Effects of high-γ-linolenic acid canola oil compared with borage oil on reproduction,growth, and brain and behavioral development in mice

Previous research in rats and mice has suggested that γ-linolenic acid (GLA) derived from borage oil (BO: 23% GLA) may be an appropriate source for increasing levels of long-chain n−6 FA in the developing brain. Recently, transgenic technology has made available a highly enriched GLA seed oil from the canola plant (HGCO: 36% GLA). The first objective of this study was to compare the effects of diets containing equal levels of GLA (23%) from either BO or HGCO on reproduction, pup development, and pup brain FA composition in mice. The second objective was to compare the effects of the HGCO diluted to 23% GLA (GLA-23) with those of undiluted HGCO containing 36% GLA (GLA-36). The diets were fed to the dams prior to conception and throughout pregnancy and lactation, as well as to the pups after weaning. The behavioral development of the pups was measured 12 d after birth, and anxiety in the adult male offspring was assessed using the plus maze. The findings show that despite equivalent levels of GLA, GLA-23 differed from BO in that it reduced pup body weight and was associated with a slight increase in neonatal pup attrition. However, there were no significant effects on pup behavioral development or on performance in the plus maze. An increase in dietary GLA resulted in an increase in brain 20∶4n−6 and 22∶4n−6, with a corresponding decrease in 22∶6n−3. Again, despite their similar levels of GLA, these effects tended to be larger in GLA-23 than in BO. In comparison with GLA-23, GLA-36 had larger effects on growth and brain FA composition but no differences with respect to effects on reproduction and behavioral development. These findings suggest that the HGCO can be used as an alternative source of GLA.     

Phase equilibria of palm oil,palm kernel oil,and oleic acid + supercritical carbon dioxide and modeling using Peng–Robinson EOS

Vapor–liquid equilibria of the binary supercritical carbon dioxide (scCO₂) + oleic acid, scCO₂ + palm oil, and scCO₂ + palm kernel oil were measured at a wide range of temperatures from 333.2 to 373.2 K and pressures from 8.5 to 35 MPa in a circulation-type phase equilibrium apparatus. The samples from liquid and vapor phases were analyzed using UV–vis spectrometer and a liquid hold-up equipment. The phase equilibrium data were correlated with Peng–Robinson Equation of State (PR-EOS) using Wong–Sandler mixing rule and optimum values of binary interaction parameters were determined. The relative deviation between experimental data and predicted data was in the range of 6.9–8.7%, suggesting that the PR-EOS with Wong–Sandler mixing rule is capable of predicting the vapor–liquid equilibria of oleic acid + scCO₂, palm oil + scCO₂, and palm kernel oil + scCO₂.     

Hybrid films synthesised from epoxidised castor oil, γ-glycidoxypropyltrimethoxysilane and tetraethoxysilane

Novel organic–inorganic hybrid films were synthesised through the reaction of epoxidised castor oil (ECO) with γ-glycidoxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The amounts of GPTMS employed were sufficient to react with 25, 50 or 75% of the epoxy groups present in the ECO, whilst the mass proportions of ECO to TEOS varied from 90:10 to 70:30. Films were pre-cured at room temperature under an inert atmosphere, and subsequently submitted to thermal curing. Macro and microscopic properties of the films, including adhesion, hardness, swelling in toluene, microstructure (scanning electron microscopy) and thermal properties were determined as a function of the proportion of organic to inorganic precursor. Morphologic studies showed that the hybrid films were microscopically homogeneous when lower proportions of inorganic precursors were employed. Hardness and tensile strength increased, and swelling in toluene decreased, with the increase in the concentration of inorganic precursors. Good adhesion of the films to an aluminium surface was observed throughout the hybrid series.     

Enhancing oil–solid and oil–water separation in heavy oil recovery by CO2-responsive surfactants

Interfacial properties are of critical importance to various separation applications. In heavy oil recovery, for example, a low oil–water interfacial tension (IFT) benefits the separation of heavy oil from their host rocks, which becomes problematic in the later stage of oil–water separation. CO₂-responsive surfactants were investigated to enhance the overall heavy oil recovery by switching their interfacial activity to the desired state in each stage. The surfactants at interfacially active state greatly enhanced the separation of heavy oil from hosting solids, as demonstrated by measuring contact angle and oil liberation using a custom-designed on-line visualization system. Meanwhile, the resulting heavy oil-in-water emulsions could also be easily demulsified by the bubbling of CO₂ gas, which switched off the interfacial activity of the surfactants. Furthermore, CO₂-responsive surfactants could be partially recycled in process water to improve sustainability, making CO₂-responsive surfactants to be promising chemical aids in heavy oil production and many other vital industries.     

Properties of α-, γ-, and δ-tocopherol in purified fish oil triacylglycerols

The effect of α-tocopherol (αTOH) (50–2000 ppm), γ-tocopherol (γTOH) (100–2000 ppm), and δ-tocopherol (δTOH) (100–2000 ppm) on the formation and decomposition of hydroperoxides in purified fish oil triacylglycerols (TAG) was studied. The tests were conducted at 30°C in the dark. Purified fish oil TAG oxidized very rapidly with no apparent induction period. The relative ability of the tocopherols to retard the formation of hydroperoxides decreased in the order αTOH> γTOH>δTOH at a low level of addition (100 ppm), but a reverse order of activity was found when the initial tocopherol concentration was 1000 ppm. This dependence of relative antioxidant activity on tocopherol concentration was caused by the existence of concentrations for maximal antioxidant activity for αTOH and for γTOH. An inversion of activity, on the basis of hydroperoxide formation, was observed for αTOH at 100 ppm and for γTOH at 500 ppm, whereas the antioxidant activity of δTOH increased with level of addition up to 1500–2000 ppm. None of the tocopherols displayed any prooxidant activity. All three tocopherols strongly retarded the formation of volatile secondary oxidation products in a concentration-dependent manner. At concentrations above about 250 ppm there appeared to be a linear relationship between rate of consumption of αTOH and initial αTOH concentration, in accordance with the linear relationship observed between the initial rate of formation of hydroperoxides and the initial αTOH concentration. The rate of consumption of γTOH also increased with initial concentration, but to a lesser extent than for αTOH. At high levels of addition the rate of consumption of δTOH was independent of initial concentration, appearing to reflect the greater stability of this tocopherol homolog and participation in reactions with lipid peroxyl radicals only. Presented in part at the AOCS annual meeting in San Diego, California, April 2000.     

Replacing fossil oil with fresh oil – with what and for what?

Industrial chemicals and materials are currently derived mainly from fossil‐based raw materials, which are declining in availability, increasing in price and are a major source of undesirable greenhouse gas emissions. Plant oils have the potential to provide functionally equivalent, renewable and environmentally friendly replacements for these finite fossil‐based raw materials, provided that their composition can be matched to end‐use requirements, and that they can be produced on sufficient scale to meet current and growing industrial demands. Replacement of 40% of the fossil oil used in the chemical industry with renewable plant oils, whilst ensuring that growing demand for food oils is also met, will require a trebling of global plant oil production from current levels of around 139 MT to over 400 MT annually. Realisation of this potential will rely on application of plant biotechnology to (i) tailor plant oils to have high purity (preferably >90%) of single desirable fatty acids, (ii) introduce unusual fatty acids that have specialty end‐use functionalities and (iii) increase plant oil production capacity by increased oil content in current oil crops, and conversion of other high biomass crops into oil accumulating crops. This review outlines recent progress and future challenges in each of these areas. Practical applications: The research reviewed in this paper aims to develop metabolic engineering technologies to radically increase the yield and alter the fatty acid composition of plant oils and enable the development of new and more productive oil crops that can serve as renewable sources of industrial feedstocks currently provided by non‐renewable and polluting fossil‐based resources. As a result of recent and anticipated research developments we can expect to see significant enhancements in quality and productivity of oil crops over the coming decades. This should generate the technologies needed to support increasing plant oil production into the future, hopefully of sufficient magnitude to provide a major supply of renewable plant oils for the industrial economy without encroaching on the higher priority demand for food oils. Achievement of this goal will make a significant contribution to moving to a sustainable carbon‐neutral industrial society with lower emissions of carbon dioxide to the atmosphere and reduced environmental impact as a result.     

Asphaltene precipitation and deposition in oil reservoirs – Technical aspects,experimental and hybrid neural network predictive tools

Precipitation of asphaltene is considered as an undesired process during oil production via natural depletion and gas injection as it blocks the pore space and reduces the oil flow rate. In addition, it lessens the efficiency of the gas injection into oil reservoirs. This paper presents static and dynamic experiments conducted to investigate the effects of temperature, pressure, pressure drop, dilution ratio, and mixture compositions on asphaltene precipitation and deposition. Important technical aspects of asphaltene precipitation such as equation of state, analysis tools, and predictive methods are also discussed. Different methodologies to analyze asphaltene precipitation are reviewed, as well. Artificial neural networks (ANNs) joined with imperialist competitive algorithm (ICA) and particle swarm optimization (PSO) are employed to approximate asphaltene precipitation and deposition with and without CO₂ injection. The connectionist model is built based on experimental data covering wide ranges of process and thermodynamic conditions. A good match was obtained between the real data and the model predictions. Temperature and pressure drop have the highest influence on asphaltene deposition during dynamic tests. ICA-ANN attains more reliable outputs compared with PSO-ANN, the conventional ANN, and scaling models. In addition, high pressure microscopy (HPM) technique leads to more accurate results compared with quantitative methods when studying asphaltene precipitation.     

Modeling and optimization for oil well production scheduling☆

In this paper, an oil wel production scheduling problem for the light load oil wel during petroleum field exploi-tation was studied. The oil well production scheduling was to determine the turn on/off status and oil flow rates of the wel s in a given oil reservoir, subject to a number of constraints such as minimum up/down time limits and well grouping. The problem was formulated as a mixed integer nonlinear programming model that minimized the total production operating cost and start-up cost. Due to the NP-hardness of the problem, an improved par-ticle swarm optimization (PSO) algorithm with a new velocity updating formula was developed to solve the problem approximately. Computational experiments on randomly generated instances were carried out to eval-uate the performance of the model and the algorithm's effectiveness. Compared with the commercial solver CPLEX, the improved PSO can obtain high-quality schedules within a much shorter running time for all the instances.     

Effect of oil viscosity on the flow structure and pressure gradient in horizontal oil–water flow

The flow patterns and pressure gradient of immiscible liquids are still subject of immense research interest. This is partly because fluids with different properties exhibit different flow behaviours in different pipe's configurations under different operating conditions. In this study, a combination of oil–water properties (σ = 20.1 mN/m) not previously reported was used in a 25.4 mm acrylic pipe. Experimental data of flow patterns, pressure gradient and phase inversion in horizontal oil–water flow are presented and analyzed together with comprehensive comments. The effect of oil viscosity on flow structure was assessed by comparing the present work data with those of Angeli and Hewitt (2000) and Raj et al. (2005). The comparison revealed several important findings. For example, the water velocity required to initiate the transition to non-stratified flow at low oil velocities increased as the oil viscosity increased while it decreased at higher oil velocities. The formation of bubbly and annular flows and the extent of dual continuous region were found to increase as the oil–water viscosity ratio increased. Dispersed oil in water appeared earlier when oil viscosity decreased.     

Effects of conjugated linoleic acid, fish oil and soybean oil on PPARs (α & γ) mRNA expression in broiler chickens and their relation to body fat deposits

An experiment was conducted on broiler chickens to study the effects of different dietary fats (Conjugated linoleic acid (CLA), fish oil, soybean oil, or their mixtures, as well as palm oil, as a more saturated fat), with a as fed dose of 7% for single fat and 3.5 + 3.5% for the mixtures, on Peroxisome Proliferator-Activated Receptors (PPARs) gene expression and its relation with body fat deposits. The CLA used in this experiment was CLA LUTA60 which contained 60% CLA, so 7% and 3.5% dietary inclusions of CLA LUTA60 were equal to 4.2% and 2.1% CLA, respectively. Higher abdominal fat pad was found in broiler chickens fed with a diet containing palm oil compared to chickens in the other experimental groups (P ≤ 0.05). The diets containing CLA resulted in an increased fat deposition in the liver of broiler chickens (P ≤ 0.05). The only exception was related to the birds fed with diets containing palm oil or fish oil + soybean oil, where contents of liver fat were compared to the CLA + fish oil treatment. PPARγ gene in adipose tissue of chickens fed with palm oil diet was up-regulated compared to other treatments (P ≤ 0.001), whereas no significant differences were found in adipose PPARγ gene expression between chickens fed with diets containing CLA, fish oil, soybean oil or the mixture of these fats. On the other hand, the PPARα gene expression in liver tissue was up-regulated in response to the dietary fish oil inclusion and the differences were also significant for both fish oil and CLA + fish oil diets compared to the diets with palm oil, soybean oil or CLA as the only oil source (P ≤ 0.001). In conclusion, the results of present study showed that there was a relationship between the adipose PPARγ gene up-regulation and abdominal fat pad deposition for birds fed with palm oil diet, while no deference was detected in n-3 and n-6 fatty acids, as well as CLA on PPARγ down regulation in comparison to a more saturated fat. When used on its own, fish oil was found to be a more effective fat in up-regulating hepatic PPARα gene expression and this effect was related to a less fat deposition in liver tissue. A negative correlation coefficient (-0.3) between PPARα relative gene expression and liver tissue fat content confirm the anti-lipogenic effect of PPARα, however, the change in these parameters was not completely parallel.     

Protection of α-tocopherol in nonpurified and purified fish oil

Menhanden oil was purified by column chromatography to remove minor components. The effect of α-tocopherol (α TOH) (50–500 ppm) on the rate of formation of hydroperoxides in the original menahaden oil and in the purified menhaden triacylglycerol (TAG) fraction was studied at 30°C in the dark. An increase in the initial rate of formation of hydroper-oxides was observed at αTOH concentrations above 100 ppm in both substrates. The original menhaden oil oxidized more rapidly than the purified menhaden, TAG at all antioxidant levels tested, and the presence of minor components in the menhaden oil was found to contribute only to a limited extent to the peroxidizing effect of αTOH. The αTOH did not display any prooxidant activity at either of the concentrations tested when the control oil was the purified menhaden TAG. Addition of ascorbyl palmitate eliminated the initial peroxidizing effect of αTOH, and this emphasizes the participation of the α-toco-pheroxyl radical in the reactions causing an accumulation of hydroperoxides at high concentrations of αTOH. Presented in part at the Annual Meeting of the American Oil Chemists’ Society in San Diego, April 25–28, 2000.     

Synthesis and characterization of tall oil fatty acids-based alkyd resins and alkyd–acrylate copolymers

The polymerization and properties of environmentally friendly waterborne binders for wood coatings were studied. Conjugated and non-conjugated tall oil fatty acids-based alkyd resins were synthesized and further copolymerized via miniemulsion polymerization with acrylates (butyl acrylate and methyl methacrylate). The ratio between alkyd resin and acrylate monomers was varied and the effect on copolymerization and the copolymer binder properties, such as particle size, molecular weight, grafting of acrylate to alkyd resin and reaction of double bonds, were studied. It was observed that the use of MMA influenced on the degree of grafting of acrylate and monomer conversion because the steric hindrances prevent MMA to react with alkyd double bonds as eagerly as BA. The increasing amount of alkyd resin was noticed to decrease the polymerization rate. The research showed that it was possible to prepare stable hybrids, alkyd–acrylate copolymers, with varied chemical composition.     

β-oxidation capacity of red and white muscle and liver in Atlantic salmon (<Emphasis Type="Italic">Salmo salar</Emphasis> L.)—Effects of increasing dietary rapeseed oil and olive oil to replace capelin oil

Post-smolt Atlantic salmon (Salmo salar) were fed six diets in which capelin oil was replaced with 0, 25, 50, 75, or 100% rapeseed oil (RO; low-erucic acid) or 50% olive oil (OO). The experimental diets were fed to single groups of Atlantic salmon for 42 wk, whereas the 100% capelin oil (0% RO) diet was fed in duplicate. The β-oxidation capacity of palmitoyl-CoA was determined, using a method optimized for salmon tissues, at the start of the experiment, after 21 wk (October), and after 42 wk (March) in red and white muscle and in liver. Red muscle showed the highest specific β-oxidation capacity, but when expressed as total β-oxidation capacity for the whole tissue, white muscle was the most important tissue for the β-oxidation of FA. From the initial to the final sampling, the β-oxidation capacity of white muscle increased significantly, whereas the β-oxidation capacity in liver decreased significantly. After 22 wk, white muscle exhibited an increased β-oxidation capacity when the dietary RO content was raised from 25 to 75%, with similar effects in red muscle and liver after 42 wk of feeding. The present results also show that the β-oxidation capacity increased with an increase in fish size.