Presence Of Caffeic Acid Research Articles

Reduced graphene oxide foams modified with caffeic acid for water decontamination: Capture and safe storage of Hg2+

Graphene-based materials are attractive adsorbents for water decontamination. In this work, we have produced eco-friendly reduced graphene oxide (rGO)-based sorbents by the hydrothermal reduction of graphene oxide (GO) in presence of caffeic acid (CA) and further modification with chitosan (CA_CS). Scanning electron microscopy observations show porous macrostructures that turn more compact after CA or CA_CS modification. The specific surface area achieves a maximum value of 293 m2 g−1 for the pristine rGO foam. The macropores are mainly distributed in a range between 1–170 µm. The Hg2+ removal efficiency of the rGO-based foams was investigated across several different parameters. The foam modified with caffeic acid exhibited the most promising performance, demonstrating the highest removal efficiency at pH 4–6, with a maximum sorption capacity of 2.79 mg/g as determined by the Sips equation. Kinetic analysis indicates that intraparticle diffusion and the sorption itself are the rate-limiting steps. The notable sorption efficiency, the low desorption rate, and the applicability in real complex water matrices, including tap water, position rGO_CA as a viable material for efficiently capturing Hg(II) from large volumes of water and securely storing it in a small solid volume.

Effect of polyphenolic dendrimers on biological and artificial lipid membranes

The use of dendrimers as nanovectors for nucleic acids or drugs requires the understanding of their interaction with biological membranes. This study investigates the impact of 1st generation polyphenolic carbosilane dendrimers on biological and model lipid membranes using several biophysical methods. While the increase in the z-average size of DMPC/DPPG liposomes correlated with the number of caffeic acid residues included in the dendrimer structure, dendrimers that contained polyethylene glycol chains generated lower zeta potential when interacting with a liposomal membrane. The increase in the fluorescence anisotropy of DPH and TMA-DPH probes incorporated into erythrocyte membranes predicted the ability of dendrimers to affect membrane fluidity in the hydrophobic interior and hydrophilic/polar region of a lipid bilayer. The presence of caffeic acid and polyethylene glycol chains in the dendrimer structure affected the thermodynamical properties of the membrane lipid matrix.

Polyphenol Contents, Antibacterial and Antioxidant Effects of Four Palestinian Honey Samples, and their Anticancer Effects on Human Breast Cancer Cells

The phenolic compounds of four Palestinian honey samples (PH1-PH4) and their antibacterial effects as well as their cytotoxic, cytostatic, and antimigration effects in human breast cancer cell line (MDA) were evaluated here. HPLC analysis of PH2 (Cornflower), PH3 (Milk thistle), and PH4 (Ziziphus) revealed 15 phenolic compounds, namely, caffeic acid, carvacrol, chrysin, ellagic acid, galangin, gallic acid, kaempferol, p-coumaric acid, pinobanksin, pinocembrin, protocatechuic acid, quercetin, rutin, salicylic acid, and silydamin. The minimum inhibitory concentration (MIC) method applied to Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). A strong positive correlation was detected between antimicrobial activity (E. coli) and p-coumaric acid, quercetin, and silydamin. IC50 values for DPPH neutralization varied from 0.19 w/w% to 10 w/w%. The potential anticancer properties of the honey samples were evaluated on MDA cells. Samples PH2 and PH3 demonstrated cytostatic activity, reducing cell viability by about 43% at non-toxic concentration of 4 mg/mL. The cytostatic effects were strongly correlated with the presence of caffeic acid, chrysin, protocatechuic acid, rutin, and salicylic acid (p < 0.01). Moreover, the cell migration rate was significantly reduced (by up to 85%) with PH2 and PH3 compared to untreated cells (p < 0.05). A strong positive correlation was observed between the cytostatic effects of the concentration of carvacrol and Pinocembrin (p < 0.01). Our findings validate honey’s antibacterial properties and suggest its anticancer benefits may stem from cytostatic and antimigration effects.

Kamchatka Berry (Lonicera caerulea L.) Pomace Bioferment as an Innovative Cosmetic Raw Material

Kamchatka berries (Lonicera caerulea L.) are known for their high content of phenolic compounds or vitamins, which is reflected in their antibacterial, detoxifying and anti-inflammatory properties. They are used in the production of jams, juices, wines and as natural dye. A bioferment was prepared from the pomace of the Kamchatka berry varieties Aurora and Indigo Gem and the strains Saccharomyces cerevisiae and Lacticaseibacillus paracasei, which was used to prepare a cosmetic preparation with a concentration of 5% in accordance with the guidelines of the COSMOS certification body. We conducted physico-chemical and organoleptic analyses and bioactive profile characterisation (UHPLC-DAD and UHPLC-ESI-MS/MS). The results showed that the presence of caffeic acid (4.47 ± 0.07 mg/100 g) was detected after fermentation of Kamchatka berry pomace. In addition, vitamin C content increased by 141% after fermentation. The results of stability tests showed that in the process of physico-chemical analysis of the cosmetic preparation with bioferment of Kamchatka berry pomace, the pH should oscillate in the range of 4.38–4.76 ± 0.01. Stability tests showed that the cosmetic should be protected from high temperatures and UV radiation and proved that the product is stable under changing conditions, resulting in lower transport and storage costs.

A COMPARATIVE STUDY OF THE COMPONENT COMPOSITION OF THE HERBS OF SOME SPECIES OF THE GENUS ACHILLEA L.

The article presents the results of a comparative study of the component composition of herbs of some species of the genus Achillea L. growing in the Samara region - common yarrow (Achillea millefolium L.), cartilaginous yarrow (Achillea cartilaginea (Ledeb. ex Rchb.) and noble yarrow (Achillea nobilis (L.). Spectrophotometry and high performance liquid chromatography were used as methods of investigation.
 As a result of comparative spectrophotometric analysis of water-alcoholic extracts of common yarrow herbs, yarrow cartilaginous herbs and noble yarrow herbs revealed that the absorption curve of their UV spectra is due mainly to hydroxycinnamic alcohols, in particular chlorogenic and caffeic acids (290 sh. and 330 nm). When aluminum (III) chloride solution was added to the water-alcoholic extracts of yarrow herb from the studied species, a bathochromic shift of the long-wave band at 400 nm was observed due to the flavonoids.
 The content of total flavonoids in the plant raw material is: common yarrow - 0.68±0.01%, cartilaginous yarrow - 0.65±0.02%, noble yarrow - 0.69±0.02%.
 Chlorogenic acid, cynaroside, cosmosiin, apigenin and luteolin were identified in water-alcoholic extracts from the above described species using HPLC method. In addition, the presence of caffeic acid was detected in the water-alcoholic extracts of noble yarrow herbs.
 The content of cosmosiin in the plant raw material is: common yarrow - 0.61±0.01%, cartilaginous yarrow - 0.56±0.02%, noble yarrow - 0.62±0.02%.
 The results of the study can be used in the development of regulatory documentation for medicinal plant material "Yarrow herb" for inclusion in the State Pharmacopoeia of the Russian Federation.

A novel inhibitor study on peroxidase activity in the presence of caffeic acid: An in vitro and in silico mechanism research

The present study aims to investigate the substrate specificity of peroxidase (POD), an enzyme held responsible for enzymatic browning, in the presence of caffeic acid, guaiacol, chlorogenic acid and catechol. The use of in silico studies provided additional support for the identification of optimal substrate candidates. Considering the Vmax/Km (EU/mL.min.mM) values obtained, caffeic acid was found to have the highest value (11.85) and to be the best substrate for POD. The inhibitory mechanism of ascorbic acid, citric acid and salicylic acid on the activity of POD was studied in the presence of caffeic acid. Competitive inhibition was observed in the kinetic studies involving ascorbic acid and salicylic acid, whereas non-competitive inhibition was observed in the case of citric acid. The lowest calculated dissociation constant (Ki) of the enzyme-inhibitor complex was that of salicylic acid (0.044 mM). Furthermore, the in vitro Ki results for the inhibitors used were consistent with the in silico studies. The mechanism of POD inhibition by salicylic acid in the presence of a caffeic acid substrate was explained by molecular docking studies. The POD inhibition has been attributed to a decrease in substrate oxidation as a result of ferric (H2O2) interactions with salicylic acid, in addition to a decrease in enzyme stabilization as a result of Pi-lone pair interactions.

Conformational dynamics of trypsin in the presence of caffeic acid: a spectroscopic and computational investigation

Caffeic acid is one of the widely distributed phenolic compounds in nature and can be found in planet products. On the other hand, trypsin is a vital digestive enzyme in the intestine that plays an essential role in the immune response, blood coagulation, apoptosis and protein maturation like protein digestion. Several studies have revealed the inhibitory effects of the phenolic compound on the digestive enzyme. The present study reports functional and conformational alteration of trypsin after caffeic acid addition using multiple experimental and computational techniques for the first time. The intrinsic fluorescence of trypsin is quenched in the presence of caffeic acid via a static mechanism. The percent of secondary structures (α-helix and β-sheet) of trypsin alter after caffeic acid addition. In the kinetic study, a reduction in the trypsin function is obtained with a lower V max and K cat upon interaction with caffeic acid. The thermal study reveals an unstable structure of trypsin upon complex formation with this phenolic compound. Also, the binding sites and conformational changes of trypsin are elucidated through molecular docking and molecular dynamic simulation. Communicated by Ramaswamy H. Sarma

Structural characteristics, emulsifying and foaming properties of laccase-crosslinked bovine α-lactalbumin mediated by caffeic acid

In this study, laccase (LA) was chosen as a commonly employed enzyme to research the impacts of enzyme-catalyzed crosslinking (polymerization) on the structural, emulsifying and foaming properties of bovine α-lactalbumin (α-LA) in the presence of caffeic acid (CA). High pressure size exclusion chromatography (HPSEC) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated the formation of α-LA aggregates (dimers, trimers, and polymers) by LA-induced crosslinking with CA, consistent with the particle size distribution results. LA-induced treatment exhibited pronounced influences on the conformation, secondary and tertiary structure of α-LA, as confirmed by circular dichroism (CD), and fluorescence spectroscopy. For α-LA-LA-CA, α-helix content was progressively decreased from 33.3% (0 h) to 24.7% (24 h). LA-catalyzed crosslinking resulted in the exposure of interior hydrophobic groups, and the increase of zeta-potential values of α-LA. Apparent viscosity of α-LA was considerably enhanced by LA-induced crosslinking with CA. The emulsifying activity and stability of α-LA can be considerably improved with LA-catalyzed crosslinking with CA except at 24 h incubation time. Compared with controls, LA-catalyzed polymerizations of α-LA molecules with CA led to the increase of foaming activity and stability regardless of incubation time. After 24 h incubation, the foaming stability (FS) of α-LA was 81.0%, whereas the value was 88.0% for α-LA-LA-CA. This research indicates that LA-induced modification possesses great potential in ameliorating the emulsifying and foaming capacities of α-LA. • Laccase led to the significant polymerization of α-lactalbumin with caffeic acid. • Laccase-catalyzed crosslinking led to the changes of the structure of α-lactalbumin. • Laccase-catalyzed crosslinking increased the emulsifying properties of α-lactalbumin. • Laccase-catalyzed crosslinking increased the foaming activity of α-lactalbumin. • Laccase-crosslinked α-lactalbumin aggregates showed potential as functional ingredients.

Reactivities of Hydroxycinnamic Acid Derivatives Involving Caffeic Acid toward Electrogenerated Superoxide in N,N-Dimethylformamide

Reactivity of (2E)-3-(3,4-dihydroxyphenyl)prop-2-enoic acid (caffeic acid), classified as a hydroxycinnamic acid (HCA) derivative, toward electrogenerated superoxide radical anion (O2•−) was investigated through cyclic voltammetry, in situ electrolytic electron spin resonance spectrometry, and in situ electrolytic ultraviolet–visible spectrometry in N,N-dimethylformamide (DMF), aided by density functional theory (DFT) calculations. The quasi-reversible redox of dioxygen/O2•− is modified in the presence of caffeic acid, suggesting that O2•− is scavenged by caffeic acid through proton-coupled electron transfer. The reactivities of caffeic acid toward O2•− are mediated by the ortho-diphenol (catechol) moiety rather than by the acryloyl group, as experimentally confirmed in comparative analyses with other HCAs. The electrochemical and DFT results in DMF suggested that a concerted two-proton-coupled electron transfer mechanism proceeds via the catechol moiety. This mechanism embodies the superior kinetics of O2•− scavenging by caffeic acid.

Binding Studies of Caffeic and p-Coumaric Acid with α-Amylase: Multispectroscopic and Computational Approaches Deciphering the Effect on Advanced Glycation End Products (AGEs).

Alpha-amylase (α-amylase) is a key player in the management of diabetes and its related complications. This study was intended to have an insight into the binding of caffeic acid and coumaric acid with α-amylase and analyze the effect of these compounds on the formation of advanced glycation end-products (AGEs). Fluorescence quenching studies suggested that both the compounds showed an appreciable binding affinity towards α-amylase. The evaluation of thermodynamic parameters (ΔH and ΔS) suggested that the α-amylase-caffeic/coumaric acid complex formation is driven by van der Waals force and hydrogen bonding, and thus complexation process is seemingly specific. Moreover, glycation and oxidation studies were also performed to explore the multitarget to manage diabetes complications. Caffeic and coumaric acid both inhibited fructosamine content and AGE fluorescence, suggesting their role in the inhibition of early and advanced glycation end-products (AGEs). However, the glycation inhibitory potential of caffeic acid was more in comparison to p-coumaric acid. This high antiglycative potential can be attributed to its additional –OH group and high antioxidant activity. There was a significant recovery of 84.5% in free thiol groups in the presence of caffeic acid, while coumaric attenuated the slow recovery of 29.4% of thiol groups. In vitro studies were further entrenched by in silico studies. Molecular docking studies revealed that caffeic acid formed six hydrogen bonds (Trp 59, Gln 63, Arg 195, Arg 195, Asp 197 and Asp 197) while coumaric acid formed four H-bonds with Trp 59, Gln 63, Arg 195 and Asp 300. Our studies highlighted the role of hydrogen bonding, and the ligands such as caffeic or coumaric acid could be exploited to design antidiabetic drugs.

UPLC-MS profiling, antimicrobial and antipyretic activities of Deverra scoparia Coss. & Dur. extracts

Deverra scoparia Coss. & Dur. a traditional medicinal plant which present important biological properties, due to the presence of secondary metabolites. The aim of this study was to evaluate antimicrobial and antipyretic activities of infusion and ethereal extracts. The antimicrobial activity was tested using disk diffusion method against bacterial and fungal strains. While the antipyretic activity was evaluated by yeast induced pyrexia in rats at doses of 250, 500 and 1000mg/kg for each extract. Results showed a large antimicrobial activity range by the extracts; the infusion extract has an increased inhibition from 45± 0.004 mm and 52± 0.003 mm with bactericidal effect against all bacterial strains tested. The ethereal extract presented a strong antimicrobial activity about 32± 0.001 mm and 48± 0.001 mm with bacteriostatic effect with a value equal to 8 for all strains. The administration of infusion and ethereal extracts produced significant (P <0.05) and dose-dependent decrease in rectal temperature. The UPLC-MS analysis indicated the presence of caffeic acid and quercetin with a quantity of 16.4 and 1224.6 µg/g sample respectively. These findings indicate that Deverra scoparia Coss. & Dur. aerial part contains compounds with antimicrobial and antipyretic properties, thus justifying its use in traditional medicine.

Chitosan-based films enriched by caffeic acid with poly(ethylene glycol) – A physicochemical and antibacterial properties evaluation

In this work, chitosan/caffeic acid mixtures in the weight ratios of 80/20 and 50/50 were used to obtain thin films enriched with poly(ethylene glycol). It was hypothesized that the presence of caffeic acid indicates the antibacterial properties of the materials (i) and that poly(ethylene glycol) acts as a films modifier (ii). The results showed that by poly(ethylene glycol) addition, the surface free energy as well as mechanical and thermal properties were improved. Moreover, water vapor permeability was observed. All the tested materials showed antioxidant properties in the range of approximately 90%. They also showed antibacterial effectiveness against both Gram-positive and Gram-negative bacteria. The most appropriate material for the application as packaging was composed of chitosan and caffeic acid mixed in a 50/50 weight ratio with 20% PEG addition.

Phytochemical analysis of herbal teas containing caffeic acid

Objectives. The present analysis was to investigate the content of caffeic acid derivatives, antioxidant activity, and the presence of caffeic acid in alcoholic extracts obtained from 16 simple teas from the following medicinal plants: Vaccinium mуrtilluѕ, Camеllia ѕinеnѕiѕ, Coffea arabica, Mеlіssa οffіcіnalіs, Οcіmum basіlіcum, Rοsmarіnus οffіcіnalіs, Salvіa οffіcіnalіs, Ηyssοрus οffіcіnalіs, Αrtеmіsіa absіntһіum, Cynara scοlymus, Calendula officinalis, Cοrіandrum satіvum, Fοеnіculum vulgarе, Carum carvі, Rοsa canіna, Crataеgus mοnοgyna. Materials and methods. The presence of caffeic acid was evaluated using the thin layer chromatography method (TLC). The total content of phenylpropanoids from the medicinal herbs alcoholic extracts was determined using a spectrophotometric method. Outcomes. Results were in the range of 0.046-2.426% caffeic acid derivatives (CAE%). The antioxidant properties were measured using the DPPH radical scavenging mechanism. The results were found to be in the range of 63.93% and 0.38% inhibition level (I%). The greatest antioxidant activity was measured for Camellia sinensis (I = 45.54%), followed by Vaccinium myrtillus (I = 50.289%). Conclusions. In this paper it was shown that these medicinal plants are rich in caffeic acid derivatives with antioxidant action capitalized in the prevention of serious diseases.

Joining Caffeic Acid and Hydrothermal Treatment to Produce Environmentally Benign Highly Reduced Graphene Oxide.

Reduced graphene oxide (rGO) is a promising graphene-based material, with transversal applicability to a wide range of technological fields. Nevertheless, the common use of efficient—but hazardous to environment and toxic—reducing agents prevents its application in biological and other fields. Consequently, the development of green reducing strategies is a requirement to overcome this issue. Herein, a green, simple, and cost-effective one-step reduction methodology is presented. Graphene oxide (GO) was hydrothermally reduced in the presence of caffeic acid (CA), a natural occurring phenolic compound. The improvement of the hydrothermal reduction through the presence of CA is confirmed by XRD, Raman, XPS and TGA analysis. Moreover, CA polymerizes under hydrothermal conditions with the formation of spherical and non-spherical carbon particles, which can be useful for further rGO functionalization. FTIR and XPS confirm the oxygen removal in the reduced samples. The high-resolution scanning transmission electron microscopy (HRSTEM) images also support the reduction, showing rGO samples with an ordered graphitic layered structure. The promising rGO synthesized by this eco-friendly methodology can be explored for many applications.

Antioxidant Packaging Films Based on Ethylene Vinyl Alcohol Copolymer (EVOH) and Caffeic Acid.

The main objective of this research activity was to design and realize active films with tunable food functional properties. In detail, caffeic acid (CA), a polyphenol with high antioxidant effect, was used as active ingredient in poly (vinyl alcohol-co-ethylene) (EVOH) films at 5 wt.% and 15 wt.% and successfully realized by means of the solvent casting process. Optical, morphological, thermal and mechanical studies were considered to define the effect of the presence of the CA component on the structural properties of the matrix. In addition, moisture content and antioxidant activity were evaluated, to have clear information on the CA effect in terms of functional characteristics of realized food packaging systems. Results from tensile tests showed increased values for strength and deformation at break in EVOH_CA based films. Results from colorimetric and transparency analysis underlined that the presence of caffeic acid in EVOH copolymer induces some alterations, whereas the addition of the active ingredient determined a positive radical scavenging activity of the formulations, confirming the possibility of practically using these polymeric systems in the food packaging sector.

The Presence of Caffeic Acid in Cerebrospinal Fluid: Evidence That Dietary Polyphenols Can Cross the Blood-Brain Barrier in Humans

Epidemiological data indicate that a diet rich in plant polyphenols has a positive effect on brain functions, improving memory and cognition in humans. Direct activity of ingested phenolics on brain neurons may be one of plausible mechanisms explaining these data. This also suggests that some phenolics can cross the blood-brain barrier and be present in the brain or cerebrospinal fluid. We measured 12 phenolics (a combination of the solid-phase extraction technique with high-performance liquid chromatography) in cerebrospinal fluid and matched plasma samples from 28 patients undergoing diagnostic lumbar puncture due to neurological disorders. Homovanillic acid, 3-hydroxyphenyl acetic acid and caffeic acid were detectable in cerebrospinal fluid reaching concentrations (median; interquartile range) 0.18; 0.14 µmol/L, 4.35; 7.36 µmol/L and 0.02; 0.01 µmol/L, respectively. Plasma concentrations of caffeic acid (0.03; 0.01 µmol/L) did not correlate with those in cerebrospinal fluid (ρ = −0.109, p = 0.58). Because food (fruits and vegetables) is the only source of caffeic acid in human body fluids, our results indicate that the same dietary phenolics can cross blood-brain barrier in humans, and that transportation of caffeic acid through this barrier is not the result of simple or facilitated diffusion.

PHYTOCHEMICAL EVALUATION OF ARTOCARPUS HIRSUTUS LAM. FRUIT EXTRACT: A POTENTIAL WILD ENDEMIC PLANT

Objective: The present study includes the qualitative and quantitative estimation of phytochemical constituents and HPTLC (High-performance thin layer chromatography) analysis of phenolic acids in the fruit extract of Artocarpus hirsutus.
 Methods: Qualitative and quantitative analysis of Artocarpus hirsutus methanol fruit extract using standard methods. HPTLC analysis was performed by the CAMAG HPTLC system (Switzerland) for gallic acid, caffeic acid and ferulic acid determination.
 Results: The Preliminary phytochemical analysis revealed the presence of phytoconstituents such as flavonoids, phenols, tannins, steroids, glycosides, alkaloids, carbohydrate and protein. The methanol fruit extract has high carbohydrate content (267±0.02 mg/g FW). And good amount of protein, phenol, flavanoid were also found. The results of mineral studies shows that elements such as potassium (1.601%) and nitrogen (1.4%) were present in higher quantity. The result showed the presence of caffeic acid within peak 7 with an Rf (Retension factor) value 0.49, ferulic acid within peak 8 with an Rf value 0.60, and gallic acid within peak 5 with an Rf value 0.25.
 Conclusion: The results indicated that the Artocarpus hirsutus fruit contains an appreciable amount of bioactive compounds.

Electrochemical Determination of the Effect of Caffeic Acid onto the Interaction between Idarubicin and DNA by Single‐use Disposable Electrodes

AbstractNow it is well known, antioxidant may affect the interaction of anticancer drugs and DNA. This study aims to investigate the interaction between Idarubicin and DNA and the effect of caffeic acid on this interaction. Disposable, inexpensive, easy handle electrodes were used in this study to investigate the interaction of idarubicin and DNA electrochemically. Idarubicin (IDR) is an anthracyline antitumor antibiotic, which used against one or more types of leukemia.Electrochemical behaviour of IDR was investigated by using cyclic voltammetry. The interaction between anticancer drug, IDR and calf thymus double‐stranded DNA (ctdsDNA) was investigated by using differential pulse voltammetry (DPV) technique in the absence and presence of caffeic acid.

Interaction of Caffeic Acid with SDS Micellar Aggregates.

Micellar systems consisting of a surfactant and an additive such as an organic salt or an acid usually self-organize as a series of worm-like micelles that ultimately form a micellar network. The nature of the additive influences micellar structure and properties such as aggregate lifetime. For ionic surfactants such as sodium dodecyl sulfate (SDS), CMC decreases with increasing temperature to a minimum in the low-temperature region beyond which it exhibits the opposite trend. The presence of additives in a surfactant micellar system also modifies monomer interactions in aggregates, thereby altering CMC and conductance. Because the standard deviation of β was always lower than 10%, its slight decrease with increasing temperature was not significant. However, the absolute value of Gibbs free enthalpy, a thermodynamic potential that can be used to calculate the maximum of reversible work, increased with increasing temperature and caffeic acid concentration. Micellization in the presence of caffeic acid was an endothermic process, which was entropically controlled. The enthalpy and enthropy positive values resulted from melting of “icebergs” or “flickering clusters” around the surfactant, leading to increased packing of hydrocarbon chains within the micellar core in a non-random manner. This can be possibly explained by caffeic acid governing the 3D matrix structure of water around the micellar aggregates. The fact that both enthalpy and entropy were positive testifies to the importance of hydrophobic interactions as a major driving force for micellization. Micellar systems allow the service life of some products to be extended without the need to increase the amounts of post-harvest storage preservatives used. If a surfactant is not an allowed ingredient or food additive, carefully washing it off before the product is consumed can avoid any associated risks. In this work, we examined the influence of temperature and SDS concentration on the properties of SDS–caffeic acid micellar systems. Micellar properties can be modified with various additives to develop new uses for micelles. This allows smaller amounts of additives to be used without detracting from their benefits.

Eco-friendly preparation of electrically conductive chitosan - reduced graphene oxide flexible bionanocomposites for food packaging and biological applications

Electrically conductive materials have been highlighted in the biomedical and food packaging areas. Conventional electrically conductive polymers have limited biodegradability and biocompatibility and should be replaced by suitable biomaterials. Herein, electrically conductive bionanocomposites of chitosan and reduced graphene oxide were produced by a green methodology. The reduced graphene oxide was hydrothermally reduced in the presence of caffeic acid and was dispersed into chitosan. The final bionanocomposites achieved an electrical conductivity of 0.7 S/m in-plane and 2.1 × 10−5 S/m through-plane. The reduced graphene oxide promoted a great enhancement of antioxidant activity and a mechanical reinforcement of chitosan matrix, increasing the tensile strength and decreasing the water solubility. The electrical conductivity, mechanical properties and antioxidant activity of the bionanocomposites can be tuned according to the filler content. These active bionanocomposites, prepared using a green methodology, revealed good electrical and mechanical properties, which make them promising materials for food packaging and biological applications.