Cost of producing linoleic acid from safflower oil

Linoleic acid of 97% purity can be made from safflower oil by liquid-liquid extraction at a “cost to make” of about 21 cents a 1b. Calculations for the cost estimate were based on pilot-plant investigations. Fixed capital investment for a plant with an annual capacity of 20 million 1b has been estimated at approximately $1,800,000. Such a plant could be converted readily to the production of a variety of other fatty acids. A laboratory of the No. Utiliz. Res. & Dev. Div. ARS, U.S.D.A.     

Preparation of conjugated linoleic acid from safflower oil

Synthetically prepared mixtures of conjugated linoleic acid (CLA) are widely used in animal and cell culture studies to investigate the potential effects of the Δ9c, 11t-18:2 isomer found in food products from ruminant animals. Alkali isomerization of linoleic acid is a common method used in the synthesis of a mixture of CLA isomers containing predominantly the Δ9c, 11t-18:2 and Δ10t, 12c-18:2 isomers. Some biological activity might also be mediated by the Δ10t, 12c-18:2 isomer. Currently few published methodologies exist describing procedures for the enrichment of these two isomers. A method is described herein to take advantage of an inexpensive oil, safflower oil, for use in synthesis of CLA and a procedure to enrich the Δ10t, 12c-18:2 isomer.     

Rigid urethane foams from hydroxymethylated castor oil,safflower oil,oleic safflower oil,and polyol esters of castor acids

Castor, safflower, and oleic safflower oil derivatives with enhanced reactivity and hydroxyl group content were prepared by hydroformylation with a rhodium-triphenylphosphine catalyst, followed by hydrogenation. Rigid urethane foams prepared from these hydroxymethylated derivatives had excellent compressive strengths, closed cell contents, and dimensional stability. Best properties were obtained from hydroxymethylated polyol esters of castor acids.     

Autoxidation of linoleic acid and behavior of its hydroperoxides with and without tocopherols

The autoxidation of linoleic acid dispersed in an aqueous media and the effect of α-, γ- and δ-tocopherols were studied. The quantitative analysis of the hydroperoxide isomers (13-cis,trans; 13-trans,trans; 9-trans,cis; 9-trans,trans) by direct high-performance liquid chromatography exhibited a prooxidant activity of α-tocopherol at high concentration (3.8% by weight of linoleic acid). On the other hand, α-tocopherol at lower concentrations (0.38 and 0.038%) and γ- and δ-tocopherols at high concentration (3.8%) were antioxidant. Furthermore, the addition of tocopherols modified the distribution of the geometrical isomers. The formation of thetrans,trans hydroperoxide isomers was completely inhibited by the highest concentration of the three tocopherols independently of their antioxidant or prooxidant activity and only delayed by the lower concentrations of α-tocopherol. The addition of tocopherols to hydroperoxide isomers reduced the decomposition rate of these isomers in the order α-tocopherol < γ-tocopherol < δ-tocopherol for thecis,trans hydroperoxide isomer and α-tocopherol ≪ γ-tocopherol ⋍ δ-tocopherol for thetrans,trans hydroperoxide isomer. With these hydroperoxides, as during linoleic acid autoxidation, α-tocopherol was completely oxidized whatever its initial concentration, while γ-tocopherol underwent partial oxidation and δ-tocopherol was practically unchanged.     

Autoxidation of cholesterol fatty acid esters in solid state and aqueous dispersion

Cholesteryl stearate, oleate, linoleate, linolenate and arachidonate were oxidized in solid form (at 100 C) and in a water dispersion (in the presence of potassium stearate, pH 7.5, 80 C). The unsaponifiable fraction was analyzed by capillary gas liquid chromatography. In the solid state, the oxidation rates of esterified cholesterol were high for stearate and oleate, low for the polyunsaturated esters and very low for free cholesterol. In water dispersion, the rates were reversed, e.g., free cholesterol oxidized more quickly than its stearic and oleic acid esters. The fatty chains in 18∶0 and 18∶1 inhibited the autoxidation of cholesterol. Hydroxylation of the cholesterol side chain only occurred during solid-state autoxidation as previously observed by others. The 20- and 25-hydroxycholesterols were never detected in the products of micellar reactions, regardless of which surfactant was used for micelle formation.     

Linoleic acid from safflower oil by liquid-liquid extraction

Summary Tests conducted on a pilot-plant scale have demonstrated that linoleic acid of about 95% purity may be produced from safflower fatty acids containing about 75% linoleic acid, by a liquid-liquid extraction process. Furfural was employed as the selective solvent, hexane as a secondary solvent, and the fractionation was made in a Podbielniak “double-pup” centrifugal extractor. Best results were obtained when the proc This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Thermal interaction of linoleic acid and its esters with valine

When linoleic acid or its esters were heated in the presence of valine a number of interaction products were formed. The major product was 2-pentylpyridine which is thought to be produced by the reaction of 2,4-decadienal with ammonia. Also formed were two secondary amides, isobutyloctanamide and isobutyllinoleylamide. Additional interaction products found include alkylpyridines and alkylpyrroles. The formation of these compounds is similar to the formation of 2-pentylpyridine. They can result by reaction of an aldehyde with an amine or ammonia to form a Schiff base intermediate, followed by cyclization and rearrangement to form either the pyridine ring or the pyrrole ring. In addition, a branched nitrile compound was produced. This compound is considered to be formed by cleavage of the pyridine ring in 2-pentylpyridine.     

Synthesis of biodiesel fuel from safflower oil using various reaction parameters

Biodiesel fuel is gaining more and more importance because of the depletion and uncontrollable prices of fossil fuel resources. The use of vegetable oil and their derivatives as alternatives for diesel fuel is the best answer and as old as Diesel Engine. Chemically biodiesel fuel is the mono alkyl esters of fatty acids derived from renewable feed stocks like vegetable oils and animal fats. Safflower oil contains 75-80% of linoleic acid; the presence of this unsaturated fatty acid is useful in alleviating low temperature properties like pour point, cloud point and cold filter plugging point. In this paper we studied the effect of various parameters such as temperature, molar ratio (oil to alcohol), and concentration of catalyst on synthesis of biodiesel fuel from safflower oil. The better suitable conditions of 1:6 molar ratio (oil to alcohol), 60 degrees C temperature and catalyst concentration of 2% (by wt. of oil) were determined. The finally obtained biodiesel fuel was analyzed for fatty acid composition by GLC and some other properties such as flash point, specific gravity and acid value were also determined. From the results it was clear that the produced biodiesel fuel was with in the recommended standards of biodiesel fuel with 96.8% yield.     

Preparation and purity of linoleic acid from commercial corn,cottonseed, and safflower oils

Linoleic acid from commercial corn, cottonseed, and safflower oils was prepared by low temperature crystallization using acetone and petroleum ether as solvents; temperatures ranged between −70 and 50C. This method has the advantages of simple equipment and of flexibility in preparatory capacity. The crystalline fraction obtained at −55C was shown to be “pure” linoleic acid. Isomerization with potassium tertiary butoxide, oxidative cleavage by periodate-permanganate, and analysis by liquid-liquid and gas-liquid partition chromatography were used to ascertain the purity and the presence of isomers in the final product. This fraction was found to contain 90 to 95%, 9,12 dienoic acid; approximately 5% of dienes with the first double bond at the C₈ position and the second bond either at the C₁₂ or C₁₃ positions; and small amounts of nonconjugatable 9,15cis,cis dienes. Linoleic acid from these oils was similar in composition, except that from corn oil showed the presence of diene with the first double bond at the C₁₁ position. This paper includes research conducted by B. Sreenivasan both at Ohio State University and at the Northern Utilization Research and Development Division. Presented at spring meeting, American Oil Chemists' Society, St. Louis, Mo., May 1–3, 1961. A laboratory of the Northern Utilization Research and Development Division, U.S.D.A.     

Buttonweed seed oil a source of linoleic acid

Summary Buttonweed seeds (Abutilon theophrasti) contain 15 to 17% oil. The oil contains about 58% linoleic acid which may be concentrated by simple fractionation into fractions containing as high as 83% of the acid. This suggests the possible use of the oil as a source of linoleic acid. The seed also has an appreciable sterol content.     

Autoxidation of polyunsaturated fatty esters on Silica

The stability of unsaturated methyl esters of fatty acid adsorbed on silica gel and silicic acid was studied by gas liquid chromatographic estimation of disappearance relative to a saturated internal standard. Variables included silica-ester ratio, agitation, adsorbent particle size, and degree of unsaturation. Under the conditions of the experiment, destruction of substrate unsaturated ester at 80 C was more a function of time than of unsaturation or initial purity.     

Super acid catalyzed dimerization of fatty acids derived from safflower oil and dehydrated castor oil

Dimerization of fatty acids derived from dehydrated castor oil and safflower oil was carried out on the recently described sulphate-treated zirconia catalyst and trifluoromethane sulphonic acid (triflic acid) under autogeneous pressure in the temperature range of 160–240 C. Triflic acid was observed to be highly active; however, the product obtained was deeply colored. Zirconia exhibited high activity for the reaction. The important features of this catalyst were the high selectivity for dimer (low yields of trimer) and no significant coloration of the products. The zirconia catalyst shows promise for industrial use.     

Photochemical production of conjugated linoleic acid from soybean oil

Conjugated linoleic acid (CLA), an anticarcinogenic compound with numerous other health benefits, is present mainly in dairy and beef lipids. The main CLA isomer present in dairy and beef lipids is cis 9, trans 11 CLA at a 0.5% concentration. The typical minimum human dietary intake of CLA is 10 times less than the 3 g/d suggested requirement that has been extrapolated from animal and cell-line studies. The objectives of this study were to produce CLA isomers from soybean oil by photoisomerization of soybean oil linoleic acid and to study the oxidation status of the oil. Refined, bleached, and deodorized soybean oil with added iodine concentrations of 0, 0.1, 0.25, and 0.5% was exposed to a 100-W mercury lamp for 0 to 120 h. An SP-2560 fused-silica capillary GC column with FID was used to analyze the esterified CLA isomers in the photoisomerized oil. The CLA content of the individual isomers was optimized by response surface methodology. Attenuated total reflectance (ATR)-FTIR spectra in the 3400 to 3600 cm⁻¹ range and ¹H NMR spectra in the 8 to 12 ppm range of the photoisomerized soybean oil were obtained to follow hydroperoxide formation. The largest amount of cis 9, trans 11 CLA isomer in soybean oil was 0.6%, obtained with 0.25% iodine and 84 h of photoisomerization. Lipid hydroperoxide peaks in the ATR-FTIR spectra and aldehyde peaks in the ¹H NMR spectra were not observed in the photoisomerized soybean oil, and the spectra were similar to that of fresh soybean oil. This study shows that CLA isomers can be produced simply and inexpensively from soybean oil by photoisomerization.     

Oxidative stability of safflower oil

Oils from a number of varieties of safflower (Carthamus tinctorius L.) seeds (achene) were measured for oxidative stability by the gain in weight method. The induction periods of oils containing 75% to 80% linoleic acid ranged from 288 to 715 hr. Safflower oils containing 79% to 80% oleic acid and only 11% to 15% linoleic acid had induction periods ranging from 1274 to 2374 hr. No correlation between induction period and total tocopherol content was observed. However, there were indications that oils from pigmented seeds were less stable than oils from pigmentless seeds. Blending of an oil containing a high amount of linoleic acid with an oil containing a high amount of oleic acid gave a blend with an induction period intermediate between the two. However, the induction period was considerably less than the theoretical average calculated for the mixture. Arizona Agricultural Experiment Station Technical Paper No. 1389.     

Autoxidation of methyl esters of cyclopentenyl fatty acids

The early stages of the autoxidation of methyl hydnocarpate, chaulmoograte and gorlate in air have been examined at 40, 60 and 80 C, and the initial products have been compared by several methods with those derived from methyl oleate and linoleate autoxidized at 60 C. To supplement information about oxygen absorption and peroxide development in relation to time, other information about the early products, and some information about the reduced products, have been obtained by ultraviolet (UV) and infrared (IR) spectrophotometry, and by thin layer chromatography (TLC). The kinetic and other data presented in this study strongly support the conclusion that the methyl esters of cyclopentenyl fatty acids yield initial autoxidation products that, although they are primarily peroxides, differ in some ways (as expected) in the kinetics of their formation and their chemical nature, compared to those of oleate and linoleate. Nevertheless, all the data obtained strongly support the surmise that the peroxides are formed autocatalytically by a chain mechanism, and that secondary products not derived from peroxide decomposition, are formed pari passu in lesser, but increasing amounts with increasing temperature, probably from free radical intermediates. The autoxidation of esters of cyclopentenyl fatty acids has potential importance in several ways, 3 of which are mentioned briefly.     

核桃油中亚油酸分离工艺研究

通过尿素包合法分离出核桃油中的亚油酸,采用高效液相色谱法测定亚油酸的含量,讨论包合时间、脂肪酸/尿素(w/w)和甲醇/尿素(v/w)对亚油酸得率和纯度的影响。结果显示,当包合温度为-5℃,包合时间为24 h,脂肪酸/尿素(w/w)为0.5,甲醇/尿素(v/w)为5,亚油酸的纯度67.17%,得率87.61%。     

Pilot-plant preparation of edible safflower oil

Summary Tests conducted on a pilot-plant scale with two lots of commercial, alkali-refined safflower oil demonstrate that no difficulty is experienced in producing a salad oil of good, initial quality with good flavor stability when stored at 60°C. in the dark. Although results indicate safflower oil is suitable for a salad oil, they should not be construed as indicating its stability as a cooking oil since tests of this type were not conducted. The addition of citric acid improved the oxidative stability of the oil, and citric acid plus propyl gallate gave even further improvement. No significant increase in flavor stability resulted from these additives. One of the divisions of the Agricultural Research Service, U. S. Department of Agriculture.     

The role of safflower oil in edible oil applications

Safflower oil has been used as an edible oil in numerous countries for many years. In the US, commercial use of safflower oil as an edible product was noted in the 1950's and the use continues at progressively higher levels each year. One use of safflower oil in “dressing” type products is related to the natural cold resistance of the oil. Other applications include oil, margarine and some imitation dairy products. Additional development work has been done on other food products so that the scope of usage could be broadened if there should be increased demands for safflower oil. The susceptibility of safflower oil to oxidation has been minimized by improved processing and packaging. Further use of safflower oil appears to be dependent upon availability, pricing, good cold resistance and the role of polyunsaturates in the diet.