Carrageenan Films Research Articles

Synergistic effects of starch and carrageenan from Kappaphycus alvarezii in composite film formation: Physicochemical and degradable properties

Rising concerns around plastic pollution from single-use plastic (SUPs), especially food packaging, have driven interest in sustainable alternatives. As such, algae biomass has gained attention for bioplastic production due to algae's rapid growth and abundant polysaccharides. This research focuses on extracting carrageenan from Kappaphycus alvarezii, extensively cultivated in Sabah, Malaysia, and utilizing it in combination with starch and glycerol to develop algae-based films. The physicochemical properties and degradation rate of these films were evaluated, revealing that the addition of carrageenan enhanced overall thermal stability meanwhile increasing water solubility, water content but reducing the degradation rate and swelling degree. This is primarily due to the crystalline structures of carrageenan, which provide a more rigid arrangement compared to the network of starch polymers. However, the incorporation of starch into the blends has enhanced the elongation and surface morphology, resulting in more balanced properties. Overall, these carrageenan films displayed impressive thermal, mechanical, and biodegradability characteristics, establishing their viability as substitutes for conventional plastics.

Effect of potassium salt type on physicochemical properties of carrageenan films and rehydrated hydrogels

This study focused on the effect of potassium salt type on the physicochemical properties of carrageenan (Car) films and rehydrated hydrogels, with the aim of developing a new method for the preparation of Car hydrogels. The addition of potassium salt decreased the tensile strength (TS) of Car films, especially those containing KI. After rehydration, the weight and thickness change ratios of the Car films decreased with salt addition, and the sequence was as follows: K2CO3 < KH2PO4 < CH3COOK < KCl < K2SO4 < KSCN < KI < C6H5K3O7. The effect of potassium salt type on the TS and thermal transition temperature of rehydrated hydrogels was opposite that on weight and thickness change ratios. The hydrogels with K2CO3, KH2PO4, CH3COOK, KCl, and K2SO4 exhibited lower transverse relaxation time (T2) and smaller pore size compared with the other hydrogels. On the other hand, the effect of potassium salt type on hydrogels prepared using Car films soaked in potassium salt solution (S-Car) was similar to that observed on hydrogels prepared using Car films with potassium salt soaked in ultrapure water (U-Car). Compared with U-Car hydrogels, the S-Car hydrogels had higher TS and thermal transition temperature and lower elongation at break, T2, pore size, and hydrogen bond intensity. In conclusion, the potassium salt type and soaking method can be used to regulate the properties of Car hydrogels and provide a theoretical basis for the design of Car hydrogels.

Fabrication and characterization of carrageenan-based multifunctional films integrated with gallic acid@ZIF-8 for beef preservation

The development of environmentally friendly biodegradable films is urgently required for reducing the plastic pollution crisis and ensuring food safety. Thus, here we aimed to prepare ZIF-8 that has delivery ability for gallic acid (GA) and further incorporated this material (GA@ZIF-8) into carrageenan (CA) matrix to obtain a series of CA-GA@ZIF-8 films. This design significantly improved the mechanical strength and UV barrier and reduced water vapor permeability, moisture content, and swelling rate of the CA films. CA-GA@ZIF-8 films exhibited sustainable release of GA and controlled migration of Zn2+ up to 144 h in a high-fat food simulator. Also, the composite films performed high-efficiency antioxidant activities (83.29 % for DPPH and 62.11 % for ABTS radical scavenging activity) and 99.51 % antimicrobial effects against Escherichia coli O157:H7 after 24 h. The great biocompatibility of GA@ZIF-8 and CA-GA@ZIF-8-10 % was confirmed by hemolysis, cell cytotoxicity, and mice model. Finally, the preservation experiments showed that CA-GA@ZIF-8 films could effectively maintain freshness and reduce the growth of microorganisms and oxidation of lipids during the preservation of beef. These results suggest that CA-GA@ZIF-8 films hold promising potential for improving the quality preservation of beef.

Development of hydroxypropylmethylcellulose acetate succinate and kappa carrageenan films loaded with curcumin for wound healing

Curcumin (CUR) has demonstrated significant anti-inflammatory and antimicrobial activity, which has motivated its use in wound healing. Films have shown to be promising systems as they can provide a sustained release, reducing the number of applications and microbial resistance problems. In this new study, CUR-loaded films presenting different proportions of k-carrageenan (κ-CAR) and hydroxypropylmethylcellulose succinate acetate (HPMCAS) were prepared by the solvent casting method. The use of polymer combinations allows for more precise adjustment of release profile and mechanical properties. FTIR and thermal analyses suggested strong chemical interactions between these polymers, which contributed to explaining the improved mechanical properties, such as high values of elastic modulus, of the films. The amorphous state of the materials and the formation of pores in the internal structure of the matrix, as evidenced by SEM analysis, would enhance the penetration of wound exudate, leading to the consequent release of CUR. Moreover, a sustained CUR release and a local distribution in the human skin, with no systemic exposure and high retention in the epidermis, were found. The formulations also showed to be active against Staphylococcus aureus (MIC = 2000 mg L−1) and Pseudomonas aeruginosa (MIC = 2000 mg L−1), which are the two main pathogens found in wounds. Taken together, these results suggest that HPMCAS/κ-CAR films are promising systems for application in wound healing.

Carrageenan films as promising mucoadhesive ocular drug delivery systems

Polymer mucoadhesive films being developed for use in ophthalmology represent a new tool for drug delivery and are considered an alternative to traditional dosage forms. Due to their mucoadhesive properties, carrageenans (CRGs) are widely used in various forms for drug delivery. In this study, films based on CRGs of various structural types (κ/β, κ, x, and λ) for use in ophthalmology were studied. The films were loaded with the active substance echinochrome (ECH), a sea urchin pigment used in ophthalmology. Spectral data showed that ECH remained stable after its incorporation into the CRG films and did not oxidize for at least six months. Hydrophilic CRG films with a thickness of 10−12 µm were characterized in terms of their swelling and mucoadhesive properties. The rheological properties of solutions formed after film dissolution in artificial tears were also assessed. κ- and κ/β-CRG films with ECH exhibited pseudoplastic behavior after rehydrating films with an artificial tear solution. The CRG-loaded films had different swelling characteristics depending on the structure of the CRG used. The films based on highly sulfated CRGs dissolved in artificial tears, while the films of low-sulfated κ/β-CRG exhibited limited swelling. All studied ECH-loaded films exhibited mucoadhesive properties, which were evaluated by a texture analyzer using mucous tissue of the small intestine of the pig as a model. There was a slight prolongation of ECH release from CRG films in artificial tears. The effect of CRG/ECH on the epithelial cell lines of the outer shell of the human eye was investigated. At low concentrations, ECH in the composition of the CRG/ECH complex had no cytotoxic effect on corneal epithelial and conjunctival human cells. The use of ECH-containing films can prevent the drug from being immediately washed away by tears and help to retain it by increasing viscosity and having mucoadhesive properties.

Effect of fish gelatin as a structure forming agent to enhance transparency and speed up degradability of bionanocomposite semi-refined kappa carrageenan film reinforced with ZnO and SiO2 filler

Biodegradable films have been developed as a potential replacement for plastic in food packaging. Apart from reducing environmental pollution, biodegradable films can be used to prevent quality degradation and extend the storage life of food products. Hybrid kappa carrageenan biopolymers have been developed by introducing SiO2 and ZnO nanoparticles to enhance film characteristics with good packaging quality. However, the composite possessed low transparency and high solubility. Therefore, this study aimed to introduce fish gelatin (FG) into a semi-refined kappa-carrageenan (SRkC) composite to improve the transparency and decrease the solubility properties. The films were prepared at various concentrations of blended polymers of SRkC and FG at different ratios (1:3, 1:1, 3:1) and SiO2–ZnO nanoparticles as fillers. The results concluded that as the increase of FG concentrations, the solubility properties of films are likely to decrease. Among the blended films, the films with a ratio of SRkC:FG (1:1) revealed the highest transparency with high UV screening. It also produced films prone to be degraded by the environment. Thus, this knowledge of the bionanocomposite film properties could provide useful contributions to food packaging applications.

Enhancing Tensile Strength, Thermal Stability, and Antioxidant Characteristics of Transparent Kappa Carrageenan Films Using Grapefruit Essential Oil for Food Packaging Applications.

The trends in food packaging technologies are shifting toward utilizing natural and environmentally friendly materials prepared from biopolymers such as kappa carrageenan to replace synthetic polymers. In the current study, varying amounts (0.1, 0.2, and 0.3%) of grapefruit essential oil (GFO) were incorporated in kappa carrageenan-based edible films to improve their physicochemical properties. The developed film samples were characterized for their barrier, mechanical, morphological, optical, thermal, antioxidant, and biodegradable properties. The results obtained showed that the tensile strength of the carrageenan films enhanced significantly from 65.20 ± 4.71 to 98.21 ± 6.35 MPa with the incorporation of GFO in a concentration-dependent manner. FTIR and SEM analysis confirmed the intermolecular bonding between carrageenan and GFO, resulting in the formation of compact films. Incorporating GFO significantly enhanced the thermal resistance of oil-loaded films, as confirmed by TGA, DSC, and DTG analysis. The addition of GFO led to a substantial increase in the radical scavenging activity of the films, as evidenced by the DPPH and ABTS assays. Furthermore, the developed films were biodegradable in soil and seawater environments, indicating their potential as a sustainable alternative to traditional plastics. Findings demonstrated that GFO can be used as a natural antioxidant agent in kappa carrageenan-based films for potential applications in food packaging.

산화아연 나노입자 유형이 카라기난 기반 복합 필름의 구조, 기계적 및 항균 특성에 미치는 영향

In this study, zinc oxide nanoparticles (ZnONPs) were synthesized using three distinct zinc salts: zinc acetate, zinc chloride, and zinc nitrate. These ZnONPs were subsequently utilized in the fabrication of carrageenan-ZnONPs (Car-ZnONPs) composite films. The study assessed influence of the various ZnONPs on the morphological, water vapor barrier, color, optical, and antimicrobial properties of the Car-ZnONPs composite films. The surface morphology and UV-blocking attributes of the composite films were affected by the type of ZnONPs used, but their surface color, transparency, and chemical structure remained unaltered. The composite film's thickness and elongation at break (EB) significantly increased, while the tensile strength significantly decreased. In contrast, film’s elastic modulus (EM) and water vapor permeability coefficient (WVP) showed no significant difference. All the composite films with added ZnONPs demonstrated potent antibacterial activity against Escherichia coli O157:H7 and Listeria monocytogenes. Among the carrageenan-based composite films, Car-ZnONPsZC showed the highest antibacterial and UV-blocking properties, and its elongation at break was significantly higher than that of the pure carrageenan films. This suggests that ZnONPs composite films have the potential to be used as an active packaging film, preserve the safety of the packaged food and extend shelf life.

Isolation of microcrystalline cellulose (MCC) from pistachio shells and preparation of carrageenan-based composite films

Utilizing agricultural waste for material innovation, particularly in food packaging, is an emerging trend aimed at enhancing sustainability and reducing environmental impact. In this study, the goal was to valorize agricultural waste by isolating microcrystalline cellulose (MCC) from pistachio shell powder (PSP) and integrating it into carrageenan films as a filler. Alkaline hydrogen peroxide (AHP) was used to extract PSP fiber at various AHP liquor ratios (NaOH:H2O2), followed by hydrochloric acid hydrolysis of the PSP fibers. Detailed analyses assessed the impact of AHP concentration on the thermal, morphological, microscopic, and crystalline properties of the resulting MCC. Elevated NaOH and H2O2 ratio in the AHP process notably improved the MCC's thermal stability and crystallinity index. FTIR spectroscopy indicated the efficient removal of amorphous regions and impurities, such as lignin and hemicellulose, during AHP pre-hydrolysis. The 4.0:4.4 AHP liquor ratio emerged as particularly promising, considering thermal stability, impurity removal, and crystallinity index. Carrageenan films with the derived MCC showed improved UV resistance, oxygen barrier, thermal stability, and mechanical properties. This research highlights the potential of pistachio shell-derived MCC as a sustainable filler, emphasizing a novel strategy for repurposing agricultural waste.

Characterization of pectin and carrageenan edible films in the presence of lemon balm infusion

The present study aimed the formation of edible films with antioxidant properties. Initially, 20 herbs were evaluated for their total phenolics content (TPC) and antioxidant activity (AA). The majority of the herbs had high AA (>80%), while lemon balm had the best TPC performance. As such, the lemon balm infusion was subsequently used in film formation, along with high and low methoxyl pectin and iota-carrageenan (on their own or in mixtures) at a concentration of 1.5% w/w. For comparison reasons, films prepared in water were also studied. Regarding the films’ properties, their weight varied from 0.74 to 0.81 g, thickness from 71 to 90 μm, density from 1.29 to 1.56 g/cm3, moisture content from 71 to 84% and WVP from 3.81 10−8 - 4.5 10−8 g mm/h cm2 Pa. Maximum force and modulus values ranged from 7.4 to 17.2 N and 186.8–397.2 kPa, respectively. According to the statistics, for the same formulation, the presence of the infusion was not statistically important for weight, thickness, density and moisture content. All infusion films showed significantly greater TPC and AA values and were more opaque and less bright than water films. The type of biopolymer was important for all measured properties. Carrageenan films had greater moisture content and were more opaque, less bright, stronger and stiffer than the remaining films. They also had the lowest TPC and AA values. Possible biopolymer-biopolymer and biopolymer –extract interactions were suggested by FT-IR.

Co-encapsulation of anthocyanin and cinnamaldehyde in nanoparticle-filled carrageenan films: Fabrication, characterization, and active packaging applications

Nanoparticle-filled films were fabricated as smart and active packaging materials to monitor and preserve the freshness of foods (fish). Antisolvent precipitation was used to produce zein nanoparticles containing anthocyanin in their hydrophobic cores and cinnamaldehyde on their surfaces. These nanoparticles were then coated with a layer of carrageenan, resulting in the formation of anthocyanin-zein-cinnamaldehyde-carrageenan (AZCC) composite nanoparticles. Dynamic light scattering, electrophoresis, infrared spectroscopy, and scanning electron microscopy were used to characterize the properties of these composite nanoparticles. The particles formed were spherical and had relatively small diameters (563 nm) and high negative charges (−24.6 mV). The particles were mainly held together by hydrophobic, hydrogen bonding, and electrostatic interactions. The impact of nanoparticle concentration on the physical, structural, and functional properties of nano-composite films was investigated. Increasing the nanoparticle concentration led to changes in the opacity (17.42 A mm−1), microstructure, thermal stability (65.3%), and antioxidant activity of the films, as evaluated through DPPH (48.39%) and ABTS (92.77%) assays. The changes in color (SLab: 16.98%–85.98%) of the nanoparticle-loaded films was sensitive to pH and ammonia content, which meant that they could be used as quality sensors. The release of anthocyanins from the films depended on the polarity of the model food they were in contact with. Optimized films significantly extended the freshness of Mandarin fish, resulting in a 13.3% reduction in total volatile base-nitrogen levels, which highlights their potential for monitoring and controlling the freshness of packaged foods.

Edible Carrageenan Films Reinforced with Starch and Nanocellulose: Development and Characterization

Currently, from the sustainable development point of view, edible films are used as potential substitutes for plastics in food packaging, but their properties still have limitations and require further improvement. In this work, novel edible carrageenan films reinforced with starch granules and nanocellulose were developed and investigated for application as a bio-based food packaging system. The nanocellulose was used to improve film mechanical properties. Aloe vera gel was incorporated for antibacterial properties. Glycerol and sesame oil were added as plasticizers into the nanocomposite film to improve flexibility and moisture resistance. The interactions between charged polysaccharide functional groups were confirmed by FTIR spectroscopy. The migration of starch particles on the upper film surface resulting in increased surface roughness was demonstrated by scanning electron and atomic force microscopy methods. Thermogravimetric analysis showed that all films were stable up to 200 °C. The increase in nanocellulose content in films offered improved mechanical properties and surface hydrophilicity (confirmed by measurements of contact angle and mechanical properties). The film with a carrageenan/starch ratio of 1.5:1, 2.5 mL of nanocellulose and 0.5 mL of glycerol was chosen as the optimal. It demonstrated water vapor permeability of 6.4 × 10−10 g/(s m Pa), oil permeability of 2%, water solubility of 42%, and moisture absorption of 29%. This film is promising as a biodegradable edible food packaging material for fruits and vegetables to avoid plastic.

Effects of filler type and content on mechanical, thermal, and physical properties of carrageenan biocomposite films

This study investigates the influence of various fillers on the properties of carrageenan, a natural polymer derived from red seaweed. Despite its potential for enhanced biocomposite film development, carrageenan faces challenges related to strength. The incorporation of nanoclay into the carrageenan film resulted in a significant increase in film thickness from 0.026 to 0.068 mm. The UV light transmission value for the carrageenan film alone was measured at 30.9 %, whereas films containing 5 wt% of Tetraethyl orthosilicate (TEOS), 3-Aminopropyltriethoxysilane (APTES), and nanoclay exhibited reduced transmission values of 23 %, 18 %, and 1 %, respectively. Notably, the tensile strength of the unfilled carrageenan film was 38.4 MPa, which increased to 38.6, 57, and 60 MPa upon the addition of 3 wt% of nanoclay, APTES, and TEOS fillers, respectively. All fillers contributed to improved tensile strength, with TEOS demonstrating the highest enhancement. The optimal filler content was determined to be 3 wt%. Regarding thermal properties, films containing TEOS displayed higher thermal stability compared to those with APTES, while films incorporating nanoclay exhibited the lowest stability. Findings provide insights into the effects of different fillers on the mechanical, physical and thermal properties of carrageenan films, supporting the development of improved biocomposite materials suitable for application in food packaging.

Design of cationic surfactant reinforced carrageenan waterproof composite films and applied as water induced electricity generator

Carrageenan (CR) is a renewable polysaccharide material for packaging application due to its good film-forming property, but its use can be limited by the water solubility. In this research, CR hydrogels were modified by quaternary ammonium surfactants with different length of hydrocarbon tails (n, 8≦n≦16) by adsorption method and waterproof films were obtained after drying. The composition and charge interaction of composite films was confirmed by FTIR. Both thermogravimetric analysis and energy dispersive spectrometer indicated that the surfactant ions replaced K+ to form complexes with CR. The X-ray diffraction revealed the decreased amorphous nature of composite films compared to neat CR film. Water-related physical properties, such as water content, weight percentage change after contact with water, water vapor transmission, and water contact angle were intimately related to n. When 8≦n≦14, the waterproof properties were enhanced with the increase of n. Meanwhile, the waterproof property of composite film was ascertained by the no leakage result in the boiling water packaging experiment. When n = 16, sandwich structure was found in the sectional micromorphology images, and water bag structure formed after immersed into water. By comparing the mechanical properties of the composite films in different condition, we found that quaternary ammonium surfactants improved significantly the tensile strength in water and increased elongation at break in dry state. The composite films can be used as water induced voltage generator for their polyelectrolyte nature. Benefiting from the high stability of the composite films in water, their water-induced voltage generation process had good recyclability. Due to the antimicrobial activity of the quaternary ammonium salts and the waterproof property, composite films were more stable and degraded more slowly than neat CR film in nature environment.

Fabrication and Characterization of Semi-refined Carrageenan Films Incorporated with TiO2 Nanoparticles

In this study, a packaging film was developed using semi-refined carrageenan, incorporating varying concentrations of TiO2 nanoparticles. The aim of this study was to investigate the effect of TiO2 nanoparticles on the properties of the SRC-based film. The films were prepared through a casting method, and the resulting samples were characterized in terms of their functional, mechanical, and physical properties. The SRC film containing 1 wt% of TiO2 nanoparticles demonstrated the highest tensile strength. However, with the addition of TiO2 nanoparticles at any concentrations (1, 3, 5, and 7 wt%), the elongation at break of the SRC film decreased in comparison to the SRC film without TiO2 nanoparticles. Moreover, as the concentration of TiO2 nanoparticles increased from 1 to 7 wt%, the moisture content, and water solubility of the SRC films decreased. The FTIR spectra analysis provided valuable information on the interaction between SRC and TiO2 nanoparticles. The results suggest that incorporating TiO2 nanoparticles into semi-refined carrageenan films shows promise for developing packaging materials with improved mechanical strength and physical performance.

In Vivo evaluation of wound healing efficacy of κ -Carrageenan blended polyvinyl pyrrolidinone films for wound dressing applications

The requisite for novel potential dressings has emerged as a consequence of the incidences of injuries caused due to second intention and expensive treatment costs for the management of them. New generation dressings are capable to accelerate proliferation of cells and regeneration of tissue despite of the protective role to the wounds. Moreover, patient compliance persists as an integral factor with regard to the fact that they create no damage to the newly regenerated tissue on removal of the same. In the current study, we developed a κ- carrageenan film dressing, which is capable to accelerate tissue repair and aids its removal by external stimulus without disturbing the regenerated tissue. The dressing is capable to absorb excessexudate from the wound by maintaining hydrationto wound bed. The medical dressing was evaluated in male Wistar rats by generating a pocket wound. The dressings were implanted in incised pocket wound for 16 days. Histological analyses demonstrated that the dressing inserted on the injured area have showed minimal level of inflammatory events and generated denser connective tissue on comparison to wounds devoid of dressings. The injured site sheltered with the dressing demonstrated re-epithelization and angiogenesis to promote wound closure.

Fabrication and Characterization of Carrageenan/ZnO/Chitosan Composite Films.

In this study, a high-performance carrageenan/ZnO/chitosan composite film (FCA/ZnO/CS) was fabricated by the solution/dispersion casting method and layer-by-layer method. The first layer was nano-ZnO dispersed in carrageenan solution, and the second layer was chitosan dissolved in acetic acid. The morphology, chemical structure, surface wettability, barrier properties, mechanical properties, optical properties, and antibacterial activity of FCA/ZnO/CS were evaluated compared with a carrageenan film (FCA) and carrageenan/ZnO composite film (FCA/ZnO). This study revealed that the Zn element in FCA/ZnO/CS existed in the form of Zn2+ in FCA/ZnO/CS. There existed electrostatic interaction and hydrogen bonding between CA and CS. As a result, the mechanical strength and transparency of FCA/ZnO/CS were enhanced and the water vapor transmittance of FCA/ZnO/CS was decreased compared with that of FCA/ZnO. Furthermore, the addition of ZnO and CS greatly enhanced the antibacterial activity of Escherichia coli and also had a certain inhibitory effect on Staphylococcus aureus. FCA/ZnO/CS is expected to be a potential candidate material for food packaging, wound dressings, and various surface antimicrobial coatings.

Mechanical, Structural and Physical Properties of Carrageenan-Gum Arabic Biocomposite Film for Hard Capsule Application

The hard capsule market growth is mainly driven by the demand for gelatin capsules made of animals. Plant-based hard capsules, such as hydroxypropyl methylcellulose are currently in high demand for drug delivery, but the manufacturing process is costly with limited reagent supply. As an alternative, carrageenan from seaweed was used as a film-forming agent in this work. Carrageenan film possesses low mechanical strength, thus gum Arabic is incorporated to strengthen the biocomposite film. The films and hard capsules were produced with different concentrations of gum Arabic, ranging from 0 to 2.0 w/v%. The tensile strength and elongation at break were enhanced to 56.8 MPa and 23.7%, respectively. The highest capsule loop strength is 32.5 N, which was achieved at 1.2 w/v% of gum Arabic. All biocomposite films were kept at a moisture content of 13%, which is comparable to gelatin hard capsules. These results demonstrate that gum Arabic can strengthen the carrageenan biocomposite to be an alternative to gelatin hard capsules.

A high-efficient and stable artificial superoxide dismutase based on functionalized melanin nanoparticles from cuttlefish ink for food preservation

Natural superoxide dismutase (SOD), consisting of proteins and metal cofactors, is widely used in food preservation because of its good antioxidant activity. However, due to the poor stability of SOD enzyme, its activity was reduced in the process of moving into the film, resulting in limited application. Based on the structure of the active site of the natural enzyme, Cu2+ was used to functionalize the melanin nanoparticles (NMPs) in ink of cuttlefish, and an SOD-like nanozyme (Cu-NMPs) with high stability, high activity and strong free radical scavenging capacity was constructed. In order to apply the constructed simulated enzyme to food preservation, the simulated enzyme was embedded into carrageenan (Carr) films to prepare the composite film for food packaging. The results showed that when the concentration of Cu-NMPs was 10 μg/mL, the ·O2– rate could reach more than 80 %, the activity exceeded that of 60 U/mL natural SOD. In addition, the fresh-keeping test of cherry tomatoes showed that Carr/Cu-NMPs composite film extended the storage time of cherry tomatoes by more 3 days. Therefore, the present work showed that nanozymes with advanced catalytic capabilities can be constructed by metal ions and NMPs, thus successfully combined with food packaging for food preservation.

Investigation of a novel smart and active packaging materials: Nanoparticle-filled carrageenan-based composite films

In this study, curcumin, zein, epigallocatechin gallate (EGCG) and carrageenan were used to fabricate curcumin-zein-EGCG-carrageenan (CZEC) layer-by-layer nanoparticles. These nanoparticles were embedded within carrageenan films to form composite films with enhanced antioxidant activity and smart responses. Light scattering, micro-electrophoresis, FTIR, and SEM were used to characterize the size, charge, interactions, and morphology of CZEC nanoparticles. The optical, mechanical, morphological, spectroscopic, thermal, and other functional attributes of the films were evaluated. The CZEC nanoparticles were uniformly dispersed within the carrageenan matrices, and improved their UV barrier (2.4–11.1 A mm−1), mechanical (7.09 %–9.35 %), and thermal resistance properties. The films exhibited a color change, from yellow to red, in response to an increase in pH (2.0–12.0) or ammonia concentration (8.0 mM). The films also displayed relatively high DPPH (79.46 %) and ABTS (73.34 %) free radical scavenging activities. Finally, the composite film exhibited the ability of monitoring and extending the freshness of packaged fish.