Antioxidant Activity Of Essential Oil Research Articles

Study of Chemical Composition, Antibacterial and Antioxidant Activity of Thyme Leaves and Stems Essential Oil

Given the increase in drug resistance of microorganisms and the tendency in using medicinal plants, the present study was carried out to investigate the chemical compounds of Thymol as a constituent of essential oil and antimicrobial activity against several pathogenic bacteria and its antioxidant activity. In this study, the chemical compounds of Thymol extracted from the two parts of the plant together (the leaves and stems) were performed by making use of gas chromatography and the other gas chromatography linked to the mass spectrograph and its antibacterial activity against Ecoli, Klebsiella, Pseudomonas, Staphylococcus, Salmonella Paratyphi B, Salmonella Typhi typhus and enterococci through Microdilution and the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) were investigated. The antioxidant activity of essential oils was measured through the ability of essential oil compounds in decolorizing diphenyl picrilhydrazyl (DPPH) free radicals. Chemical analysis of thyme essential oil resulted in the identification of 23 (83.68%) compounds, which Thymol with 25.30% was considered as the main part of the essential oil compound. The highest inhibitory effect was imposed on Klebsiella, Escherichia coli, and Staphylococcus aureus, and the largest inhibitory zone diameter of essential oil appeared against growth Salmonella paratyphi B. Concerning the results, total phenol was equal to 114.3 mg of gallic acid.g and IC50 of thyme was considered to be 49.94 μM/ml. The achieved results from this study declared that thyme essential oil had a suitable inhibitory effect against pathogenic bacteria and also possessed antioxidant properties. In other words, thyme was considered as an alternative to synthetic drugs and food additives.

Antioxidant and anti-inflammatory properties of essential oils from three Eucalyptus species

Abstract Eucalyptus essential oils are used as traditional medicines in many countries. The objective of this study was to evaluate the antioxidant and anti-inflammatory activities of leaf essential oils extracted from three different Eucalyptus species on HepG2 and RAW264.7 cells. Essential oils were distilled from fresh leaf samples, and the chemical constituents were analyzed using gas chromatography–mass spectrometry. The antioxidant activities of essential oils were determined using ABTS and hydroxyl radical scavenging assays, and hydrogen peroxide (H2O2)-induced oxidative stress in HepG2 cells. Additionally, lipopolysaccharide (LPS)-activated RAW264.7 macrophages were used to evaluate the anti-inflammatory properties. The results revealed that Eucalyptus citriodora and Eucalyptus urophylla leaf essential oils had a high content of oxygenated monoterpenes, whereas Eucalyptus deglupta contained a high amount of monoterpene hydrocarbons. Essential oils extracted from the three Eucalyptus species showed antioxidant and anti-inflammatory activities. E. citriodora and E. urophylla leaf essential oils had strong antioxidant activity against H2O2-induced oxidative stress in human HepG2 cells. Additionally, E. citriodora leaf essential oil, which contains a high amount of citronellal, exhibited the most potent anti-inflammatory activity in LPS-activated RAW264.7 macrophages. The antioxidant and anti-inflammatory effects of essential oils depended on their chemical composition. A principal component analysis explained 100% of the variance was performed to construct three groups based on the chemical components and antioxidant and anti-inflammatory activities. This study suggests that E. citriodora leaf essential oil, which represents a good source of oxygenated monoterpenes, could be considered a potential phytochemical agent for the prevention of oxidative stress and inflammation. Keywords: Antioxidant, Anti-inflammatory effect, Eucalyptus essential oils, Gas chromatography–mass spectrometry, Principal component analysis

Composition and Anti-Inflammatory and Antioxidant Activity of Essential Oil from Aucuba japonica var. variegata

Composition and Anti-Inflammatory and Antioxidant Activity of Essential Oil from Aucuba japonica var. variegata

Assessment of phytochemical screening, total phenolic content, antioxidant activity of leaves and stems extract from Adenocarpus bacquei and its essential oil antioxidant activity

The researchers’ focus has recently been directed towards finding new natural antioxidants especially those originated from plants. This work is about the screening of phytochemical constituents and the variation of total phenolic and flavonoid content for different parts of Adenocarpus bacquei (leaves and stems) harvested from Morocco. It regards also extracting its essential oil , analyzing its chemical composition by gas chromatography-mass spectrometry (GC/MS) which reveals the presence of 25 compounds where the major one is the (+)-2-Bornanone (38.26%) followed by Eucalyptol (27.74%).Yet, this essential oil proved great antioxidant capacities measured with TAC and DPPH assays. On the other hand, the phytochemical analysis of Adenocarpus bacquei‘s leaves and stems showed the existence of principal groups of secondary metabolites (tannins, flavonoids, mucilage, oses and holosides sterols and triterpenes and combined antraquinons). Quantifying total phenolic and flavonoid content of different crudes extracts of leaves and stems of Adenocarpus bacquei was done using solvents with different polarity (hexane, dichloromethane, ethyl-acetate, ethanol and water). These crude extracts’ total antioxidant activity and radical scavenging activity were respectively evaluated with the phosphomolybdenum and DPPH assays. Therefore, the results showed a simultaneous increasing in total phenolic content of crude extract and the solvent polarity. Yet, the aqueous leaves extract indicates the highest TPC. Also, the results show a significant positive correlation between TAC and DPPH assay in relation with the total phenolic and flavonoid content. These results revealed the powerful capacity of Adenocarpus bacquei’s essential oil and crudes extracts which comes to conclude that Adenocarpus bacquei can be a natural resource of antioxidants.

The variation in essential oils composition, phenolic acids and flavonoids is correlated with changes in antioxidant activity during Cinnamomum loureirii bark growth

Cinnamomum loureirii is one of the most important medicinal and aromatic plants. It is used by the food, perfumery, cosmetic, and pharmaceutical industries. The objective of this study was to examine the relationships between the chemical composition and antioxidant activity of essential oil (EOs) and ethanol extracts from 10 samples of the bark from C. loureirii trees (6–15 years old). Obtained results showed that C. loureirii bark EO content at 12–15 years old had high oil yields (4.52–5.48%). The major components in the EOs were trans-cinnamaldehyde (50.2–92.9%) and α-copaene (0.5–21.3%). The highest content of trans-cinnamaldehyde in bark EOs was obtained from 10 to 12-year-old trees, while the highest content of α-copaene was obtained at 13–15 years. The highest total phenolic (429.85 and 474.45 mg TAE /g DW) and total flavonoid contents (85.54 and 102.80 mg RE /g e DW) were obtained from the 13- to 14-year-old trees. Our results indicated that the EO and ethanol extract of 13- to 14-year-old bark showed the strongest antioxidant properties. Moreover, GC–MS, PCA and correlation analysis indicated that the changes in α-copaene, beta-caryophyllene, τ-muurolene, γ-muurolene, δ-cadinene and τ-muurolol were positively correlated with the changes in antioxidant activity in oils. Meanwhile, procyanidin B2 and hyperoside were the main contributors to the antioxidant activity of the ethanol extract from C. loureirii bark. This study is the first one that report the antioxidant potential and phenolic profile of C. loureirii plant. These results provide reference information for the rational utilization of C. loureirii resources and the harvest of C. loureirii bark as medicinal materials during the optimal period.

Biological Activity of Extracts from Aromatic Plants as Control Agents against Spoilage Molds Isolated from Sheep Cheese.

The aim of this work was to assess the antifungal and antioxidant activity of essential oils and ethanolic extracts from distilled solid by-products from aromatic plants (Artemisia dracunculus, Hyssopus officinalis, Lavandula stoechas, Origanum vulgare and Satureja montana) against 14 fungi strains isolated from sheep cheese and identified at species level using DNA barcoding based on β-tubulin sequence analysis. In addition, capacity of fungi to produce ochratoxin A, patulin, cyclopiazonic acid and sterigmatocystin was analyzed. Of the isolates, 85.7% belonged to Penicillium (P. commune/biforme, P. crustosum) and 14.3% to Aspergillus (A. puulaauensis and A. jensenii), the first time that these Aspergillus species have been found in sheep’s cheese. All P. commune isolates were producers of cyclopiazonic acid, and the two Aspergillus strains produced sterigmatocystin, but the others did not produce any tested mycotoxin. Among the essential oils tested, oregano, savory and tarragon had a significant antifungal activity against all the isolated strains, but no ethanolic extract showed antifungal activity. By contrast, ethanolic extracts showed great potential as antioxidants. The identification of new molds in cheese will help the dairy industry to know more about those molds affecting the sector, and the use of aromatic plants in the control of fungal spoilage could be a suitable alternative to chemical preservatives used in the agri-food industry.

Chemical Composition and Antioxidant Activity of Essential Oil of Coriandrum sativum L. Seeds Cultivated in Afghanistan

Coriandrum sativum L. is an aromatic plant belonging to the Apiaceae (Umbelliferae) family, originating in the Mediterranean region. C. sativum is widely cultivated worldwide and has nutritional and medicinal values. The C. sativum seeds contain an essential oil that is used in different industries like pharmaceuticals, cosmetics, and food. This study aims to extract, analyze, and evaluate the antioxidant activity of C. sativum seed essential oil cultivated in Afghanistan. The essential oil was extracted by hydro-distillation (HD) extraction and analyzed by High-performance thin-layer chromatography (HPTLC). The HD extraction provided an essential oil yield of 0.16 % (v/w). Also, HPTLC analysis of the essential oil determined two components of the oil, linalool and myrcene. The quantification of linalool content and HPTLC method validation were determined using densitometric analysis. As a result, the linalool content was identified 60.06 %, and the HPTLC method proved as a valid method for analysis of the essential oil. Furthermore, the antioxidant activity of the essential oil was determined using DPPH radical scavenging assay and reported as IC50. The ascorbic acid utilized as the positive control, and the antioxidant activity of the essential oil evaluated in comparison with ascorbic acid. The IC50 of ascorbic acid and the essential oil were determined 0.02 ± 0.0004 (mg/ml) and 21.05± 0.284 (mg/ml), respectively. Thus, the essential oil showed lower antioxidant activity than ascorbic acid. This study is the first report on the extraction, chemical composition, and antioxidant activity of C. sativum seed essential oil cultivated in Afghanistan.

Comparative Analysis of Intracellular and in vitro Antioxidant Activities of Essential Oil From White and Black Pepper (Piper nigrum L.).

Ethnopharmacological Relevance: Pepper essential oils have potential immunomodulatory, anti-tumor, and anti-cancer activities. Pepper exhibits the potential to prevent or attenuate carcinogenesis as therapeutic tools. However, the related mechanism remains unelucidated. Aim of the Study: The present study aims to provide reasonable information for the explanation of the dissimilarity of the essential oils from white (WPEO) and black pepper (BPEO). Materials and Methods: WPEO, BPEO, and their single active component, as well as synthetic antioxidants, were compared by the cell model methods and chemical methods, including intracellular antioxidant activity (CAA), total antioxidant activities (TAA), superoxide radical (SR), hydroxyl radical (HR), DPPH radical (DR) scavenging activities and inhibition ability of lipoprotein lipid peroxidation (ILLP). Results: The median effective concentration (EC50) values (mg/mL) of the WPEO and BPEO of SR, HR, DR, and ILLP were 0.437 and 0.327, 0.486 and 0.204, 7.332 and 6.348, 0.688, and 0.624 mg/mL, respectively. The CAA units of WPEO and BPEO were 50.644 and 54.806, respectively. CAA, DR, and TAA of BPEO were significantly higher than those of WPEO (p < 0.05). The BPEO and WPEO can be differentiated as the former have higher correlations with 3-carene, α-pinene, β-pinene, and limonene while the latter has a higher caryophyllene correlation. The WPEO and BPEO show a good intracellular scavenging ability of reactive oxygen species in HeLa cells. Conclusion: Generally, pepper oil has stronger activities than single components, indicating that pepper is a broad-spectrum natural antioxidant.

Physicochemical characterization and evaluation of the antioxidant activities of essential oil extracted from Eucalyptus globulus

Physicochemical characterization and evaluation of the antioxidant activities of essential oil extracted from Eucalyptus globulus

Insecticidal, antimicrobial and antioxidant activities of essential oil from Lavandula latifolia L. and its deterrent effects on Euphoria leucographa

Lavandula latifolia L. is a medicinal plant has fungicidal, antibacterial and antioxidant properties. The aim of this study was to determine the chemical composition, antioxidant and antimicrobial activities of essential oil (EO) of L. latifolia L. extracted by hydrodistillation method. A total of 22 constituents were identified in L. latifolia L. using Gas chromatography–mass spectrometry analysis. The compounds such as, gamma-terpinene (26.8 %), camphor (13.8 %), 1,8-cineole (10.2 %), lavandulol (9.3 %), terpinen-4-ol (9.1 %), linalool (8.9 %), b-elemene (3.2 %), b-pinene (3.1 %), 1,4-cineole (3.07 %), camphene (2.32 %), a-terpineol (2.3 %), and a-copaene (2.2 %) were determined. The antifungal activity of this EO against five phytopathogenic fungi revealed their broad-spectrum and strong antifungal properties. Notably, the EO showed potent activity on Trichophyton mentagrophytes (31 ± 1 mm) and the minimum inhibitory concentration value was 0.125 ± 0.05 μg/mL. The oil, analyzed for its DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2_-azinobis-(3-ethylbenzothiazoline-6- sulphonic acid)] free radical scavenging activity. Hydrodistilled EO had higher ABTS scavenging capacity than DPPH free radical scavenging power. Essential oil was used to test pesticide activity against Euphoria leucographa (Order: Coleoptera; Family: Scarabaeidae) infected in custard apple (Annona muricata) fruit. Results indicated that the spike lavender EO had contact toxicity on E. leucographa upon topical treatment. The effective concentration at 50 % (EC50) value of EC of L. latifolia L. was 0.37 % revealed considerable fumigant activity mainly due to the presence of fragrant compounds. Interestingly, custard apple (A. muricata) treated with EO effectively controlled the growth of T. mentagrophytes. Overall, antifungal and insecticidal properties of lavender EO, as a natural choice to preserve the harvested fruits thereby protecting the industrial crops.

Evaluation of antioxidant activity and phytochemical composition of Baeckea frutescens and Leptospermum javanicum essential oils

Plant extracts such as essential oils are a common yet valuable source of antioxidants for application in pharmaceutical and food preservative. In this study, the phytochemical profile of Baeckea frutescens (BF) and Leptospermum javanicum (LJ) essential oils were determined using GC-FID and GC/MS analyses. This resulted in the identification of 13 components (82.03%) in the essential oil of BF, the major compounds were p-cymene (1, 31.06%), α-pinene (2, 24.53%), 1,8-cineole (3, 11.49%), and γ-terpinene (4, 8.31%). Whilst, 32 components (84.62%) were detected in the essential oil of LJ, in which sabinene (5, 25.83%) and α-pinene (2, 12.17%) were the major components. The antioxidant activity of the essential oils were evaluated using a wide array of radical scavenging assays, such as DPPH radical scavenging, reducing power, metal chelating, and β-carotene bleaching assays. From the results, both BF and LJ essential oils exhibited appreciable antioxidant activity in all assays (EC50 0.29–1.39 mg/mL), except in DPPH radical scavenging assay (EC50 > 50 mg/mL). The essential oil of BF had a higher overall antioxidant capacity than LJ. With reference to the phytochemical profile, compounds 1–5 are potent antioxidants, which may substantially contribute to the antioxidant capacity of the essential oils.

Evaluation of Antibacterial and Antioxidant Activities of Essential Oil of Lime (Citrus aurantifolia) Pomace Powder

This study aimed to determine the chemical compounds, antioxidant and antimicrobial activities of Essential Oil (EO) derived from lime pomace. Gas chromatography/mass spectrometry (GC-MS) was used to determine the major components of the obtained EO. The antioxidant activities of this EO were determined by radical scavenging activity (DPPH) and the Ferric Reducing Antioxidant Power (FRAP) test. For antimicrobial activity, the disk diffusion method was used and the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were studied against common foodborne pathogens including; Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The result showed that the Gram-positive bacteria were more susceptible than gram-negative bacteria. The result shows that lime pomace powder with IC50 83.061 mg/mL has a high antioxidant capacity and also, the chemical analysis of the EO showed that the EO contained a complex mixture of several components and the main constituents were D-limonene (28.86%), α- terpinene (15.65%) and γ-terpinene (12.72%) respectively.

Anti-Quorum Sensing and Antioxidant Activity of Essential Oils Extracted From Juniperus Species, Growing Spontaneously in Tebessa Region (East of Algeria)

The chemical composition of essential oils (EOs) extracted from the aerial parts of 2 species of Juniperus was determined by Gas Chromatography-Mass Spectrometry (GC-MS). In total, 65 and 58 compounds accounting for 90.3% and 89.8% of the whole chemical composition of Juniperus oxycedrus (JO) and Juniperus phoenicea (JP) were identified, respectively, with α-pinene, α-amorphene, terpinen-4-ol, α-terpinene, and β-elemene, as major components. For the first time, the capacity to inhibit quorum-sensing for Chromobacterium violaceum CV026 and CV12472 by the investigated EOs was evaluated. Both oils exhibited good violacein inhibition on CV12472 with 100.0 ± 0.0% inhibition at minimal inhibition concentration (MIC) values. Besides, the quorum-sensing inhibition of CV026 was high at MIC for JO essential oil from fruits (JOF, 16.3 ± 2.0 mm), JO leaves (JOL, 12.5 ± 3.5 mm), JP fruits (JPF, 19.7 ± 2.5 mm), and JP leaves (JPL, 21.1 ± 5.0 mm). On both CV12472 and CV026, essential oil from J. phoenicea leaves was the most active inhibitor. All investigated EOs inhibited swarming motilities in flagellated Pseudomonas aeruginosa (PA01) in a concentration-dependent manner, and those from JP were more active than EOs from JO. Moreover, these EOs showed good antioxidant potential according to DPPH● and FRAP methods, especially the EO from JO leaves with an IC50 DPPH● inhibition value of 20.2 ± 1.0 mg/mL. Based on the obtained results, the investigated EOs are good candidates to combat microbial resistance be used as alternatives to conventional antibiotics, and equally find applications in food biosafety as preservatives.

Chemical composition, antimicrobial, antioxidant and cytotoxic activity of the essential oil from the leaves of Stachys pilifera Benth.

Stachys pilifera Benth is an endemic species of Stachys family found in Iran with a wide application as an herbal tea. The objective of this research was to evaluate the antimicrobial, antioxidant and cytotoxic activity of the essential oil from the aerial parts of S. pilifera. Essential oil (EO) composition analysis showed that cis-Chrysanthenyl acetate (24.9%), viridiflorol (18.3%), trans-Caryophyllene (9.8%), caryophyllene oxide (4.6%), α-terpineol (3.3%) and linalool (3.1%) were the most abundant components. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the EO showed a higher antimicrobial activity against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) than Gram-negative organisms (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella enterica subsp. Enterica). The antioxidant activity of EO was studied using DPPH, FRAP and β-carotene/linoleic acid assays. IC50 for the DPPH, FRAP and β-carotene/linoleic acid tests were 23.2, 28.7 and 16.1µg/mL, respectively, that it was higher than the results for BHT (P≤0.05). The cytotoxic activity of the EO was evaluated using HT29 and HUVEC cells and it was observed that by increasing in EO concentration from 0.026 to 19.4 ug/mL, the viability of the cells for HT29 and HUVEC reduced to 6.8 and 7.1%, respectively. The results from this study suggest the possibility to use the essential oils from S. pilifera Benth as a natural preservative in processed or packaged food due to its high antibacterial, antioxidant and cytotoxic activities.

Antioxidant and antimicrobial activities of fennel, ginger, oregano and thyme essential oils

AbstractIn this study, the aim was to evaluate the antimicrobial and antioxidant activities of thyme (Thymus vulgaris), oregano (Origanum vulgare), ginger (Zingiber officinale) and fennel (Foeniculum vulgare) essential oils in addition to their chemical compositions. Based on the results of gas chromatography‐mass spectrometry (GC—MS) analysis, major components were thymol andp‐cymene in thyme, carvacrol, andp‐cymene in oregano, α‐zingiberene and ar‐curcumene in ginger and (E)‐anethole in fennel essential oils. Essential oils were investigated for their antimicrobial activities by agar well diffusion and broth microdilution methods againstCampylobacter jejuniandCampylobacter coli. The inhibition zone diameters varied from 9.2 ± 0.7 to 28.7 ± 2.1 mm forC. jejuniand 14.7 ± 2.0 to 27.8 ± 2.8 mm forC. coli. While the minimum inhibitory concentrations (MICs) were lower for thyme and oregano EOs (5.65–43.20 μg/ml), the highest MIC value was obtained in fennel EO againstC. jejuni(28530 μg/ml). Total phenolic contents and antioxidant activities of these essential oils were evaluated by using Folin Ciocalteu, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), Cupric Reducing Antioxidant Capacity (CUPRAC) and 2, 2‐azinobis(3‐ethylbenzo‐thiazoline)‐6‐sulphonic acid (ABTS) methods. The total phenolic content of the essential oils ranged between 7.72 (ginger) to 193 (thyme) mg GAE/L. Antioxidant activities of thyme and oregano were found to be the highest according to the ABTS method, whereas thyme was found to be the highest by the CUPRAC method and ginger by the DPPH method.

Chemical Composition and Antioxidant Activities of Essential oil from Leaf and Stem of Elettaria cardamomum from Eastern India

Elettaria cardamomum (L.) Maton (Zingiberaceae), commonly known as green or true cardamom, is a commercially important species, the seeds of which are extensively used in the pharmaceutical, cosmetic and food industries. In spite of the increasing demand for cardamom essential oil in the international market, the chemical profiling of volatile compounds of different plant parts are not well explored. Though there are a few studies on the chemical characteristics of its leaf oil from other phytogeographical regions, the presence and chemical composition of essential oil from stems have not yet been reported. Therefore, the present study was undertaken to characterize the chemical composition and antioxidant activity of leaf and stem essential oil of E. cardamomum. The essential oil extracted by hydro-distillation from the leaf and stem revealed the presence of 43 and 37 compounds, representing 92.71 % and 92.12 % of total oil respectively by GC/MS analysis. The major constituents of the leaf essential oil were 1,8-cineole (20.66 %), camphene (18.09 %), camphor (10.02 %) and tricyclene (7.36 %); whereas α-terpinyl acetate (19.75 %), 1,8-cineole (10.38 %), caryophyllene oxide (7.13 %) and β-eudesmol (4.85 %) were rich in the stem essential oil. Oxygenated monoterpenes were the major terpenic fraction in the leaf and stem essential oil of E. cardamomum. The free radical scavenging ability assessed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assay showed that leaf oil had better activities as compared to stem oil. The present findings demonstrated that E. cardamomum growing wild in Eastern India could be considered as an important bioresource and natural antioxidant.

Chemical Constituents, In Vitro Antibacterial Properties and Antioxidant Activity of Essential Oils from Marrubium vulgare L. Leaves

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Investigation of the effect of essential oil along with nanocoatings containing gums in the development of fish fillet storage time

In this study, the antioxidant activity of Bunium persicum essential oil (EO) at different concentrations of 1%, 1.5%, and 2% (W/V) was evaluated. Also, antibacterial effect of three types of nano-coatings, i.e., basil seed gum (BSG), Lepidium perfoliatum seed gum (LPSG), and their combination (1:1 ratio), was examined for extending the shelf life of rainbow trout (Oncorhynchus mykiss) fillets for 16 days at 4 °C. The amount of phenolic compounds for Bunium persicum was 133.81 ± 2.74 mg/g. The antioxidant activity of EO was assessed by two methods of DPPH and beta-carotene at different concentrations (200, 400, 600, 800, and 1000 mg/L). The size of the prepared nano-coatings ranged from 265.17 to 454.66 nm and the zeta potential was negative for all of them. In order to study the effect of nanocomposite coating on the shelf life, 10 treatments including control, BSG, LPSG, and their combination with EO (at 1, 1.5, and 2%) were prepared and peroxide value, thiobarbituric acid, as well as pH, total volatile nitrogen, total viable count, total psychrotrophic count were measured in 4-day intervals. The results showed that the nano-coatings containing EO had antioxidant and antimicrobial properties and were able to improve the above-mentioned properties. The data obtained from this study revealed that the nano-coatings containing EO could delay the oxidation process and microbial spoilage of the treatments (p < 0.05); by increasing the concentration of EO, better results were observed. According to the results, BSG-LPSG containing 2% EO can be used as a proper substitute for artificial and chemical food preservatives.

Laurus nobilis, Salvia sclarea and Salvia officinalis Essential Oils and Hydrolates: Evaluation of Liquid and Vapor Phase Chemical Composition and Biological Activities.

Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs and HYs. 1,8-Cineole (42.2%, 33.5%) and α-pinene (16.7%, 39.0%) were the main compounds of L. nobilis EO; 1,8-cineole (30.3%, 48.4%) and camphor (17.1%, 8.7%) were for S. officinalis EO; linalyl acetate (62.6%, 30.1%) and linalool (11.1%, 28.9%) were for S. sclarea EO for the liquid and vapor phase, respectively. Chemical profile of HYs was characterized by 1,8-cineole (65.1%, 61.4%) as a main constituent of L. nobilis and S. officinalis HYs, while linalool (89.5%) was the main constituent of S. sclarea HY. The antioxidant activity of EOs and HYs was carried out by DPPH and ABTS assays and antimicrobial properties were also investigated by microdilution and the disc diffusion method for liquid and vapor phase against five different bacterial strains such as Escherichia coli ATCC 25922, Pseudomonas fluorescens ATCC 13525 and Acinetobacter bohemicus DSM 102855 among Gram-negative and Bacillus cereus ATCC 10876 and Kocuria marina DSM 16420 among Gram-positive. L. nobilis and S. officinalis EOs demonstrated considerable antibacterial activity, while S. sclarea EO proved to be less effective. Agar diffusion method and vapor phase test showed the EOs activity with the biggest halo inhibition diameters against A. bohemicus and B. cereus. A remarkably high antioxidant activity was determined for L. nobilis showing low EC50 values and also for S. sclarea; good EO results were obtained in both of the used assays. S. officinalis EC50 values were slightly higher to which corresponds to a lower antioxidant activity. Concerning the HYs, the EC50 values for L. nobilis, S. officinalis and S. sclarea were remarkably high corresponding to an extremely low antioxidant activity, as also obtained by expressing the values in Trolox equivalent antioxidant capacity (TEAC).

Chemical composition and antioxidant activity of essential oils from barks of Pinus pumila using microwave-assisted hydrodistillation after screw extrusion treatment

A screw extrusion treatment method successfully applies to the extraction of essential oils from Pinus pumila barks under microwave-assisted hydrodistillation conditions, which effectively promotes the increase of the yield of essential oils. Moreover, some potential factors affecting the yield of essential oils have been systematically analyzed and optimized through single factor screening method and Box-Behnken design, and the optimum operating conditions were liquid-solid ratio 5.82 mL/g, microwave irradiation power 585 W, and microwave irradiation time 30 min. Meanwhile, the satisfactory yield of essential oils was 16.51 ± 0.83 mL/kg in the derived optimum conditions, which was highly consistent with the predicted result (17.14 mL/kg) by the Box-Behnken design model. By comparing the kinetic curves of the separation of essential oils by different methods, the bark after the screw extrusion process can obtain higher yield and separation efficiency of essential oils through the microwave-assisted hydrodistillation method. The antioxidant properties and the yield of the essential oils separated by different methods were compared, and the antioxidant capacity and the yield of the essential oils obtained from the barks that were processed by screw extrusion treatment were significantly better than other treatment methods. By comparing the raw materials obtained by different treatment methods and their residues after essential oil separation, it was confirmed that the screw extrusion treatment method greatly increases the yield of the essential oils. The results show that the introduction of screw extrusion treatment and microwave-assisted hydrodistillation in the separation of essential oil has produced significant changes, which may become a new type of essential oil separation technology and be applied to the market.