Pure Essential Oil Research Articles

Characterisation of complex perfume and essential oil blends using multivariate curve resolution-alternating least squares algorithms on average mass spectrum from GC-MS

Quality control of essential oil blends and the discovery of potential adulterations and product fraud is a significant challenge within the natural oil and perfume industry. In this research, total chromatogram average mass spectra (TCAMS), created from the GC-MS three-way raw data, were employed for the characterisation of complex samples of perfumes and essential oil blends. A multivariate approach for curve resolution was used to resolve the TCAMS of pure essential oils within such perfume and essential oil blends. Resolved TCAMS, in combination with unsupervised pattern recognition approaches revealed the distillation grade and origin of used ylang-ylang oils in perfume mixtures. TCAMS resolved from the essential oil blends were used with a supervised machine learning classification model to identify oils, used in creating the blends. Quantification was performed using a multivariate curve resolution approach, resulting in relative errors of prediction lower than 17.84% with root mean square errors of prediction smaller than 3.43.

Antimicrobial Effect of Essential Oil of Thymus capitatus from Northern Cyprus and Its Gargle Preformulation

Aims: The aim of this study is to prepare herbal gargle preformulations making use of essential oil of aerial parts of Thymus capitatus growing wild in Northern Cyprus and comparing antimicrobial efficacy between these formulations with pure essential oil.
 Place and Duration of Study: Department of Pharmaceutical Technology, Faculty of Pharmacy, Near East University, Nicosia, TRNC and Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Ankara University, Ankara, Turkey, between January 2017 and June 2017.
 Methodology: Preformulations with three different concentrations of Thymus capitatus essential oil were prepared by using simple preparation method. Preformulation studies were done in lab with less than 500 ml. There is not specific process parameters. Manufacturing process and process parameters will be clarified with further studies. These compositions and the essential oil were tested in-vitro for antimicrobial activity studies by using broth microdilution method. Staphylococcus aureus ATCC 43300, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae RSKK 574, Salmonella paratyphi C, Pseudomonas aeruginosa ATCC 9027, Pseudomonas aeruginosa ATCC 27853 as bacteria and Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019 as yeasts were used for antimicrobial activity tests.
 Results: All trials were found to be more effective than EO, and a significant effect was observed when compared to the values ​​of standard antimicrobial agents.
 Conclusion: TheThymus capitatus growing in Northern Cyprus could be used as a herbal raw material, essential oil source in developing herbal gargle preformulations to reduce fungal and bacterial infections in mouth.

Essential Oils Encapsulation into Nanoliposome and Novel Application of Nanoliposome as a Storage Pesticide

This study attempted to evaluate the physicochemical characteristics of essential oil nanoliposomes from three plants by two preparation methods including thin film sonication and heating. Also, the durability of fumigation toxicity of the essential oil nanoliposome and pure essential oil of Mentha pulegium against Tribolium castaneum Herbst adults were compared. The smallest mean size of the nanoliposome was prepared by the thin film sonication method (P<0.05). The encapsulation efficiency of the nanoliposome was higher than 96%. Nanoliposmes prepared by using two methods showed high stability during storage. The release profile of essential oils at the heating method showed that the essential oil diffusion from the nanoliposome was in the following order: Mentha pulegium > Ferula gummosa > Zattaria multiflora. These findings indicate that both preparation methods had the same effect on the formation of nanoliposomes, their characteristics, and their storage stability. The durability of fumigation toxicity of the nanoliposome M. pulegium essential oil had a significant effect on mortality of T. castaneum adults in comparison with pure essential oil of this plant. The result showed that nanoliposome encapsulation of M. pulegium essential oil significantly increased fumigation toxicity against T. castaneum. Therefore, essential oil encapsulation into a nanoliposome carrier can potentially be used in pest management.

Does the ubiquitous use of essential oil-based products promote indoor air quality? A critical literature review.

Essential oils are frequently used as natural fragrances in housecleaning products and air fresheners marketed as green and healthy. However, these substances are volatile and reactive chemical species. This review focuses on the impact of essential oil-based household products on indoor air quality. First, housecleaning products containing essential oils are explored in terms of composition and existing regulations. Specific insight is provided regarding terpenes in fragranced housecleaning products, air fresheners, and pure essential oils. Second, experimental methodologies for terpene monitoring, from sampling to experimental chambers and analytical methods, are addressed, emphasizing the experimental issues in monitoring terpenes in indoor air. Third, the temporal dynamics of terpene emissions reported in the literature are discussed. Despite experimental discrepancies, essential oil-based products are significant sources of terpenes in indoor air, inducing a high exposure of occupants to terpenes. Finally, the fate of terpenes is explored from sorptive and reactive points of view. In addition to terpene deposition on surfaces, indoor oxidants may induce homogeneous and heterogeneous reactions, resulting in secondary pollutants, such as formaldehyde and secondary organic aerosols. Overall, essential oil-based products can negatively impact indoor air quality; therefore, standard protocols and real-scale approaches are needed to explore the indoor physics and chemistry of terpenes, from emissions to reactivity.

Inhalation aromatherapy on nausea, vomiting and anxiety during autologous hematopoietic stem cell transplantation: An open-label randomized controlled trial

IntroductionInhalation aromatherapy may help in controlling nausea, vomiting, and anxiety during autologous hematopoietic stem cell transplantation (AHSCT) by masking the malodor of dimethyl sulfoxide. This study examined the preventative effects of inhalation aromatherapy with orange essential oil on severity of nausea, vomiting episodes, and anxiety during AHSCT. MethodsThis open-label randomized controlled trial was conducted at two stem cell transplantation units in Ankara, Turkey. A total of 70 patients were randomly assigned to either an intervention (n = 35) or a control group (n = 35). Patients in the intervention group inhaled the odor from six drops of pure orange essential oil during AHSCT. Patients in the control group received routine care. Nausea severity was evaluated at baseline and the beginning of each new infusion bag. Number of vomiting and retching episodes was recorded during the AHSCT. Anxiety level was measured just after the completion of AHSCT. ResultsThe nausea severity (p = 0.931; 0.721 and 0.363 for the first, second and third bags, respectively), and the number of retching episodes (p = 0.741 and 0.485 for the first and second bags, respectively) and vomiting episodes (p = 0.396 and 0.957 for the first and second bags, respectively) showed no significant differences between the groups. The mean anxiety score was significantly lower for the intervention group than for the control group (p = 0.007). ConclusionInhalation aromatherapy with orange essential oil may be useful to alleviate anxiety during AHSCT; however, it does not appear to decrease nausea severity, and number of vomiting and retching episodes. Further studies are needed to confirm the study findings.

Evaluation of Chemical and Physical Properties of Commercial Sandalwood Essential Oils and their Comparison with Essential Oil Extracted from Santalum album L

Indian sandalwood oil is an essential oil (EO) obtained from the heartwood of Santalum album L tree. Thirty-eight sandalwood (SW) EO samples, including ten samples from heartwood of S. album and twenty-eight trade samples of SW EOs, were assessed for refractive index (RI), relative density (RD) and α- and β-santalol content. RI and RD values were found within the ranges of 1.4554 to 1.5035 and 0.943 to 1.472 respectively. The percentage of α- and β-santalols in these samples ranged from 0 to 54.28 % and 0 to 25.94 % respectively. The EO samples with α- and β-santalol content from 48.2 to 54.28 % and 19.15 to 25.94 % respectively were comparable with the pure sandalwood EO as described in Indian Standard (IS329-2004). Only about less than one third of the commercial SW EOs met with IS329-2004. The statistical significant difference and prioritization analysis were checked by Duncan’s Multiple Range Test and Grey Relational Analysis method, respectively. The presence of the adulterants diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP) in some of the EOs were ascertained and quantified by respective standard and regression curve of standard. Very high content of DEP (up to 4.4 x105 ppm) and DEHP (up to 8.0 x105 ppm) were detected in some of the commercially available sandalwood EOs. Thus, it is concluded that quality control and authentication for high valued sandalwood EO should mainly rely on its physical (RI and RD), chemical analysis (level of α- and β-santalol content).

Novel Clove Essential Oil Nanoemulgel Tailored by Taguchi's Model and Scaffold-Based Nanofibers: Phytopharmaceuticals with Promising Potential as Cyclooxygenase-2 Inhibitors in External Inflammation.

PurposeClove essential oil is a phytochemical possessing a vast array of biological activities. Nevertheless, fabricating nano topical delivery systems targeted to augment the anti-inflammatory activity of the oil has not been investigated so far. Accordingly, in this study, controlled release nanoparticulate systems, namely nanoemulgel and nanofibers (NFs), of the oil were developed to achieve such goal.MethodsThe nanoemulsion was incorporated in the hydrogel matrix of mixed biopolymers – chitosan, guar gum and gum acacia – to formulate nanoemulsion-based nanoemulgel. Taguchi’s model was adopted to evaluate the effect of independently controlled parameters, namely, the concentration of chitosan (X1), guar gum (X2), and gum acacia (X3) on different dependently measured parameters. Additionally, the nanoemulsion-based NFs were prepared by the electrospinning technique using polyvinyl alcohol (PVA) polymer. Extensive in vitro, ex vivo and in vivo evaluations of the aforementioned formulae were conducted.ResultsBoth Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) established the complete dispersion of the nanoemulsion in the polymeric matrices of the prepared nanoemulgel and NFs. The ex vivo skin permeation data of clove essential oil from the prepared formulations showed that NFs can sustain its penetration through the skin comparably with nanoemulgel. Topical treatment with NFs (once application) and nanoemulgel (twice application) evoked a marvelous in vivo anti-inflammatory activity against croton oil-induced mouse skin inflammation model when compared with pure clove essential oil along with relatively higher efficacy of medicated NFs than that of medicated nanoemulgel. Such prominent anti-inflammatory activity was affirmed by histopathological and immunohistochemical examinations.ConclusionThese results indicated that nanoemulsion-based nanoemulgel and nanoemulsion-based NFs could be introduced to the phytomedicine field as promising topical delivery systems for effective treatment of inflammatory diseases instead of nonsteroidal anti-inflammatory drugs that possess adverse effects.

Essential Oils-Loaded Electrospun Biopolymers: A Future Perspective for Active Food Packaging

The growth of global food demand combined with the increased appeal to access different foods from every corner of the globe is forcing the food industry to look for alternative technologies to increase the shelf life. Essential oils (EOs) as naturally occurring functional ingredients have shown great prospects in active food packaging. EOs can inhibit the growth of superficial food pathogens, modify nutritious values without affecting the sensory qualities of food, and prolong the shelf life when used in food packaging as an active ingredient. Since 2016, various reports have demonstrated that combinations of electrospun fibers and encapsulated EOs could offer promising results when used as food packaging. Such electrospun platforms have encapsulated either pure EOs or their complexation with other antibacterial agents to prolong the shelf life of food products through sustained release of active ingredients. This paper presents a comprehensive review of the essential oil-loaded electrospun fibers that have been applied as active food packaging material.

Nanoformulations as a modern form of biofungicide

PurposeThe aim of this study was to elaborate new forms of biofungicide formulations which could increase biological activity of essential oil against various strains of pathogenic fungi of plants, dermatophytes, and molds.MethodsThe nanoemulsions containing four various essential oils (cinnamon, thyme, manuka, and tea tree oil) were obtained by using the low-energy (PIC) and the high-energy emulsification methods (ultrasonification). The physicochemical properties and activity of prepared systems against strains of pathogenic fungi of plants (F. culmorum, Ph. cactorum), dermatophytes (T. mentagrophytes M. gypseum) and molds (S. brevicaulis, A. niger) were examined. Fungicidal activity was tested by the method of linear growth of mycelium on an agar medium. Macroemulsions containing the oils and the pure essential oils were used as comparative samples.ResultsIt was found that nanoemulsions prepared by ultrasonification showed excellent fungicidal activity compared to pure oils and macroemulsions. Among others, the manuka oil nanoformulations showed the highest activity against the tested fungi.ConclusionsNanoemulsions can be applied as the effective carriers of essential oils. They allow the reduction of the concentration of the bioactive oils while maintaining biological activity. The obtained nanosystems can be applied as safe, biodegradable, eco-friendly antifungal products in pharmaceutical, cosmetic, and agrochemical industries as they increase the biological activity of the tested oils against various type of fungi.

The Essential Oil and Hydrolats from Myristica fragrans Seeds with Magnesium Aluminometasilicate as Excipient: Antioxidant, Antibacterial, and Anti-inflammatory Activity.

Nutmeg (Myristica fragrans) essential oil has antimicrobial, antiseptic, antiparasitic, anti-inflammatory, and antioxidant properties. We have recently demonstrated that hydrodistillation of nutmeg essential oil by applying magnesium aluminometasilicate as an excipient significantly increases both the content and amount of bioactive substances in the oil and hydrolats. In this study, we aimed to compare the antioxidant, antimicrobial, and anti-inflammatory activity of hydrolats and essential oil obtained by hydrodistillation in the presence and absence of magnesium aluminometasilicate as an excipient. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method revealed that magnesium aluminometasilicate did not significantly improved antioxidant activity of both essential oil and hydrolat. Antibacterial efficiency was evaluated by monitoring growth of 15 bacterial strains treated by a range of dilutions of the essential oil and the hydrolats. Essential oil with an excipient completely inhibited the growth of E. faecalis, S. mutans (referent), and P. multocida, whereas the pure oil was only efficient against the latter strain. Finally, the anti-inflammatory properties of the substances were assessed in a fibroblast cell culture treated with viral dsRNR mimetic Poly I:C. The essential oil with an excipient protected cells against Poly I:C-induced necrosis more efficiently compared to pure essential oil. Also, both the oil and the hydrolats with aluminometasilicate were more efficient in preventing IL-6 release in the presence of Poly I:C. Our results show that the use of magnesium aluminometasilicate as an excipient might change and in some cases improve the biological activities of nutmeg essential oil and hydrolats.

Cinnamon essential oil Pickering emulsion stabilized by zein-pectin composite nanoparticles: Characterization, antimicrobial effect and advantages in storage application

Recently, the use of emulsion as a delivery system for essential oils has attracted increasing attention. In this research, cinnamon essential oil Pickering emulsion (ZCCPEs) stabilized by zein-pectin composite nanoparticles (ZCPs) was constructed as an effective antimicrobial system. Thereafter, the influence of ZCPs concentration on the stability of ZCCPEs was studied. The results showed that 0.25% ZCPs could reduce the bioorganic matter by four times compared with 1% ZCPs while maintaining good physical stability. The inhibitory effect of ZCCPEs on two food-related microorganisms (i.e. Alternaria alternata and Botrytis cinerea) was evaluated by antimicrobial assay. In addition, two fresh-cut apple slices models were constructed to systematically evaluate the application potential of ZCCPEs in food preservation. Due to the well dispersibility and sustained-release ability, ZCCPEs showed superior antibacterial performance than pure essential oil. The fabricated zein-pectin based Pickering emulsions might provide a promising alternative for the delivery of antimicrobial essential oils in the food industries.

Antibacterial effects of essential oils of Cymbopogon citratus and Amomum compactum under self-nanoemulsifying drug delivery system (SNEDDS)

Microbial populations in the gastrointestinal tracts of broiler chicken can be modulated by herbal additives that contained phytochemical substances. Essential oils (EOs) have potential phytochemical compounds but are lipophilic and have low solubility in water. Therefore, self-nanoemulsifying drug delivery system (SNEDDS) might be one of the formulation strategies to improve the solubility of essential oils. In this study, the anti-bacterial activity of Cymbopogon citratus and Amomum compactum EOs by SNEDDS was conducted using disc diffusion method on Escherichia coli and Salmonella typhimurium. Inhibition zone was found on both pure EOs and SNEDDS formulations. SNEDDS formulations of C. citratus and A. compactum EOs were effective against E. coli and S. typhimurium (P<0.05). C. citratus essential oil has the highest inhibition zone when compared to the other formulations, followed by A. compactum essential oil. On the other hand, SNEDDS formula of C. citratus and A. compactum essential oil showed similar antibacterial activity as tetracycline and penicillin antibiotics in inhibiting the growth of E. coli and S. typhimurium. It can be concluded that the use of SNEDDS formula of essential oil would be useful to reduce the population of pathogen in the intestine of poultry.

Evaluation of the in vitro release and permeation of Cordia verbenacea DC essential oil from topical dosage forms

abstract The first fully developed herbal medicine in Brazil, Acheflan®, contains the essential oil of Cordia verbenacea DC that is present at 0.5% in both a cream and aerosol form. Its topical use is indicated for the treatment of muscle aches and tendinitis to alleviate discomfort related to associated inflammatory processes. The two principal components of the essential oil involved in the anti-inflammatory activity are α-humulene and (-)-trans-caryophyllene, which need to penetrate the skin to exert their effects. The objective of this work was to evaluate, for the first time, the in vitro release profiles and the permeation of these commercial phytotherapeutics using Franz diffusion cells. The results indicate that the commercial products have a low release profile that appears to restrict permeation of the oil components. This was in contrast to the pure essential oil, which presented a good capacity to permeate through skin. To improve release, new nanoemulsion formulations were developed and evaluated for their release profiles, permeation and kinetic parameters. The transition to a nanoemulsion system was shown to improve the permeation profiles of the essential oil as these formulations had a high in vitro permeation and release flux rate. In addition, the final formulation presented an adequate droplet distribution size, polydispersity index and pH. Overall, we observed that the composition of formulations that contain Cordia verbenacea DC can directly influence the diffusion of the oil components through dermal barriers, which can potentiate their intended anti-inflammatory effects.

Preparation and evaluation of antioxidant packaging films made of polylactic acid containing thyme, rosemary, and oregano essential oils

Τhyme, rosemary, and oregano essential oils (EOs) were incorporated into Polylactic acid resin (PLA) at a concentration of 10% (w/w) using the solvent casting method to generate antioxidant packaging films. Pure EOs showed a radical scavenging activity (RSA) ranging between 84.57% and 87.92% at 10,000 mg/L (ppm) using the 1,1‐Diphenyl‐2‐picrylhydrazyl radical (DPPH) method. The antioxidant activity of film methanolic extracts was 4%–6% lower than EOs at the same concentration. A significant reduction (p 0.05) permeation, migration, and percentage elongation at break of film properties. On the contrary, tensile strength, and Young's modulus significantly decreased (p < 0.05) in films containing EOs. PRACTICAL APPLICATIONS: The ability to prepare active packaging films that inhibit lipid oxidation and assist in shelf life extension of perishable foods is of great concern to the food industry and the research community. The incorporation of thyme, rosemary, and oregano EOs in PLA films resulted in the preparation of active packaging materials, as shown by: (i) the retardation of the lipid oxidation (ii) a considerable increase in the shelf‐life of the product. PLA films, enriched with EOs, may serve as alternative solutions to synthetic antioxidants for food preservation.

Antimicrobial influence of nanoemulsified lemon essential oil and pure lemon essential oil on food-borne pathogens and fish spoilage bacteria

The antimicrobial activities of lemon oil based nanoemulsion and two different concentrations of lemon essential oil (100% and 10%) on food-brne pathogens (Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis and Salmonella Paratyphi A) and fish spoilage bacteria (Photobacterium damselae, Enterococcus faecalis, Vibrio vulnificus, Proteus mirabilis, Serratia liquefaciens, and Pseudomonas luteola) were compared in terms of disc diffusion, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The constitutes of extracted lemon essential oil were identified by using GC–MS. Viscosity, the mean droplet size, thermodynamic stability and refractive index of nanoemulsions were determined. The main components detected in the lemon essential oil were d-limonene, p-cymene, β-pinene with percentages of 52.85%, 14.36%, and 13.69%, respectively. It was found that lemon nanoemulsion was more effective on food-borne pathogens except K. pneumoniae than 100% lemon essential oil. 10% lemon essential oil showed the highest inhibition effect on S. Paratyphi A. The conversion of the essential oil into nanoemulsion improved antimicrobial activity. According to value of MIC, both nanoemulsion and 100% essential oil inhibited bacterial growth of all of the pathogen bacteria tested whereas they were less effective on inhibition of fish spoilage bacteria. However, 10% essential oil was more effective on spoilage bacteria than pathogens. MBC showed that nanoemulsion and 100% lemon essential oil presented a noticeable bactericidal activity against S. paratyphi A whereas 10% lemon essential oil was found as ≥25 mg/mL against pathogens and spoilage bacteria. Therefore, the use of nanoemulsion based on lemon essential oil can have potential as a natural antimicrobial agent against food-borne pathogen and spoilage bacteria for fish processing industry.

The Chemical Composition of Boswellia occulta Oleogum Resin Essential Oils

Frankincense is an aromatic oleogum resin that has been traded for thousands of years for medicine and incense and is today frequently distilled into essential oils for aromatherapy and perfume. A new species of frankincense, Boswellia occulta Thulin, DeCarlo, &amp; S.P. Johnson, was recently described from Somaliland (northern Somalia), but pure essential oils from this species have not yet been described. Samples of resin were collected directly from 12 individual B. occulta trees, hydrodistilled, and analyzed via GC-MS, GC-FID, and agglomerative hierarchical clustering. This revealed a significant level of methyl ethers in all samples (34.5%-62.6%), especially 1-methoxydecane (26.6%-47.9%) and 1-methoxyoctane (3.6%-8.6%). All samples were similar, but 3 groups were defined: (1) a methoxydecane/serratol/methoxyoctane group with 26.6% to 47.4% 1-methoxydecane, 14.5% to 31.8% serratol, and 3.6% to 8.6% 1-methoxyoctane; (2) a methoxydecane/di- epi-guaiol/serratol group with 26.6% to 29.1% 1-methoxydecane, 11.1% to 15.1% 4,10-di- epi-guaiol, and 10.3% to 16.8% serratol; and (3) a methoxydecane/methoxyoctane/di- epi-guaiol group with 38.9% to 47.9% 1-methoxydecane, 7.0% to 9.2% 1-methoxyoctane, and 2.2% to 12.3% 4,10-di- epi-guaiol.

EXTRACT THE AROMATIC OIL OF THE ROSEMARY PLANT BY STEAM DISTILLATION AND HYDRO-DISTILLATION METHODS

Pure essential oils are extracted from various parts of plants and are widely used in various fields of industries, such as perfumery and pharmaceutical industries. These essential oils have a high commercial value because of their therapeutic properties. The objective of this study is to study the behavior of rosemary oil extraction by using both steam distillation and hydro distillation method including quantity, components and ratios of distilled oil analysis and oil analysis. Gas chromatography for the effect of extraction time (5, 10, 15, 30, 60, 90 and 120 min) on yield and composition of essential oil obtained by water distillation method and steam distillation method at three different levels of water vapor flow (3 l / min, 6 l / min and 9 l / min) was also investigted. This research revealed different behaviors of the main components of rosemary oil. α-pinene and 1.8-cineole and camphor in the treatment with the amount of vapor flow rate. Experience has shown that steam distillation method is better than water distillation based on the ratio of oil and its components.

Green insecticide against Chagas disease: effects of essential oil from Myrciaria floribunda (Myrtaceae) on the development of Rhodnius prolixus nymphs

ABSTRACTThe main strategy of interrupting Trypanossoma cruzi transmission is to control the vector populations. Studies of new agents with activity against these vectors have a priority interest. This study evaluated the insecticidal activity of the essential oil of Myrciaria floribunda against nymphs of R. prolixus. M. floribunda was collected in Jurubatiba Sandbank (southeastern Brazil). Leaves were extracted by hydrodistillation and the essential oil analyzed by mass spectrometry and flame ionization gas chromatography. The pure essential oil at various dilutions or purified 1,8-cineole was topically applied to R. prolixus. Sesquiterpenes were the main group detected followed by monoterpenes. M. floribunda essential oil, but not 1,8-cineole, significantly increased mortality and disrupted metamorphosis. Overaged nymphs and juvenoid-like insects were also observed. Our data indicate the special metabolites in the essential oil of M. floribunda as promising candidates for studying insecticidal activity and for use as environmentally friendly control compounds to Chagas disease vectors.

Nanoencapsulation of thyme essential oil in chitosan-gelatin nanofibers by nozzle-less electrospinning and their application to reduce nitrite in sausages

Application of natural preservatives, such as essential oils, has attracted increasing attentions. Shirazi thyme essence with different phenolic compounds has antimicrobial and antioxidant properties. While it is sensitive to light, oxygen, humidity and high temperature. In this study, nanofibers were prepared by gelatin/chitosan in ratios of 1:6, 1:8 and 1:10 and thyme concentrations of 20 and 40% using nozzle-less electrospinning. Solution properties (i.e. viscosity and electrical conductivity) were measured. Results showed that encapsulation efficiency values were higher than 92% and loading capacity enhanced with increasing essence concentration. Diameter and morphology of fibers were analyzed by scanning electron microscopy (SEM). The nanofibers fabricated by gelatin/chitosan ratio of 1:6 containing 40% essences were the best samples with diameters in the range of 97–343nm. Fourier transform infrared (FT-IR) indicated that not any chemical interaction was occurred between ingredients during electrospinning and differential scanning calorimetry (DSC) data demonstrated that thermal stability of the essential oil enhanced by encapsulation. Antioxidant activity and antimicrobial property of pure and encapsulated essential oils against Clostridium perfringens were examined and approved the efficiency of encapsulation for protection of antioxidant activity. The nanofibers containing thyme essential oil were then used for reducing nitrite in sausages and their microbial properties, moisture content, pH, color and sensory features were evaluated. The results indicated that the encapsulated thyme essence had bactericidal effect against C. perfringens, did not have significant adverse impact on color and sensory properties of sausages in comparison to sample containing 120ppm nitrite. The data showed that nanofiber containing thyme essential oil could be a suitable nitrite substitute for meat products.

PLGA nanoparticles optimized by Box-Behnken for efficient encapsulation of therapeutic Cymbopogon citratus essential oil

This study aimed to optimize Cymbopogon citratus essential oil loaded into PLGA-nanoparticles by investigating the effect of processing variables (sonication time, ultrasound power, and essential oil/polymer ratio) on encapsulation efficiency and particle mean hydrodynamic diameter using Box-Behnken design. Nanoparticles were prepared by an emulsification/solvent diffusion method and physicochemically characterized by FTIR, DSC and TGA/DTA. Cytotoxicity was evaluated in human HaCat keratinocytes by WST-1 and LDH assays. The optimized formulation had a hydrodynamic mean diameter of 277 nm, a polydispersity index of 0.18, a Zeta potential of −16 mV and an encapsulation efficiency of 73%. Nanoparticle characterization showed that only citral was incorporated in nanocarriers, with some amount adsorbed on their surface, and highlighted the potential in increasing the oil thermal stability. The drug release profile demonstrated a biphasic pattern with a substantial sustained release depending on diffusion from the polymeric matrix. Toxicity effects on cell viability of pure essential oil at low concentrations were significantly eliminated when encapsulated. Results revealed the ability of PLGA-nanoparticles to improve essential oil physicochemical characteristics, by controlling release and reducing toxicity, suggesting their potential use in pharmaceutical preparations.