首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Vegetable oils that are important to the chemical industry include both edible and industrial oils, which contribute 24% and 13.5%, respectively, compared to 55% for tallow, to the preparation of surfactants, coatings, plasticizers, and other products based on fats and oils. Not only the oils themselves but also the fatty acids recovered from soapstock represent a several billion pound resource. Coconut oil is imported to the extent of 700-1,000 million pounds per year. Its uses are divided about equally between edible and industrial applications. Safflower oil has a relatively small production, but 15–25% of the oil goes into industrial products. Soybean oil, the major edible oil of the world, is produced in the United States at the rate of 11,000 million pounds per year with more than 500 million pounds going into industrial uses, representing 5% of the total production. Castor oil is imported to the extent of about 100 million pounds per year. Linseed oil production has declined drastically over the last 25 years but still amounts to about 100 million pounds per year. Oiticica and tung oils are imported in lesser amounts than castor and linseed oils. New crops that have industrial potential, as well as the traditional vegetable oil crops, include seed oils from crambe,Limnanthes, Lesquerella, Dimorphotheca, Vernonia, andCuphea plants. Crambe oil contains up to 65% erucic acid. Oil fromLimnanthes contains more than 95% of fatty acids above C18.Lesquerella oil contains hydroxy unsaturated acids resembling ricinoleic acid from castor oil.Dimorphotheca oil contains a conjugated dienol system.Vernonia oils contain as much as 80% epoxy acids. TheCuphea oils contain a number of short chain fatty acids. Of these, crambe,Limnanthes, andVernonia are probably the most developed agronomically. Competition between vegetable oils and petrochemicals for the traditional fats and oil markets has been marked over the past 25 years, but prices for petrochemicals have accelerated at a greater rate than those for vegetable oils; and, it is now appropriate to reexamine the old as well as the new markets for fatty acids.  相似文献   

2.
Coconut oil prices will exert much influence on synthetic fatty acid commercialization; if domestic oil prices maintain at 12–13¢/lb, demand for coco acids and derivatives could triple during the next three years; however, at an oil price of 22–24¢/lb, about 90% of domestic research and development on lauric acid products would be dropped. Synthetic fatty acids could hold the market if they can be commercialized near present prices. Proportionally higher food uses will be evident for coconut oil for the next several years. Increased demand for short chain (C5–C9) acids in high temperature synthetic lubricants, estimated to grow from the present 25 million lb/year to 50 million lb/year by 1973, will exert an increased demand. Conducted at the AOCS Meeting, San Francisco, April 1969.  相似文献   

3.
Under peroxidative conditions (i.e., illumination in the presence of Cu2+ or ap-nitro diphenylether herbicide), the xanthophycean microalga,Bumilleriopsis filiformis, evolves C2 and C5 hydrocarbons besides substantial amounts of propane and propene. Fatty acids were separated as methyl esters by argentation and reversed-phase thin layer chromatography and the fractions subsequently peroxidized by illuminated and copper-supplementedAnacystis thylakoids. These membranes do not contain polyunsaturated fatty acids and are, therefore, unable to evolve volatile hydrocarbons by itself. The C2 and C5 hydrocarbons formed by the fractions added match with their content of ω-3 and ω-6 fattyacid species having 2–4 double bonds. The fractions yielding C3 hydrocarbons contain a fatty acid hitherto unknown forBumilleriopsis, which was isolated and identified as 16∶3ω4.  相似文献   

4.
Grain sorghum wax has been judged to be a potential source of natural wax with properties similar to carnauba wax. Approximately 0.16–0.3% (w/w) wax can be extracted from grain sorghum depending on the efficiency of the organic solvents. Although the melting points of carnauba wax and sorghum wax are similar, i.e., 78–86 and 77–85°C, respectively, they differ in acid values, i.e., 2–10 and 10–16, respectively, and saponification numbers, i.e., 77–95 and 16–49, respectively. Improved knowledge of the properties, composition, and analysis of grain sorghum wax would assist in efforts for industrial application of this product. Major components of sorghum wax are hydrocarbons, wax esters, aldehydes, free fatty alcohols, and FFA. The hydrocarbons consist mainly of C27 and C29, and the aldehydes, alcohols, and acids are mainly C28 and C30. The wax esters are mostly esters of C28 and C30 alcohols and acids.  相似文献   

5.
The fatty acids of three strains of extremely thermophilic bacteria and three strains of moderately thermophilic bacteria were examined by gas liquid chromatography. All the thermophiles contained straight, iso, and ante-iso branched fatty acids. Iso C17∶0 acid was abundant in both the moderately thermophilic strains (10–33%) and the extremely thermophilic strains (50–61%). The pair of fatty acids iso C15∶0 and iso C17∶0 was the predominant pair in both the moderately (34–64%) and extremely (76–87%) thermophilic strains. The pair of fatty acids ante-iso C15∶0 and ante-iso C17∶0 was present in larger amount in moderately (25–34%) than in extremely (8.5–15%) thermophilic strains. No hydroxy cyclopropane, or unsaturated fatty acids were found. One extreme thermophile,Flavobacterium thermophilum HB-8 was grown at 6 different culture temperatures from 49–82 C, and the changes of its fatty acid composition were studied. The ratios of iso C17∶0/iso C15∶0 and ante-iso C17∶0/ante-iso C15∶0 were much greater at higher culture temperatures, indicating chain elongation.  相似文献   

6.
The degree of glyceride syntheses by lipase TOYO (Chromobacterium viscosum) and lipase OF (Candida cylindracea) using individual free fatty acids C18∶1, C18∶2, C18∶3, C18∶4, C20∶4, C20∶5 and C22∶6 were compared. Lipase TOYO incorporated each of the fatty acids into glycerol at levels of greater than 89%. Lipase OF incorporated most of the fatty acids at levels above 70% (docosahexaenoic acid incorporation was 63%). It was concluded that these two lipases are feasible for producing glycerides from unsaturated fatty acids.  相似文献   

7.
J. J. Myher  A. Kuksis  G. Steiner 《Lipids》1984,19(9):673-682
Structural analyses were performed on milk fat samples obtained 3–10 days postpartum from a lactating patient with primary Type 1 hyperlipidemia. The milk triacylglycerols contained 3–7% C10, 14–21% C12, 20–30% C14, 22–26% C16 and 20–30% C18 (largely oleic) acids. Gas liquid chromatographic (GLC) analyses of the X-1,3- and X-1,2-diacylglycerols on polar siloxane columns showed a markedly non-random association of acyl chains. Stereospecific analyses indicated that the short chain length fatty acids were confined essentially to the sn-3-position of the triacylglycerol molecule. Furthermore, these acids were largely absent from the phosphatidylcholines and the endogenous sn-1,2-diacylglycerols of the milk fat. It is concluded that the short chain fatty acids are incorporated into the milk triacylglycerols during the final stage of biosynthesis via the phosphatidic acid pathway, and that the overall fatty acid distribution is consistent with the 1-random 2-random 3-random hypothesis.  相似文献   

8.
About 1949, with the advent of effective fractional distillation, the tall oil industry came of age, and tall oil fatty acids (TOFA), generally any product containing 90% or more fatty acids and 10% or less of rosin, have grown in annual volume ever since, until they amount to 398.8 million pounds annual production in the U.S. in 1978. Crude tall oil is a byproduct of the Kraft process for producing wood pulp from pine wood. Crude tall oil is about 50% fatty acids and 40% rosin acids, the remainder unsaps and residues; actually, a national average recovery of about 1–2% of tall oil is obtained from wood. On a pulp basis, each ton of pulp affords 140–220 pounds black liquor soaps, which yields 70–110 pounds crude tall oil, yielding 30–50 pounds of TOFA. Separative and upgrading technology involves: (a) recovery of the tall oil; (b) acid refining; (c) fractionation of tall oil; and occasionally (d) conversion to derivatives. TOFA of good quality and color of Gardner 2 corresponds to above 97% fatty acids with the composition of 1.6% palmitic & stearic acid, 49.3% oleic acid, 45.1% linoleic acid, 1.1% miscellaneous acids, 1.2% rosin acids, and 1.7% unsaponifiables.  相似文献   

9.
The fatty acid composition of a new strain of Vibrio alginolyticus, found in the alga Cladophora coelothrix, was studied. Among 38 different fatty acids, a new fatty acid, 9-methyl-10-hexadecenoic acid and the unusual 11-methyl-12-octadecenoic acid, were identified. Linear alkylbenzene fatty acids, such as 10-phenyldecanoic acid, 12-phenyldodecanoic acid and 14-phenyltetradecanoic acid, were also found in V. alginolyticus. The alga contained 43% saturated fatty acids, and 28% C16–C20 polyunsaturated fatty acids of the n−3 and n−6 families.  相似文献   

10.
Dimer acids are the commercial products resulting from clay-catalyzed, high temperature polymerization of unsaturated fatty acids, usually tall oil fatty acids. The products have been commercially available since the 1950s and now, in all forms, represent 40–50 million pounds per year sales in the United States. The products are high boiling, mobile to viscous liquids. Their most important chemical property is carboxyl multifunctionality, which allows conversion to high polymers, mostly polyamides in commercial practice. Dimer-based polyamides have sizeable application as hot-melt adhesives and as reactive components of epoxy resins. There are much smaller uses in other polymer systems. Dimer acids are relatively nontoxic, and are not flammable. In February 1979, single-distilled dimer acids sold in tankcar quantities in the range $0.45–0.55/lb. There were six producers in the business, with one almost entirely a captive consumer.  相似文献   

11.
Manufacture of fatty acids from petroleum and natural gas is a large industry worldwide and has important implications in the U.S. Eastern Europe produces an estimated 1.2 billion pounds by air oxidation of hydrocarbons compared to an estimated 956 million pounds of natural fatty acids from the U.S., in 1978 (exclusive of tall oil fatty acids). The enormous production of SFA’s in Eastern European countries and in Russia is done by continuous air oxidation of fresh and recycled mixed aliphatic hydrocarbons. Since the products contain proportions of odd-numbered straight chain acids, they have not been used edibly, but have been applied to the manufacture of industrial products such as soap, lubricants, plasticizers and the like. Another European approach (Liquichimica, Italy) for SFA is the caustic fusion (and oxidation) of branched chain alcohols produced by carbonylation and reduction of olefins. American potential technology is diversified but has not yet been translated to production scale, presumably because of the plentiful supply of natural fats and oils that is available.  相似文献   

12.
Hopkins CY  Chisholm MJ  Prince L 《Lipids》1966,1(2):118-122
Seed kernel oils of seven species of Lauraceae were examined and the fatty acid composition of six of these was determined. The oil ofLindera umbellata had 4% ofcis-4-decenoic, 47% ofcis-4-dodecenoic, and 5% ofcis-4-tetradecenoic acid in the total fatty acids. Positive identification of these acids was made and new derivatives were prepared. Possible routes of biosynthesis are discussed. Oils from the other species did not contain more than a trace of unsaturated C10−C14 acids. Their major acids were capric and lauric with varying amounts of unsaturated C18 acids. Issued as NRC No. 8928. Presented at the AOCS Meeting, Cincinnati, October 1965.  相似文献   

13.
Sreerama Shetty  S. N. Hegde 《Lipids》1991,26(11):930-933
Pigeon “milk” (PM) collected from the crop of 1- to 5-day-old squabs was analyzed to examine whether there were changes in lipid composition during the first week of secretion. The high PM fat content (9–11%) remained fairly constant in the first 5 days of secretion. The mean percentage of neutral lipids, glycolipids and phospholipids was 80, 12 and 8%, respectively. Unlike the content of neutral lipids, glycolipid and phospholipid levels increased significantly between day 1 and day 5 of secretion. Triglycerides, the major neutral lipids, decreased by 24% between day 1 and day 5, while free sterols, monoglycerides and hydrocarbons increased by 8%, 11% and 2.5%, respectively, during the same period; diglycerides and sterol esters, however, remained unchanged. The ratio of saturated to unsaturated fatty acids was 0.27 and it remained unchanged. Medium-chain (C10, C12 and C14) and oddchain (C15 and C17) fatty acid contents were low. Fatty acids longer than C20 were absent. Palmitic acid, the major saturated fatty acid, increased by 42% from day 1 to day 5, whereas stearic acid decreased by 48% during the same period. Oleic acid, the predominant unsaturated fatty acid, also decreased from 51 to 45% between the first and fifth day of PM secretion. Polyunsaturated acids (18∶2, 18∶3 and 20∶4) accounted for 26% and 30% of the total fatty acids on day 1 and day 5, respectively. Although lipid changes in the crop of squabs prior to collection of samples cannot totally be ruled out, the nature of lipid changes is likely to reflect cellular breakdown that precedes PM secretion by parent pigeons.  相似文献   

14.
Lipid and fatty acid levels in the edible flesh of 17 freshwater fish from Brazil’s southern region were determined. Analyses of fatty acid methyl esters were performed by gas chromatography. Palmitic acid (C16:0) was the predominant saturated fatty acid, accounting for 50–70% of total saturated acids. Oleic acid (C18:1θ9) was the most abundant monounsaturated fatty acid. Linoleic acid (C18:2θ6), linolenic acid (C18:3θ3), and docosahexaenoic acid (C22:6θ3) were the predominant polyunsaturated fatty acids (PUFA). The data revealed that species such as truta, barbado, and corvina were good sources of eicosapentaenoic acid (C20:5θ3) and docosahexaenoic acid (C22:6θ3), and that most freshwater fish examined were good sources of PUFA θ3.  相似文献   

15.
The fatty acid compositions of the seed lipids from four Ephedra species, E. nevadensis, E. viridis, E. przewalskii, and E. gerardiana (four gymnosperm species belonging to the Cycadophytes), have been established with an emphasis on Δ5-unsaturated polymethylene-interrupted fatty acids (Δ5-UPIFA). Mass spectrometry of the picolinyl ester derivatives allowed characterization of 5,9- and 5,11–18∶2; 5,9,12–18∶3; 5,9,12,15–18∶4; 5,11–20∶2; 5,11,14–20∶3; and 5,11,14,17–20∶4 acids. Δ5-UPIFA with a Δ11-ethylenic bond (mostly C20 acids) were in higher proportions than δ5-UPIFA with a δ9 double bond (exclusively C18 acids) in all species. The total δ5-UPIFA content was 17–31% of the total fatty acids, with 5, 11, 14–20∶3 and 5, 11, 14, 17–20∶4 acids being the principal δ5-UPFIA isomers. The relatively high level of cis-vaccenic (11–18∶1) acid found in Ephedra spp. seeds, the presence of its δ5-desaturation product, 5, 11–18∶2 acid (proposed trivial name: ephedrenic acid), and of its elongation product, 13–20∶1 acid, were previously shown to occur in a single other species, Ginkgo biloba, among the approximately 170 gymnosperm species analyzed so far. Consequently, Ephedraceae and Coniferophytes (including Ginkgoatae), which have evolved separately since the Devonian period (≈300 million yr ago), have kept in common the ability to synthesize C18 and C20 δ5-UPIFA. We postulate the existence of two δ5-desaturases in gymnosperm seeds, one possibly specific for unsaturated acids with a δ9-ethylenic bond, and the other possibly specific for unsaturated acids with a δ11-ethylenic bond. Alternatively, the δ5-desaturases might be specific for the chain length with C18 unsaturated acids on the one hand and C20 unsaturated acids on the other hand. The resulting hypothetical pathways for the biosynthesis of δ5-UPIFA in gymnosperm seeds are only distinguished by the position of 11–18∶1 acid. Moreover, 13C nuclear magnetic resonance spectroscopy of the seed oil from two Ephedra species has shown that δ5-UPIFA are essentially excluded from the internal position of triacylglycerols, a characteristic common to all of the Coniferophytes analyzed so far (more than 30 species), with the possibility of an exclusive esterification at the sn-3 position. This structural feature would also date back to the Devonian period, but might have been lost in those rare angiosperm species containing δ5-UPIFA.  相似文献   

16.
Marine fish have an absolute dietary requirement for C20 and C22 highly unsaturated fatty acids. Previous studies using cultured cell lines indicated that underlying this requirement in marine fish was either a deficiency in fatty acyl Δ5 desaturase or C18–20 elongase activity. Recent research in turbot cells found low C18–20 elongase but high Δ5 desaturase activity. In the present study, the fatty acid desaturase/elongase pathway was investigated in a cell line (SAF-1) from another carnivorous marine fish, sea bream. The metabolic conversions of a range of radiolabeled polyunsaturated fatty acids that comprised the direct substrates for Δ6 desaturase ([1-14C]18∶2n−6 and [1-14C]18∶3n−3), C18–20 elongase ([U-14C]18∶4n−3), Δ5 desaturase ([1-14C]20∶3n−6 and [1-14C]20∶5n−3), and C20–22 elongase ([1-14C]20∶4n−6 and [1-14C]20∶5n−3) were utilized. The results showed that fatty acyl Δ6 desaturase in SAF-1 cells was highly active and that C18–20 elongase and C20–22 elongase activities were substantial. A deficiency in the desaturation/elongation pathway was clearly identified at the level of the fatty acyl Δ5 desaturase, which was very low, particularly with 20∶4n−3 as substrate. In comparison, the apparent activities of Δ6 desaturase, C18–20 elongase, and C20–22 elongase were approximately 94-, 27-, and 16-fold greater than that for Δ5 desaturase toward their respective n−3 polyunsaturated fatty acid substrates. The evidence obtained in the SAF-1 cell line is consistent with the dietary requirement for C20 and C22 highly unsaturated fatty acids in the marine fish the sea bream, being primarily due to a deficiency in fatty acid Δ5 desaturase activity.  相似文献   

17.
The changes in the triacylglycerol (TAG) composition of colostrum fat of three cows were studied. In addition to the determination of fatty acid composition by gas chromatography, the distribution of TAG according to the acyl carbon number (ACN) and molecular weight was analyzed utilizing both supercritical fluid chromatography (SFC) and ammonia negative-ion chemical ionization mass spectrometry (MS). Colostrum TAG contained substantially less stearic and oleic acids and more myristic and palmitic acids than the normal Finnish milk fat. The major trends in the changes of fatty acids and TAG were similar for each cow, although clear differences between individuals were found. During the first week of parturition, the proportions of short-chain fatty acids (C4–C10) typically increased as well as those of stearic and oleic acids, whereas the relative amounts of C12–C16 acids decreased, especially those of myristic and palmitic acids. Distinct changes occurred also in TAG distributions: the proportions of molecules with ACN 38–40 increased and those with ACN 44–48 decreased. Although there were distinct differences between individuals shortly after delivery, both the fatty acid compositions and TAG distributions of the milk samples of the cows started to resemble each other after one week. The theoretical profiles of colostrum TAG calculated based on the fatty acid compositions differed clearly from the ACN distributions analyzed by SFC and MS. Thus, the analysis of TAG is essential, because the changes in molecular species composition of colostrum TAG cannot be estimated according to the fatty acid analysis alone.  相似文献   

18.
B. F. Szuhaj  R. L. McCarl 《Lipids》1973,8(5):241-245
Fatty acid composition of neutral and polar lipid fractions from rat hearts was determined in rats of different ages as their diet source changed. Piebald rats were weaned at 21 days and were fed standard lab chow. Lipids from rat hearts, mothers milk and lab chow were purified on a Sephadex G-25 fine column and separated into neutral and polar lipid fractions by silicic acid column chromatography. These lipid fractions were then hydrolyzed and methylated with BF3 in methanol, prior to gas liquid chromatographic separation on a 1/8 in. × 10 ft aluminum column of 15% EGS on 80–100 mesh acid-washed Chromosorb W. Three major fatty acids in the neutral lipid fraction comprised 72% of total neutral lipid fatty acids from young hearts. At sexual maturity (at least 74 days old) C18∶1 was the major fatty acid, followed by C16∶0 and C18∶0. The same three fatty acids comprised 83% of total polar lipid fatty acids, but C18∶0 was the major fatty acid, followed by C16∶0 and C18∶1. The fatty acid composition of dietary lipids influenced the total neutral lipid fatty acid composition of the rat heart, but had little influence on the fatty acid composition of the polar lipid fraction. Presented in part at the AOCS Meeting, New Orleans, April 1970.  相似文献   

19.
The first total syntheses of the naturally occurring acetylenic fatty acids—6-heptadecynoic acid (59% overall yield) and 6-icosynoic acid (34% overall yield)—was accomplished in four steps. Using the same synthetic sequence the naturally occurring fatty acids (6Z)-heptadecenoic acid (46% overall yield) and (6Z)-icosenoic acid (27% overall yield) were also synthesized. The Δ6 acetylenic fatty acids displayed good antiprotozoal activity towards Leishmania donovani promastigotes (EC50 = 1–6 μg/mL), but the 6-icosynoic acid was the most effective in the series. In addition, the (6Z)-icosenoic acid was a much better antiprotozoal compound (EC50 = 5–6 μg/mL) than the (6Z)-heptadecenoic acid (EC50 > 25 μg/mL). The saturated fatty acids n-heptadecanoic acid and n-eicosanoic acid were not effective towards L. donovani, indicating that the Δ6 unsaturation in these fatty acids is necessary for leishmanicidal activity. In addition, both the 6-icosynoic acid and the (6Z)-icosenoic acid were inhibitors of the Leishmania DNA topoisomerase IB enzyme (EC50’s = 36–49 μM), a possible intracellular target for these compounds. This is the first study assessing fatty acids as inhibitors of the Leishmania DNA topoisomerase IB enzyme.  相似文献   

20.
The lipid composition of a Bacillus sp., isolated from Lake Pomorie in Bulgaria, was unusual and consisted of 26 different fatty acids between C12 and C26, with anteiso C15−C17 saturated fatty acids predominating. The furan fatty acid, 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid, was also identified, a new finding for this genus. The hydrocarbons consisted of 30 different monounsaturated hydrocarbons, between C25 and C30, with the iso-iso, iso-anteiso, anteiso-anteiso, iso-normal, and anteiso-normal methyl branching for odd-numbered chains, and the iso-iso, iso-anteiso, iso-normal, and anteiso-normal methyl branching for even-numbered chains. The double bond positions in these hydrocarbons were determined by dimethyl disulfide derivatization followed by GC-MS, and the double-bond cis configuration was confirmed by infrared spectroscopy. Some previously unknown hydrocarbons in bacteria, such as (Z)-3,21-dimethyl-9-tricosene, (Z)-3,21-dimethyl-10-tricosene, (Z)-2,24-dimethyl-11-pentacosene, and (Z)-2,25-dimethyl-13-hexacosene were identified. Sterols were detected and were based on the sitosterol nucleus.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号