A novel biopolymeric composite edible film based on sunnhemp protein isolate and potato starch incorporated with clove oil: Fabrication, characterization, and amino acid composition.

Composite edible films were developed by casting method using sunnhemp protein isolate (SHPI) and potato starch (PS) at various proportions (100:0, 90:10, 80:20; 70:30, 60:40, and 50:50) containing glycerol as a plasticizer and clove oil. All the edible films were evaluated for thickness, moisture content, solubility, swelling ratio, water activity. Further characterization of edible films was done on the basis of mechanical, optical, thermal and structural attributes along with morphology. Among all the films, composite film containing 50 % SHPI, 50 % PS and 1 % clove oil were having better characteristics. The solubility and WVP decreased, while the tensile strength and elongation at break of composite film increased with the inclusion of potato starch and clove oil. Intermolecular interactions in the composite film matrix were confirmed by FTIR and XRD analysis. SEM images confirmed the structural compactness and integrity of all the developed films. The amino acid composition of edible films indicated presence of most of the essential amino acids. The present finding of this research work shows that the utilization of sunnhemp protein in the development of biocomposite edible films represents an alternative opportunity of sustainable edible food packaging.

Nanoemulsions containing amphotericin b and paromomycin for the treatment of cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) is a vector-borne disease characterized by skin lesions that can evolve into high-magnitude ulcerated lesions. Thus, this study aimed to develop an innovative nanoemulsion (NE) with clove oil, Poloxamer® 407, and multiple drugs, such as amphotericin B (AmB) and paromomycin (PM), for use in the topical treatment of CL. METHODS: Droplet size, morphology, drug content, stability, in vitro release profile, in vitro cytotoxicity on RAW 264.7 macrophages, and antileishmanial activity using axenic amastigotes of Leishmania amazonensis were assessed for NEs. RESULTS: After optimizing the formulation parameters, such as the concentration of clove oil and drugs, using an experimental design, it was possible to obtain a NE with an average droplet size of 40 nm and a polydispersion index of 0.3, and these parameters were maintained throughout the 365 days. Furthermore, the NE showed stability of AmB and PM content for 180 days under refrigeration (4 °C), presented a pH compatible with the skin, and released modified AmB and PM. NE showed the same toxicity as free AmB and higher toxicity than free PM against RAW 264.7 macrophages. The same activity as free AmB, and higher activity than free PM against amastigotes L. amazonensis. CONCLUSION: It is possible to develop a NE for the treatment of CL; however, complementary studies regarding the antileishmanial activity of NE should be carried out.

Enhancing bread preservation through non-contact application of starch-based composite film infused with clove essential oil nanoemulsion.

In this study, we have successfully produced a corn starch-based composite film through the casting method, formulated with clove essential oil nanoemulsion (NCEO) and corn starch. The physical and chemical changes of the composite films were investigated at various concentrations (10 %, 20 % and 40 %) of NCEO. Furthermore, the non-contact preservation effects of the composite films on bread during 15-day storage were also examined in this study. As the concentration of NCEO increased, the composite films presented a gradual thinning, roughening, and yellowing in appearance. Following this, the water content, water vapor permeability rate, and elongation at break of the films decreased, while their hydrophobicity, tensile strength, antioxidant and antimicrobial activity increased accordingly. Through FT-IR, X-ray diffraction and thermal gravimetric analysis, it was demonstrated that NCEO has strong compatibility with corn starch. Additionally, the indices' analysis indicated that utilizing the composite film incorporating 40 % NCEO can significantly boost the shelf life and quality of bread. Moreover, it was revealed that application of the non-contact treatment with composite film could potentially contribute certain preservation effects towards bread. In light of these findings, the composite film with non-contact treatment exhibits potential as an effective, safe, and sustainable preservation technique for grain products.

Polyvinyl alcohol films incorporated with clove essential oil emulsions stabilized by soy protein isolate-derived amyloid fibrils: Fabrication, characterization, and its application for active packaging.

This study aimed to prepare a novel emulsion film with high stability, using soy protein-derived amyloid fibrils (SAFs) as an emulsifier incorporating clove essential oil (CEO) as the active component, and the polyvinyl alcohol (PVA) matrix to stabilize the system. The results demonstrated that SAFs can successfully stabilize CEO. Emulsion prepared by SAFS and CEO (SAC) exhibited a small droplet size and better dispersibility compared with SPI and CEO (SC) emulsion. According to FT-IR results, PVA addition increased the hydrogen bond interactions among emulsion film components, thus further reinforcing the protein matrix, increasing the tensile strength (TS) (41.18 MPa) and elongation at break (E) (121.62 %) of the films. The uniform appearance of SAC-PVA (SACP) emulsion films was confirmed by SEM images. Furthermore, SACP emulsion films show distinctive barrier properties, optical properties, and outstanding antioxidant properties. Finally, emulsion films exhibited excellent preservation of strawberries, resulting in an effective decline of the decay rate.

Clove essential oil loaded chitosan nanocapsules on quality and shelf-life of blueberries.

In this study, the formation of clove essential oil loaded chitosan nanocapsules (CEO/CS-NCs) was achieved by the ionotropic gelation technology. The spherical shape and core-shell structure of CEO/CS-NCs were characterized by SEM, TEM, and FT-IR. CEO/CS-NCs have a reasonable encapsulation efficiency rate of 39 % and an average size of 253.63 nm. The simulated release of CEO/CS-NCs in a citric acid buffer solution shows that the nano-encapsulation technology could control the sustained release of clove essential oil (CEO). The shelf life of untreated blueberries at room temperature is only about 3 days, while CEO/CS-NCs combined with low-temperature storage can extend the shelf life to about 12 days. The quality characteristic of blueberries, including fruit firmness and moisture content, were effectively maintained, and the rotting rate of blueberries was significantly reduced with CEO/CS-NCs. As a natural preservative, CEO/CS-NCs have a good antioxidant activity close to the commercial antioxidant butylated hydroxytoluene (BHT) and a high antibacterial activity against pathogenic bacteria (PB) isolated from naturally occurring blueberries. Therefore, this study not only gives a theoretical basis for the development of CEO as a commercial preservative but also provides a practical solution to solve the protection challenge of preserving blueberries.

Bio-molluscicidal potential and biochemical mechanisms of clove oil and its main component eugenol against the land snail, Theba pisana.

The land snail, Theba pisana is a serious pest that adversely affects various crops in sustainable agriculture. Essential oils and their constituents represent an environmentally sound alternative to synthetic pesticides. Our study aimed to investigate the lethal and sub-lethal toxicity of clove oil and its main component eugenol to understand the mechanisms underlying its toxic action against T. pisana. The GC-MS profile of the clove oil composition was characterized. In the laboratory experiment, LD50 of clove oil and eugenol via the contact testing were determined after 48 and 72 h. Moreover, sub-lethal effects of clove oil or eugenol on the survivors following the exposure of snails to the 25 and 50% of the LD50/48 and 72 h were evaluated through using snail tissues for biochemical measurments. The GC-MS analysis showed that eugenol (64.87%) was the major constituent present in the oil. The results also showed that LD50 values at 48 and 72 h were 2006.5 and 1493.5 µg/g b.w for oil and 239.6 and 195.3 µg/g b.w for eugenol, respectively. Compared to control, the sub-lethal effects of clove oil or eugenol at 48 and 72 h showed a significant increase in reduced glutathione (GSH) levels. Catalase (CAT) and glutathione-S-transferase (GST) activities significantly elevated in oil- or eugenol-treated snails, except at low dose after 48 h. After two exposure times, snails exposed to oil or eugenol at both sub-lethal effects had considerably higher γ-glutamyltransferase (γ-GT) and aspartate aminotransferase (AST) activities. Moreover, markedly augmentation in alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities at all exposure times, with the exception of snails treated with low dose of eugenol after 48 h was observed. Both clove oil and eugenol at the tested doses caused a significant inhibition in acetylcholinesterase (AChE) activity at two exposure times. Our findings highlight the potential of clove oil and eugenol, as an efficient natural molluscicide alternative to its synthetic counterparts for snail control.

In Vitro Antiviral Potential, Antioxidant, and Chemical Composition of Clove (Syzygium aromaticum) Essential Oil.

Viral infections are spread all around the world. Although there are available therapies, their safety and effectiveness are constrained by their adverse effects and drug resistance. Therefore, new natural antivirals have been used such as essential oils, which are natural products with promising biological activity. Accordingly, the present study aimed to identify the components of clove (Syzygium aromaticum) essential oil (EOCa) and verify its antioxidant and antiviral activity. The oil was analyzed using GC/MS, and the antioxidant capacity was evaluated as a function of the radical scavenging activity. A plaque reduction test was used to measure the antiviral activity against herpes simplex virus (HSV-1), hepatitis A virus (HAV), and an adenovirus. GC/MS analysis confirmed the presence of eugenol as the main component (76.78%). Moreover, EOCa had powerful antioxidant activity with an IC50 of 50 µg/mL. The highest antiviral potential was found against HAV, with a selectivity index (SI) of 14.46, while showing poor selectivity toward HSV-1 with an SI value of 1.44. However, no relevant effect was detected against the adenovirus. The antiviral activity against HAV revealed that its effect was not related to host cytotoxicity. The findings imply that EOCa can be utilized to treat diseases caused by infections and free radicals.

Antibacterial Activity of Syzygium aromaticum (Clove) Bud Oil and Its Interaction with Imipenem in Controlling Wound Infections in Rats Caused by Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infection worldwide. Clove oil's ability to inhibit the growth of MRSA was studied through in vitro and in vivo studies. The phytochemical components of clove oil were determined through gas chromatography-mass spectrometry (GC-MS) analysis. The antibacterial effects of clove oil and its interaction with imipenem were determined by studying MIC, MBC, and FIC indices in vitro. The in vivo wound-healing effect of the clove oil and infection control were determined using excision wound model rats. The GC-MS analysis of clove oil revealed the presence of 16 volatile compounds. Clove oil showed a good antibacterial effect in vitro but no interaction was observed with imipenem. Clove bud oil alone or in combination with imipenem healed wounds faster and reduced the microbial load in wounds. The findings of this study confirmed the antibacterial activity of clove oil in vitro and in vivo and demonstrated its interaction with imipenem.

Synthesis and characterization of poly(lactic acid)/clove essential oil/alkali-treated halloysite nanotubes composite films for food packaging applications.

In this study, nanocomposites of polylactic acid (PLA) with clove essential oil (CEO) and alkali treated halloysite nanotubes (NHNT) as fillers were synthesized by using simple solvent casting method. The treatment of halloysite nanotubes with NaOH increased the surface area from 50.16 m2⋅g-1 to 57.01 m2⋅g-1 and pore volume from 0.25 cm3⋅g-1 to 0.32 cm3⋅g-1. The as-synthesized nanocomposite films were characterized for physical, thermal, mechanical and water vapor barrier properties towards their use as food packaging material. The nanocomposite film PCOH0.5 (consisting 0.5 wt% NHNT and 200 µL CEO) possessed the best physical properties with percentage enhancements over PLA as: surface hydrophobicity (20.2 %), water vapor barrier (42.1 %), thermal stability (3.2 %), flexibility (682 %), tensile strength (20 %), elastic modulus (38 %), UV barrier property (62 %). In addition, a practical packaging test was performed on cut apples stored at room temperature for 6 days. The PCOH0.5 films showed substantially improved results (as compared to PLA) as follows: weight loss (40.5 %), mesophilic count (4.0 %), firmness (116.6 %), titratable acidity (110.8 %), pH (2.9 %) and total soluble solids (8.9 %). The results clearly indicate the efficiency of PLA/CEO/NHNT nanocomposite films as potential active food packaging material.

Eugenol ß-Amino/ß-Alkoxy Alcohols with Selective Anticancer Activity.

Eugenol, 4-allyl-2-methoxyphenol, is the main constituent of clove essential oil and has demonstrated relevant biological activity, namely anticancer activity. Aiming to increase this activity, we synthesized a series of eugenol ß-amino alcohol and ß-alkoxy alcohol derivatives, which were then tested against two human cancer cell lines, namely gastric adenocarcinoma cells (AGS) and lung adenocarcinoma cells (A549). An initial screening was performed to identify the most cytotoxic compounds. The results demonstrated that three ß-amino alcohol derivatives had anticancer activity that justified subsequent studies, having been shown to trigger apoptosis. Importantly, the most potent molecules displayed no appreciable toxicity towards human noncancer cells. Structure-activity relationships show that changes in eugenol structure led to enhanced cytotoxic activity and can contribute to the future design of more potent and selective drugs.

Olive oil and clove oil-based nanoemulsion for topical delivery of terbinafine hydrochloride: in vitro and ex vivo evaluation.

In this article, formulation studies for terbinafine hydrochloride nanoemulsions, prepared by high-energy ultrasonication technique, are described. Pseudo-ternary phase diagram was constructed in order to find out the optimal ratios of oil and surfactant/co-solvent mixture for nanoemulsion production. Clove and olive oils were selected as oil phase. Based on the droplet size evaluation, maximum nanoemulsion region were determined for formulation development. Further characterization included polydispersity index (PDI), zeta potential, Fourier transform infrared (FT-IR) spectroscopy, morphology, pH, viscosity, refractive index, ex vivo skin permeation, skin irritation, and histopathological examination. Droplet sizes of optimized formulations were in colloidal range. PDI values below 0.35 indicated considerably homogeneous nanoemulsions. Zeta potential values were from 13.2 to 18.1 mV indicating good stability, which was also confirmed by dispersion stability studies. Ex vivo permeation studies revealed almost total skin permeation of terbinafine hydrochloride from the nanoemulsions (96-98%) in 6 hours whereas commercial product reached only 57% permeation at the same time. Maximum drug amounts were seen in epidermis and dermis layers. Skin irritation and histopathological examination demonstrated dermatologically safe formulations. In conclusion, olive oil and clove oil-based nanoemulsion systems have potential to serve as promising carriers for topical terbinafine hydrochloride delivery.

In Vitro Assessment of the Cytotoxic and Antiproliferative Profile of Natural Preparations Containing Bergamot, Orange and Clove Essential Oils.

Medicinal plants and essential oils (EOs), in particular, were intensively studied in recent years as viable alternatives for antiproliferative chemical synthetic agents. In the same lines, the present study focuses on investigating the effects of natural preparations (emulsions) based on EOs obtained from Citrus bergamia Risso (bergamot-BEO), Citrus sinensis Osbeck (orange-OEO), and Syzygium aromaticum Merill et L. M. Perry (clove-CEO) on different healthy (human immortalized keratinocytes-HaCaT and primary human gingival fibroblasts-HGF) and human tumor cell lines (human melanoma-A375 and oral squamous carcinoma-SCC-4) in terms of the cells' viability and cellular morphology. The obtained results indicate that the CEO emulsion (ECEO) induced a dose-dependent cytotoxic in both healthy (HaCaT and HGF) and tumor (A375 and SCC-4) cells. OEO emulsion (EOEO) increased cell viability percentage both for HaCaT and A375 cells and had an antiproliferative effect at the highest concentration in HGF and SCC-4 cells. BEO emulsion (EBEO) decreased the viability percentage of SCC-4 tumor cells. By associating OEO with CEO as a binary mixture in an emulsified formulation, the inhibition of tumor cell viability increases. The E(BEO/OEO) binary emulsion induced an antiproliferative effect on oral health and tumor cells, with a minimal effect on skin cells. The non-invasive tests performed to verify the safety of the test compound's emulsions at skin level indicated that these compounds do not significantly modify the physiological skin parameters and can be considered safe for human skin.

[Development and biological activity evaluation of clove essential oil-based emulsion]. / Mise au point et activité biologique d'une crème à base d'huile essentielle de clou de girofle.

INTRODUCTION: Clove essential oil is isolated from the dried flower buds of Syzygium aromaticum from which many biological activities have been reported. The aim of this work was to develop a cream for topical use containing clove essential oil (HE) as an active ingredient and to test its biological activity. MATERIAL AND METHODS: Clove EO was extracted by hydrodistillation, its chemical composition was analysed by Gas chromatography-mass spectrometry (CG-SM). The EO was then incorporated into a cream where its stability was studied. The antifungal activity was evaluated by disc-diffusion method. The in vivo anti-inflammatory activity of EO and the cream was assessed y by carrageenan-induced rat paw edema model. RESULTS: Clove EO contains two major constituents: eugenol (69.14%) and ß-Caryophyllene (18.8%). The cream had good organoleptic and physicochemical properties. Both EO and the cream showed growth inhibitory effects on the two studied dermatophytes strains. The incorporation of EO in the cream provided a good anti-inflammatory activity, similar to the reference drug. CONCLUSION: The developed creme was stable, had good anti-inflammatory properties and moderate antifungal activity. Long-term stability studies and in vivo tests would lead to the use of clove essential oil in the development of new pharmaceutical forms.

Chitosan/pullulan based films incorporated with clove essential oil loaded chitosan-ZnO hybrid nanoparticles for active food packaging.

Herein, we developed clove essential oil (CEO) loaded Chitosan-ZnO hybrid nanoparticles (CS-ZnO@CEO (CZC NPs)) integrated chitosan/pullulan (CS/PL) nanocomposite films. SEM images revealed a homogenous distribution of CZC NPs with minimum aggregation in nanocomposite films. The incorporation of CZC NPs led to enhanced tensile strength (~39.82%), film hydrophobicity (~35.36%), UV light blocking ability, water vapor barrier (~84.64%), and oxygen barrier (~57.66%) compared to the bare CS/PL film and overall migration limit of CPCZC films were found below the permitted limit of 1000 µg/dm2. Besides, incorporation of CZC NPs into the CS/PL films enhanced antioxidant activity and showed strong antibacterial activity against P. aeruginosa, S. aureus, and E. coli. Also, the CPCZC films displayed potential to extend the shelf-life of chicken meat by up to 5 days when stored at 8 ± 2 °C. These results suggest that the prepared CPCZC films acquire the ideal prerequisites for potential active packaging materials.

Antimicrobial and indicator properties of edible film containing clove bud oil-loaded chitosan capsules and red cabbage for fish preservation.

For safe preservation and consumption of fish, freshness monitoring and antimicrobial control is crucial. Edible films comprising natural antimicrobial and spoilage indicator agents represent a convenient method for such preservation. Edible chitosan-based films were prepared using red cabbage (RC) and clove bud oil (CBO)-loaded chitosan/carrageenan capsules as spoilage indicator and antimicrobial agents, respectively. CBO-loaded capsules were prepared by the ionic gelation of chitosan and carrageenan. Films containing CBO capsules exhibited significantly higher antimicrobial activity than films containing non-encapsulated free CBO, as confirmed by minimum inhibitory concentration and time-kill assays. The highest antimicrobial activity was observed in the largest capsules (1.7 µm). After incubation for 48 h, the pH of fish peptone agar containing Pseudomonas fluorescens increased from approximately 6.0 to 9.0, and a color change from purple to deep blue was clearly observed during the growth of fish-spoiling bacteria. Thus, our results suggested that edible films containing CBO-loaded capsules and RC showed the potential to inhibit microbial growth in fish and to visibly indicate fish freshness.

Investigating Antiarthritic Potential of Nanostructured Clove Oil (Syzygium aromaticum) in FCA-Induced Arthritic Rats: Pharmaceutical Action and Delivery Strategies.

The combined application of clove oil in a lipid nanocarrier opens a promising avenue for bone and joints therapy. In this study, we successfully developed a tunable controlled-release lipid platform for the efficient delivery of clove oil (CO) for the treatment of rheumatoid arthritis (RA). The ultra-small nanostructured lipid carriers co-loaded with CO (CONCs) were developed through an aqueous titration method followed by microfluidization. The CONCs appeared to be spherical (particle size of 120 nm), stable (zeta potential of -27 mV), and entrapped efficiently (84.5%). In toluene:acetone:glacial acetic acid (90:9:1 percent v/v/v) solvent systems, high-performance thin layer chromatography (HPTLC) analysis revealed the primary components in CO as eugenol (RF = 0.58). The CONCs greatly increased the therapeutic impact of CO in both in vitro and in vivo biological tests, which was further supported by excellent antiarthritic action. The CONC had an antiarthritic activity that was slightly higher than neat CO and slightly lower than standard, according to our data. The improved formulation inhibited serum lysosomal enzymes and proinflammatory cytokines while also improving hind leg function. This study provides a proof of concept to treat RA with a new strategy utilizing essential oils via nanodelivery.

Anticancer Properties of Eugenol: A Review.

Conventional cancer treatments have shown several unfavourable adverse effects, as well as an increase in anticancer drug resistance, which worsens the impending cancer therapy. Thus, the emphasis is currently en route for natural products. There is currently great interest in the natural bioactive components from medicinal plants possessing anticancer characteristics. For example, clove (Syzygium aromaticum L.) (Family Myrtaceae) is a highly prized spice that has been historically utilized as a food preservative and for diverse medical uses. It is reckoned amongst the valued sources of phenolics. It is indigenous to Indonesia but currently is cultivated in various places of the world. Among diverse active components, eugenol, the principal active component of S. aromaticum, has optimistic properties comprising antioxidant, anti-inflammatory, and anticancer actions. Eugenol (4-allyl-2-methoxyphenol) is a musky oil that is mainly obtained from clove. It has long been utilized all over the world as a result of its broad properties like antioxidant, anticancer, anti-inflammatory, and antimicrobial activities. Eugenol continues to pique investigators' interest because of its multidirectional activities, which suggests it could be used in medications to treat different ailments. Anticancer effects of eugenol are accomplished by various mechanisms like inducing cell death, cell cycle arrest, inhibition of migration, metastasis, and angiogenesis on several cancer cell lines. Besides, eugenol might be utilized as an adjunct remedy for patients who are treated with conventional chemotherapy. This combination leads to a boosted effectiveness with decreased toxicity. The present review focuses on the anticancer properties of eugenol to treat several cancer types and their possible mechanisms.

Clove Essential Oil (Syzygium aromaticum L. Myrtaceae): Extraction, Chemical Composition, Food Applications, and Essential Bioactivity for Human Health.

Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, ß-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfume, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. The impacts of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the concentration of the main volatile compounds in clove essential oil and organic clove extracts are shown. Eugenol is the major compound, accounting for at least 50%. The remaining 10-40% consists of eugenyl acetate, ß-caryophyllene, and α-humulene. The main biological activities reported are summarized. Furthermore, the main applications in clove essential oil in the food industry are presented. This review presents new biological applications beneficial for human health, such as anti-inflammatory, analgesic, anesthetic, antinociceptive, and anticancer activity. This review aims to describe the effects of different methods of extracting clove essential oil on its chemical composition and food applications and the biological activities of interest to human health.

Improving the functionality of chitosan-based packaging films by crosslinking with nanoencapsulated clove essential oil.

The study aimed to obtain chitosan composite films with gratifying physical and functional properties. First, we developed a Pickering emulsion containing clove essential oil (CEO)-loaded nanoparticles with 1:2 (w/w) zein and sodium caseinate (NaCas). We found that in this ratio, the CEO-loaded zein-NaCas (C/ZN) nanoparticles had smaller particle size, proper polydispersity index (PDI) and zeta potential as well as higher encapsulation efficiency. Then, the acquired C/ZN nanoparticles were incorporated into chitosan film at three levels (0.2%, 0.4% and 0.6%), reducing the water vapor permeability to 4.62 × 10-6 g·s-1·m-1·Pa. Also, the tensile strength and break elongation of chitosan films were increased, reaching 38.67 MPa and 1.56%, respectively. The infrared spectroscopy verified that the intermolecular hydrogen bonds exist between chitosan and C/ZN nanoparticles. The chitosan composite films showed a controlled-release property of CEO in 96 h. Finally, the chitosan composite films showed the improved antibacterial property by creating larger inhibition zones against Escherichia coli (3.29 mm) and Staphylococcus aureus (6.15 mm). In general, we improved the water resistance, light blocking, mechanical strength, controlled-release and antibacterial properties of chitosan film with C/ZN nanoparticles. The current edible antibacterial films have great potential on applications for food preservation and food delivery system.

Towards a Bioactive Food Packaging: Poly(Lactic Acid) Surface Functionalized by Chitosan Coating Embedding Clove and Argan Oils.

Here we introduce a new method aiming the immobilization of bioactive principles onto polymeric substrates, combining a surface activation and emulsion entrapment approach. Natural products with antimicrobial/antioxidant properties (essential oil from Syzygium aromaticum-clove and vegetal oil from Argania spinosa L-argan) were stabilized in emulsions with chitosan, a natural biodegradable polymer that has antimicrobial activity. The emulsions were laid on poly(lactic acid) (PLA), a synthetic biodegradable plastic from renewable resources, which was previously activated by plasma treatment. Bioactive materials were obtained, with low permeability for oxygen, high radical scavenging activity and strong inhibition of growth for Listeria monocytogenes, Salmonella Typhimurium and Escherichia coli bacteria. Clove oil was better dispersed in a more stable emulsion (no separation after six months) compared with argan oil. This leads to a compact and finely structured coating, with better overall properties. While both clove and argan oils are highly hydrophobic, the coatings showed increased hydrophilicity, especially for argan, due to preferential interactions with different functional groups in chitosan. The PLA films coated with oil-loaded chitosan showed promising results in retarding the food spoilage of meat, and especially cheese. Argan, and in particular, clove oil offered good UV protection, suitable for sterilization purposes. Therefore, using the emulsion stabilization of bioactive principles and immobilization onto plasma activated polymeric surfaces we obtained a bioactive material that combines the physical properties and the biodegradability of PLA with the antibacterial activity of chitosan and the antioxidant function of vegetal oils. This prevents microbial growth and food oxidation and could open new perspectives in the field of food packaging materials.