Single Oil Research Articles

Antioxidant Effect of Two Virgin Olive Oils Depends on the Concentration and Composition of Minor Polar Compounds

In vitro studies show that some individual minor polar phenolic compounds (MPC) present in virgin olive oil prevent oxidation of human low-density lipoproteins (LDL), but few data are available on the antioxidant effect of whole oil extract. Thus, whole virgin olive extracts were studied to determine whether they maintain the antioxidant activity and whether this last is linked to MPC composition of a single virgin oil. Using HPLC-DAD the MPC content in Taggiasca and Seggianese virgin olive oils was measured. Taggiasca oil was less rich in total MPC (208.5 mg/L) than Seggianese oil (441.9 mg/L). In addition, the major compounds of Taggiasca oil were lignan derivatives, whereas the major compounds in Seggianese oils were secoiridoid derivatives. Moreover, Taggiasca oil was practically free of 5-hydroxytyrosol and 5-hydroxytyrosol derivatives, deacetoxy-oleuropein aglycone and oleuropein aglycone. The antioxidant activity of the oils on human LDL was evaluated by measuring malondialdehyde and conjugate diene generation induced by copper ions. In both tests, the oil extracts dose-dependently reduced malondialdehyde and conjugate diene generation. Moreover, antioxidant potency correlated with total MPC; thus, Seggianese extract was more active. The two oils differed quantitatively and qualitatively, and these differences influenced their biological activities; thus clinical trials focused on studying the effects of olive oils should specify the oils used.

Field-Scale Compositional Simulation of a CO2 Flood in the Fractured Midale Field

Abstract A stimulation test using electric heating was conducted on a single oil production well in the Schoonebeek reservoir in The Netherlands during 1989 and 1990. The performance of the test and its interpretation is described. The Bentheim reservoir sands are 31 m thick with a porosity of 0.3 and a permeability in the range 0.2 - 4 µm2; the oil has an in-situ viscosity at 160 mPa.s and is waxy with a cloud point very close to the reservoir temperature of 40 °C. The reservoir pressure of about 7000 kPa is supported by a strong edge aquifer. The objective of the test was to stimulate oil production with heat and, particularly, to melt wax that was suspected to be present either near the wellbore or uniformly throughout the reservoir. Prior to stimulation the oil production rate was 13 m3/d at a water cut of 35%. As the surface power dissipated was increased above 60 kW, the oil production rate increased abruptly to 30 m3/d with a bottomhole temperature in the range 54 to 60 °C; at higher power levels no further increase of production rate was observed. Analytical methods proved very useful for understanding the electric healing process, particularly for tracing the electric current flow path in the reservoir and for modelling the heat distribution and production response. Numerical simulations of the well's performance showed that the observed abrupt increase of oil production rate was compatible with the melting 01 wax at 60 °C and partial removal of a skin (of approximately 27) but not of a wax deposited uniformly throughout the reservoir. Introduction Though electrical heating has been used to stimulate well productivity al various times over the last 25 years, it is not widely applied. A lest of the stimulation method was recently completed on Well SCH-280 in the RW2-E area of the Schoonebeek oil reservoir of The Netherlands (see Figs. 1 and 2) by the Nederlandse Aardolle Maatschappij B. V. (NAM). In this paper we describe the properties of the Schoonebeek reservoirand the characteristics of Well SCH-280 and review the objectives, test programme and actual performance of the electric heating stimulation (EHS) test. In several respects, the information required to interpret the test unambiguously was not available. To circumvent these limitations, methods were developed for inferring the electric current flow path and heat distribution in the reservoir, Using both analytical and numerical simulation methods, a broadly consistent interpretation of the test was developed and this is described herein. FIELD PERFORMANCE OF OTHER ELECTRIC HEATING TESTS Over the last 25 years there have been a number of reports in the literature of planned or executed field tests of the electric heating process, mostly based on the ohmic dissipation of electric energy in the formation. Electrothermic Co., for example, stimulated four wells of the Little Tom field in South Texas. The reservoir there contains 8 - 12 °API gravity oil with a high pour point [1,2].

Identification of nutritionally adequate mixtures of vegetable oils by linear programming

To determine the types and proportions of vegetable oils to recommend for a healthy diet. Optimal vegetable oil combinations were designed, using linear programming and, as decision variables, nine single oils and 29 basic food items. 'Oil models' were run to determine whether reasonable amounts of individuals oils or oil mixtures satisfied a set of constraints on essential fatty acids and vitamin E. 'Meal models' were run to test whether selected mixtures could be used as the sole source of added fat in a meal that met micronutrient and macronutrient recommendations. The cheapest mixture (0.97 euro L(-1)) that solved the oil models contained 81% rapeseed and 19% sunflower oils. About 10-15 g of this mixture, alone or with olive, soya bean, wheat germ or walnut oils, also solved the meal models. Mixtures that contained a high proportion (>or=50%) of the tasty olive and walnut oils also solved the models but were more expensive (4.9 euro L(-1) and 8.5 euro L(-1), respectively). The consumption of a mixture composed of rapeseed and sunflower oils in a 4 : 1 proportion is an inexpensive and simple way to meet current dietary recommendations for essential fatty acids and vitamin E, favouring overall dietary nutrient adequacy.

Deformation of single emulsion drops covered with a viscoelastic adsorbed protein layer in simple shear flow

The small-deformation behavior of single Newtonian oil drops covered by an adsorbed viscoelastic protein layer is investigated in simple shear flow. Adsorption and network formation of the protein (lysozyme) at the oil/water interface are tracked by interfacial rheology and tension. While uncovered drops deform to the expected steady ellipsoidal shape, protein-covered drops are able to resist the bulk shear stress to a much higher degree, leading to a smaller average deformation and oscillating drop shapes. The results show direct evidence for a commanding role of in-plane interfacial stresses of a viscoelastic protein network on the macroscopic drop deformation as opposed to the equilibrium interfacial tension.

Design and Application of an Alkaline‐Surfactant‐Polymer Flooding System in Field Pilot Test

We have developed an inexpensive sort of flooding reagent whose major components are natural mixed carboxylates from proportionally mixed saponification residuals of cottonseed oil, tea oil, vegetable oil, and soybean oil. An orthogonal test design method was used to select one form of this flooding reagent (which is named SD) by measuring the phase behavior and another form of the flooding system: alkaline/surfactant/polymer (named SD‐ASP). The optimal composition was obtained by measuring the transient interfacial tension (IFT) at the crude oil/aqueous interface. Results of the tests show that the SD‐ASP flooding systems are tolerant to salt up to 1.5×105 mg/L and to Ca2+ and Mg2+ to 5.0×103 mg/L at 90°C, the IFTmin (the minimum of IFT) is 10−3 mN/m, and the oil recovery ratio reaches 22.77% by using the core flood experiment. The pilot tests, including a putting in and sending out in a single oil well, a group oil well and a larger well region, were all very successful, with an average input‐output ratio of 1∶4.15. All these results demonstrate that the SD‐ASP formulation is a new, very inexpensive, and highly effective flooding system.

Characterisation of 39 varietal virgin olive oils by their volatile compositions

Thirty-nine single virgin olive oils from eight producer countries, but cultivated in the same orchard under identical agronomic and pedoclimatic conditions, were characterised by 64 volatile compounds quantified by dynamic headspace-gas chromatography. The method was validated by analysing the relative standard deviation in repeatability and intermediate reproducibility of each volatile compound. Data on the total content of volatiles and C6 compounds – responsible for the green odour perception-, and the total content of hydrocarbons, aldehydes, alcohols, ketones and esters are displayed and discussed for each individual virgin olive oil. Fifty volatile compounds were characterised by their sensory attributes, determined by olfactometry. The Student t-test was used to determine the level of significance of each volatile compound characterising the varieties. The odour threshold and the maximum concentration of the most notable volatiles are also displayed. Finally, the Brown-Forsythe test and stepwise linear discriminant analysis were used to check the ability of the volatiles to cluster the varietal virgin olive oils according to their autochthonous geographical origin.

Antibacterial activity of essential oils from Australian native plants

To date, of the Australian essential oils, only tea tree (Melaleuca alternifolia) and Eucalyptus spp. have undergone extensive investigation. In this study a range of Australian essential oils, including those from Anethole anisata, Callistris glaucophyllia, Melaleuca spp. and Thyptomine calycina, were assayed for in vitro antibacterial activity. M. alternifolia was also included for comparison purposes. Activity was determined using standard disc diffusion assays with each oil assayed at 100%, 10% and 1% against five bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa and Alcaligenes faecalis) and the yeast, Candida albicans. All bacteria, with the exception of Ps. aeruginosa, were susceptible to one or more of the essential oils at 100%, with only Eremophilia mitchelli inhibiting the growth of any bacteria at 1% (inhibition of Sal. typhimurium). Where multiple samples of a single oil variety were tested variability in activity profiles were noted. This suggests that different methods of preparation of essential oils, together with variability in plant chemical profiles has an impact on whether or not the essential oil is of use as an antimicrobial agent. These results show that essential oils from Australian plants may be valuable antimicrobial agents for use alone or incorporated into cosmetics, cleaning agents and pharmaceutical products.

Egg Development of Paralichthys orbignyanus (Valenciennes, 1839)

Eggs of the Southern Brazilian flounder Paralichthys orbignyanus were obtained through spawning induction and reared in laboratory. The eggs released were free-floating or pelagic. Other important characteristics were: spherical shape, smooth chorion, narrow perivitelline space, and a single oil globule. Egg and oil globule diameter were about 0.792 ± 0.008 mm and 0.114 ± 0.003 mm, respectively. The blastodisc was observed approximately 1 h after fertilization and followed by blastodisc cleavage. Blastula stage started after about 5 h and gastrula stage after 9 h. Approximately 20 h after fertilization, blastopore closure was observed. Neurula or early embryo occurred after 24 h. Cardiac beats and movements of the free embryonic tail were recorded after 40 h of incubation. Hatching occurred after an incubation period of 40-50 h at temperatures ranging from 18 to 20 ºC. Newly hatched larvae were about 2.04 ± 0.024 mm long and quite undeveloped, with a large yolk sac with a posterior oil globule and sparse pigmentation. These results were greatly similar to those obtained by previous studies regarding congener species. This is one of the first steps towards the artificial propagation of this species under controlled conditions.

Chronic toxicity and carcinogenicity of 1,2,3,4,6,7,8-heptachlorodibenzo- p-dioxin displays a distinct dose/time toxicity threshold ( c × t = k) and a life-prolonging subthreshold effect

Chronic toxicity of 1,2,3,4,6,7,8-heptachlorodibenzo- p-dioxin (HpCDD) including its carcinogenicity was studied in female Sprague–Dawley rats in lifetime experiments. Six single dose and three multiple dose rate experiments were conducted with a single dose corn oil control group and a multiple dose rate corn oil control group, respectively. The lowest dose (1.0 mg/kg) of HpCDD and multiple dose rates of corn oil (4.0 ml/kg every other week) both prolonged the life of rats by about 2 months over that of single dose corn oil controls. Higher doses resulted in a predictable shortening of the life of rats after single dose administrations as well as after multiple dose rate administrations. The c × t = k paradigm previously validated for acute toxicity [Toxicol. Sci. 49 (1999) 102] was confirmed for chronic toxicity including carcinogenicity of HpCDD. The c × t = k product was independent of dosing regimen. Anemia and squamous cell carcinoma of the lungs were the earliest and most prevalent endpoints of toxicity. A dose of 2.1 mg/kg and 3.1 mg/kg of HpCDD caused 16.6% and 73.3% lung cancer, respectively. Liver cancer had a low prevalence and was a very late effect occurring only at doses lethal acutely for most rats in the three highest dosage groups. There was no correlation in the dose-dependence of non-malignant hepatic lesions and liver cancer.

Oil-Viscosity Predictions From Low-Field NMR Measurements

Summary Canada contains vast reserves of heavy oil and bitumen. Viscosity determination is key to the successful recovery of this oil, and low-field nuclear magnetic resonance (NMR) shows great potential as a tool for estimating this property. An NMR viscosity correlation previously had been developed that is valid for order-of-magnitude estimates over a wide range of viscosities and temperatures. This correlation was built phenomenologically, using experiments relating NMR spectra to viscosity. The present work details a more thorough investigation into oil viscosity and NMR, thus providing a theoretical justification for the proposed correlation. A novel tuning procedure is also presented, whereby the correlation is fitted using the Arrhenius relationship to improve the NMR viscosity estimates for single oils at multiple temperatures. Tuning allows for NMR to be potentially used in observation wells to monitor thermal enhanced oil recovery (EOR) projects or online to monitor the viscosity of produced-fluid streams as they cool.

Kinetic Analysis of Ion Pair Extraction of an Alkyl Sulfate Anion across a Liquid/Liquid Interface by Fluorescence Microspectroscopy and Microelectrochemistry of Single Microdroplets

Mass transfer of an alkyl sulfate anion with a (ferrocenylmethyl)trimethylammonium cation from water into single oil microdroplets was kinetically studied by microcapillary injection, fluorescence microspectroscopy, and microelectrochemistry. The partitioning ratio and the extraction rate significantly depended on the alkyl chain length of the alkyl sulfate anion. The extraction rate for the n-dodecyl sulfate or n-tridecyl sulfate ion was proportional to both the alkyl sulfate ion and ferrocene derivative concentrations while that for the n-undecyl sulfate ion was proportional to the anion concentration alone. The results are discussed in terms of transfer of the individual ions across the microdroplet/water interface and adsorption/ion pair formation of the alkyl sulfate ion at the microdroplet/water interface.

Effect of Supplementation with Docosahexaenoic Acid Ethyl Ester and sn-2 Docosahexaenyl Monoacylglyceride on Plasma and Erythrocyte Fatty Acids in Rats

Background/Aims: Docosahexaenoic acid (C22:6, DHA) is an omega-3 fatty acid required for the normal development of the mammalian nervous and visual system. DHA is provided by the mother during pregnancy and lactating period. Mother’s DHA supplementation during pregnancy, and even before pregnancy, has been suggested. DHA can be provided by marine oils, egg’s yolk phospholipids, single cell algae oils, the pure fatty acid, or by the ethyl ester derivative (DHA-EE). Another way to provide DHA can be by sn-2 docosahexaenyl monoacylglyceride (DHA-MG), obtained by the treatment of fish oil with stereospecific lipases. sn-2 Fatty acid monoacylglycerides can be more easily absorbed at the intestine than other fatty acid derivatives. Methods: Female rats fed with a synthetic, which provided essentially no DHA, received a 40-day supplementation of either DHA-EE or DHA-MG. Plasma and erythrocyte fatty acid composition were assessed by gas chromatography at day 0 and 40 of supplementation. Results: DHA-EE increased plasma and erythrocyte DHA by 15 and 11.9%, respectively, with no modification of arachidonic acid (AA) content. DHA-MG supplementation increased plasma and erythrocyte DHA by 24 and 23.8%, respectively, but reduced AA by 5.5 and 3%, respectively. Conclusions: We conclude that in the rat, DHA-MG supplementation allows a higher plasma and erythrocyte DHA content than DHA-EE with minor modification of AA content.

Ultrastructure of oogenesis in the bluefin tuna,Thunnus thynnus

Ovarian ultrastructure of the Atlantic bluefin tuna (Thunnus thynnus) was investigated during the reproductive season with the aim of improving our understanding of the reproductive biology in this species. The bluefin, like the other tunas, has an asynchronous mode of ovarian development; therefore, all developmental stages of the oocyte can be found in mature ovaries. The process of oocyte development can be divided into five distinct stages (formation of oocytes from oogonia, primary growth, lipid stage, vitellogenesis, and maturation). Although histological and ultrastructural features of most these stages are similar among all studied teleosts, the transitional period between primary growth and vitellogenesis exhibits interspecific morphological differences that depend on the egg physiology. Although the most remarkable feature of this stage in many teleosts is the occurrence of cortical alveoli, in the bluefin tuna, as is common in marine fishes, the predominant cytoplasmic inclusions are lipid droplets. Nests of early meiotic oocytes derive from the germinal epithelium that borders the ovarian lumen. Each oocyte in the nest becomes surrounded by extensions of prefollicle cells derived from somatic epithelial cells and these form the follicle that is located in the stromal tissue. The primary growth stage is characterized by intense RNA synthesis and the differentiation of the vitelline envelope. Secondary growth commences with the accumulation of lipid droplets in the oocyte cytoplasm (lipid stage), which is then followed by massive uptake and processing of proteins into yolk platelets (vitellogenic stage). During the maturation stage the lipid inclusions coalesce into a single oil droplet, and hydrolysis of the yolk platelets leads to the formation of a homogeneous mass of fluid yolk in mature eggs.

Characterization of Sicilian virgin olive oils. Note X. A comparison between <i>Cerasuola and Nocellara del Belice</i>Un noventa por ciento de los olivos de la cuenca mediterránea son destinados a la producción de aceite. Dentro de un amplio es varieties

Ninety percent of the olive trees are destined to oil production in the Mediterranean basin. Within a wide study of Southern Italian olive oils, with a particular reference to Sicily, several varieties of olive have been studied. The result of an analytical study carried out with two cultivars Nocellara del Belice and Cerasuola for six consecutive years is described in this paper. Parameters related to olive oil purity and shelf-life together with the composition (%) of sterols and fatty acids of the single oils are shown. Data were analyzed by the univariate non-parametric Mann-Whitney test and the multivariate procedure of Factor Analysis.

Ontogeny of the mandarinfish Siniperca chuatsi (Perciformes: Sinipercidae) reared in aquarium

Early-stage morphologies of the mandarinfish Siniperca chuatsi are described on the basis of an ontogenetic series of reared specimens in an aquarium. Spherical eggs (diameter 1.70–1.82 mm) with a single oil globule (0.40–0.48 mm) were free-demersal and easily floated when agitated. Hatching occurred about 3 days after spawning at about 24°C. Newly hatched larvae (3.8–4.2 mm in notochord length: NL) had many melanophores on the yolk sac. After reaching ca. 5.5 mm NL (8–9 + 19–20 = 27–28 myomeres), larvae had almost completely absorbed the yolk, possessed a large mouth and sharp teeth, and were starting to prey on other fish larvae. Three large preopercle spines appeared at ca. 5.5 mm NL, five spines by ca. 8.5 mm NL, and eight by ca. 21 mm in standard length (SL). The interopercle bore a single spine at ca. 8.5 mm NL and two spines at ca. 13.5 mm SL. A single spine appeared at the supracleithrum and another at the opercle at ca. 10 mm SL. Dorsal fin spines and pelvic, anal, and caudal fins were completed at ca. 10 mm SL. Dorsal fin rays and pectoral fins were completed at ca. 13.5 mm SL. Four ontogenetic characters (free-demersal eggs, large jaws with large teeth, conspicuous head spination, and precocious completion of dorsal fin spines) are rare among freshwater percoids.

Extraction of tributyltin and triphenyltin across a single oil droplet/water interface

Extraction of tributyltin and triphenyltin across a single oil droplet/water interface

Attenuation of water coning using dual completion technology

Water coning causes a reduction of oil production and an increase of production costs. Dual completion (downhole water sink) is one of the methods adopted to attenuate water coning. This work describes numerical results associated with this completion technique. The water cone shape and water breakthrough time are investigated to define the mechanism and performance of this technical procedure. The numerical results show that dual completion deforms the shape of the cone. For instance, the top of the water–oil interface is shifted away from the well yielding (under high water production rates) oil breakthrough into water perforations. The water breakthrough is proportional to dimensionless density difference and horizontal permeability and inversely proportional to oil production rate, mobility, and anisotropy ratios. High oil production rates yield elevation of water coning height that intercepts oil flow. Paradoxically, high production rate at water sink is not recommended, the improvement of water breakthrough begins when dimensionless density difference is greater than 0.05. The dual completion technique delays water breakthrough time (BT*). In general, the BT* is delayed by two times that of single completion and critical oil rate is augmented compared to single completion.

Extraction of tributyltin and triphenyltin across a single oil droplet/water interface

Tributyltin (TBT +) and triphenyltin (TPT +) were extracted with merocyanine 540 (MC −) from water into a 1,6-dichlorohexane droplet with the radius of 40 μm and the absorption spectra of MC − were measured by a single microdroplet manipulation and microabsorption technique. The mass transfer rate and the partitioning ratio of MC − were characteristically influenced by the TBT +, TPT +, MC −, and Cl − concentrations in water. The ion pair extraction processes of the organotin compounds with the anions were discussed in terms of the ion transfer and adsorption–desorption of the solutes.

Thermodynamic consideration on single oil in water emulsion film stabilized by cationic surfactant

The emulsion film has become the focus of the study of emulsion because the film stability and structure play a crucial role on the whole stability and structure of emulsions. In this study, the single emulsion film stabilized by tetradecyltrimethylammonium bromide (C14TAB) in dodecane phase has been investigated thermodynamically. In order to make clear the theoretical treatment, it has been reviewed how the thermodynamic quantities of extremely thin films are defined and how it is related to the experimental variables such as temperature, pressure, and concentrations of solutes. By using the equations demonstrated here, the film tension and film surface tension, which were evaluated from the measurement of contact angle between the emulsion film and the surrounding bulk meniscus, have been inspected thermodynamically from the viewpoint of the influence of added salt (KBr) concentration on the structure of thin emulsion film. In addition, the comparison of the results obtained has also been made between the foam and emulsion films to reveal the effect of an ambient dodecane phase on the properties of the film.

A direct liquid, non-equilibrium solid-phase micro-extraction application for analysing chemical variation of single peltate trichomes on leaves of Salvia officinalis.

A non-equilibrium solid phase micro-extraction application was tested for the rapid extraction of essential oil from single oil glands of sage and the oil components compared with those determined by solvent extract and distillation. Oil glands were directly ruptured with a polydimethylsiloxane-coated fused silica fibre and the essential oil was sorbed. Three insertion levels of an individual plant of Salvia officinalis involving an immature apical young leaf, an expanding and a fully developed leaf, respectively, were used to determine the applicability of this method. Thirty-eight components in the oil could be identified by GC-MS. The method only showed small semi-quantitative differences compared with conventional methods. Chemical variation of single oil glands within the immature and premature leaf was higher than within the homogeneous mature leaf. The intermediary, still-expanding leaf was used to carry out a detailed study of the glands. The basal region of the intermediary leaf contained compounds in high conformity with the young leaf trichomes. The remaining oil glands of this leaf showed inconsistent accumulation patterns.