bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of dietarytrans fatty acids on microsomal enzymes and membranes
Authors: Östlund‐Lindqvist Ann‐Margret , Albanus Lennart , Croon Lars‐Börje 
Published: November 2006

AbstractThree groups of rats were maintained on diets containing different proportions oftrans fatty acids (0, 18.3 or 36.6% of the total fatty acids) for eight weeks. No differences in body weight were observed among the three groups, but the fat cell size, determined in epididymal fat, differed significantly between the controls and the rats fed diets containingtrans fatty acids. The supernatant obtained by centrifuging homogenates of liver from the rats at 9000×g (S‐9 fraction) was used as an activator in a bacterial test for mutagenicity of 2‐aminofluorene and aflatoxin B1 usingSalmonella typhimurium strains TA 98 and TA 100, respectively. The mutagenicities of 2‐aminofluorene in strain TA 98 and of aflatoxin B1 in strain TA 100 were significantly lower with the liver S‐9 fraction from rats fed a diet containing 36.6%trans fatty acids than with the liver S‐9 fraction from rats fed a control diet with notrans fatty acids.
A study of fatty acid methyl esters with epoxy or alkyne functionalities
Authors: Samuelsson Johan , Johansson Mats 
Published: November 2006

AbstractDescribed are the physical and chemical properties of the methyl esters of two uncommon fatty acids: vernolic acid, containing an epoxy group, and crepenynic acid, containing a triple bond. The incorporation of an epoxy or alkyne group into the fatty acid structure is shown to greatly affect the properties compared to conventional unsaturated fatty acids. The methyl esters have been characterized and compared with ordinary fatty acid methyl esters (i.e., methyl oleate and linoleate) with respect to spectroscopic characterization [1H nuclear magnetic resonance (NMR)], 13C NMR, and Fourier transform infrared), rheological properties, and oxidative reactivity (using chemiluminescence). Both methyl vernoleate and methyl crepenynate could successfully be produced by transesterification under basic conditions without reaction of the epoxy or alkyne groups. Rheological measurements showed that the methyl esters had a significantly lower viscosity compared to their triglyceride analogs. Smaller differences were seen when comparing the different methyl esters where methyl vernoleate had the highest viscosity due to the presence of the more polar oxirane group. Very large differences were found with respect to the oxidation rate of the different methyl esters. Methyl crepenynate was shown to oxidize extremely rapidly, whereas methyl vernoleate was very stable toward oxidation.
Effects of microwave heating on changes in chemical and thermal properties of vegetable oils
Authors: Tan C. P. , Che Man Y. B. , Jinap S. , Yusoff M. S. A. 
Published: November 2006

AbstractThe effects of microwave heating on the cooling profiles of two vegetable oils (corn oil and soybean oil) were studied using differential scanning calorimetry (DSC) and compared to changes in chemical parameters. These oils were exposed for several periods of time to three controlled treatments: low‐, medium‐, and high‐power settings, respectively. The DSC results were derived from the cooling curve of oils at a scanning rate of 5°C/min. The chemical analyses of the oils included peroxide value, anisidine value, free fatty acid content, iodine value, and C18∶2/C16∶0 peak area ratio. A statistical comparison was carried out between DSC and the chemical parameters. In general, correlations were good between these parameters. Likewise, the experimental data showed that, for a given microwave power setting, a good correlation existed between DSC curve parameters and heating periods. These results indicate that DSC can be used as an objective nonchemical, instrumental technique to monitor lipid oxidation in both traditionally heated and microwave‐heated oils.
Enzymatic synthesis of structured lipid containing arachidonic and palmitic acids
Authors: Shimada Yuji , Nagao Toshihiro , Hamasaki Yukiko , Akimoto Kengo , Sugihara Akio , Fujikawa Shigeaki , Komemushi Sadao , Tominaga Yoshio 
Published: November 2006

AbstractHuman milk fat contains 20–25% palmitic acid, and about 70% of the fatty acid is esterified to the 2‐position of triglycerides. It was also reported that arachidonic acid (AA) accelerated the growth of preterm infants. Thus, we attempted the synthesis of 1,3‐arachidonoyl‐2‐palmitoyl‐glycerol by acidolysis of tripalmitin with AA using 1,3‐specific Rhizopus delemar lipase. When a mixture of 10 g tripalmitin/AA (1∶5, w/w) and 0.7 g immobilized Rhizopus lipase was incubated at 40°C for 24 h with stirring, the AA content in glycerides reached 59 mol%. The immobilized lipase could be used five times without a decrease in the extent of acidolysis. Glycerides were extracted from the reaction mixture with n‐hexane, and regiospecific analysis was performed. As a result, the AA contents at the 1,3‐ and 2‐positions were 56.9 and 3.2 mol%, respectively. It was therefore confirmed that the fatty acids at the 1,3‐positions of triglyceride were exchanged for AA. High‐performance liquid chromatography showed that the contents of triarachidonin, 1,3‐arachidonoyl‐2‐palmitoyl‐glycerol, and 1(3)‐arachidonoyl‐2,3(1)‐palmitoyl‐glycerol were 7.3, 75.9, and 12.4 wt%, respectively.
Esterification reaction of oleic acid with a fusel oil fraction for production of lubricating oil
Authors: Özgülsün Aykut , Karaosmanôglu Filiz , Tüter Melek 
Published: November 2006

AbstractIn this study, the esterification of oleic acid with a fraction of fusel oil was investigated. The variables that affect ester yield, such as temperature, molar ratio of oleic acid to alcohol, and amount of catalyst, were determined. Powdered silica gel was chosen to remove water instead of granular silica gel, magnesium sulfate, or benzene. The behavior of amyl alcohols and the fusel oil fraction was compared. The esterification reaction was carried out under the reaction conditions selected as optimal, and the ester conversion of the reaction was 97.3%. The product mixture compressed products, excess reactants, catalyst, and desiccant. Oleate ester and oleic acid (2.7%) were obtained using the refinement steps of filtration, evaportation, washing with distilled water, and drying over sodium sulfate.
Catalytic effect of solid metals on thermal stability of olive oils
Authors: Paz Isabel , Molero Mariano 
Published: November 2006

AbstractThe influence of a series of metals—iron, copper, tin, and lead—on the thermal stability of olive oils of different origins and refined grades has been studied by applying thermal analysis techniques: thermogravimetry (TG) and derivative thermogravimetry (DTG). From thermogravimetric data it is deduced that iron and tin have a greater influence on oil oxidation, since the degradation rate increases. In the presence of copper and lead, important changes in the degradation rate are not observed, compared with the degradation in the absence of metals. The kinetic parameters, activation energy, and frequency factor of the oil degradation reaction were also calculated. The results obtained for both parameters confirm the negative influence of iron and tin on the oil oxidation process, regardless of the kind of oil tested.
Factors affecting the electrical resistivity of soybean oil methyl ester
Authors: Tekin Aziz , Hammond Earl G. 
Published: November 2006

AbstractFactors affecting the electrical resistivity of soybean oil methyl ester (which is important in some industrial applications) were investigated by the addition of polar constituents [free fatty acids (FFA), water, phospholipids, monoglyceride, sterol, tocopherol, peroxides, and β‐carotene] to aluminapurified soybean oil methyl ester (APSBOMe). Investigation of measuring conditions showed that reproducible results were obtained when the potential was greater than 25 V, and the charging time was greater than 10 s. The resistivity of APSBOMe increased logarithmically as temperature decreased linearly. FFA had little effect on resistivity. Saturation with water lowered the resistivity of APSBOMe much more than that of alumina‐purified soybean oil (APSBO). Phospholipids reduced the resistivity significantly when added to dry ester, but the addition of water affected the resistivity of the samples containing phospholipids only slightly. Monoglyceride, sterol, tocopherol, and hydroperoxide affected the resistivity of dry methyl ester similarly, but only monoglyceride showed a significant synergistic effect with water. Diacylperoxide and β‐carotene had little effect on the resistivity of the ester.
Enrichment of eicosapentaenoic acid and docosahexaenoic acid in saponified menhaden oil
Authors: Chen Tor‐Chern , Ju Yi‐Hsu 
Published: November 2006

AbstractEicosapentaenoic acid (EPA, 20∶5n−3) and docosahexaenoic acid (DHA, 22∶6n−3) in free fatty acids (FFA) derived from saponified menhaden oil were concentrated by the solubility differences of FFA‐salts in organic solvent. FFA‐salts were formed by adding NaOH to a solution containing FFA. A Buchner funnel was used to separate solid phases from liquids containing FFA‐salts. FFA that are rich in EPA and DHA can be recovered from the liquid phase by the addition of 12 N HCl. The effects of reaction time, the amount of NaOH, and solvent used on the concentration of EPA and DHA were systematically investigated. With a total volume of 112 mL, made up of 1.85% 15 N NaOH, 88.1% acetone, and 10.0% FFA, a reaction temperature of 30°C, and a reaction time of 1 h, the resulting liquid phase contained 65.4 wt% EPA and DHA, with a corresponding yield of 41.5%. By replacing the acetone with a mixture of 45% acetone and 55% acetonitrile and then storing the liquid phase at −70°C overnight, the content and yield of EPA and DHA in the final liquid phase were 61.4 wt% and 66.2%, respectively.
Lipase‐catalyzed acidolysis of tristearin with oleic or caprylic acids to produce structured lipids
Authors: Yankah Vivienne V. , Akoh Casimir C. 
Published: November 2006

AbstractTwo different structured lipids (SL) were synthesized by transesterifying tristearin with caprylic acid (C8∶0) or oleic acid (C18∶1). The objective was to synthesize SL containing stearic acid (C18∶0) at the sn‐2 position as possible nutritional and low‐calorie fats. The reaction was catalyzed by IM60 lipase from Rhizomucor miehei in the presence of n‐hexane. The effects of reaction parameters affecting the incorporation of caprylic acid into tristearin were compared with those for incorporating oleic acid into tristearin. For all parameters studied, oleic acid incorporation was higher than caprylic acid. The range of conditions favorable for synthesizing high yields of C8∶0‐containing SL was narrower than for oleic acid. An incubation time of 12–24 h and an enzyme content of 5% (w/w total substrates) favored C8∶0 incorporation. The mole percentage of incorporated C18∶1 did not increase further at enzyme additions greater than 10%. C18∶1 incorporation decreased with the addition of more than 10% water (w/w total substrates) to the tristearin‐oleic acid reaction mixture. Increasing the mole ratio of fatty acid (FA) to triacylglycerol increased oleic acid incorporation. The highest C8∶0 incorporation was obtained at a 1∶6 mole ratio of tristearin to FA. Positional analysis confirmed that C18∶0 remained at the sn‐2 position of the synthesized SL. The melting profiles of tristearin‐caprylic acid and tristearin‐oleic acid SL displayed peaks between −20 to 30°C and −20 to 40°C, respectively. Their solid fat contents (∼25%) at 25°C suggest possible use in spreads or for inclusion with other fats in specialized blends.
Effects of temperature and temperature shift on docosahexaenoic acid production by the marine microalge Crypthecodinium cohnii
Authors: Jiang Yue , Chen Feng 
Published: November 2006

AbstractThe effects of temperature and temperature shift on the fatty acid composition and docosahexaenoic acid (DHA, C22∶6n−3) content and productivity of the marine microalga Crypthecodinium cohnii ATCC 30556 were investigated. The microalga grew well over the entire range of temperatures (15–30°C) studied. High temperature favored the growth of the microalga with the highest specific growth rate of 0.092 h−1 at 30°C. In contrast, low temperature favored the formation of polyunsaturated fatty acids. The highest DNA content was obtained at 15°C in the early stationary phase (i.e., 72h). In order to achieve high DHA productivity, a shift from high temperature to low temperature at a later stage of cultivation (i.e., 48h) was also attempted. A temperature shift from 25°C (for 48 h) to 15°C (for 24 h) resulted in an increase in cellular DHA content by 19.9% and productivity by 6.5% as compared to that maintained at 25°C (for 72 h).
Preparation of glycol esters of soybean oil fatty acids and their potential as coalescent aids in paint formulations
Authors: Jiratumnukul N. , Van De Mark Michael R. 
Published: November 2006

AbstractSoy oil glycol monoesters have been prepared through the transesterification of soybean oil with ethylene, diethylene, propylene, and dipropylene glycols. The molar ratio of soybean oil to glycol used in these reactions was 1∶6. The catalyst used in these reactions was lithium carbonate, 0.5%, based on soybean oil. The transesterifications were carried out at 180–190°C. The composition of soy oil glycol esters and their physical properties were determined. The soy oil glycol esters were incorporated in a water‐based paint formulation as the coalescent aid, and the minimum film formation temperature was determined. The minimum film formation temperature results indicated that these esters can be used as coalescent aids in latex paint formulations to help in continuous film formation at or below room temperature.
Nondestructive quantitative determination of docosahexaenoic acid and n−3 fatty acids in fish oils by high‐resolution 1H nuclear magnetic resonance spectroscopy
Authors: Igarashi Tomoji , Aursand Marit , Hirata Yoshiaki , Gribbestad Ingrid S. , Wada Shun , Nonaka Michio 
Published: November 2006

AbstractBy using a 500 MHz proton nuclear magnetic resonance (1H NMR) spectrometer we have developed a quantitative method for determining the contents of docosahexaenoic acid (DHA) in fish oils (mg/g), the molar proportions (mol%) of DHA to all other fatty acids composing the fish oils, and the molar proportions of total n‐3 fatty acids to all other non‐n‐3 fatty acids in the fish oils. After examining the suitability of ethylene glycol dimethyl ether (EGDM), methanol, and 1,4‐dioxane as internal standards, experimental conditions were optimized by mainly using EGDM as an internal standard. By setting the pulse repetition time at 30 s, five times longer than the longest T1 of the 1H NMR signals of fish oils, good reproductibility of data and analytical times less than 10 min were achieved. The use of the internal standard also allowed us to quantify DHA on a weight basis (mg/g). Verification of the method was carried out in an interlaboratory study between Japan and Norway on bonito, tuna, and salmon oils. The relative errors in the 1H NMR data between Japan and Norway were 0.57–5.29% for quantification of DHA, 0.7–2.09% for the molar proportion of DHA, and 0.1–1.41% for the molar proportion of total n‐3 fatty acids. Good agreement was observed between the 1H NMR data and those obtained by gas chromatography (GC). The sample preparation before 1H NMR measurements required only two steps: sample weighing and preparation of an internal standard solution. Based on the high reproducibility, simplicity of the procedure, and clarity of principle, the proposed 1H NMR method was judged to be a promising alternative to the GC method in quantification of DHA and n‐3 fatty acids in fish oils.
Fractionation of squid visceral oil ethyl esters by short‐path distillation
Authors: Liang Jer‐Hour , Hwang Lucy Sun 
Published: November 2006

AbstractSquid visceral oil contains high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Its ethyl esters were fractionated by short‐path distillation in this study. The elimination temperatures of squid visceral oil ethyl esters (SVOEE) ranged from 50 to 140°C, increasing with the carbon number of ethyl esters. The elimination temperature of cholesterol was higher than those of SVOEE. The SVOEE of Illex argentinus (SVOEE‐A) was more advantageous as the raw material (feed) than that of Ommastrephes bartrami (SVOEE‐B) for the isolation of EPA and DHA, because SVOEE‐A contained less 20∶1 and 22∶1. When SVOEE‐A originally containing 9.0% EPA, 14.7% DHA, and 1,121 mg/100 g of cholesterol was distilled from 50 to 150°C with 20°C interval, the 130°C distillate could give 15.5% EPA and 34.7% DHA with 99 mg/100 g of cholesterol, and the yield was 21.8%. The 150°C distillate could give 43.1% DHA with 496 mg/100 g of cholesterol. Furthermore, the distillates collected from 110 to 150°C contained 24.4 to 50.2% of EPA plus DHA, and their total yield was 58.3%. The final residue after 150°C distillation contained 77% of the total cholesterol in the initial SVOEE‐A, and the yield was 6.0%.
Lipase‐catalyzed synthesis of lysophosphatidylcholine using organic cosolvent forin situwater activity control
Authors: Kim Juhan , Kim Byung‐Gee 
Published: November 2006

AbstractLysophosphatidylcholines (LPC) were synthesized froml‐α‐glycerophosphatidylcholine (GPC) by lipase‐catalyzed esterification in a solvent‐free system. Adding small amounts of a water‐mimicking solvent such as dimethylformamide (DMF) to the reaction media significantly enhanced the reaction rate and the product yield. The role of solvent was studied with regard to changes in substrate solubility, the water activity of the reaction system, and the water content of the enzyme. Whereas the solubility of GPC was virtually unaffected by the addition of DMF at controlled water activity, it was considerably affected by water activity. DMF itself lowered the water activity of the system and deprived Lipozyme IM of water. The LPC production was also controlled by varying the initial water content of the enzyme. When two kinds of controls were employed together, a synergistic effect was observed and a 90% conversion was achieved. As a result, an operating window was suggested for LPC production, including water activity of Lipozyme IM and concentration of DMF as two parameters.
Determination of wax concentration in sunflower seed oil
Authors: Martini S. , An M. C. 
Published: November 2006

AbstractIsothermal crystallization of waxes was studied by using an optical setup. The induction time of crystallization was assessed as a function of wax concentration. The relationship was found to be a decreasing exponential curve. The wax content of some of the solutions prepared in the laboratory was determined by calculating the crystallization induction time. The values obtained were compared to those from different methods (cold test, microscopic, and turbidimetric methods). The results obtained with the optical setup method are similar to those obtained with other methods for concentrations greater than 100 ppm. An analysis of variance test was used to verify the authenticity of the values obtained with the optical method. Results showed that the method used to determine wax concentration, the concentration of the sample, and the relationship between both parameters do not affect significantly the values of percentage relative errors (P<0.05) obtained for concentrations greater than 100 ppm. Values obtained for wax content within the range 0–100 ppm could not be compared since the microscopic and turbidimetric methods are not sensitive enough, unlike the optical setup, to detect wax amounts in such low concentration.
How green is green? Sampling and perception in assessing green seeds and chlorophyll in canola
Authors: Daun James K. , Symons Stephen 
Published: November 2006

AbstractGreen seeds are used as a grading factor in estimating chlorophyll in canola and rapeseed in the Canadian and U.S.A. grading systems. This work examines the effect that sampling and perception have on the estimation of green seeds as well as the effect that sampling has on the determination of chlorophyll. Individual seed analysis indicated that in order to be considered as green, seeds needed to contain between 200 and 400 mg/kg chlorophyll. Variation due to binomial sampling played a predominant role in the error in determining the green seed levels in canola. Sampling of large numbers of seeds, as in the loading of export shipments, reduced the error. Binomial sampling also contributed to the error in chlorophyll determination even with sample sizes as large as 500. Differences in perception of green also were noted between individuals with coefficients of variation as high as 50% at the 1% green seed level. The combination of perception error and sampling error may result in samples of 1,000 seeds drawn from a mass with 2% green seeds having green seed counts ranging from 0.96 to 3.04%, 19 times out of 20.
Isopropanol fractionation of butter oil and characteristics of fractions
Authors: Pal P. K. , Bhattacharyya D. K. , Ghosh S. 
Published: November 2006

AbstractFractionation of butter oil from isopropanol and characterization of the chemical composition and the melting properties of the fractions obtained have been investigated. Butter oil was fractionated from isopropanol (1∶4 wt/vol) at 15 to 30°C. The yields of stearins and oleins were dependent on the temperature employed during fractionation. Thus, 24.8 to 48.9% of stearins and 51.5 to 75.2% of oleins could be obtained as the crystallization temperature varied from 15 to 30°C. The stearin fractions displayed a distinct variation in the fatty acid compositions. The palmitic acid content of the stearin fractions varied from 39.1 to 44.0%, and that of stearic from 15.1 to 16.8%, respectively. The olein fractions contained 43.2% stearic acid, and 2.4 to 2.8% palmitoleic acid (C16∶1). The solid fat content values of the stearin fractions obtained were 62–67, 39–50, and 21–25 at 10, 20, and 30°C, respectively. From the results, it is evident that anhydrous milk fat can be fractionated at relatively high temperatures from isopropanol to produce stearin and olein fractions of specific composition and properties.
Selection of alcohols through Plackett‐Burman design in lipase‐catalyzed synthesis of anthranilic acid esters
Authors: Babu C. V. Suresh , Divakar S. 
Published: November 2006

AbstractLipase‐catalyzed synthesis of esters of anthranilic acid was attempted by employing alcohols of carbon chainlength C1–C18 using Plackett‐Burman experimental design. Of the alcohols employed, methanol, decanol, cetyl alcohol, and stearyl alcohols showed 99.9% significance. Esterification of anthranilic acid with methanol gave the highest yield at 45.6%. This study allows the selection of better alcohols for esterification of anthranilic acid.