Home About us Contact
|
Home About us Contact | ||
|
|
||
Oil Samples (oil + sample)
Kinds of Oil Samples Selected AbstractsVoltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron-Doped Diamond Micropore Array ElectrodesELECTROANALYSIS, Issue 12 2009Xiaohang Zhang Abstract Mineral oil microdroplets containing the model antioxidant N,N -didodecyl- N,,N, -diethyl-phenylene-diamine (DDPD) are immobilized into a 100×100 pore-array (ca. 10,,m individual pore diameter, 100,,m pitch) in a boron-doped diamond electrode surface. The robust diamond surface allows pore filling, cleaning, and reuse without damage to the electrode surface. The electrode is immersed into aqueous electrolyte media, and voltammetric responses for the oxidation of DDPD are obtained. In order to further improve the current responses, 20,wt% of carbon nanofibers are co-deposited with the oil into the pore array. Voltammetric signals are consistent with the oxidation of DDPD and the associated transfer of perchlorate anions (in aqueous 0.1,M NaClO4) or the transfer of protons (in aqueous 0.1,M HClO4). From the magnitude of the current response, the DDPD content in the mineral oil can be determined down to less than 1,wt% levels. Perhaps surprisingly, the reversible (or midpoint) potential for the DDPD oxidation in mineral oil (when immersed in 0.1 NaClO4) is shown to be concentration-dependent and to shift to more positive potential values for more dilute DDPD in mineral oil solutions. An extraction mechanism and the formation of a separate organic product phase are proposed to explain this behavior. [source] Acephate, methamidophos and monocrotophos residues in a laboratory-scale oil refining processEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 6 2009Chee Beng Yeoh Abstract Acephate, methamidophos and monocrotophos are insecticides used in oil palm plantations for the control of bagworms and leaf-eating caterpillars. The main purpose of this study was to determine whether the physical refining process at laboratory scale, which simulated the manufacturing process, could remove the residues of these three insecticides in crude palm oil, in the unlikely event that crude palm oil were contaminated with these organophosphorus insecticides. A series of crude palm oil samples spiked with low (0.1,µg/g) and high (1.0,µg/g) levels of these insecticides were subjected to a laboratory-scale physical oil refining process. Oil samples drawn at various stages of the refining process, namely, degumming, bleaching and deodorization, were analyzed using an in-house analytical method. The results obtained from these experiments suggest that the physical refining process is capable of effectively removing residual insecticides from crude palm oil. The final product of crude palm oil refining, the refined, bleached and deodorized palm oil, was found to have no detectable levels of acephate, methamidophos and monocrotophos. [source] Characterization of hydroxyaromatic compounds in vegetable oils by capillary electrophoresis with direct injection in an oil-miscible KOH/propanol/methanol mediumELECTROPHORESIS, Issue 17 2005Carla R. B. Mendonça Abstract The separation of hydroxyaromatic compounds in vegetable oils, including synthetic antioxidants (3- tert -butyl-4-hydroxyanisol and 2,6-di- tert -butyl-4-hydroxytoluene), E-vitamers and other natural oil components, by nonaqueous capillary electrophoresis in an oil-miscible background electrolyte (BGE) was investigated. The BGE contained 40,mM KOH in a methanol/1-propanol (PrOH) mixture (15:85 v/v). The oil samples were 1:1 diluted with PrOH and directly injected in the capillary. Under negative polarity (cathode at the injection end), the anionic solutes moved faster than the electroosmotic flow, being well-resolved among them and from the triacylglycerols. Using virgin palm, extra virgin olive, wheat germ, virgin soybean and other oils, the capability of the procedure to quickly yield a characteristic profile of the biophenols present in the sample was demonstrated. The , -, (,,+,,)- (as unresolved pair) and , -tocopherols of a soybean oil sample were quantified. [source] Automated ultrasound-assisted method for the determination of the oxidative stability of virgin olive oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2007José Platero-López Abstract A fast and automated method is proposed for determining the oxidative stability of virgin olive oil by using ultrasound. The ultrasound microprobe (3,mm in diameter) was directly immersed into the olive oil sample contained in a test tube. The most influential variables in the oxidation process, namely pulse amplitude, duty cycle, irradiation time, and sample amount, were optimized. The oil absorbance at 270,nm was continuously monitored by oil recirculation through a 0.1-mm path length flow cell connected to a fiber optic microspectrometer. This short path length allowed the direct monitoring of absorbance without needing any sample dilution. The ultrasound energy was applied during 35,min, and the resulting increase in absorbance was continuously monitored. The difference between the final and the initial absorbance at 270,nm of a set of virgin olive oil samples was closely correlated with their oxidative stability calculated by the Rancimat method (R2,=,0.9915). The resulting equation enabled the prediction of the oxidative stability of virgin olive oil in a short period of time (35,min), by using a simple, inexpensive, automatic and easy-to-use system. [source] Chemical composition of essential oils of two Hyptis suaveolens (L.) Poit leaves from NigeriaFLAVOUR AND FRAGRANCE JOURNAL, Issue 5 2005Adeolu O. Eshilokun Abstract The essential oils of the leaves of Hyptis suaveolens (L.) Poit collected from two different sources were isolated by hydrodistillation. The oils were analysed by GC and GC_MS; 36 constituents were identified in the oil of sample collected from the campus of Lagos State University (LASU), while 33 constituents were identified in the oil of sample from Obafemi Awolowo University (OAU). , -Pinene (13.6%), sabinene (13.2%), p -cymene (11.7%), terpinen-4-ol (9.8%) and terpinolene (6.3%) were the major monoterpenes in the LASU oil sample, while sabinene (30.0%), terpinen-4-ol (11.4%), terpinolene (5.6%), 1,8-cineole (5.2%), , -pinene (4.4%) and , -terpinene (4.2%) were the main monoterpenes in the OAU oil sample. , -caryophyllene (5.1_5.9%) and trans - , -bergamotene (1.6_5.2%) represented the major sesquiterpenes in both oils. Copyright © 2005 John Wiley & Sons, Ltd. [source] Persistent Organic Pollutants in Fish Oil Supplements on the Canadian Market: Polychlorinated Biphenyls and Organochlorine InsecticidesJOURNAL OF FOOD SCIENCE, Issue 1 2009Dorothea F.K. Rawn ABSTRACT:, Fish and seal oil dietary supplements, marketed to be rich in omega-3 fatty acids, are frequently consumed by Canadians. Samples of these supplements (n,= 30) were collected in Vancouver, Canada, between 2005 and 2007. All oil supplements were analyzed for polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) and each sample was found to contain detectable residues. The highest ,PCB and ,DDT (1,1,1-trichloro-di-(4-chlorophenyl)ethane) concentrations (10400 ng/g and 3310 ng/g, respectively) were found in a shark oil sample while lowest levels were found in supplements prepared using mixed fish oils (anchovy, mackerel, and sardine) (0.711 ng ,PCB/g and 0.189 ng ,DDT/g). Mean ,PCB concentrations in oil supplements were 34.5, 24.2, 25.1, 95.3, 12.0, 5260, 321, and 519 ng/g in unidentified fish, mixed fish containing no salmon, mixed fish with salmon, salmon, vegetable with mixed fish, shark, menhaden (n,= 1), and seal (n,= 1), respectively. Maximum concentrations of the other OCs were generally observed in the seal oil. The hexachlorinated PCB congeners were the dominant contributors to ,PCB levels, while ,DDT was the greatest contributor to organochlorine levels. Intake estimates were made using maximum dosages on manufacturers' labels and results varied widely due to the large difference in residue concentrations obtained. Average ,PCB and ,DDT intakes were calculated to be 736 ± 2840 ng/d and 304 ± 948 ng/d, respectively. [source] Determination of polycyclic aromatic hydrocarbons in olive oil by a completely automated headspace technique coupled to gas chromatography-mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 6 2006Francisco J. Arrebola Abstract A new and completely automated method for the determination of ten relevant polycyclic aromatic hydrocarbons (PAHs) in olive oil is proposed using an extraction by the headspace (HS) technique. Quantification and confirmation steps are carried out by gas chromatography-mass spectrometry (GC-MS) combining simultaneously selected-ion monitoring (SIM) and tandem mass spectrometry (MS/MS). This combination offers on one hand an increased sensitivity and on the other hand, selective and reliable qualitative information. Sample pretreatment or clean-up are not necessary because the olive oil sample is put directly into an HS vial, automatically processed by HS and introduced into the GC-MS instrument for analysis. Because of its high selectivity and sensitivity, a triple-quadrupole (QqQ) detector coupled with the gas chromatograph allows us to limit handling. Each sample is completely processed in approximately 63 min (45 min for HS isolation and 18 min for GC-MS determination), a reduced time compared with previously published methods. The chemical and instrumental variables were preliminarily optimized using uncontaminated olive oil samples spiked with 25 µg kg,1 of each target compound. The final method was validated to ensure the quality of the results. The precision was satisfactory, with relative standard deviation (RSD) values in the range 3,9%. Recovery rates ranged from 96 to 99%. Limits of detection (LOD) were calculated as 0.02,0.06 µg kg,1 and the limits of quantification (LOQ) were obtained as 0.07,0.26 µg kg,1. It must be mentioned that the LOD and LOQ are much lower than the maximum levels established by the European Union (EU) in oils and fats intended for direct human consumption or for use as an ingredient in foods, which are set at 2 µg kg,1. All the figures of merit are completely in accordance with the latest EU legislation. This fact makes it possible to consider the proposed method as a useful tool for the control of PAHs in olive oils. Copyright © 2006 John Wiley & Sons, Ltd. [source] GEOCHEMICAL CHARACTERIZATION OF A BIODEGRADED CRUDE OIL, ASSRAN FIELD, CENTRAL GULF OF SUEZJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2009A. H. Hegazi A crude oil sample from the Assran field in the Central Gulf of Suez (Egypt) was analysed geochemically and characterized in terms of a variety of source and maturity dependent biomarkers. Biodegradation was indicated by increasing concentration ratios of Pr/n-C17 and Ph/n-C18. However, biodegradation was only slight as GC-MS analyses of the saturate and aromatic fractions showed that hopanes, steranes, aromatic steroids and polycyclic aromatic compounds including sulphur heterocycles remained intact. The sterane and hopane distributions showed a predominance of C27 steranes, a low diasterane index, an abundance of gammacerane, a high homohopane index and an oleanane index < 0.2. The results indicate that the Assran-10 crude oil was derived from a marine carbonate source deposited in a highly reducing saline environment with a high bacterial contribution, consistent with the Upper Cretaceous Brown Limestone or Lower Eocene Thebes Formation containing Type IIS kerogen. Maturity parameters based on changes in the stereochemistry at chirality centres in hopane and sterane nuclei, such as C30,,/(,,+,,) and C31 22S/(22S+22R) hopanes and C29,,/(,,+,,) and C29 20S/(20S+20R) steranes, together with triaromatic sterane cracking ratios, indicate that the oil sample was marginally mature. The results also suggest that biodegradation is probably due to sulphate-reducing anaerobic bacteria. [source] A chromametric method for the rapid assessment of deep frying oil qualityJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2003Xin-Qing Xu Abstract A rapid chromametric method was developed for the assessment of deep frying oil quality based on the strong correlation between colour index and total polar compounds in deep frying oil. Colour indices of frying oil samples, measured by chromameter, decreased significantly during frying and were strongly correlated with frying time (r , 0.95, p < 0.001). Colour indices of a set of oil samples taken from 0 to 80 h of deep frying were also significantly correlated with total polar compounds of the same samples determined using the official method of the American Oil Chemists' Society (r = 0.96, p < 0.001). The equation for conversion of the colour index (x) to the content of total polar compounds (y) in an oil sample is y = 0.0174x2 , 2.9506x + 124.34. In addition, colour indices of 10 different types of frying oils were strongly correlated with the corresponding contents of total polar compounds in the oils with samples taken from 0 to 80 h of deep frying in duplicate (r = 0.95, p < 0.001, n = 220). The results of colour index analyses agreed well with the results of chemical and sensory analyses of the frying oils tested. This chromametric method is rapid, convenient and reliable. Copyright © 2003 Society of Chemical Industry [source] Phenolic compounds and some quality parameters of pumpkin seed oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2010Mirjana Andjelkovic Abstract Pumpkin seed oil has become a recognized source of phenolic compounds. The main aim of this paper was to evaluate the concentration of phenolic compounds and their extraction from pumpkin seed oil. The total phenolics content (TPC) measured in the pumpkin seed oil samples ranged from 24.71 to 50.93,mg GAE/kg of oil. The individual phenolics were tyrosol, vanillic acid, vanillin, luteolin and sinapic acid. Hexane and acetone were the best solvents for the washing step, and methanol for the elution of the phenolics in the solid-phase extraction (diol-SPE), whereas bleaching caused a significant increase in the TPC obtained (24.5,30.7%). Additionally, some other oil characteristics were evaluated. The mean oxidative stability of the oils (OSI) was around 4,h, with 5.43,h for the most stable oil. The maximum antioxidant capacity measured by the reduction of the DPPH radical was 62%, which was comparable to 0.16,mM Trolox equivalent. The color of the oil was expressed by L*a*b* coefficients and its hue and saturation. Whereas all samples had similar lightness, their rates of green, red, yellow and blue color were different. Moreover, TPC correlated negatively with lightness, b* and saturation (,0.49, ,0.48, and ,0.43), and positively with a* and hue (0.58 and 0.52). [source] Comparison of fatty acid profiles and mid-infrared spectral data for classification of olive oilsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2010Gozde Gurdeniz Abstract The composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier-transform infrared (FT-IR) spectroscopy data in combination with chemometric methods were used to classify extra-virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30,different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT-IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils. [source] Determination of cypermethrin in palm oil matricesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 10 2009Badrul Hisyam Zainudin Abstract In this study, a new method was developed for the determination of cypermethrin residue in both crude palm oil (CPO) and crude palm kernel oil (CPKO) using GC with electron capture detector. In this method, the oil was extracted with acetonitrile. Aliquots were cleaned-up using combined solid phase extraction (SPE), and a primary-secondary amine in combination with graphitized carbon black. The SPE cartridges were first conditioned and then eluted with acetonitrile. Cypermethrin recoveries from the fortified CPO samples were 87,98% with relative standard deviation (RSD) values of 4,8%, while those for the fortified CPKO samples were 83,100% with RSD values of 3,10%. Since good recoveries were obtained with RSD values below 10% in most cases, the proposed methodology will be useful for the analyses of palm oil samples. The method was successfully applied to the analysis of cypermethrin in real palm oil samples from various parts of Malaysia. No cypermethrin residue was found among 30 samples analyzed. [source] Effect of location on virgin olive oils of the two main Tunisian olive cultivarsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2009Mokhtar Guerfel Abstract The olive oil content in phenolic compounds depends on the variety of the fruit used for its extraction as well as on the predominant climate conditions in the tree cultivation area. Here, we report on the characterization of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivars Chemlali and Chétoui, grown in three different Tunisian locations, Zaghouan (North), Sousse (Center) and Sfax (South). Chétoui olive oil samples obtained from fruits of olive trees cultivated in Zaghouan and Chemlali olive oil samples obtained from fruits of olive trees cultivated in Sousse were found to have a higher mean total phenol content (1004 and 330,mg/kg, respectively). Olive oil samples obtained from fruits of both cultivars had different phenolic profiles and a higher content in 3,4-DHPEA-EDA when the olive trees were cultivated in Zaghouan. Both olive cultivars were found to have different responses to environmental conditions. Chétoui olive oil showed decreased oxidative stability when the fruits were obtained from olive trees cultivated in the center of Tunisia (34.8,h) and in Sfax (16.17,h). Furthermore, statistical data showed that the phenolic composition and oxidative stability of Chétoui olive oil varied more by location than those of Chemlali olive oils. [source] Acephate, methamidophos and monocrotophos residues in a laboratory-scale oil refining processEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 6 2009Chee Beng Yeoh Abstract Acephate, methamidophos and monocrotophos are insecticides used in oil palm plantations for the control of bagworms and leaf-eating caterpillars. The main purpose of this study was to determine whether the physical refining process at laboratory scale, which simulated the manufacturing process, could remove the residues of these three insecticides in crude palm oil, in the unlikely event that crude palm oil were contaminated with these organophosphorus insecticides. A series of crude palm oil samples spiked with low (0.1,µg/g) and high (1.0,µg/g) levels of these insecticides were subjected to a laboratory-scale physical oil refining process. Oil samples drawn at various stages of the refining process, namely, degumming, bleaching and deodorization, were analyzed using an in-house analytical method. The results obtained from these experiments suggest that the physical refining process is capable of effectively removing residual insecticides from crude palm oil. The final product of crude palm oil refining, the refined, bleached and deodorized palm oil, was found to have no detectable levels of acephate, methamidophos and monocrotophos. [source] Characterization of volatile compounds and triacylglycerol profiles of nut oils using SPME-GC-MS and MALDI-TOF-MSEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2009Stefanie Bail Abstract Several nut oil varieties mainly used as culinary and overall healthy food ingredients were subject of the present study. Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was employed in order to determine the qualitative composition of volatile compounds. Furthermore, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used in order to assess the profiles and relative composition of the prevalent triacylglycerols (TAG) within the oils. The headspace of the majority of oil samples was dominated by high contents of acetic acid (up to 42%) and hexanal (up to 32%). As nut oils are typically gained by cold-pressing from previously roasted nuts, characteristic pyrazine derivatives as well as degradation products of long-chain fatty acids were detected. TAG analysis of these oils revealed a quite homogeneous composition dominated by components of the C52 and C54 group composed mainly of oleic (18:1), linoleic (18:2), stearic (18:0) and palmitic (16:0) acid residues representing together between 65 and 95% of the investigated nut oils. The TAG profiles showed characteristic patterns which can be used as ,fingerprints' of the genuine oils. Nut oils exhibiting quite similar fatty acid composition (e.g. hazelnut, pistachio and beech oil) could be clearly discriminated based on TAG showing significant differences between the oils. [source] Automated ultrasound-assisted method for the determination of the oxidative stability of virgin olive oilEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 2 2007José Platero-López Abstract A fast and automated method is proposed for determining the oxidative stability of virgin olive oil by using ultrasound. The ultrasound microprobe (3,mm in diameter) was directly immersed into the olive oil sample contained in a test tube. The most influential variables in the oxidation process, namely pulse amplitude, duty cycle, irradiation time, and sample amount, were optimized. The oil absorbance at 270,nm was continuously monitored by oil recirculation through a 0.1-mm path length flow cell connected to a fiber optic microspectrometer. This short path length allowed the direct monitoring of absorbance without needing any sample dilution. The ultrasound energy was applied during 35,min, and the resulting increase in absorbance was continuously monitored. The difference between the final and the initial absorbance at 270,nm of a set of virgin olive oil samples was closely correlated with their oxidative stability calculated by the Rancimat method (R2,=,0.9915). The resulting equation enabled the prediction of the oxidative stability of virgin olive oil in a short period of time (35,min), by using a simple, inexpensive, automatic and easy-to-use system. [source] The role of methylnaphthalene in EHV cable oil as related to oil breakdown and discharge velocityEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 6 2002A. Al-Sulaiman This experimental investigation explores the effect of high voltage lightning surges on the insulating oil used in the oil filled extra high voltage cables that serve electric power networks worldwide. Using non-uniform electrode configuration, the breakdown voltage and corresponding discharge propagation velocities in oil samples that are doped with trace amounts of 1-Methylnaphthalene are investigated under both polarities of applied stresses in gap spacing of up to 10 mm. Two distinct ranges of additive concentrations are observed which effect these characteristics. Generally, the positive discharge growth decreases with increase in gap spacing while the negative ones show opposite behaviour. Anomalous behaviour of discharge growth is observed at an optimum concentration of additive, as it attains supersonic velocity which increases with the increase in gap spacing. A correlation between the positive impulse breakdown voltage and the discharge propagation velocity is also established. [source] Pittosporum undulatum Vent. grown in Portugal: secretory structures, seasonal variation and enantiomeric composition of its essential oilFLAVOUR AND FRAGRANCE JOURNAL, Issue 1 2007Nicolau J. Ferreira Abstract Aerial parts of Pittosporum undulatum were collected fortnightly for 1 year at the Parque de Saúde de Lisboa. Collective samples of two populations were investigated, i.e. from pruned and non-pruned trees, and in addition samples from one pruned and one non-pruned individual. An SEM study of the aerial parts showed the presence of non-glandular T-shaped trichomes, and capitate trichomes with an elongated stalk and two to four round-shaped cells on the top. Numerous canals were seen at the level of the capsule wall as well as in the leaves and stems. Essential oil samples were isolated from the (deep-frozen) aerial parts by hydrodistillation to estimate the oil yields, and by distillation,extraction to determine their percentage composition, and analysed by GC and GC,MS. Monoterpenes (59,97%) were dominant in all oils, sabinene (5,58%), limonene (2,37%) and terpinen-4-ol (4,27%) being the major components, although in different relative amounts during the year of collection. Benzyl benzoate (8%) and benzyl salicylate (10%) attained high relative amounts in the oils from fully developed flowers, whereas in the oils from the other plant parts their relative amounts did not exceed 1%. The enantiomeric ratio of sabinene, limonene and terpinen-4-ol was investigated in the leaf, flower and capsule oils, showing dominance of the (+)-forms and homogeneity between all the oil samples. Copyright © 2006 John Wiley & Sons, Ltd. [source] Chemical composition of the essential oils of Astrodaucus persicus (Boiss.) Drude root, stem/leaves and flowers/fruitsFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2006Y. T. Bazargani Abstract The essential oils of Astrodaucus persicus (Boiss.) Drude were obtained by hydrodistillation of root and aerial parts and examined by GC and GC,MS. The composition of oil samples was compared; 22, 20 and 14 compounds were identified in the essential oils of the root, stem/leaves and flowers/fruits, representing 94.4%, 99.7% and 99.9%, respectively, of the total oils. The major components were bornyl acetate (26.5%), , -sesquiphellandrene (25.9%) and exo -fenchyl acetate (25.1%) for the root oil, , -pinene (56.4%) and exo -fenchyl acetate (37.7%) for the stem/leaves oil and , -pinene (46.1%), , -pinene (26.1%) and , -thujene (14.4%) for the flowers/fruits oil. The highest amount of sesquiterpenes was found in the root oil (30.7%). Copyright © 2005 John Wiley & Sons, Ltd. [source] Chemical composition of the essential oils of Marrubium parvi,orum Fisch.FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2005& C. A. Mey., Marrubium vulgare L. from Iran Abstract The composition of essential oil samples obtained by hydrodistillation of the aerial parts of Marrubium parvi,orum Fisch. & C. A. Mey. and Marrubium vulgare L. (family Lamiaceae), were investigated by GC and GC,MS. Fifty-one components in the oil of M. parvi,orum, representing 96.8% of the total oil, and 34 components in the oil of M. vulgare, representing 95.1% of the total oil, were identi,ed. Both essential oils were characterized by a high amount of sesqiterpenes (77.8% and 82.5%, respectively) with bicyclogermacrene (26.3%), germacrene D (21.5%) and , -caryophyllene (15.6%) as the major constituents of M. parvi,orum, and , -bisabolene (25.4%), , -caryophyllene (11.6%), germacrene D (9.7%) and E - , -farnesene (8.3%) as the major component of M. vulgare. Copyright © 2004 John Wiley & Sons, Ltd. [source] Variation in essential oil composition of rose-scented geranium (Pelargonium sp.) distilled by different distillation techniques,FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2005Kiran G. D. Babu Abstract The rose-scented geranium (Pelargonium sp.) cultivar ,Kelkar', grown in the agroclimatic conditions of the western Himalayas, was processed by various hydrodistillation methods, which revealed that water distillation of the herb gave a higher oil yield (0.16,0.22%) than the water,steam distillation (0.09,0.12%) and steam distillation methods (0.06,0.18%). The samples were analysed by GC and GC,MS to study and compare the essential oil compositions which revealed that the oil distilled by the water,steam distillation method contained a higher content of monoterpene hydrocarbons (1.7%), followed by steam distillation without cohobation and without recycling (1.5%). A higher content of sesquiterpene hydrocarbons (4.4%) was found in cumulative oil followed by ,direct oil' (4.2%) obtained by steam distillation with cohobation and without recycling of hydrosol, followed by the water,steam distillation method (3.4%). ,Decanted oil', recovered from redistilling the hydrosol obtained by steam distillation with cohobation and without recycling, contained maximum monoterpene cyclic ethers (1.1%) and carbonyl content (9.9%), closely followed by water,steam distillation method (1.1% and 7.2%, respectively). Steam distillation without cohobation and without recycling of hydrosol yielded essential oil with a higher percentage of esters (21.1%), followed by ,direct oil' (16.6%). Lower ester content (5.3%) was noticed in ,decanted oil', followed by oil distilled by steam distillation with cohobation and with recycling (11.8%) and oil distilled in a Clevenger apparatus by the water distillation method (12.2%), whereas maximum total alcohols were found in the ,decanted oil' (75.1%), followed by oil from the Clevenger apparatus (72.8%) and steam distillation with cohobation and with recycling (69.1%). A lower alcohol content was found in the ,direct oil' (55.2%) closely followed by ,cumulative oil' (55.8%). The variation in total alcohol and ester contents in geranium oil samples, distilled by using different processing techniques on pilot scale distillation, is mainly due to hydrolysis of some volatile constituents. This was further supported by acid values of the oils, along with other physicochemical properties, such as speci,c gravity, optical rotation, refractive index, solubility in alcohol, ester value with cold and hot methods, estimation of ester content as geranyl formate and geranyl tiglate, ester number after acetylation, and ester number after formylation with aceto-formic acid and formic acid. Methods have been standardized and proposed for distillations of speci,c quality, e.g. ester-rich and alcohol-rich geranium oils, to meet different requirements of the industry. Copyright © 2004 John Wiley & Sons, Ltd. [source] Composition of the essential oil of Phlomis persica Boiss and Phlomis chorassanica Bunge from IranFLAVOUR AND FRAGRANCE JOURNAL, Issue 6 2004Parisa Sarkhail Abstract Two essential oil samples obtained by hydrodistillation from aerial parts of Phlomis persica Boiss. and Phlomis chorassanica Bunge. (Lamiaceae), were analysed by GC and GC,MS; 41 compounds in the oil of P. persica, representing 97.3%, and 42 compounds in the oil of P. chorassanica, representing 99.5%, were identi,ed. Both essential oils were rich in sesquiterpenes (81.3% and 90.1%, respectively) with germacrene D (32.5% and 51.5%, respectively) as the major component. Copyright © 2004 John Wiley & Sons, Ltd. [source] Essential oils from the buds of Betula spp. growing in Turkey,FLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2003Betül Demirci Abstract The essential oils from buds of Betula browicziana A. Güner, B. litwinowii Doluch., B. medwediewii Regel, B. pendula Roth and B. recurvata V. Vassil. (Betulaceae) were either hydrodistilled using a Clevenger-type apparatus or were subjected to Likens,Nickerson simultaneous distillation,extraction (SDE) when the plant material amounts were insuf,cient. The resulting bud essential oils were analysed by GC,MS. Main components were detected as 14-hydroxy- , -caryophyllene (1) and 14-hydroxy-4,5-dihydro- , -caryophyllene (2) in all the oil samples. Copyright © 2003 John Wiley & Sons, Ltd. [source] Volatile constituents of Vietnamese pummelo, orange, tangerine and lime peel oilsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2002N. T. Minh Tu Abstract The compositions of Vietnamese pummelo (Citrus grandis Osbeck), orange (C. sinensis Osbeck), tangerine (C. reticulata Blanco var. tangerine) and lime (C. limonia Osbeck) peel oil samples have been investigated by GC and GC,MS. The essential oils were extracted by the cold-pressing method. Hydrocarbons, followed by aldehydes and alcohols, were the most abundant compounds in all four kinds of samples. Their percentages, respectively, were >98.7%, >97.6%, >98.6% and >95.4% in hydrocarbons; >0.3%, 0.4%, >0.3% and 1.1% in total aldehydes; 0.2%, 0.5%, 0.4% and 0.7% in alcohols. In Vietnamese pummelo oil, ,-terpinene was not detected, while terpinolene was detected in small amounts and nootkatone only at a level of <0.05%. Orange oil composition was comparable to that of other sweet orange oils. ,-3-Carene was detected at a level of 0.1%. Tangerine oil is easily distinguished from other citrus oils by its content of various aliphatic aldehydes. Lime oil presented a very different composition from the other oils studied. Its limonene content was substantially lower than that of pummelo, orange and tangerine oils, whereas ,-terpinene, ,-pinene and ,-pinene occurred in higher proportions, moreover, the sesquiterpene hydrocarbon fraction of this oil is qualitatively more complex and quantitatively more abundant than in the other oils. Copyright © 2002 John Wiley & Sons, Ltd. [source] Essential oil composition of genetically diverse stocks of Murraya koenigii from IndiaFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2002V. K. Raina Abstract An Erratum for this article has been published in Flavour and Fragrance Journal 17(5) 2002, 404. The essential oil composition of four genetically diverse stocks of Murraya koenigii leaves cultivated at the CIMAP Research Farm, Lucknow, were analysed by GC and GC,MS. The oil from the stock of the northern Indian plains, Lucknow, showed ,-pinene (70.0%), ,-caryophyllene (6.5%) and ,-pinene (5.4%) as the major constituents, while the oil from the stock of the lower Himalayan range, Pant Nagar, showed ,-pinene (65.7%), ,-pinene (13.4%) and ,-phellandrene (7.4%) as the major constituents. In contrast to the above, the oil from the stock of southern India, Kozhikode, showed ,-caryophyllene (53.9%), aromadendrene (10.7%) and ,-selinene (6.3%) as the major constituents. On the other hand, the oil from the stock of eastern India, Bhubaneshwar, showed ,-phellandrene (30.2%), ,-caryophyllene (24.2%), ,-pinene (15.0%), (E)-,-ocimene (5.0%) and aromadendrene (4.5%) as the major constituents. The GC,MS analysis of the stock oil samples from the northern Indian plains, lower Himalayan range, southern and eastern India resulted in the identification of 65, 56, 57 and 66, constituents, representing 99.2%, 98.8%, 87.4% and 98.2% of the oils, respectively. Copyright © 2002 John Wiley & Sons, Ltd. [source] Used Motor Oil as a Source of MTBE, TAME, and BTEX to Ground WaterGROUND WATER MONITORING & REMEDIATION, Issue 4 2002Ronald J. Baker Methyl tert-butyl ether (MTBE), the widely used gasoline oxygenate, has been identified as a common ground water contaminant, and BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) have long been associated with gasoline spills. Because not all instances of ground water contamination by MTBE and BTEX can be attributed to spills or leaking storage tanks, other potential sources need to be considered. In this study, used motor oil was investigated as a potential source of these contaminants. MTBE in oil was measured directly by methanol extraction and gas chromatography using a flame ionization detector (GC/FID). Water was equilibrated with oil samples and analyzed for MTBE, BTEX, and the oxygenate tert-amyl methyl ether (TAME) by purge- and-trap concentration followed by GC/FID analysis. Raoult's law was used to calculate oil-phase concentrations of MTBE, BTEX, and TAME from aqueous-phase concentrations. MTBE, TAME, and BTEX were not detected in any of five new motor oil samples, whereas these compounds were found at significant concentrations in all six samples of the used motor oil tested for MTBE and all four samples tested for TAME and BTEX. MTBE concentrations in used motor oil were on the order of 100 mg/L. TAME concentrations ranged from 2.2 to 87 mg/L. Concentrations of benzene were 29 to 66 mg/L, but those of other BTEX compounds were higher, typically 500 to 2000 mg/L. [source] Volatile compounds characterising Tunisian virgin olive oils: the influence of cultivarINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2010Dhouha Krichene Summary In this work, the volatile profiles of four Tunisian virgin olive oils were established by headspace-solid phase microextraction and gas chromatography, using flame ionisation and mass spectrometer detectors. More than eighty compounds were isolated and characterised, representing 97,99% of the total GC area. The main volatile compounds present in the oil samples were determined quantitatively, the major constituents were often aldehydes, particularly (E)-2-hexenal (48,90%). Significant differences in the content of volatile constituents were observed. These quantitative differences were used to distinguish between virgin olive oils from different varieties. [source] Safety evaluation of individual non-fried and fried sunflower oil, paraffin oil, jojoba oil and their binary mixtures on rat healthINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2008Radwan S. Farag Summary Sunflower, jojoba, paraffin oils and binary oil mixtures of sunflower, jojoba and sunflower,paraffin oils were continuously heated at 180 °C for 12 h. Aliquots of potato chips were fried in the aforementioned oil samples. Organoleptic tests were performed on fried chips and safety limits of the oil samples were measured by certain biochemical tests. Histopathological examinations of rat liver and kidney tissues were microscopically done. Organoleptic results for fried potato chips indicate that all types of chips obtained from heated oils were categorised good. Histopathological examinations indicate changes in rat tissues of liver and kidney paralleled the biochemical data. In general, the results suggest that paraffin oil alone and in mixtures with sunflower oil have to ban its use in frying processes. [source] INFLUENCE OF SUPERCRITICAL CARBON DIOXIDE AND METHANOLIC EXTRACTS OF ROSEMARY ON OXIDATION AND SENSORY PROPERTIES OF WHEAT GERM OILJOURNAL OF FOOD QUALITY, Issue 6 2009OZLEM YESIL-CELIKTAS ABSTRACT Both supercritical CO2 and methanolic extracts from the leaves of rosemary (Rosmarinus officinalis) harvested from three different locations of Turkey at four different times of the year were added at a concentration of 100 mg/kg to wheat germ oil. Wheat germ oil samples were stored in an incubator for 10 days at 50C in order to promote oxidation and for the efficacy of the extracts for stabilization purposes to be examined. Degree of oxidation was determined by peroxide and p -anisidine values, which were performed every 2 days. Extracts from Mersin and Canakkale regions performed better results. Additionally, June and September harvests had lower peroxide values. According to the descriptive sensory analysis, both locations and extraction methods were found to effect flavor. Some flavor attributes, such as wheatlike/starchy, fishy and rubbery/metallic changed during storage regardless of locations and extraction methods. Supercritical CO2 extracts performed better results in terms of both oxidation and sensory properties. PRACTICAL APPLICATIONS From the perspective of the food industry, wheat germ oil stabilized with a natural antioxidant such as rosemary can be marketed as a functional product that can create a niche. Rosemary extracts containing higher amounts of rosmarinic acid and carnosic acid should be preferred in order to provide a better shelf life of an edible oil such as wheat germ oil. [source] PRELIMINARY EVALUATION OF THE APPLICATION OF THE FTIR SPECTROSCOPY TO CONTROL THE GEOGRAPHIC ORIGIN AND QUALITY OF VIRGIN OLIVE OILSJOURNAL OF FOOD QUALITY, Issue 4 2007ALESSANDRA BENDINI ABSTRACT A rapid Fourier transform infrared (FTIR) attenuated total reflectance spectroscopic method was applied to determine qualitative parameters such as free fatty acid (FFA) content and the peroxide value (POV) in virgin olive oils. Calibration models were constructed using partial least squares regression on a large number of virgin olive oil samples. The best results (R2 = 0.955, root mean square error in cross validation [RMSECV] = 0.15) to evaluate FFA content expressed in oleic acid % (w/w) were obtained considering a calibration range from 0.2 to 9.2% of FFA relative to 190 samples. For POV determination, the result obtained, built on 80 olive oil samples with a calibration range from 11.1 to 49.7 meq O2/kg of oil, was not satisfactory (R2 = 0.855, RMSECV = 3.96). We also investigated the capability of FTIR spectroscopy, in combination with multivariate analysis, to distinguish virgin olive oils based on geographic origin. The spectra of 84 monovarietal virgin olive oil samples from eight Italian regions were collected and elaborated by principal component analysis (PCA), considering the fingerprint region. The results were satisfactory and could successfully discriminate the majority of samples coming from the Emilia Romagna, Sardinian and Sicilian regions. Moreover, the explained variance from this PCA was higher than 96%. PRACTICAL APPLICATIONS The verification of the declared origin or the determination of the origin of an unidentified virgin olive oil is a challenging problem. In this work, we have studied the applicability of Fourier transform infrared coupled with multivariate statistical analysis to discriminate the geographic origin of virgin olive oil samples from different Italian regions. [source] | |||||||||||||||||||||||||||||||||||||