Release Of Cinnamaldehyde Research Articles

Antimicrobial film based on polylactic acid and carbon nanotube for controlled cinnamaldehyde release

A controlled-release antibacterial active food packaging film was prepared from polylactic acid (PLA), poly (ε-caprolactone) (PCL), carbon nanotubes (CNTs), and cinnamaldehyde (CIN) by solvent evaporation method. The properties and antibacterial activities of CIN loaded PLA/CNTs/CIN film was characterized. Furthermore, the release behavior of CIN from PLA-based antibacterial film was quantified. The introduction of CNT and CIN would not significantly affect the barrier properties of PLA-based film, but would significantly enhance the UV resistance of the film. The co-action of CNTs and CIN led to the decrease of the glass transition temperature of the film and enhanced the elongation at break of the film. The PLA/CNTs/CIN film could continuously release CIN for 21 days in ambient storage, and antibacterial effect of the film on Staphylococcus aureus and Escherichia coli could be maintained for 21 days, during which the antibacterial effect gradually reduced and maintained for 7 days longer than the film without CNTs. According to the research results, The PLA/CNTs/CIN composites have great application potential in antibacterial active food packaging film.

Longer mosquito control using a sodium alginate–chitosan nanocarrier for cinnamaldehyde in larvicide formulations

The proliferation of mosquito-borne diseases is a major health concern worldwide. An effective strategy to prevent the transmission of mosquito-borne diseases is using larvae control. Cinnamaldehyde, a substance from the cinnamon tree, is widely used in larvicide formulations, yet applications are limited due to the poor water solubility of cinnamaldehyde. Therefore, we prepared a sodium alginate–chitosan nanocomposite as a nanocarrier of cinnamaldehyde, and we tested the effect of this encapsulated cinnamaldehyde on Aedes aegypti larvae. The nanocomposites/cinnamaldehyde formulations were characterised by Fourier transform infrared spectroscopy and nuclear magnetic resonance, which evidenced encapsulation. A ratio of 150:1 w/w nanocomposite/cinnamaldehyde induced the highest encapsulation efficiency of 95.25%, a loading capacity of 81.42%. This extended the cinnamaldehyde release by 28 h and controlled mosquito larvae.

Effect of functionalized silica nanoparticles on the mass transfer process in active PLA nanocomposite films obtained by supercritical impregnation for sustainable food packaging

Nanocomposite films based on PLA with 1.0 % w/w silica nanoparticles (NP) and surface-functionalized silica nanoparticles with lactic acid (NP-LA), respectively, were obtained by extrusion process. Subsequently, cinnamaldehyde (ci) was incorporated through supercritical impregnation in the films at a pressure of 12 MPa, 40 °C temperature and 1.0 MPa min−1 depressurization rate. The developed materials were characterized on their thermal-mechanical, structural and barrier properties. Simultaneously, a phenomenological mass transfer was used to describe the release of cinnamaldehyde from the bionanocomposite in an aqueous food simulant (ethanol 10 % v/v solution). A 44 % decrease in oxygen permeability concerning the material without nanoparticles was checked as well as the plasticizing effect of cinnamaldehyde. Regarding the release of the active compound, the incorporation of functionalized nanoparticles NP-LA decreased the diffusion coefficient from 3.5·10−14 to 0.9·10−14 (m2/s), obtaining the filling effect of the silica nanoparticles, delaying the active compound release.

Microencapsulation optimization of cinnamon essential oil in the matrices of gum Arabic, maltodextrin, and inulin by spray‐drying using mixture design

AbstractA simple centroid mixture design was used to optimize the ratio of the wall materials for the production of the cinnamon essential oil microcapsules by spray‐drying. Gum Arabic (GA), maltodextrin (MD), and inulin (IN) were used as wall materials. Four parameters were evaluated as responses, containing the surface cinnamaldehyde, the encapsulation efficiency of cinnamaldehyde, the release of cinnamaldehyde (RC), and powder recovery (PR). The cinnamon essential oil was purely formed of cinnamaldehyde (about 99.96%), based on results obtained from the gas chromatography device. The multiple response optimization analysis showed that the optimum compound concentration for walls will be 27.87% wt/wt GA, 27.59% MD, and 44.53% IN. It can be concluded that the optimal compound was suitable to the RC in the mouth medium due to its Tg. The microscopy images of the optimal compound showed a smooth surface, spherical, and slight crack in the microparticles. Furthermore, the optimum compound improved the stability of antioxidant activity compared to the pure oil during 30 days storage. It was observed that the Fickian diffusion was the main mechanism involved in the release process of the microencapsulated cinnamon essential oil in the mouth medium.Practical ApplicationsIn the food industry, the major aromatic components utilized are essential oils, synthetic flavoring agents, and natural oleoresin. The key constituent of cinnamon essential oil is cinnamaldehyde. Cinnamaldehyde is often used as a flavoring agent, but its importance as a natural antimicrobial, antioxidant, and antiseptic agent has recently been established. The knowledge of encapsulation techniques allows the control of the bioactive components, the release time, and the dosage of essential oil in the structure of the food. Moreover, the encapsulation of essential oils helps to reduce the oxidation of process by exposure to the environment, increasing the shelf life and the solubility. The results of this work lead to the use of flavored components for implementation in similar products, thereby improving their flavor.

The Intestinal Cinnamaldehyde Release and Antioxidative Capacity of Broiler Chickens Fed Diets Supplemented with Coated Oleum Cinnamomi

SUMMARY Oleum cinnamomi (OCM, cinnamon oil), which is produced by aromatic cinnamon plants, is increasingly used as a feed additive to animal diets. OCM is a natural product rich in polyphenolic compounds that exhibit strong antioxidative property. However, the direct addition of OCM to the feed is questionable due to several limiting physical–chemical factors such as the high hydrophobicity, volatility, odor, fast decomposition, and poor availability in the lower gastrointestinal tract of animals. Therefore, the coated form of OCM (cOCM) is one of the ways to solve these concerns. We have demonstrated that dietary cOCM supplementation did not improve the growth performance of broiler chickens, but it showed beneficial effects on immunity and intestinal integrity. In the current study, we further investigated the intestinal cinnamaldehyde release and antioxidative capacity of chickens fed cOCM-supplemented diets. As cinnamaldehyde is a major constituent of OCM, we evaluated the release of cOCM in the intestine of birds by determining the contents of cinnamaldehyde in the digesta of small intestine and cecum. The increased availability of OCM in the lower intestine supplied a foundation for exerting its antioxidative effects. The activities of antioxidative enzymes were increased and superoxide levels were decreased in the plasma and intestinal mucosa of birds fed cOCM-supplemented diets. The improvement of antioxidative capacity was achieved by modulating the gene expression of nuclear factor erythroid 2-related factor 2 and downstream antioxidative enzymes.

Regulating intracellular ROS signal by a dual pH/reducing-responsive nanogels system promotes tumor cell apoptosis.

Purpose: The levels of reactive oxygen species (ROS) in tumor cells are much higher than that in normal cells, and rise rapidly under the influence of exogenous or endogenous inducing factors, eventually leading to the apoptosis of tumor cells. Therefore, this study prepared a dual pH/reducing-responsive poly (N-isopropylacrylamide-co-Cinnamaldehyde-co-D-α-tocopheryl polyethylene glycol 1000 succinate, PssNCT) nanogels, which employed two exogenous ROS inducers, cinnamaldehyde (CA) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), to selectively induce apoptosis by regulating ROS levels in tumor cells.Methods: The PssNCT nanogels were prepared by the free radical precipitation polymerization under the crosslink between pH-sensitive hydrazone and reducing-sensitive disulfide bonds, followed by the physicochemical and morphological characteristics investigations. Plasma stability, dual pH/reducing responsive degradation and in vitro release were also assessed. In cell experiments, cytotoxicity in different cells were first detected. The intracellular ROS levels and mitochondrial functions of tumor cells were then evaluated. Moreover, the apoptosis and western-blot assays were employed to verify the association between ROS levels elevation and apoptosis in tumor cells.Results: The nanogels exhibited a round-like hollow structure with the diameter smaller than 200nm. The nanogels were stable in plasma, while showed rapid degradation in acidic and reducing environments, thus achieving significant release of CA and TPGS in these media. Furthermore, the sufficient amplification of ROS signals was induced by the synergistically function of CA and TPGS on mitochondria, which resulted in the opening of the mitochondrial apoptotic pathway and enhanced cytotoxicity on MCF-7 cells. However, nanogels barely affected L929 cells owing to their lower intracellular ROS basal levels.Conclusion: The specific ROS regulation method achieved by these nanogels could be explored to selectively kill tumor cells according to the difference of ROS signals in different kinds of cells.

Encapsulation of Cinnamaldehyde using Chitosan: Stability, Mucoadhesive and Cinnamaldehyde Release

Cinnamaldehyde contained in cinnamon oil is useful as an antidiabetic; however, it has very low oral bioavailability. One effort to increase oral bioavailability of cinnamaldehyde is by encapsulation using chitosan. Encapsulation of cinnamaldehyde in chitosan has been successfully made in the form of powder. The aim of this study was to obtain data of stability, mucoadhesive and cinnamaldehyde release from cinnamaldehyde encapsulated chitosan. Stability tests were performed physically and chemically. Mucoadhesive tests were carried out in vitro in two steps, which were granule fabrication and then mucoadhesive test. The results showed that the levels of cinnamaldehyde decreased within 4 weeks, from the first to the fourth week 100%; 99.87%; 98.85%; 97.33%, respectively. Cinnamaldehyde powder did not change significantly in specific gravity, pH, centrifugation and organoleptic after a month. The release precentage of cinnamaldehyde in acidic media pH 1.2 for 180 minutes was 83.4%, whereas in alkaline media pH 7.4 for 360 minutes was 61%. The cinnamaldehyde encapsulated chitosan nanoparticle powder performed mucoadhesive capacity in the gastric mucosa and in the intestinal mucosa of 91.5% and 84.61%, respectively.

Gelatin and pectin complex coacervates as carriers for cinnamaldehyde: Effect of pectin esterification degree on coacervate formation, and enhanced thermal stability

This study developed the multinuclear microcapsules by the complex coacervation between gelatin (G) and high methyl pectin (HMP), low methyl pectin (LMP) as a delivery system for cinnamaldehyde. The parameters affecting the formation of such carriers were investigated by dynamic light scattering and microscopic techniques. Fluorescence analysis and Fourier-transform infrared (FTIR) were used to study protein conformation change during coacervate formation between gelatin and pectin. The results showed that high yield of coacervates with good size and morphology occurred at pH 4.23 and 4.37 for G/HMP with a ratio of 3:1 and G/LMP with a ratio of 6:1 respectively. Fluorescence and FTIR analysis further confirmed their electrostatic interaction and gelatin molecules exhibited a conformational change following the complexation. Thermal gravimetric analysis revealed that microencapsulation of cinnamaldehyde by complex coacervation using gelatin and pectin significantly increased the degradation temperature from 180-220 °C to 350–400 °C. Moreover, high methyl pectin revealed a higher encapsulation efficiency (89.2%) and controlled release of cinnamaldehyde in hot water (33% for 120 min at 80 °C). It could be suggested conformation of pectin types and gelatin might significantly contribute to the overall complexation and cinnamaldehyde microcapsule properties. These findings could be useful for design an ideal carrier to deliver flavors like cinnamaldehyde by complex coacervation using protein and different pectin types.

Effect of organoclay and preparation method on properties of antimicrobial cellulose acetate films

The aim of the present study was oriented to evaluate the effect of a commercial organoclay and the technique of preparation on the physical and antimicrobial properties of active eco‐friendly nanocomposites films. To this antimicrobial nanocomposite films were fabricated from cellulose acetate (CA) powder, triethyl citrate (TEC) plasticizer, a commercial organoclay Cloisite30B (C30B), and cinnamaldehyde (Ci) as active agent. All nanocomposites showed the intercalation of the polysaccharide inside the organoclay structure, however, the level of the intercalation and the quality of the clay dispersion were dependent on the method selected to prepare them (solution‐casting or extrusion). In addition, nanocomposites obtained by extrusion evidenced a better dispersion of organoclay. Important changes on the color properties of films were evidenced, which was associated to the thermal degradation of the quaternary ammonium surfactant of the Cloisite30B. On the other hand, organoclay was unable to reduce the cinnamaldehyde loss during the extrusion and storage, nevertheless, a slight effect of the Cloisite30B on the cinnamaldehyde release to a food simulant was observed to nanocomposites prepared by extrusion. Finally, despite cinnamaldehyde loss was observed over time, the content of residual active compound into the films was able to impart antimicrobial activity against Escherichia coli for 14 weeks. POLYM. COMPOS., 40:2311–2319, 2019. © 2018 Society of Plastics Engineers

Anti quorum sensing and anti biofilm efficacy of cinnamaldehyde encapsulated chitosan nanoparticles against Pseudomonas aeruginosa PAO1

The encapsulation of cinnamaldehyde into biodegradable polymeric systems represents a possible strategy to overcome the bioavailability issues and enhance the sustained release of the drug at the target sites. In the present study, the efficacy of cinnamaldehyde encapsulated chitosan nanoparticles (CANPs) in attenuating the quorum sensing (QS) regulated virulence of P. aeruginosa PAO1 was investigated. CANPs were synthesized by ionic gelation method, characterized by dynamic light scattering (DLS), and transmission electron microscopic (TEM) analysis. The DLS and TEM analysis confirmed the synthesis of CANPs with a mean diameter of 208.12 nm. The encapsulation efficiency was observed to be 65.04 ± 3.14% and in vitro release study confirmed the slow and sustained release of cinnamaldehyde. CANPs showed significant anti quorum sensing activity by down regulating the QS regulated virulence factors and associated biofilm formation as evidenced from microscopic observation. CANPs also significantly altered the swimming and swarming motility of P. aeruginosa PAO1. The present results suggested the greater prospective of the application of CANPs as potential anti quorum sensing agents as compared to native cinnamaldehyde and suggested new avenues for development of novel anti-infective agents in the post antibiotic era.

Modifying an Active Compound's Release Kinetic Using a Supercritical Impregnation Process to Incorporate an Active Agent into PLA Electrospun Mats.

The main objective of this work was to study the release of cinnamaldehyde (CIN) from electrospun poly lactic acid (e-PLA) mats obtained through two techniques: (i) direct incorporation of active compound during the electrospinning process (e-PLA-CIN); and (ii) supercritical carbon dioxide (scCO2) impregnation of CIN within electrospun PLA mats (e-PLA/CINimp). The development and characterization of both of these active electrospun mats were investigated with the main purpose of modifying the release kinetic of this active compound. Morphological, structural, and thermal properties of these materials were also studied, and control mats e-PLA and e- were developed in order to understand the effect of electrospinning and scCO2 impregnation, respectively, on PLA properties. Both strategies of incorporation of this active compound into PLA matrix resulted in different morphologies that influenced chemical and physical properties of these composites and in different release kinetics of CIN. The electrospinning and scCO2 impregnation processes and the presence of CIN altered PLA thermal and structural properties when compared to an extruded PLA material. The incorporation of CIN through scCO2 impregnation resulted in higher release rate and lower diffusion coefficients when compared to active electrospun mats with CIN incorporated during the electrospinning process.

Antimicrobial properties and release of cinnamaldehyde in bilayer films based on polylactic acid (PLA) and starch

Cinnamaldehyde (CIN) loaded amorphous PLA films were obtained by casting, using ethyl acetate as solvent. Likewise, bilayer films were obtained by thermocompression of the PLA active layer and compression moulded cassava starch (S) films or semi crystalline PLA films. Starch-PLA laminated materials were considered to improve the barrier capacity (high oxygen barrier through the starch layer and high water vapour capacity through the polyester layer), while CIN incorporation confers antimicrobial activity on the films. The PLA bilayers were obtained for comparison purposes. The antimicrobial activity of the CIN loaded PLA films and S bilayer films was proved against Escherichia coli and Listeria Innocua through in vitro tests, which indicates that the active amount released into the growth medium exceeded the minimum inhibitory concentration (MIC) of both bacteria. The release kinetics of the active compound in different food simulants demonstrated that a part of CIN was tightly bonded to the PLA matrix, whereas the free compound diffused more easily through the starch layer, making S bilayers more active against the bacteria when the starch layer was in direct contact with the culture medium. CIN entrapped in PLA bilayers did not exhibited any antibacterial effect due to its release inhibition, associated to its bonding within the PLA matrix and the lower degree of relaxation in the semi crystalline PLA layer in contact with the food simulants.

Laboratory antimicrobial activity of cinnamaldehyde and pomegranate‐based polycaprolactone films

ABSTRACTPolycaprolactone (PCL) was incorporated separately with cinnamaldehyde (CNMA), pomegranate methanolic extract (PME), freeze dried arils of pomegranate (FDAP), and seed flour of pomegranate (SF) to form antimicrobial films to be used for active food packaging. PCL–CNMA films completely inactivated growth of the artificially inoculated Escherichia coli and Staphylococcus aureus, whether at 5% or 10% concentrations (wt/wt of polymer), at all studied temperatures (4, 20, and 37 °C). PCL–PME films (10% wt/wt of polymer) delayed the growth of E. coli and S. aureus for up to 7 and 6 days, respectively, at 37 °C. Two‐day delays in the growth of both bacteria were achieved with FDAP and SF films (10% wt/wt of polymer) at 20 °C. The release of CNMA was slower than the release of PME during film processing, as measured by Fourier transform infrared spectroscopy. Thus, CNMA and pomegranate‐based films perhaps should be planned further for use in controlled release food packaging. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45347.

Preparation of a calcium carbonate-based bone substitute with cinnamaldehyde crosslinking agent with potential anti-inflammatory properties.

Calcium sulfate (CS), also known as POP (Plaster of Paris) is a self-setting, biocompatible, and osteoconductive biomaterial with a long history for the treatment of skeletal defects. However, CS cements show a too fast resorption rate and are unable to provide a long-term 3D framework during the osteogenesis process. In our previous studies, it was found that the incorporation of CaCO3 and CaCO3 hydrogel provided enhanced mechanical and degradation properties of POP composites. Furthermore, it was also found that the use of cinnamaldehyde to crosslink CaCO3 hydrogel may have some advantages, for example to crosslink the hydrogel and to act as anti-inflammatory control agent. The objective of the current study was to evaluate the effect of adding cinnamaldehyde crosslinked CaCO3 hydrogel into POP on the diametral tensile strength, weight loss, age swelling, degradation, cinnamaldehyde release, and porosity. The following composites were prepared: POP/HCin-025 (25% addition of hydrogel microsphere) and POP/HCin-050 (50% addition of hydrogel microsphere). The composites were assessed on their diametral tensile strength, weight loss of the POP composite, age swelling, degradation of the hydrogel CaCO3 , cinnamaldehyde release, and porosity, as well as XRD-patterns and FT-IR spectra. It was confirmed from the study that incorporation of cinnamaldehyde into CaCO3 hydrogel system significantly increased the mechanical strength of the POP composite. Weight loss, swelling ratio in both acid to neutral pH, and biodegradability of the POP composites were controllable by the addition of cinnamaldehyde-CaCO3 hydrogel. Moreover, the cinnamaldehyde incorporated into the hydrogel was proven to be released in a controlled manner. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1055-1062, 2017.

Use of Electrospinning to Develop Antimicrobial Biodegradable Multilayer Systems: Encapsulation of Cinnamaldehyde and Their Physicochemical Characterization

In this work, three active bio-based multilayer structures, using a polyhydroxybutyrate-co-valerate film with a valerate content of 8 % (PHBV8) as support, were developed. To this end, a zein interlayer with or without cinnamaldehyde (CNMA) was directly electrospun onto one side of the PHBV8 film and the following systems were developed: (1) without an outer layer; (2) using a PHBV8 film as outer layer; and (3) using an alginate-based film as outer layer. These multilayer structures were characterized in terms of water vapour and oxygen permeabilities, transparency, intermolecular arrangement and thermal properties. The antimicrobial activity of the active bio-based multilayer systems and the release of CNMA in a food simulant were also evaluated. Results showed that the presence of different outer layers reduced the transport properties and transparency of the multilayer films. The active bio-based multilayer systems showed antibacterial activity against Listeria monocytogenes being the multilayer structure prepared with CNMA and PHBV outer layers (PHBV + zein/CNMA + PHBV) the one that showed the greater antibacterial activity. The release of CNMA depended on the multilayer structures, where both Fick’s and Case II transport—polymer relaxation explained the release of CNMA from the multilayer systems. Overall, the deposition of electrospun CNMA-loaded zein fibres on a PHBV8 layer is a promising methodology for the development of active bio-based multilayer systems, with a great potential for food packaging applications.

Calcium carbonate hydrogel construct with cynnamaldehyde incorporated to control inflammation during surgical procedure

The incorporation of CaCO3 hydrogel has been proven to enhance the bone biological activity of Plaster of Paris (POP) and to decrease its degradability. However, the installation of this bone substitute in a bone defect will still be associated with an inflammatory response. In this study, the influence of cinnamaldehyde as anti-inflammatory agent, was investigated. In addition, it is known that aldehyde chains of cinnamaldehyde may also act as crosslinking agent and function as a plastisizer to the CaCO3 hydrogel construct. Therefore, different concentrations of cinnamaldehyde were added to CaCO3 hydrogel and the effect on the diametral tensile strength, age swelling, gel fractination, cinnamaldehyde release, antimicrobial effect, and cell cytotoxycity were investigated. The incorporation of cinnamaldehyde was found to decrease the age swelling and degradation rate of CaCO3 hydrogel and to have no toxic effect to human gingival fibroblast cells. Moreover, the incorporation of cinnamaldehyde essential oil into the CaCO3 hydrogel was beneficial and acted as an antiinflammatory agent. Further research in vivo is warranted to determine the final favorable effect of cinnamaldehyde incorporated CaCO3 hydrogel in POP to provide a bone substitute. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 768-774, 2016.

Physical Stability and Antimicrobial Activity of Encapsulated Cinnamaldehyde by Self‐Emulsifying Nanoemulsion

AbstractIn the present study, natural cinnamaldehyde was encapsulated in self‐emulsifying emulsion systems. After optimization, the stability of encapsulated cinnamaldehyde was evaluated by dynamic light‐scattering and electronic nose. The antimicrobial activity of cinnamaldehyde was investigated by minimum inhibition concentration and time‐kill assay. The results showed that pure cinnamaldehyde as oil phase could not form stable emulsion under different oil‐to‐surfactant ratio. Stable cinnamaldehyde nanoemulsions were achieved with the addition of medium‐chain triglyceride. With the exception of temperature, the obtained nanoemulsions were stable against pH and NaCl. Phase separation was observed after 12 days of storage under 37C. Encapsulation efficiency of cinnamaldehyde in nanoemulsions was maintained around 80% within 1 week. Radar plots from electronic nose indicated that encapsulation could slow the release of cinnamaldehyde from nanoemulsion. Hence, the antimicrobial activity of cinnamaldehyde encapsulated in nanoemulsion could provide a long‐term inhibition on the bacterial growth of Escherichia coli compared with pure cinnamaldehyde.Practical ApplicationsThe applications of natural essential oils with their excellent antibacterial activities, such as cinnamon essential oils, as a food additive and green preservative are limited in the food systems, due to their highly instability against environmental conditions including temperature, light, air and others. The emulsification technique has been successfully utilized to overcome this drawback. However, it is known that emulsions with essential oils as oil phase will be highly unstable due to Ostwald ripening. Although the evaluation of the stability and bioactivities of encapsulated essential oil is an important and critical issue during the practical application, hence, studies of the physical properties such as environmental stability, volatility and antibacterial activity can explore the ideal formulation and applications of natural essential oils.

Reversible Covalent Immobilization of Cinnamaldehyde on Chitosan Films via Schiff Base Formation and Their Application in Active Food Packaging

In this work, cinnamaldehyde was reversibly anchored to chitosan films via imino-covalent bonding. The Schiff base was synthesized in solid phase employing neutralized chitosan films immersed in acidified 95 % (v/v) ethanolic solution in which the aldehyde was dissolved. The substitution degree (%) of cinnamaldehyde to the amine group was close to 70 %. Attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR) analysis revealed the formation of the chitosan-cinnamaldehyde Schiff base. The hydrolysis of the imino bond and subsequent release of cinnamaldehyde were studied after the films had been subjected to different combinations of temperature/time treatments simulating food preservation methods. The amount of aldehyde that remained covalently attached to the films was monitored by ATR-FTIR, and the substitution degree was determined by elemental analysis. Surface contact angle and colour parameters of cinnamaldehyde-imine-chitosan films and these films subjected to different treatments were also evaluated. The antimicrobial properties of chitosan-Schiff base films were tested in vitro against Staphylococcus aureus and Escherichia coli and in milk inoculated with Listeria monocytogenes. The antimicrobial activity varied depending on the treatment applied and consequently the degree of imino bond hydrolysis achieved and cinnamaldehyde released. Films of Schiff base-chitosan derivative subjected to different time/temperature treatments inhibited the growth of L. monocytogenes for 12 days under refrigeration conditions, which may extend the microbiological shelf life of such products. Sensory analysis of milk in contact with the films showed that a cinnamon smell does not cause any rejection among potential consumers. These novel films could be used in the design of antimicrobial food packaging and in various other technological areas where sustained-release systems are required.

Electrospinning an essential oil: Cinnamaldehyde enhances the antimicrobial efficacy of chitosan/poly(ethylene oxide) nanofibers

Due to the persistent spread of antibiotic resistance, commercial antibiotic treatments are proving ineffective. Cinnamaldehyde (CA), a volatile essential oil, eradicates pathogens non-specifically. However, the ability to incorporate essential oils into nanofiber mats has not yet been demonstrated, and, only six studies have electrospun two immiscible phases. Here, CA (0.5 and 5.0%) was incorporated into chitosan/poly(ethylene oxide) (PEO) solutions that were successfully electrospun into mats with ∼50nm fiber diameters. Solid-state NMR results corroborated with release studies wherein the 5.0% CA mats released a statistically higher amount of CA-liquid (545% more) and CA-vapor (279% more) than the 0.5% CA mats. In time dependent cytotoxicity studies, the intrinsic antibacterial activity of chitosan along with the quick release of CA enabled high inactivation rates against Escherichia coli and Pseudomonas aeruginosa. For the first time we have demonstrated chitosan/CA/PEO nanofiber mats can serve as CA delivery vehicles that potentially eradicate pseudomonas infections.

Retention and Release of Cinnamaldehyde from Wheat Protein Matrices

Cinnamaldehyde treatment of gliadin films provided a means of decreasing their solubility, increasing their molecular weight profile, and reducing their overall migration into food simulants as a consequence of the high degree of polymerization achieved. Despite losses incurred in the film manufacturing process, and the amount that remained covalently bonded with protein because of cross-linking, the addition of 1.5, 3, and 5% of cinnamaldehyde (g/100 g protein) to gliadins at pH 2 rendered 1.8, 4.8, and 11.0 mg cinnamaldehyde/g film, respectively, available to be released, and therefore to exert antimicrobial activity. Cinnamaldehyde diffusivity was largely dependent on environmental conditions, increasing from 0.49×10(-15) m2/s at 30% relative humidity (RH) to 13.1×10(-15) m2/s at 90% RH and 23 °C. This water sensitivity of films provides a mechanism with a noteworthy potential to retain the compound before its use, to trigger its release when needed, and to modulate the release rate according to the product humidity.