ANTIOXIDATIVE AND ANTIBACTERIAL POTENTIALS OF ESSENTIAL OILS AND EXTRACTS ISOLATED FROM VARIOUS SPICE MATERIALS†

The antioxidant and antibacterial potentials of essential oils and acetone extracts of black pepper, cumin, black cumin and mace were carried out by different techniques. The antioxidative capacity of the essential oils and acetone extracts were evaluated against mustard oil by measuring peroxide and thibarbituric acid values at fixed intervals. In addition, their antioxidant potential was evaluated by 2, 2′‐diphenyl‐1‐picrylhydracyl radical and conjugated diene assays. Their reducing power was determined with standards, which proved the strong antioxidant capacity of essential oils and extracts. The antioxidant activity of essential oils and extracts exerted by all the antioxidant assays can be compared with synthetic antioxidants such as butylated hydroxyanisole and butylated hydroxytoluene. The antibacterial activity was studied by disk diffusion and poison food methods. Black cumin essential oil showed complete zone of inhibition (P < 0.05) against tested bacterial strains of Staphylococcus aureus, Bacillus cereus and Bacillus subtilis at 2 and 6 µL level by disk diffusion method. Black cumin and black pepper extracts showed complete reduction of colonies against tested bacterial strains of S. aureus, B. cereus and B. subtilisat 5 and 10 µL level by poison food method. Poison food method exhibited good results for the tested essential oils and extracts. Essential oils of black pepper, cumin, black cumin and mace may be used to stabilize mustard oil after screening.     

Comparative Antibacterial,Chemical and Morphological Study of Essential Oils of Thymbra spicata var. spicata Leaves by Solvent-Free Microwave Extraction and Hydro-Distillation

The essential oils of Thymbra spicata var. spicata were obtained by both hydrodistillation and solvent-free microwave extraction methods. Chemical composition and antibacterial activity of the essential oils were examined. The main constituents of both essential oils obtained by solvent-free microwave extraction and hydrodistillation from Thymbra spicata var. spicata were carvacrol (44.8–36.1%), γ-terpinene (23.8–26.1%), and p-cymene (7.3–9.6%), respectively. The essential oil obtained from solvent-free microwave extraction contained substantially higher amounts of oxygenated compounds and lower amounts of monoterpenes than hydrodistillation. The antibacterial activities of the essential oils from solvent-free microwave extraction and hydrodistillation were evaluated by the disc diffusion method against six bacterial strains. The essential oil extracted by solvent-free microwave extraction was more effective than the essential oil extracted by hydrodistillation against the tested bacteria except for E. coli ATCC 25922- and S. aureus ATCC 25923+. Especially, S. aureus ATCC 25923+ was more sensitive against the essential oils obtained from Thymbra spicata var. spicata. Scanning electron microscopy measurements show that glands (that are filled with essential oils) were subjected to more severe thermal stresses and localized high pressure by microwave heating, the pressure build up within the glands could have exceeded their capacity for expansion and break down of cell walls. Solvent-free microwave extraction resulted in more extract release more rapidly than in hydrodestillation.     

Insecticidal and repellent activity of essential oil from Amomum villosum Lour. and its main compounds against two stored-product insects

The Amomum villosum essential oil was obtained from hydrodistillation and was investigated by GC-MS. The main constituents were bornyl acetate (51.6%), camphor (19.8%), camphene (8.9%) and limonene (6.2%). Insecticidal toxicity of the essential oil was evaluated in this study. It showed that the essential oil possessed contact toxicity against Tribolium castaneum and Lasioderma serricorne (LD₅₀ = 32.4 and 20.4 μg/adult). Three monoterpenoids camphor, camphene and limonene showed strong fumigant toxicity against T. castaneum (LC₅₀ ＜ 2.3, LC₅₀ ＝ 6.2 and 6.2 mg/L air). In addition, repellency of the essential oil was also evaluated. Data showed that the essential oil and all four compounds had repellent activity against T. castaneum and L. serricorne at high concentration (78.63 nL/cm²). But with the decrease of concentration, they showed a different degree of attractant properties.     

Stereoisomeric flavour compounds LXXI: determination of the origin of aroma-active dihydrofuranones

The odour characteristics of chiral 3[2H]-furanones, which are important aroma compounds, have been evaluated by sniffing the separated enantiomers through the port of a gas chromatograph (gc-sniffing). The results revealed great differences in the odour quality and thresholds of the single enantiomers. The determination of the origin of 2,5-dimethyl-4-hydroxy-3[2H]-furanone and 2,5-dimethyl-4-methoxy-3[2H]- furanone from strawberries, pineapples and commercial samples has been achieved using GC-isotope ratio mass spectrometry (GC-IRMS). For this technique to be successful, it is essential that preparative and storage procedures should not influence the isotope ratio of compound analysed; this is demonstrated to be the case for 2,5-dimethyl-4-hydroxy-3[2H]-furanone.     

Reaction of 3-deoxypentosulose withN-methyl- andN,N-dimethylguanidine as model reagents for protein-bound arginine and for creatine

Deoxyosones are established key-intermediates in Maillard processes. Due to their dicarbonyl structure, they undergo condensation to form heterocyclic compounds with guanidine derivatives. In biological systems, guanidino functions are present in protein-bound arginine moieties as well as in creatine. The reactivity of such structures towards 3-deoxypentosulose is investigated withN-methyl- andN,N-dimethylguanidine as model substrates. Two diastereoisomers each are isolated from both reactions; they have been characterized unequivocally, respectively, as 4-(2,3-dihydroxypropyl)-2-N-methylamino-2-imidazolin-5-one and 4-hydroxy-5-(2,3-dihydroxypropyl)-2-(N,N-dimethylamino)-5H-imidazole. In aqueous medium as well as in the crystalline state, both diastereoisomer pairs exist in different tautomeric forms.     

Influence of fibre addition on the rheological properties of peach juice

The addition of dietary fibres is a tendency in several foods. Understanding the changes in food sensory and physical properties due to fibre addition is thus, essential for food process design. The present work has evaluated the influence of peach fibre addition on the rheological properties of peach juice. Flow behaviour and influence of fibre concentration on Herschel‐Bulkley model’s parameters were evaluated. The flow behaviour of the products was changed due to fibre addition, from Newtonian to pseudoplastic and then, Herschel‐Bulkley behaviour. The parameters could be well modelled by exponential (σ₀), power law (k) and sigmoidal (n) functions (R² > 0.98). The viscoelastic properties were evaluated for the most concentrated products. Variation of storage and loss modulus with the oscillatory frequency were well described by a power function (R² > 0.96), and dependency of its parameters with temperature was well modelled by Arrhenius’ model (k′, k″, R² > 0.94) and quadratic function (n′, n″, R² > 0.90).     

OPTIMAL GRINDING CHARACTERISTICS OF BLACK PEPPER FOR ESSENTIAL OIL YIELD

Black pepper (Piper nigrum L) was ground to different particle sizes at ambient conditions, and the ground material temperatures at the mills’outlet were recorded. The surface mean diameter (d_s) and geometric mean diameter (d_ga) of the pepper grits were determined by sieve analysis. Energy for size reduction was computed using Bond's equation. The quantity of essential oil distilled, using Clevenger's method, was recorded at 30 minutes interval for each particle size. Effective diffusion coefficient (D) determined using Fick's second law, was constant (1.38 × 10^?11 m²s^?1) for higher oil concentrations and it was very less in lower oil concentrations. The essential oil yield was evaluated in terms of four major compounds using gas chromatographic analysis. The particle size (d_go) of about 0.7 mm was found to be optimal for distillation of essential oil.     

Chemical Composition and Anticancer and Antioxidant Activities of Schinus Molle L. and Schinus Terebinthifolius Raddi Berries Essential Oils

Abstract: Essential oils were obtained by steam distillation from berries of Schinus molle L. and Schinus terebinthifolius Raddi originating from southern of Tunisia and analyzed by GC-FID and GC-MS. Among 57 and 62 compounds (%[mg/100 g dry matter]) identified in these oils, the main were α-phellandrene (46.52%[1256.15] and 34.38%[859.60]), β-phellandrene (20.81%[561.74] and 10.61%[265.15]), α-terpineol (8.38%[226.26] and 5.60%[140.03]), α-pinene (4.34%[117.29] and 6.49%[162.25]), β-pinene (4.96%[133.81] and 3.09%[77.30]) and p-cymene (2.49%[67.28] and 7.34%[183.40]), respectively. A marked quantity of γ-cadinene (18.04%[451.05]) was also identified in the S. terebinthifolius essential oil whereas only traces (0.07%[1.81]) were detected in the essential oil of S. molle. The in vitro antioxidant and antiradical scavenging properties of the investigated essential oils were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Essential oil of S. terebinthifolius expressed stronger antioxidant activity in the ABTS assay, with an IC₅₀ of 24 ± 0.8 mg/L, compared to S. molle (IC₅₀= 257 ± 10.3 mg/L). Essential oils were also evaluated for their anticancer activities against human breast cancer cells (MCF-7). S. terebinthifolius essential oil was more effective against tested cell lines (IC₅₀= 47 ± 9 mg/L) than that from S. molle (IC₅₀= 54 ± 10 mg/L). Suggestions on relationships between chemical composition and biological activities are outlined.     

Determination of Chemical Composition,Total Phenolic,Antimicrobial, and Antioxidant Activities of Echinophora tenuifolia Essential Oil

In this study, the antioxidant and antimicrobial activities, total phenolic content, and essential oil composition of Echinophora tenuifolia L. subsp. sibthorpiana were investigated. The antioxidant activity of investigated essential oil was assessed by ABTS and DPPH assays. DPPH radical scavenging activity expressed by IC₅₀ was 2.84 g/L, whereas the TEAC value determined by ABTS assay was 0.032 g TEAC/kg plant. Total phenol content of essential oil determined by Folin-Ciocalteu method was calculated as 1.32 g GAE/kg plant. The essential oil extracted by hydrodistillation (Clevenger apparatus) was investigated by GC-MS technique and 78 compounds were identified. The main components of essential oils were found to be δ-3-carene (17.93%), p-cymene (8.99%), methyleugenol (16.41%), and α-phellandrene (9.33%). The antimicrobial activity of investigated essential oil was tested using a broth dilution method against 13 bacterial and 2 fungal microorganisms. The lowest minimum inhibitory concentration of essential oil against Bacillus cereus was 62.5 μg/mL while the antifungal activity was greater than 1000 μg/mL for both Candida albicans and Saccharomyces cereviciae. Investigated essential oil has a certain level of antioxidant and antimicrobial effects, which may be attributed to their chemical compounds. The antimicrobial efficiency of essential oil, especially against Bacillus cereus and Staphylocoocus spp., offers its effectiveness to treatment of wound or disease caused by Gram positive bacteria.     

Effect of essential oils of cinnamon,clove, lemon grass,oregano and palmarosa on growth of and fumonisin B1 production by Fusarium verticillioides in maize

The ability of cinnamon, clove, lemon grass, oregano and palmarosa essential oils to prevent growth of and fumonisin B₁ (FB₁) production by Fusarium verticillioides at different water activity (0.95 and 0.995 a_w) and temperature (20 and 30 °C) levels in irradiated maize grain was evaluated. All the essential oils inhibited growth of F verticillioides isolates under all conditions tested, but FB₁ production was only inhibited at 30 °C and 0.995 a_w. Moreover, stimulation of toxin production was found under certain environmental conditions. None of the essential oils showed a significantly greater ability to inhibit FB₁ production when compared with the others. At 1000 mg essential oil kg^?1 maize the essential oils showed a greater inhibitory effect on growth of F verticillioides than at 500 mg kg^?1, but there was no difference in FB₁ production between the two levels of essential oil. Copyright © 2004 Society of Chemical Industry     

IV. Yeast sequencing reports. Nucleotide sequence of the SAC2 gene of Saccharomyces cerevisiae

A temperature-sensitive mutation (act1-1) in the essential actin gene of Saccharomyces cerevisiae can be suppressed by mutations in the SAC2 gene. A cloned genomic DNA fragment that complements the cold-sensitive growth phenotype associated with such a suppressor mutation (sac2-1) was sequenced. The fragment contained an open reading frame that encodes a 641 amino acid predicted hydrophilic protein with a molecular weight of 74 445. No sequences with significant similarity to SAC2 were found in the GenBank and EMBL databases. A SAC2 disruption mutation was constructed which had phenotypes similar to the sac2-1 point mutation. A haploid SAC2 disruption strain failed to grow at low temperature and the disruption allele suppressed the temperature-sensitive act1-1 growth defect. The suppression phenotype was dependent on the strain background. The SAC2 sequence has been submitted to the EMBL data library (Accession Number Z29988).     

Antibacterial and antioxidant activities of the essential oil and methanol extracts of Bidens frondosa Linn

Antibacterial and antioxidant potential of essential oil, extract and its fractions of Bidens frondosa Linn were evaluated. Sixty‐one components representing 95.41% of the total oil were identified. The essential oil (7.5 μL disc^?1), methanol extract and its different organic subfractions (0.5 μg disc^?1) of B. frondosa displayed a great potential of antibacterial activity against Staphylococcus aureus (ATCC 6538 and KCTC 1916), Listeria monocytogenes ATCC 19116, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa KCTC 2004, Salmonella enteritidis KCTC 12021 and Enterobacter aerogenes KCTC 2190. Antioxidant activity was evaluated by using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. The free radical scavenging activity of ethyl acetate (EtOAc) fraction was superior to all other fractions (IC₅₀ = 11.96 μg mL^?1), which was higher than synthetic antioxidant butylated hydroxyanisole, (IC₅₀ = 18.27 μg mL^?1). Furthermore, the amount of total phenolic compounds was determined and its content in EtOAc fraction was the highest as compared to methanol extract or other fractions. The results indicate that the oil and extracts of B. frondosa could serve as an important bio‐resource of antimicrobial agents and antioxidants for using in the food industries.     

Three new compounds from the seeds of Trachyspermum copticum

The effect of the application of nano-silicon (SiO₂; 1.5 and 3 mM) on components of essential oils of Trachyspermum copticum was evaluated. Essential oils extracted by hydrodistillation from Iranian T. copticum was characterized by means of gas chromatography-mass spectrometry and Nuclear Magnetic Resonance. Three new compounds, (1) 2, 5-Dihydroxy-4-methoxy-phenanthrene 2-O-b-Dglucopyranoside; (2) 4-Methoxy-2,5,7,9S tetrahydroxy-9,10-dihydrophenanthrene; and (3) trans-Ethyl cinnamate along with 12 known were isolated from the Eos T. copticum. The essential oil was also subjected to antimicrobial and antioxidant activities. The new compounds were particularly active against Bacillus cereus and Candida albicans, with the lowest minimum inhibitory concentration and minimum bactericidal concentration and minimum fungicidal concentration value. Three new compounds exhibited a higher activity in each antioxidant system with a special attention for β-carotene bleaching test, lipid peroxidation inhibition, and reducing power. The Thin-layer chromatography-bioautography screening and fractionation resulted in the separation of the main antioxidant compound which were identified as trans-Ethyl cinnamate (3). These results indicated that three new compounds might be applicable in natural medicine and healthy food.     

Control of fumonisin B 1 accumulation in naturally contaminated maize inoculated with Fusarium verticillioides and Fusarium proliferatum, by cinnamon, clove, lemongrass, oregano and palmarosa essential oils

The effect of cinnamon, clove, oregano, palmarosa and lemongrass oils on fumonisin B₁ (FB₁) accumulation by one isolate each of Fusarium verticillioides and Fusarium proliferatum in non-sterilised naturally contaminated maize grain at 0.995 and 0.950 a_w and at 20 and 30 °C was evaluated. The concentration used was 500 mg kg^-1 maize. Under these conditions it was shown that antimycotoxigenic ability only took place at the higher water availabilities, and mostly at 20 °C. Only cinnamon, lemongrass and palmarosa oils were somewhat effective. Moreover, it was suggested that competing mycoflora plays an important role in FB₁ accumulation. It was concluded that the efficacy of essential oils in real substrates, such as cereals, may be much lower than in synthetic media; different essential oils may be found to be useful and at different concentrations. Their effectiveness is highly dependent on both abiotic and biotic factors involved.     

Edible mushrooms: a potential source of essential amino acids,glucans and minerals

The main chemical and biochemical constituents of nine edible mushrooms were evaluated in this study. An enzymatic method was used to determine the α‐ and β‐glucan contents, and the amino acid (AA) profiles were evaluated by RP‐HPLC‐DAD. The recommended dietary allowance (RDA) of the nutrients was evaluated. Finally, principal component analysis (PCA) was used to group the mushrooms according to their AA, glucans and chemical composition. All mushrooms evaluated can be considered as a potential and alternative source of dietary fibre (24.4–46.62%) and protein (16.47–36.96%) in a diet, with low contents of fat (1.40–2.08%). Phosphorus, potassium, iron, copper and zinc were the main minerals found in the mushrooms, whereas sodium concentration was negligible. All essential AA were detected in the mushrooms, with Pleurotus ostreatus (black oyster) representing the main source of essential amino acids among the samples. The contents of β‐glucan ranged from 1.58 to 16.91 mg g^?1 of dry matter among the mushrooms and Pleurotus eryngii presented the highest amount of this component. Pleurotus ostreatus (black oyster) and P. eryngii were also grouped together due to similarities in their phosphorous and arginine contents. Among the main results, it can highlight the high concentration of dietary fibre and essential amino acids of the edible mushrooms.     

Fungal Inactivation by Mexican Oregano (Lippia berlandieri Schauer) Essential Oil Added to Amaranth,Chitosan, or Starch Edible Films

ABSTRACT: Edible films can incorporate antimicrobial agents to provide microbiological stability, since they can be used as carriers of a wide number of additives that can extend product shelf life and reduce the risk of pathogenic bacteria growth on food surfaces. Addition of antimicrobial agents to edible films offers advantages such as the use of low antimicrobial concentrations and low diffusion rates. The aim of this study was to evaluate inhibition of Aspergillus niger and Penicillium spp. by selected concentrations of Mexican oregano (Lippia berlandieri Schauer) essential oil added to amaranth, chitosan, or starch edible films. Oregano essential oil was characterized by gas chromatography-mass spectrometry (GC/MS) analysis. Amaranth, chitosan, and starch edible films were formulated with essential oil concentrations of 0%, 0.25%, 0.50%, 0.75%, 1%, 2%, and 4%. Mold radial growth was evaluated inoculating spores in 2 ways: edible films were placed over inoculated agar, Film/Inoculum mode (F/I), or the edible films were first placed in the agar and then films were inoculated, Inoculum/Film mode (I/F). The modified Gompertz model adequately described growth curves. There was no significant difference (P > 0.05) in growth parameters between the 2 modes of inoculation. Antifungal effectiveness of edible films was starch > chitosan > amaranth. In starch edible films, both studied molds were inhibited with 0.50% of essential oil. Edible films added with Mexican oregano essential oil could improve the quality of foods by controlling surface growth of molds.     

Effect of distillation waste water and plant hormones on spearmint growth and composition

BACKGROUND: Distillation waste water (DWW) is a by‐product from steam distillation of essential‐oil crops; and currently, it is discharged into streams and rivers. The effects of DWW from 13 essential‐oil crops, extracts from two alkaloid‐containing species, and three plant hormones (methyl jasmonate, MJ; gibberellic acid, GA3; and salicylic acid, SA) were evaluated on productivity, essential‐oil content and composition of spearmint (Mentha spicata L.) cv. ‘Native’. RESULTS: Spearmint plant height was increased by the application of GA3 and Melissa officinalis DWW but suppressed by the application of Rosmarinus officinalis and Tagetes lucida DWW. Generally, MJ, GA3 and M. officinalis and Mentha arvensis DWW increased dry yields. The concentration of L ‐carvone in the oil ranged from 550 g kg^?1 (with Monarda citriodora DWW) to 670 g kg^?1 (with T. lucida DWW). M. citriodora DWW reduced the concentration of L ‐carvone in the oil by 23% relative to the control. CONCLUSION: Results suggest that DWW from essential‐oil crops may affect monoterpene synthesis in M. spicata and, hence, may have a direct effect on the essential oil composition. DWW from essential‐oil crops may be used as a growth promoter and modifier of the essential oil composition of spearmint. Copyright © 2011 Society of Chemical Industry     

Chemical composition and insecticidal properties of Cinnamomum aromaticum (Nees) essential oil against the stored product beetle Callosobruchus maculatus (F.)

BACKGROUND: Cinnamomum aromaticum is a widely used cooking ingredient in South Asian countries. In this study the essential oil of C. aromaticum was tested against the stored product beetle Callosobruchus maculatus. The objective was to identify the natural compounds with insecticidal properties in the essential oil of C. aromaticum with a view to its potential use as an alternative to synthetic pesticides. RESULTS: The chemical composition of the hydrodistilled bark essential oil of C. aromaticum was analysed by gas chromatography/mass spectrometry, and cis‐cinnamaldehyde (53.90%) was found to be the principal constituent. The surface film and fumigation toxicities and repellency activity against C. maculatus were evaluated. The extracted oil showed 94.44% mortality against adult C. maculatus through the surface film bioassay. The LD₅₀ values were 27.56 and 23.16 µg cm^?2 after 24 and 48 h of exposure respectively. The regression equations were calculated as Y = 0.39 + 3.20X and Y = 1.25 + 2.75X respectively. In the fumigation bioassay the LD₅₀ value was 434.69 µg cm^?2 after 24 h of exposure, with the regression equation Y = 0.87 + 1.57X. It was also found that the extracted oil contained compounds that had a dose‐dependent protective effect on egg hatching and adult emergence. CONCLUSION: The results obtained from this study suggest that the toxicity and insecticidal activity of C. aromaticum are attributable to its essential oil, which could be used as a biodegradable and natural bioprotectant for controlling stored product pests. Copyright © 2009 Society of Chemical Industry     

Effects of Tropical Citrus Essential Oils on Growth, Aflatoxin Production, and Ultrastructure Alterations of Aspergillus flavus and Aspergillus parasiticus

Ethyl acetate extracts and hydrodistillated essential oils from five cultivars of tropical citrus epicarps were evaluated for their inhibitory activities against Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, and Penicillium sp. using disk diffusion and broth microdilution assays. Essential oils prepared from kaffir lime (Citrus hystrix DC) and acid lime (Citrus aurantifolia Swingle) epicarps exhibited stronger antifungal activity to all fungi than their ethyl acetate extracts with minimum inhibitory concentration and minimum fungicidal concentration values of 0.56 and 1.13 mg/ml (dry matter), respectively, against aflatoxin-producing A. flavus and A. parasiticus. The dominant components of the essential oil from kaffir lime were limonene, citronellol, linalool, o-cymene, and camphene, whereas limonene and p-cymene were major components of acid lime essential oil. Pure limonene, citronellal, and citronellol were five to six times less fungicidal than the natural essential oils, indicating the synergistic activity of many active compounds present in the oils. Kaffir and acid lime essential oils significantly reduced aflatoxin production of A. flavus and A. parasiticus, particularly lime essential oil, which completely inhibited growth and aflatoxin production of A. flavus at the concentration of 2.25 mg/ml. Target cell damage caused by acid lime essential oil was investigated under transmission electron microscopy. Destructive alterations of plasma and nucleus membrane, loss of cytoplasm, vacuole fusion, and detachment of fibrillar layer were clearly exhibited in essential-oil-treated cells.     

Characterization of Essential Oil in Pine Nut Shells from Commodity Waste in China by Steam Distillation and GC-MS

The aim of the present study was to investigate the essential oil extracted from pine nut shells and its potential application. The essential oil was extracted by steam distillation method and analyzed by gas chromatography coupled with mass spectrometry. Forty-eight volatile chemical compositions were determined and identified. α-Pinene, β-pinene, 3-carene, 1-methy-4-(1-methylethenyl)-(S)-cyclohexene, and n-hexadecanoic acid are predominant volatile compositions in pine nut shells.