release kinetics have been studied in systems (SGF, pH 1.2, and SCF, pH 7.4) that simulate oral consumption, which possess good pH sensitivity. The in vitro drug release studies of SA/Cur-PLA beads suggest that the curcumin release was significantly increased in a controlled manner and within 12 h, the cumulative release of curcumin was accomplished. In vitro hemolysis study shows a 7.93 % hemolysis rate which suggests that the produced bead is hemocompatible. For SA/Cur-PLA and SA/Cur, cytotoxicity evaluation and antimicrobial study was performed. Results show that both hydrogels are cytocompatible and antimicrobial in nature. It was found that biopolymer-based hydrogel beads enhanced the bioavailability of curcumin, antioxidant, biodegradable, and considered an effective carrier for the oral delivery of several hydrophobic nutraceuticals.

Development of ternary polymeric films based on cassava starch, pea flour and green banana flour for food packaging

The development of alternative materials to replace plastics used in food packaging is an important approach to reducing environmental pollution and minimizing harmful impacts on ecosystems. In this study, biopolymeric films were formulated using cassava starch (Manihot esculenta Crantz), pea flour (Pisum sativum) and green banana flour (Musa sp.) to obtain a material for application in food packaging. The influence of a plasticizer on the optical and physicochemical properties of the films was analyzed and the synergy between higher concentrations of starch and plasticizer resulted in films with low opacity. In addition, the morphology, thermal, mechanical and barrier properties were examined. The film with the best formulation (p < 0.05) contained 12 g cassava starch, 3.6 g pea flour and 30 % glycerol (the maximum levels of the experiment). This film presented average values of thickness, moisture, solubility, opacity, maximum strength (F), maximum tensile stress (σ), elongation at break (ε) and elasticity (E) of 0.47 mm, 19.95 %, 87.45 %, 20.93 %, 9.30 N, 1.75 MPa, 30.10 % and 5.93 %, respectively. This research demonstrates the potential application of films obtained by combining starches from different sources. The sustainable production of environmentally-friendly packaging provides an alternative to fossil-based plastics, which have well-documented adverse effects on the environment.