Phytosterol accumulation in canola, sunflower, and soybean oils: Effects of genetics, planting location, and temperature

To assess the potential of traditional selection breeding to develop varieties with increased phytosterol content, we determined concentrations of those sterols in canola, sunflower, and soybean seed oils produced from breeding lines of diverse genetic backgrounds. Seed oils were extracted and saponified, and the nonsaponifiable fractions were subjected to silylation. The major phytosterols brassicasterol, campesterol, stigmasterol and β-sitosterol, were quantified by capillary gas chromatography with flame-ionization detection. Canola contained approximately twice the amount of total phytosterols (4590–8070 μg g⁻¹) as sunflower (2100–4540 μg g⁻¹) or soybean (2340–4660 μg g⁻¹) oils. Phytosterol composition varied among crops as expected, as well as within a crop. Both genetic background and planting location significantly affected total phytosterol concentrations. Soybean plants were maintained from flower initiation to seed maturity under three temperature regimes in growth chambers to determine the effect of temperature during this period on seed oil phytosterol levels. A 2.5-fold variability in total phytosterol content was measured in these oils (3210–7920 μg g⁻¹). Total phytosterol levels increased with higher temperatures. Composition also changed, with greater percent campesterol and lower percent stigmasterol and β-sitosterol at higher temperatures. In these soybean oils, total phytosterol accumulation was correlated inversely with total tocopherol levels. Owing to the relatively limited variability in phytosterol levels in seed oils produced under field conditions, it is unlikely that a traditional breeding approach would lead to a dramatic increase in phytosterol content or modified phytosterol composition.     

Levels,Sources, and Risk Assessment of Polychlorinated Biphenyls (PCBs) in Soils from Industrial Areas: A Case Study from Saudi Arabia

ABSTRACT

The objective of this study was to assess the pollution levels, sources, and human health risk of polychlorinated biphenyls (PCBs) in soils of industrial areas of the central and eastern regions of Saudi Arabia. Therefore, the surface soil samples from industrial areas (cement kiln, oil refinery, electric power plant, steel industry, and desalination plant) were collected and analyzed by High-Resolution Gas Chromatography-Mass Spectrometry/Mass Spectrometry-Time of Flight (HRGC-MS/MS-TOF) to quantify the levels of 26 PCBs (including 12 dioxin-like PCBs and 14 indicator-PCBs). The investigated 26 PCBs were detected in all soil samples. The total PCBs concentration (from tri-CBs to hepta-CBs) ranged from 171 to 4892 pg g^?1 with an average of 1369 pg g^?1 in soils of the central region and of 142–1231 pg g^?1 with an average of 302 in soils of the eastern region, showing higher values at cement factory and/or oil refinery sites. Overall, the indicator-PCBs were the main congeners and contributed dominantly to the total mass of PCBs in comparison with the dioxin-like PCB congeners, with the most abundant for PCB-180 in the soil samples of the central region. Among individual dioxin-like PCBs, PCB-126 had the highest average value of the toxicity equivalence (TEQ). The TEQ values of ∑12dioxin-like PCBs did not exceed the Canadian soil quality guidelines of dioxin (4 pg TEQ g^?1). Based on human health risk assessment via ingestion, dermal contact, and inhalation, low adverse effects of PCBs could be expected as indicated by lower values of cancer risk (≤10^?6). The principal component analysis indicated that there is a different source of PCBs with similar or different PCB profiles.     

Determination of selenium,arsenic, iodine and bromine in fish,plant and mammalian oils by cyclic instrumental neutron activation analysis

The concentrations of arsenic, selenium, iodine and bromine in a series of fish, plant and mammalian oils have been determined by cyclic instrumental neutron activation analysis (CINAA). Crude fish oils contain between 0.047 and 0.151 μg Se g⁻¹, 2.36–14.5 μg As g⁻¹, 2.36–9.63 μg Br g⁻¹ and 0.97–4.76 μgI g⁻¹. Seal oil contains the same four elements, but at levels below the lower end of the fish oil ranges. Iodine, bromine and arsenic were not detected in rape-seed or soybean oils and the concentration of selenium varied from < 0.010 to 0.042 μg g⁻¹. The levels of selenium, iodine and bromine are reduced markedly by hydrogenation of the menhaden oils. The CINAA method yielded results which were in agreement with pub-lished values obtained by other methods. The technique was rapid, requiring minimal sample manipulation, and was essentially free from interferences.     

Influence of Proportion of Skin Present During Malaxing on Pigment Composition of Cold Pressed Avocado Oil

The effect of the proportion of ‘Hass’ avocado skin tissue present during aqueous cold pressed avocado oil extraction on the pigment concentration and oil quality was determined. Increasing amounts of skin (i.e., from 0 to 100% of available skin) were included with the flesh before grinding and malaxing in a laboratory-scale cold pressed extraction process. The recovered oils were analyzed for oil quality and color. The pigment concentrations in the oil were determined by high performance liquid chromatography (HPLC). With increasing amounts of skin addition, there was an increase in the green color, as indicated by hue angle, of the avocado oils. There were also increased concentrations of carotenoids and chlorophylls in the oil as the proportion of skin during malaxing was increased. The lutein concentration in the oils increased from 1.13 to 3.21 μg g⁻¹ as the amount of skin added to the malaxer increased from 0 to 100% skin, and the total chlorophyll concentration in the same oils increased from 7.3 to 27.5 μg g⁻¹. The green color of cold pressed avocado oil and the pigment concentrations can be increased by adding more skin to the malaxer during oil extraction.     

Evaluation of the role of saturated fatty acids in sedimenting canola oils

Canola oil is generally a clear oil which does not require winterization. However, sediment formation has become an increasing problem in Australian canola oil. Canola oil stored at temperatures between −5 and 21°C formed sediment more rapidly at lower temperatures. The sediment and clear fractions of a group of sedimenting canola oils were analyzed and compared. Both fractions contained wax esters of carbon number C42–C52, the sediment fractions containing between 0.37 and 3.09 mg g⁻¹ and clear fractions containing between 0.12 and 0.85 mg g⁻¹. The triacylglycerol profiles of sediment fractions contained four compounds, PPO, PPP, PSO and PPS (where P is palmitoyl, O is oleoyl, and S stearoyl), that were not detected in clear fractions. The contents of palmitic acid and total saturated fatty acids were higher in the sediment fraction than the clear fraction. Added PPP clouded a clear oil as effectively as stearyl behanate and more than OOO or lauryl arachidate. Sedimentation may be linked to environmental conditions, as seed grown in 1997, a dry year, produced more problem oils than seed grown in previous years that had more nearly average rainfall.     

Characteristics of PAHs,PCDD/Fs,PCBs and PBDEs in the Sediment of Lake Baikal,Russia

The levels of PAHs, PCDD/Fs, PCBs, and PBDEs in Lake Baikal were monitored for the first time using deep water sediment. The sediment samples were collected from 15 stations in four regions of Lake Baikal: Ol’khon Island (n = 8), the Angara River estuary (n = 2), the Selenga River delta (n = 2), and the Baikal pulp and paper mill (BPPM) (n = 3). The highest average concentrations of PCDD/Fs (20.24 pg/g d.w.) and PCBs (68.72 ng/g d.w.) were found at Ol’khon Island. The highest total PBDE concentrations were found at BPPM, with a mean concentration of 575.76 pg/g d.w. For PCBs, PCB-52, and PCB-69 were dominant, making up 11% of the total 209 PCB congeners. BDE-209 contributed 60% of PBDEs in Lake Baikal. According to the TPEQ concentration of PAHs, PAHs contributed the most to Lake Baikal contamination. The sources of contamination of PAHs, PCDDs, and PCBs in Lake Baikal are identified as combustion, runoff from the use of the pesticides (PCP) and insulating oil, specifically for PCBs. The source of PBDEs is assumed to be production, use and disposal of products containing PBDEs, in addition to atmospheric long-range transport and deposition.     

Chemical Composition and Oxidative Stability of Kernel Oils from Two Current Subspecies of Pistacia atlantica in Iran

Pistacia atlantica subsp. mutica (PAM) and kurdica (PAK) kernel oils showed significantly lower unsaturated to saturated fatty acid ratios (6.39, 6.33, respectively) and calculated oxidizability (Cox) values (3.99, 4.13, respectively) than those of the P. vera L. cv. Ohadi (PVO) kernel oil (8.91, 4.41) samples. The highest peroxide value was observed for the PAK oil (4.07 mequiv kg⁻¹) (PAM, 1.94; PVO, 0.37) samples. Iodine values for the PAM, PAK, and PVO oils were 104.26, 104.77, and 110.66, respectively. The saponification number of the PVO oil was significantly greater than the PAM and PAK oils, which were statistically not different. The unsaponifiable contents, which were composed mainly of sterols, ranged from 5.63 to 6.14%. Statistically the total tocopherols contents of the PAM (818.58 mg α-tocopherol kg⁻¹) and PVO (815.90 mg α-tocopherol kg⁻¹) oils were significantly higher than that of the PAK oil (499.91 mg α-tocopherol kg⁻¹). Total phenolics contents differed significantly, the greatest concentration was for the PAM oil (81.12 mg gallic acid kg⁻¹), followed by the PVO (62.84 mg gallic acid kg⁻¹) and PAK (56.51 mg gallic acid kg⁻¹) oil samples. The wax contents of the oil samples were statistically in the same range, namely 5.67–6.48%. Oxidative stability data indicated that the PAM oil is the most resistant to the formation of lipid oxidation products, followed by the PAK and PVO oil samples.     

Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development

As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics, and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal-phase high-performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples ranged from 1947 to 4082 μg g⁻¹. Total tocopherol concentration ranges varied from 534 to 1858 μg g⁻¹ in sunflower, 504 to 687 μg g⁻¹ in canola, and 1205 to 2195 μg g⁻¹ among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature effects on the biosynthesis of both compounds.     

Application of a Handheld Portable Mid-Infrared Sensor for Monitoring Oil Oxidative Stability

This study evaluated the capabilities of a handheld mid-infrared (MIR) spectrometer combined with multivariate analysis to characterize oils, monitor chemical processes occurring during oxidation, and to determine fatty acid composition. Vegetable oils (corn, peanut, sunflower, safflower, cottonseed, and canola) were stored at 65 °C for 30 days to accelerate oxidation reactions. Aliquots were drawn at 5 day intervals and analyzed by benchtop and portable handheld mid-infrared devices (4,000–700 cm⁻¹) and reference methods (IUPAC 2301 [1], 2302 [1]; AOCS Cd 8-58 [2]; and Shipe 1979 [3]). PLSR and soft independent modeling of class analogy (SIMCA) models were developed for oil classification and estimation of oil stability parameters. Models developed from MIR spectra obtained with a benchtop spectrometer equipped with a 3-bounce ATR device resulted in superior discriminative performances for classifying oils as compared to those obtained from handheld spectra (single-bounce ATR). Models developed from reference tests and handheld spectra showed prediction errors (SECV) of 1 meq/kg for peroxide value, 0.09% for acid value and 2% for determination of unsaturated fatty acids in different oils. Spectral regions ~3,012–2,850 cm⁻¹ (C–H stretching bands/shoulders of fatty acids), ~1,740 cm⁻¹ (C=O stretching of esters), and ~1,114 cm⁻¹ (–C–O stretching) were found to be important for prediction. Handheld-FTIR instruments combined with multivariate-analysis showed promise for determination of oil quality parameters. Portability and ease-of-use makes the handheld device a great alternative to traditional methods.     

Physical Properties and Fatty Acid Profiles of Oils from Black,Kidney, Great Northern,and Pinto Beans

Four common beans (black, kidney, great northern, and pinto) were extracted with hexane and found to contain about 2% triacylglycerols. The fatty acids in these bean oils were mainly linolenic (41.7–46 wt%), linoleic (24.1–33.4 wt%), palmitic (10.7–12.7 wt%) and oleic (5.2–9.5 wt%). Because of the high levels of polyunsaturated fatty acids, the bean oils had iodine values between 174 and 177 g/100 g (compared to 130 g/100 g for soybean oil). Yet, the bean oils exhibited high oxidative stability due to the presence of high amounts of tocopherols (2,670–2,970 ppm). The bean oils had lower pour points (−18 to −11 °C) compared to −9 °C for soybean oil. Among the four bean oils, kidney bean oil had the highest acid value (15.4 mg KOH/g) and kinematic viscosities over a wide range of temperatures.     

Physico-Chemical Characterization of <Emphasis Type="Italic">Moringa concanensis</Emphasis> Seeds and Seed Oil

The present work reports the characterization and comparison of Moringa concanensis seed oil from Tharparkar (a drought hit area), Pakistan. The hexane-extracted oil content of M. concanensis seeds ranged from 37.56 to 40.06% (average 38.82%). Protein, fiber, moisture and ash contents were found to be 30.07, 6.00, 5.88 and 9.00%, respectively. The extracted oil exhibited an iodine value of 67.00; a refractive index (40 °C) of 1.4648; its density (24 °C) was 0.8660 mg mL⁻¹; the saponification value (mg of KOH g⁻¹ of oil) was 179.00; unsaponifiable matter 0.78%; color (1 in. cell) 1.90R + 19.00Y; and acidity (% as oleic acid) 0.34%. Tocopherols (α, γ, and δ) in the oil accounted for 72.11, 9.26 and 33.87 mg kg⁻¹, respectively. Specific extinctions at 232 and 270 nm were 3.17 and 0.65, respectively. The peroxide and p-anisidine values of the oil were found to be 1.75 and 1.84 meq kg⁻¹, respectively. The induction periods (Rancimat, 20 L h⁻¹, 120 °C) of the crude oil was 10.81 h and reduced to 8.90 h after degumming. The M. concanensis oil was found to contain high levels of oleic acid (up to 68.00%) followed by palmitic, stearic, behenic, and arachidic acids up to levels of 11.04, 3.58, 3.44 and 7.09%, respectively. The results of the present analytical study, compared with those for other Moringa species and different vegetable oils, showed M. concanensis to be a potentially valuable non-conventional seed crop for high quality oil.     

Copper and Iron Determination with [<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis(salicylidene)-2,2′-dimethyl-1,3-propanediaminato] in Edible Oils Without Digestion

A new method for the determination of copper(II) and iron(III) in liquid edible oils which does not require a digestion step was developed. The suggested method involves extraction of metals with [N,N′-bis(salicylidene)-2,2′-dimethyl-1,3-propanediaminato] (LDM) followed by flame atomic absorption spectrometry measurement. As a first step, metal complexes of copper(II) and iron(III) ions with LDM were investigated spectrophotometrically. After the analytical properties and experimental conditions of the complexation had been determined, these findings were used to determine the extraction period as a second step. Experimental conditions were optimized using a central composite design. Optimum conditions for Cu(II) and Fe(III) extractions from oil were found: the ratios of the volume of Schiff base solution used to the mass of oil (V _LDM/m _oil; mL g⁻¹) were 0.76 and 1.19 mL g⁻¹, the stirring times were 73 and 67 min, and the temperatures were 31 and 28 °C, respectively. The developed extraction and determination method was tested on certified reference materials; the recovery percentages were found to be 99.4 ± 2.8 and 100.2 ± 5.6 for Cu(II) and Fe(III), respectively. The suggested method was performed on real samples such as olive oil, sunflower oil, corn oil, canola oil and recovery values between 97.2–102.1 for Cu(II) and 94.5–98.6 for Fe(III) were determined. It was concluded that the developed method has some advantages over the common traditional method including rapidity, sensitivity, accuracy, reduced risk and cost.     

Irradiated sewage sludge for production of fennel plants in sandy soil

A field experiment was conducted to study the impact of irradiated and non-irradiated sewage sludge applied to sandy soil on the productivity of fennel plants (Foeniculum vulgare L.). Four rates of irradiated and non-irradiated sewage sludge application were used (20, 40, 60, and 80 t ha⁻¹). Samples analysis included the biomass production at the vegetative and flowering stages, seed production, volatile oil content, volatile oil constituents, chlorophyll content, total and reducing sugars, and the heavy metals content of the shoots and seeds. The biomass production increased as the sludge application rate increased for both irradiated and non-irradiated plots. However, the increase was significantly higher under all irradiated treatments than the corresponding rates of non-irradiated treatments at both the vegetative and flowering stages. At the vegetative stage, the biomass values ranged from 10.2 to 34.1 g plant⁻¹ at 80 t ha⁻¹ for non-irradiated and irradiated sewage sludge, respectively. Whereas at the flowering stage, the values ranged from 23.9 to 65.1 g plant⁻¹ at 80 t ha⁻¹ for non-irradiated and irradiated sewage sludge, respectively. Total sugars, reducing sugar, non-reducing sugar and chlorophyll content increased as the sludge application rate increased. At the 80 t ha⁻¹ of irradiated sludge application rate, the reducing sugar content was 29.39 mg g⁻¹ DW (dry weight) at the vegetative stage and 37.85 mg g⁻¹ DW at the flowering stage. Regarding heavy metals, sewage sludge was a good source to provide fennel plants with essential micronutrients (Zn and Fe) in the meantime, the translocation of (Pb and Cd) to the shoot system was very low. A linear gradual increase in seed yield was observed as the sludge application rate increased. Irradiated sewage sludge treatments showed a higher fennel seed yield than non-irradiated sewage sludge treatments. Volatile oil percentages exhibited no observable variations due to the use of sewage sludge. A few and limited fluctuations could be observed. However, total oil content (l ha⁻¹) increased due to the increase in seed yield. The magnitude of increase in volatile oil production in response to the sewage sludge application was parallel to the increase in seed yield. The GLC measurements of the fennel volatile oil reveal that the t-anethole is the predominant fraction. However, fenchone was detected in a relatively moderate concentration. The applied sewage sludge treatment induced some variations in fennel volatile oil constituents. The t-anethole is relatively higher in volatile oil obtained from plants grown on sandy soil fertilized with non-irradiated sewage sludge than that fertilized with irradiated sewage sludge. In the meantime, the increase in t-anethole was accompanied by a decline in fenchone content. Under all sludge application rates iron and zinc concentrations of fennel seeds were within the normal plant concentration range, whereas there were only traces of Cd concentration.     

Horizontal nutrient fluxes and food safety in urban and peri-urban vegetable and millet cultivation of Niamey,Niger

Urban and peri-urban agriculture (UPA) has often been accused of being nutrient inefficient and producing negative externalities. To investigate these problems for the West African capital Niamey (Niger), nutrient inputs through fertilizer and manure to 10 vegetable gardens and 9 millet fields and nutrient offtakes through harvests were quantified during 24 months, and contamination of irrigation water and selected vegetables with faecal pathogens and heavy metals was determined. Annual partial horizontal balances for carbon (C), nitrogen (N), phosphorus (P) and potassium (K) amounted to 9,936 kg C ha⁻¹, 1,133 kg N ha⁻¹, 223 kg P ha⁻¹ and 312 kg K ha⁻¹ in high input vegetable gardens as opposed to 9,580 kg C ha⁻¹, 290 kg N ha⁻¹, 125 kg P ha⁻¹ and 351 kg K ha⁻¹ in low input gardens. In high input millet fields, annual surpluses of 259 kg C ha⁻¹, 126 kg N ha⁻¹, 20 kg P ha⁻¹ and 0.4 kg K ha⁻¹ were recorded, whereas surpluses of 12 kg C ha⁻¹, 17 kg N ha⁻¹, and deficits of −3 kg P ha⁻¹ and −3 kg K ha⁻¹ were determined for low input fields. Counts of Salmonella spp. and Escherichia coli yielded above threshold contamination levels of 7.2 × 10⁴ CFU 25 g⁻¹ and 3.9 × 10⁴ CFU g⁻¹ in lettuce irrigated with river water and fertilized with animal manure. Salmonella counts averaged 9.8 × 10⁴ CFU 25 g⁻¹ and E. coli 0.6 × 10⁴ CFU g⁻¹ for lettuce irrigated with wastewater, while these pathogens were not detected on vegetables irrigated with pond water. These results underline the need for urban gardeners to better adjust the nutrients applied to crop requirements which might also reduce nutrient accumulations in the soil and further in the edibles parts of the vegetables. Appropriate pre-treatment of irrigation water would help improve the quality of the latter and enhance the food safety of vegetables determined for the urban markets.     

Adsorption of FFA in crude catfish oil onto chitosan,activated carbon,and activated earth: A kinetics study

The feasibility of using chitosan, activated carbon, and activated earth to remove FFA from crude catfish visceral oil, and the adsorption kinetics of the procedure were evaluated. The effect of adsorbents on water activity and the 18∶3 and 22∶6 content of crude catfish visceral oil was also studied. The initial adsorption kinetic coefficients of FFA (mL g⁻¹ min⁻¹) were 0.1, 0.07, and 0.03 for chitosan, activated carbon, and activated earth, respectively. The external film mass-transfer coefficient (0.001 mL s⁻¹) was similar for the three adsorbents. The adsorption capacity of FFA at saturation (mg g⁻¹) was 71.2 for chitosan, 65.5 for activated carbon, and 57.0 for activated earth. The intraparticular diffusion coefficients (mg mL⁻¹ min^−0.05) were 0.14, 0.12, and 0.09 for chitosan, activated carbon, and activated earth, respectively. Water activity of the crude oil decreased with increased contact time of the adsorbents. Results indicated that chitosan was a better adsorbent than activated carbon and activated earth for FFA removal from crude catfish visceral oil.     

Effect of Temperature and Time on the Stability of Salmon Skin Oil During Storage

The effect of 45 days of storage at 25, 4, −18 and −80 °C on the quality indices; free fatty acid (FFA) content, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and changes in the fatty acid (FA) profile of crude oil recovered from salmon fish skins were evaluated at 5 day intervals using spectrophotometric and titrimetric methods. Higher temperatures and longer storage time resulted in higher quantities of oxidative products in the salmon skin oil (SSO). By day 45, SSO stored at 25 and 4 °C had 8.50 and 8.29% FFA, 32.43 and 26.33 μg malondialdehyde (MDA) eq g⁻¹ oil, and 88.19 and 64.53 mequiv peroxide kg⁻¹ oil, respectively. No significant (p > 0.05) changes in fatty acid profile were observed at all the storage temperature and time studied.     

Paradoxical effect of n−3-containing vegetable oils on long-chain n−3 fatty acids in rat heart

Flaxseed, echium, and canola oils contain α-linolenic acid (18∶3n−3, ALA) in a range of concentrations. To examine their effect on elevating cardiac levels of long-chain n−3 FA, diets based on these n−3-containing vegetable oils were fed to rats for 4 wk. Sunflower oil, which contains little ALA, was a comparator. Despite canola oil having the lowest ALA content of the three n−3-containing vegetable oils, it was the most potent for elevating DHA (22∶6n−3) levels in rat hearts and plasma. However, the relative potencies of the dietary oils for elevation of EPA (20∶5n−3) in heart and plasma followed the same rank order as their ALA content, i.e., flaxseed>echium>canola>sunflower oil. This paradox may be explained by lower ALA intake leading to decreased competition for Δ6 desaturase activity between ALA and the 24∶5n−3 FA precursor to DHA formation.     

Supercapacitive behaviors of worm-like mesoporous carbon in non-aqueous electrolyte

This paper discusses the electrochemical behaviors of worm-like mesoporous carbon obtained in 1.0 mol L⁻¹ LiClO₄/ethylene carbonate + dimethyl carbonate solution. The capacitance for nanoporous carbon system advances up to 147 F g⁻¹ and a wide voltage window (2.5 V) for three electrode system was achieved. The specific energy and specific power reach as high as 127.6 Wh kg⁻¹ and 5.0 kW kg⁻¹. These results show that worm-like mesoporous carbon can be used for high energy density and power density non-aqueous electrolyte supercapacitors.     

Influence of PVP buffer layer on the formation of NaA zeolite membrane

The support substrates were modified with the aqueous solutions of 1 and 3 wt% of polyvinyl pyrrolidine (PVP) as intermediate buffer layer followed by NaA zeolite seed (prepared hydrothermally at 85 °C for 2 h) coating with 2.5 wt% aqueous dispersion in each case. A better surface coverage with the oriented layer of NaA seed crystals was found with 1 wt% PVP buffer layer. The secondary crystallization of NaA membranes in the PVP-seed-coated supports was carried out hydrothermally at 65 °C for 2, 4, 6 h (single-stage each) and (2 + 2), (4 + 2)h (double-stage each) crystal growth processes. The crystallization behaviours of NaA membranes were studied by X-ray diffraction (XRD) while the microstructures of the same films were observed by scanning electron microscope (SEM). The single-stage secondary crystallization at 65 °C for 4 h showed highly interlocked and oriented NaA grains in the membranes and it rendered the permeance value of 2.2 × 10⁻⁸ mol m⁻²s⁻¹Pa⁻¹ for single gas, nitrogen (N₂) at ambient temperature (30 °C).     

Changes in Lipid Class and Fatty Acid Composition of Cultures of <Emphasis Type="Italic">Pavlova lutheri</Emphasis>, in Response to Light Intensity

Aquaculture is a growing commercial activity worldwide, which resorts more and more often to microalgae as feed; the lipid composition of such microalgae is a critical factor with regard to the fish growth rate upon ingestion. The aim of this work was thus to study the influence of light intensity on the lipid profile of a known microalga, Pavlova lutheri. Several semi-continuous cultures were carried out, and biochemical parameters such as lipid, protein, carbohydrate, and chlorophyll contents were quantified. Lipids were specifically fractionated into classes by TLC, and those in each class were subjected to GC afterwards in an attempt to ascertain their fatty acid profile. Evidence was consequently provided which showed that cultures grown under low light intensity (9 W m⁻²) possess a higher fraction of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids esterified in polar classes—which are those with a more favorable role in aquaculture. It was also demonstrated that intermediate levels of light intensity (19 W m⁻²) may be misleading in terms of favorable effects upon EPA and DHA contents—because there is an increase in their total yields and productivities, but they appear mostly esterified into triacylglycerols; this may be a favorable deed for production and purification, but is metabolically not so effective in aquaculture. The highest EPA and DHA productivities attained were 1.29 and 0.69 mg L⁻¹ day⁻¹, respectively, at intermediate levels of light intensity (19 W m⁻²).