Showing papers on "Soybean oil published in 1986"

Transesterification kinetics of soybean oil 1

Abstract: Transesterification of soybean oil (SBO) and other triglycerides with alcohols, in the presence of a catalyst, yields fatty esters and glycerol. Di- and monoglycerides are intermediates. Reactions are consecutive and reversible. Rate constants have been determined for each reaction with a computerized kinetic program. The effects of the type of alcohol, 1-butanol or methanol (MeOH); molar ratio of alcohol to SBO; type and amount of catalyst; and reaction temperature on rate constants and kinetic order were examined. Forward reactions appear to be pseudo-first order or second order depending upon conditions used. Reverse reactions appear to be second order. At a molar ratio of MeOH/SBO of 6:1, a shunt reaction was observed. Energy of activation was determined for all forward and reverse reactions under a variety of experimental conditions from plots of log k vs 1/T. Values ranged from 8–20 kcal/mol.

Study on the oxidative rate and prooxidant activity of free fatty acids

Abstract: Oleic, linoleic and linolenic acids were autoxidized more rapidly than their corresponding methyl esters. Addition of stearic acid accelerated the rate of autoxidation of methyl linoleate and the decomposition of methyl linoleate hydroperoxides. Therefore, the higher oxidative rate of FFA’s than their methyl esters could be due to the catalytic effect of the carboxyl groups on the formation of free radicals by the decomposition of hydroperoxides. Addition of stearic acid also accelerated the oxidative rate of soybean oil. This result suggests that particular attention should be paid to the FFA content that affects the oxidative stability of oils.

Effect of selected oat sterols on the deterioration of heated soybean oil

Abstract: Two sterol fractions of different purity, each containing both Δ5-avenasterol and β-sitosterol, were separated from oat oil, and their antioxidant effects studied in soybean oil at 180 C. Oil samples with added pure β-sitosterol and control samples (no added sterol) also were studied.

Quantitation in the analysis of transesterified soybean oil by capillary gas chromatography 1

Abstract: A rapid quantitative capillary gas Chromatographic method has been developed for studying transesterification of soybean oil (SBO) to fatty esters. Standard solutions containing methyl linoleate, mono- , di- and trilinolein were analyzed with a 1.8 m X 0.32 mm SE- 30 fused silica column. The effect of carrier gas flow on reproducibility was determined. Prior to analysis, mono- (MG) and diglycerides (DG) were silylated with N,O- bis(trimethylsilyl) trifluoroacetamide.Tridecanoin was used as an internal standard. From plots of area and weight relationships, slopes and intercepts for all four compound classes were determined. Agreement between the measured and calculated compositions of the standard solutions was good; the overall standard deviation was 0.4. Slopes and intercepts also were determined for SBO and its methyl and butyl esters. Complete separation of ester, MG, DG and triglyceride was obtained in 12 min by temperature programming from 160 to 350 C. This method of analysis gave excellent results when used in a kinetic study of SBO transesterification.

Soybean and sunflower oil performance in a diesel engine.

Abstract: THE performance of a direct injection diesel engine operating on mechanically expelled-unrefined soybean oil and sunflower oil blended with number 2 diesel fuel on a 25:75 v/v basis was evaluated. The power remained constant throughout 200 h of operation. Excessive carbon deposits on all combustion chamber parts precludes the use of these fuel blends, at least in this engine and under the specified EMA operating conditions.

The distribution and content of ubiquinone in foods.

Abstract: We measured ubiquinone (UQ)-9 and UQ-10 content in various foods using high performance liquid chromatography. UQ-9 was detected in cereals, some vegetables and their products. Corn oil and wheat germ had large amounts of UQ-9 in particular. UQ-10 was detected in meats, fishes, pulses, nuts, dairy products and various vegetables. Migratory fishes, rapeseed oil and soybean oil had considerably large amounts of UQ-10.

Effects of dietary fat on pain threshold, thermoregulation and motor activity in rats.

Abstract: Groups of young male Sprague-Dawley (albino) or Long-Evans (hooded) rats were fed the same semi-purified diets containing 20% (w/w) fat in the form of soybean oil vs. lard, or a reference diet of standard Purina Chow (4.5% mixed fats) for 21 days. Behavioral testing after this time revealed that albino rats fed the diet containing soybean oil had increased paw-lick latencies on a 58°C hot plate compared to chow-fed rats. In addition, both strains fed the diet containing soybean oil were protected from hypothermia induced by placing animals in a 4°C cold room for 60 min following systemic injection of 10–15 mg/kg d-amphetamine. Rats of both strains fed the lard diet displayed paw-lick latencies similar to those shown by rats fed chow and hypothermic changes intermediary to those shown by rats fed soybean oil vs. chow diets. Horizontal crossings as well as rearings in a 15 min test of open field activity were the same for all diet groups within strains. No substantial differences were observed in the number of calories consumed, amount of body weight gained or basal colonic temperature across diet conditions. The results suggest that a soybean oil-based diet can alter physiological mechanisms which mediate these indices of pain perception and thermoregulation. More generally, they indicate that qualitative changes in dietary fat content may be capable of altering certain behavioral states.

Lipase-catalyzed hydrolysis of palm oil

Abstract: The hydrolysis of palm oil, palm olein and palm stearin, soybean oil, corn oil and peanut oil by the commercial lipase fromCandida rugosa (formerly known asC. cylindracea) was studied. The optimal conditions for the hydrolysis of palm oil by the lipase were established. The lipase fromC. rugosa exhibits an optimal activity at 37 C and at pH 7.5. The optimal oil to hexane ratio is 1 g of oil to 0.5 ml hexane. The rate of hydrolysis of palm oil by the lipase is linear on a logarithmic scale. Under the same conditions, palm oil and palm olein were hydrolyzed at the same rate, whereas palm stearin was hydrolyzed much more slowly.

A high performance size-exclusion chromatographic method for evaluating heated oils

Abstract: High performance size-exclusion chromatography (HPSEC) was used to measure compounds with high-molecular weight (MW) formed during the heating of oil. Formation of the high-MW compounds is believed to be a reliable indicator of heat abuse in oils. The HPSEC method employs two µ-spherogel size-exclusion columns (500 and 1000 A) in a series to separate the high-MW compounds which are detected at a wave-length of 234 nm by using a variable wavelength detector. The method was examined in the following study. Two sources of soybean oil were heated under laboratory conditions at 182 ± 2 C for eight 7-hr days. Samples were taken periodically and tested by using HPSEC. Oil samples from two commercial deep-fat frying operations were similarly tested. In all cases, size, number and apparent MW of the compounds formed increased with increasing frying time. The HPSEC procedure was compared with a method involving separation of polar and nonpolar components in a used frying fat by means of column chromatography on silica gel.

Vitamin E in foods from high and low linoleic acid diets.

Abstract: As part of a human diet study, vitamin E activity was estimated in foods used in seven daily menus. Each menu was designed to contain 35% fat calories with either 10 or 30 gm/day of linoleic acid (18:2) and 500 mg/day of cholesterol. To estimate vitamin E activity, each food used in the menus was analyzed for alpha and gamma tocopherol content by high-pressure liquid chromatography with fluorescence detection. This article reports the alpha and gamma tocopherol contents of those foods, tocopherol contributions from each food in one sample 2,400-kcal menu, and the mean daily vitamin E activity (milligram alpha tocopherol equivalents) of all seven menus at five caloric levels. Major sources of alpha tocopherol (greater than 10% of the RDA) common to both diets (10 and 30 gm linoleic acid) were olive oil and a few fruits and vegetables. Additional major sources in the 30-gm linoleic acid diets were polyunsaturated fatty acid (PUFA) vegetable oils and margarine. Contrary to a common assumption, increasing the level of PUFA in the menus did not necessarily result in higher milligram equivalents of alpha tocopherol because soybean oil, with a tocopherol composition that is predominantly gamma tocopherol, was the major source of linoleic acid in the diets. Thus, vitamin E activity was not necessarily increased when soybean oil was substituted for a less saturated fat such as olive oil, which has mostly alpha tocopherol.

Cracked soybean oil as a fuel for a diesel engine

Abstract: Refined and bleached soybean oil was thermally decomposed by using the ASTM standard method D86-82 for distillation of petroleum products. Properties of the thermally decomposed soybean oil were compared to properties of diesel fuel. A diesel engine was operated on both fuels. Thermally decomposed soybean oil produced slightly less power than diesel fuel and also produced low levels of NOx and high levels of HC's while diesel fuel produced high levels of NOx and low levels of HC's. 6 references.

Chemical evaluation of egyptian citrus seeds as potential sources of vegetable oils

Abstract: Seeds of the citrus fruits orange, mandarin, lime and grapefruit were analyzed. Petroleum ether-extracted oils of such seeds amounted to more than 40% of each. Physical and chemical properties of the extracted oils are presented. Samples of the extracted oils were saponified and the unsaponifiables and fatty acid fractions isolated. The isolated unsaponifiables and fatty acids were analyzed by GLC. GLC analysis of the unsaponifiables revealed compositional patterns differ-ent in number, type and relative concentration of fractions according to type of citrus seed oil, depending on the solvent system used for oil extraction and unsaponifiable matter isolation. The compositional patterns of the unsaponifiables were similar to that of cottonseed oil. Mandarin and grapefruit oils are free of cholesterol. The data demonstrate that the fatty acid compositional patterns of the oils differ; Mandarin seed oil contains the largest number of fatty acids, and grapefruit seed oil contains the lowest. The total amounts of volatile fatty acids in these oils are generally higher than those of other edible oils. Lime seed oil is similar, in the degree of unsaturation, to soybean oil. The orange oil pattern is similar to cottonseed oil. The amount of total essential fatty acids in lime seed oil is the highest of the oils studied.

The effect of feeding fish oils, vegetable oils and clofibrate on the ketogenesis from long chain fatty acids in hepatocytes.

Abstract: Groups of rats were fed diets containing 25% fish oil (FO), 25% soybean oil, 25% partially hydrogenated fish oil (PHFO), 25% partially hydrogenated soybean oil (PHSO), 25% partially hydrogenated coconut oil or 0.3% clofibrate for 3 wk. After the animals were fasted for 24 hr, hepatocytes were isolated and ketogenesis from added palmitate, linoleatecis andtrans, arachidonate and docosahexaenoate was measured. Ketogenesis after oil feeding was significantly stimulated (two-to threefold) only in cells from the PHFO-and PHSO-fed rats. The stimulation was most apparent with the long chain unsaturated fatty acids as substrates. These fatty acids were relatively poor ketone body precursors in control hepatocytes. Essential fatty acid deficiency did not seem to be the reason for this stimulation. Clofibrate also stimulated ketogenesis significantly (1.5- to 3-fold). The degree of stimulation increased with chain length and degree of unsaturation of the substrate. The activity of the enzyme 2,4-dienoyl-CoA reductase was also studied in the same groups. Its activity was stimulated about fourfold in the clofibrate-treated rats and to a lesser extent by the PHFO, PHSO and FO diets. The activity showed no correlation with the content of unsaturated fatty acids in the diet or their oxidation in isolated hepatocytes. The 2,4-dienoyl-CoA reductase, therefore, does not seem to be a regulatory enzyme in the metabolism of dietary polyunsaturated fatty acids. It is concluded that an induction of the peroxisomal β-oxidation system most likely is involved in the reported increases in ketogenesis from very long chain polyunsaturated fatty acids.

Limited extraction of soybeans with hexane

Abstract: Soybean flakes were extracted with lower than optimal quantities of hexane in the laboratory and comparisons were made of oil yield, phospholipids yield and phospholipids composition as a function of the volume of hexane. Although the oil yield and the total amount of phosphorus were significantly decreased with limited volumes of hexane, the distribution of phospholipid components remained essentially the same. Because the oil obtained by this limited solvent extraction contained less phosphatides, it is expected to be more easily processed by conventional techniques.

Oxidative stability of avocado oil

Abstract: This study is concerned with the extent of oxidative deterioration and oil stability as determined by measuring peroxide and conjugable oxidation products (COP) values and AOM time of refined bleached avocado oil in comparison with refined soybean and olive oil. The formation of peroxides in avocado oil exposed to daylight at room temperature is similar to that of soybean oil but greater than that of olive oil. No differences were found in peroxide formation, oxodiene values and COP values between the tested oil stored in the dark, at 60 C and at room temperature. The COP ratio in oils stored at 60 C is similar for avocado and olive oil, but differs from that of soybean oil.

The effect of temperature and wax content on the appearance of turbidity in sunflowerseed oil

Abstract: Turbidity in refined sunflowerseed oil, caused by the presence of waxes, is a frequent occurrence. As such, it is a special problem in a number of countries where clear packaging is used for this oil. The application of cold test for the determination of sunflowerseed oil clarity is not always satisfactory, as the negative cold test is not a guarantee that the waxes are completely removed and that the oil will remain clear for a longer period. In this study, the threshold value for wax content which would cause turbidity in refined sunflowerseed oil was determined. At the same time, the influence of cooling temperature and wax content on the visible turbidity appearance rate was investigated. The results show that the turbidity threshold for the cold test is 80 mg wax/kg oil, and that the rate of the visible turbidity appearance of the oil depends both on wax content and cooling temperature.

Headspace volatile analysis to evaluate oxidative and thermal stability of soybean oil. Effect of hydrogenation and additives

Abstract: Headspace gas chromatographic analysis of heated soybean oil was investigated as a tool to determine what effect hydrogenation and additives have on the formation of total and individual volatile components. Soybean oil was hydrogenated to varying linolenate (Ln) contents with either nickel (Ni) or copper catalysts. Oils were stabilized with citric acid (CA) or a combination of CA with tertiary butyl hydroquinone (TBHQ) and/or methyl silicone (MS). Volatiles were analyzed with a capillary gas chromatography equipped with a headspace sampler positioned on the injector. Oxidative stability was determined after storage of the oils at 60 C. To study thermal abuse and frying performance of oils, samples were heated for several, hours with prolonged bread frying. The deterioration of the oil was accelerated further by static heating in air within the headspace sampler. All hydrogenated oils produced less total volatiles than the unhydrogenated control oil after prolonged heating and bread frying. Static heating at 190 C for one hr showed that the oil hydrogenated with Ni to 0.4% Ln was the most stable. MS decreased the formation of volatiles in all samples and was particularly effective, in stabilizing the hydrogenated oils. However, MS had little effect on volatiles in the oil hydrogenated to 0.4% with Ni. Unique volatile compounds identified included 2,4-heptadiental in nonhydrogenated soybean oil and 2-nonenal in most hydrogenated oils. On heating, the amount of 2-heptanal decreased significantly in the Ni hydrogenated oils compared to the control. Hexanal, on the other hand, decreased in all hydrogenated oils compared to the control.

Oil-in-water emulsion glazing agent for foodstuffs

Abstract: A glazing agent for bakery products comprises a homogenized emulsion of 10-50 wt. % of an edible oil (e.g. soybean oil), 5-15 wt. % (of the aqueous phase) of a protein (e.g. sodium caseinate), 2-10 wt. % of a thin-boiling starch (e.g. a dextrin) and water. Optionally an emulsifier like lecithin can xanthan gum is being used. The emulsion may be spray-dried.

Storage Stability of Soybean Oil-Based Salad Dressings: Effects of Antioxidants and Hydrogenation

Abstract: Flavor deterioration of salad dressings was investigated to determine the effect of hydrogenation of the oil. additives and storage conditions. Flavor quality tests were developed and correlated with gas chromat­ ographic analyses of volatile compounds in oils separated from the dressings. Hydrogenation of soybean oil with copper and nickel ca­ talysts effectively increased the storage stability of salad dressings at 21°C but not at 32°C. The use of BHA as an antioxidant in the oil or EDTA as a metal inactivator in the starch base as well as nitrogen packaging were effective in prolonging the storage stability of salad dressings made with unhydrogenated soybean oil. Therefore, these additives or nitrogen packaging may provide economic substitutes for hydrogenation of soybean oil used in salad dressings.

The effect of adjuvants and oil carriers on photodecomposition of 2,4-D, bentazon, and haloxyfop.

Abstract: Laboratory photolysis rates of 2,4-D [(2,4-dichlorophenoxy)acetic acid], bentazon [3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide], and haloxyfop {2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} in dilute aqueous solution were enhanced by the presence of adjuvants. Addition of 1.0% (v/v) petroleum oil concentrate (POC), 1.0% (v/v) soybean oil concentrate (SBOC), and 0.15% (v/v) emulsifier package (EP) enhanced herbicide photolysis rates more than addition of 0.15% (v/v) oxysorbic (20 POE) (polyoxyethylene sorbitan monolaurate). Bioassays showed that phytotoxicity of photolyzed herbicide solutions was negatively correlated with time of exposure to ultraviolet light. Addition of 0.85% (v/v) acetophenone to aqueous herbicide solutions containing 0.15% (v/v) oxysorbic strongly sensitized photodegradation of 2,4-D, and to a lesser extent, haloxyfop. Acetophenone had no effect on bentazon photolysis in the presence of oxysorbic. In another study, herbicides were dissolved in white mineral oil or once-refined soybean oil and exposed to ultraviolet light. After a 6-h exposure, there was 92% loss of haloxyfop in mineral oil and 36% loss in soybean oil. There was no difference between oils in affecting the photolysis rate of 2,4-D or bentazon.

Epoxidation of Fatty Acid Esters with Aqueous Hydrogen Peroxide in the Presence of Molybdenum Oxide–Tributyltin Chloride on Charcoal Catalyst

Abstract: The epoxidation of fatty acid esters was carried out with a 30% aqueous hydrogen peroxide in the presence of a molybdenum oxide–tributyltin chloride on a charcoal catalyst in 2-propanol at 50 °C Such inner olefins as ethyl erucate and ethyl oleate gave good yields of 77 and 76%, respectively Ethyl elaidate, a trans-form of ethyl oleate, was less reactive (40% yield) Several vegetable oils such as rapeseed oil, olive oil, soybean oil, cottonseed oil, corn oil, and linseed oil were oxidized with the oxirane oxygen contents of 53 to 35%

Emulsion compositions for the parenteral and/or oral administration of sparingly water soluble ionizable hydrophobic drugs

Abstract: This disclosure describes quick breaking, in vivo , intravenous, intramuscular, intraarticular and/or oral fat emulsion compositions which incorporate the use of benzyl alcohol as a cosurfactant and/or a cosolvent in combination with materials such as synthetic surfactants, e.g. sorbitan triisostearate, triglycerol diisostearate or triglycerol pentaoleate; naturally occurring vegetable oils, e.g. sesame oil, and soybean oil; natural lecithins such as egg lecithin or soy lecithin; saturated or unsat­urated aliphatic acids, e.g. oleic acid, hexanoic acid and linolenic acid; and other excipients such as glycerine, polyvinylpyrrolidone, Pluronic® F-68 dl-α-tocopherol.

Laboratory continuous deodorizer for vegetable oils

Abstract: A laboratory-scale continuous deodorizer, based on a modified Snyder distillation column, was constructed and tested for the deodorization of alkali-refined and bleached vegetable oils. Soybean oil extracted with supercritical carbon dioxide and without further processing also was deodorized to a finished edible oil. Results of taste panel evaluations of the finished oils show that the quality of oils deodorized over a temperature range of 194–260 C is equivalent to commercial salad oils. Oil flow rates are 1 to 2 ml/min, and contact time is about 5 min; a vacuum of 0.5 to 1.0 mm Hg is maintained with countercurrent steam flow of 1 to 5% of the oil weight. Small samples of oil (250–1000 ml) are readily accommodated in this equipment, and the deodorization conditions more nearly simulate commercial practice than do traditional small-scale batch deodorizers.

Nephelometric determination of phosphorus in soybean and corn oil processing

Abstract: A procedure to measure phosphorus content of soybean and corn oil samples has been developed using nephelometry (turbidity). The method uses the relationship between phosphorus level due to phosphatides in vegetable oil and turbidity formed in phosphatide mixtures. The rapid 10-min determination of phosphorus in process samples is 30 times faster than colorimetric methods. Phosphorus vs turbidity data formed nearly linear relationships for crude, degummed, once-refined, bleached and deodorized soybean and corn oil process samples.