Studies on Apocynacea Seed Oils

The fatty acid composition of three seed oils of Apocynaceae has been studied in this investigation. The seed oils of Apocynaceae were examined for their component acids and were found to contain the following acids: Rauwolfia serpentina, Benth, (wt.%) lauric 0.2 %, myristic 0.8 %, palmitic 17.7%, stearic 4.9 %, arachidic 0.9 %, behenic 0.6 %, oleic 34.4 %, and linoleic 40.5 %. Rauwolfia tetraphylla, Linn. syn. Rauwolfia canescens, Linn., Rauwolfia heterophylla, Roem and Schult, (wt.%) lauric 0.9 %, myristic 3.4 %, palmitic 25.7 %, stearic 10.3%, arachidic 1.6%, behenic 1.4%, oleic 36.5 %, and linoleic 20.2 %. Vinca rosea Linn syn. Lochnera rosea, Linn. (wt.%) lauric 0.2%, myristic 1.0%, palmitic 1.4 %, stearic 6.8 %, arachidic 1.3 %, behenic 0.6 %, oleic 73.6 %, and linoleic 15.1 %.     

Effects of stearic acid on plasma lipid and lipoproteins in humans

More than 40 years ago, saturated FA with 12, 14, and 16 carbon atoms (lauric acid, myristic acid, and palmitic acid) were demonstrated to be “hypercholesterolemic saturated FA.” It was further concluded that the serum total cholesterol level would hardly be changed by isocaloric replacement of stearic acid (18∶0) by oleic acid (cis-18∶1n−9) or carbohydrates. These earlier studies did not address the effects of the various FA on the serum lipoprotein profile. Later studies found that the hypercholesterolemic saturated FA increase serum total cholesterol levels by raising concentrations of both the atherogenic LDL and the antiatherogenic HDL. Consequently, the ratio of total to HDL cholesterol will hardly change when carbohydrates replace these saturated FA. Compared with other saturated FA, stearic acid lowers LDL cholesterol. Studies on the effects on HDL cholesterol are less conclusive. In some, the effects on HDL cholesterol were comparable to those of palmitic acid, oleic acid, and linoleic acid, whereas in others a decrease was observed. This may suggest that in this respect the source of stearic acid is of importance, which needs however further study. From all these studies, however, it can be concluded that stearic acid may decrease the ratio of total to HDL cholesterol slightly when compared with palmitic or myristic acid. Without doubt, the effects of stearic acid are more favorable than those of trans monounsaturated FA.     

The hydrolysis of soap solutions. II. The solubilities of higher fatty acids

Summary The solubilities of capric, lauric, myristic, palmitic, and stearic acids in water at 25° and 50°C. were determined by use of conductivity measurements. Correction was made for carbon dioxide; and total solubilities, together with the concentration of dissociated and of undissociated acid were calculated. Their solubilities range from 359×10⁻⁶ M for capric acid to 2.1×10⁻⁶ M for stearic acid at 25°C. The solulility of laric and myristic is approximately doubled by an increase of temperature from 25° to 50°C., that of capric, palmitic, and stearic acids increases by 25 to 40%.     

Effects of Chain Length of Saturated Fatty Acids on Plasma Total,LDL- and HDL-Cholesterol Levels

We conducted two clinical studies to examine the effects of diets high in stearic acid and lauric + myristic acid on plasma lipids and lipoproteins of healthy young men. In the first study subjects (n = 15) were fed whole food diets high in cocoa butter, butter, olive oil and soybean oil. In the second study, subjects were fed diets very high in saturated fatty acids (> 20% of calories) that were high in either stearic acid (from cocoa butter or milk chocolate) or lauric + myristic acid (from butter). In the first study, cocoa butter elicited a neutral cholesterolemic effect, whereas the butter diet was hypercholesterolemic and the olive oil and soybean oil diets were hypocholesterolemic. In the second study, the diets high in stearic acid did not raise plasma total and LDL-cholesterol levels, whereas, as in the first study, butter was markedly hypercholesterolemic. Regression analyses performed on the individual data from these two clinical studies were conducted to establish the cholesterolemic effects of individual fatty acids. The bestfitting linear regression equations relating ΔTC (change in plasma total cholesterol) was: ΔTC = 2.3 ΔC_14:0 + 3.0 ΔC_16:0-0.8 ΔC_18:0-1.0 ΔPUFA, where Δ fatty acid = change in intake expressed as percent of calories. This predictive equation separates stearic acid from the other long-chain saturated fatty acids and suggests that it has an independent cholesterol-lowering effect. In conclusion, stearic acid is a unique long-chain saturated fatty acid.     

Fatty acid composition of tamarind kernel oil

The fatty acid composition (% by wt) of Tamarind (Tamarindus indica) kernel oil, as determined by gas liquid chromatography was: trace lauric acid, tracte myristic acid, 14.8% palmitic acid, 5.9% stearic acid, 27.0% oleic acid, 7.5% linoleic acid, 5.6% linolenic acid, 4.5% arachidic acid, 12.2% behenic acid, and 22.3% lignoceric acid.     

Selective removal of free fatty acids in oils using a microorganism

A microorganism assimilating long chain fatty acids without secreting extracellular lipases was screened from soil and was identified as aPseudomonas. Growth factors, nitrogen sources and trace elements required for growth of the microorganism namedPseudomonas strain BG1 were determined. Optimum pH and growth temperature were 6 and 30°C, respectively. BG1 was found to utilize lauric, myristic, palmitic, stearic and oleic acids as carbon sources. BG1 was shown to utilize 0.1% oleic acid almost completely in an emulsion medium within 48 hr. When BG1 was grown in a mixture of triolein and oleic acid, it selectively removed the free fatty acid without loss of triolein and did not produce mono- and diglycerides.     

Solid-liquid phase relations of some normal long-chain fatty acids in N,N-dimethylacetamide and N,N-dimethylformamide

Solubility data are reported for capric, lauric, myristic, palmitic, stearic, and arachidic acids in N,N-dimethylacetamide (DMA) and N,N-dimethylformamide (DMF). Complete binary freezing-point diagrams were constructed for the capric, myristic, and stearic acid systems. A solid, incongruently melting 1:1 molecular compound formed in all except the stearic acid-DMF system. Calculated solubility data for lauric, palmitic, and arachidic acids in both solvents were in good agreement with experimental determinations on selected compositions.     

Solubility of calcium soaps of gum rosin,rosin acids and fatty acids

Summary The solubility of calcium soaps of rosin acids and fatty acids have been determined and compared. The solubility of calcium soaps of rosin acids (d-pimaric, dihydroabietic, and l-abietic acids) present in gum rosin was found to be greater than that of the calcium soaps of the following saturated fatty acids: lauric, myristic, palmitic, and stearic acids. The calcium oleate was much more soluble than the calcium stearate. As the amount of hydrogen in the rosin acid molecule is increased, l-abietic to dihydroabietic to tetrahydroabietic acid, the solubility of the calcium soap is decreased. The author wishes to express his indebtedness to Dr. G. S. Jamieson and W. G. Rose of the Agricultural Chemical Research Division for the pure lauric, myristic, palmitic and stearic acid used in this study.     

Vernolic and Cyclopropenoic Fatty Acids in Piper nigrum Seed Oil

The seed oil of Piper nigrum has the following fatty acid composition: capric (4.1%), lauric (2.5%), myristic (3.1%), palmitic (27.2%), stearic (7.3%), oleic (29.9%), linoleie (7.7%), vernolie (7.7%), malvalie (6.3%), and sterculic (4.2%) acids.     

Analysis of Albizzia lebbeck Flower Oil

The oil of Albizzia lebbeck flowers was analysed. Saponifiable lipid contains capric, lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, arachidic and behenic acids. Unsaponifiable lipid was found to contain aliphatic alcohols, taraxerol, β-amyrin, cycloartenol, lupeol, 24-methylene cycloartanol, campesterol, sitosterol and four unidentified components.     

Surface-active properties of salts of alpha-sulfonated acids and esters

Summary In a comparison of the solubility, detergency, and surface-active properties of the mono- and disodium salts ofa-sulfonated lauric, myristic, palmitic, and stearic acids, it has been shown that the less solublea-sulfopalmitates anda-sulfostearates, and sodiuma-sulfomyristic acid as well, are the best detergents. The easily soluble disodiuma-sulfolaurate resembles a simple electrolyte with little evidence of surface-active properties. Ammoniuma-sulfopalmitic acid and triethanolammoniuma-sulfopalmitic acid are more soluble surface-active agents and detergents than the sodium salts. Triethanolammoniuma-sulfopalmitic acid is exceedingly soluble in water at room temperature. The sodium salts of alkyla-sulfopalmitates anda-sulfostearates are easily prepared from the isolated crude diacid. The esters of primary alcohols containing from one to six carbon atoms are readily soluble in water and quite stable to hydrolysis, especially in acid solution. Salts ofa-sulfonated esters of secondary alcohols are stable both to acid and to alkaline hydrolysis. This behavior extends the range of possible application. Presented at the Fall Meeting of the American Oil Chemists’ Society, Chicago, Ill., November 2–4, 1953. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

The fatty acids of menhaden oil

Summary The methyl esters of a specimen of menhaden oil have been fractionated in an efficient still. The C₁₂, C₁₄, C₁₆, and C₁₈ main fractions have been studied, mainly by low temperature crystallization procedures. The oil has been shown to contain traces of lauric and dodecenoic acids. The C₁₄ acids are made up of 2.2% tetradecenoic acid and 97.8% of myristic; based on the whole ester composition of Table I, these values amount to 0.1 and 6.8%, respectively. The C₁₆ acids are palmitic, 50.9%; hexadecenoic, 46.6%; and hexadecatrienoic (including a small amount of tetrenoic acid) 2.5%, or based on the whole esters, 15.5, 14.1 and 0.8%, respectively. A very rough calculation of the composition of the C₁₈ fraction gives the following reults, values based on the whole esters being included in parenthesis: stearic, 11.5 (3.1); octadecenoic, 58.6 (15.7); octadecadienoic, 13.4 (3.6); octadecatrienoic, 7.2 (1.9); and octadecatetrenoic, 9.3% (2.5%). In the course of this investigation the following acids and their methyl esters were isolated from the oil by crystallization procedures; myristic, tetradecenoic (80%), palmitic, hexadecenoic, stearic, and oleic. Evidence was presented that the octadecenoic acids of this oil were a mixture of oleic acid with isomeric acids of this series, a finding which is in agreement with a recent report from this laboratory (11), describing the multiple nature of the octadecenoic acids of a number of animal fats. Presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School.     

Influence of stearic acid on hemostatic risk factors in humans

Stearic acid has been claimed to be prothrombotic. Elevated plasma factor VII coagulant activity (FVIIc) may raise the risk of coronary thrombosis in the event of plaque rupture. Fibrinogen, an acute-phase protein, is necessary for normal blood clotting; however, elevated levels of fibrinogen increase the risk of coronary heart disease (CHD). Here I report the results of three controlled, human dietary intervention studies, which used a randomized crossover design to investigate the hemostatic effects of stearic acid-rich test diets in healthy young men. A diet high in stearic acid (shea butter) resulted in a 13% lower fasting plasma FVIIc than a high palmitic acid diet, and was 18% lower than a diet high in myristic and lauric acids (P=0.001) after 3 wk of intervention. The stearic acid-rich test fat increased plasma fibrinogen concentrations slightly compared with the myristic-lauric acid diet (P<0.01). When investigating the acute effects of fatty meals, those high in stearic acid (synthesized test fat) resulted in a smaller postprandial increase in FVII than those high in trans and oleic FA, indicating a smaller increase in activated FVII after ingesting stearic acid compared with fats high in monounsaturated FA, probably caused by lower postprandial lipemia. Thus, the present investigations did not find dietary stearic acid to be more thrombogenic, in either fasting effects compared with other longchain FA, or in acute effects compared with dietary unsaturated FA, including trans monounsaturated FA. The slightly increased effect on fasting plasma fibrinogen may be biologically insignificant, but it should be investigated further.     

Purification of long-chain saturated fatty acids by recrystallization of their molecular compounds with acetamide

Summary A method is described for the purification of lauric, myristic, palmitic, and stearic acid, based upon the recrystallization of the fatty acid-acetamide molecular compounds and subsequent regeneration of the acid by extraction of the acetamide with water. The choice of the crystallization solvent is rather critical because of the marked difference in the solubility characteristics of the acetamide and the fatty acids. For the purification of lauric and myristic acids acetone or a one-to-one benzene-acetone mixture by volume proved to be the best solvents, and for palmitic and stearic acids the most satisfactory results were obtained with either benzene or a two-to-one mixture by volume of benzene and acetone. Since the molecular compounds must be crystallized from concentrated solutions, the separation of the crystals from the mother liquor must be made by centrifugation. The recrystallized fatty acid-acetamide compounds provide a convenient intermediate for the preparation of pure acid amides free from homologs. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

HBr-Reactive acids ofMalva sylvestris seed oil

Malva sylvestris seed oil contained 5.6% sterculic, 11.0% malvalic, 1.6% vernolic, 15.6% lauric, 6.6% myristic, 26.6% palmitic, 5.6% palmitoleic, a trace of stearic, 23.0% oleic and 4.0% linoleic acids. The co-occurrence of malvalic and sterculic acids was established by gas liquid chromatography (GLC) of the silver nitrate-methanol treated esters usingSterculia foetida esters as the reference standard. Co-occurrence of epoxy acid (vernolic acid) was confirmed withVernonia anthelmintica as the lipid standard.     

A high-saturated fat diet enriched with phytosterol and pectin affects the fatty acid profile in guinea pigs

This paper presents the results of a study whose aim was to test the effects of several doses of pectin and phytosterols on the body weight gain and the FA content in emale guinea pigs. The treatments resulted from supplementing with pectin and plant sterol a guinea pig diet (rich in saturated FA), following a 3×3 factorial design, with three levels of pectin (0,3.67 and 6.93%) and three levels of phytosterols (0, 1.37, and 2.45%). Seventy-two female Dunkin Hartley guinea pigs were randomly assigned to the treatment groups (8 animals/group), the duration of the treatment being 4 wk. Pectin dietary intake led to a significant increase in body weight (P<0.001), food consumption (P=0.025), and feed efficiency (P<0.001), but no influence of phytosterols on weight gain or food consumption was detected. We found a significant negative effect of the addition of phytosterols on lauric, myristic, and palmitic acid concents in feces, and a positive effect on their concentration in plasma and liver, but no significant effect on stearic acid content. Apparent FA absorption was assessed by calculating the ratio of FA in feces and diets that the absorption of the different FA could be compared, and the negative effect of phytosterol supplementation on these ratios, especially for lauric and myristic acids, was established.     

Modification of butterfat by selective hydrolysis and interesterification by lipase: Process and product characterization

Butterfat was chemically modified via combined hydrolysis and interesterification, catalyzed by a commercial lipase immobilized onto a bundle of hydrophobic hollow fibers. The main goal of this research effort was to engineer butterfat with improved nutritional properties by taking advantage of the sn-1,3 specificity and fatty acid specificity of a lipase in hydrolysis and ester interchange reactions, and concomitantly decrease its level of long-chain saturated fatty acid residues (viz., lauric, myristic, and palmitic acids) and change its melting properties. All reactions were carried out at 40°C in a solvent-free system under controlled water activity, and their extent was monitored via chromatographic assays for free fatty acids, esterified fatty acid moieties, and triacylglycerols; the thermal behavior of the modified butterfat was also assessed via calorimetry. Lipase-modified butterfat possesses a wider melting temperature range than regular butterfat. The total saturated triacylglycerols decreased by 2.2%, whereas triacylglycerols with 28–46 acyl carbons (which contained two or three lauric, myristic, or palmitic acid moieties) decreased by 13%. The total monoene triacylglycerols increased by 5.4%, whereas polyene triacylglycerols decreased by 2.9%. The triacylglycerols of interesterified butterfat had ca. 10.9% less lauric, 10.7% less myristic, and 13.6% less palmitic acid residues than those of the original butterfat.     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.     

The fatty acid composition of small and large naturally occurring milk fat globules

Native milk fat globules of various mean diameters, ranging from d₄₃ = 1.5 to 7.3 μm, were obtained using microfiltration of raw whole milk acquired in winter and spring. After total lipid extraction, fatty acid composition was characterized by methyl and butyl ester analysis using gas chromatography. The oleic and linoleic acid content of milk obtained in winter increased with fat globule size, whereas myristic and palmitic acid decreased. There was significantly more lauric, myristic and palmitoleic acid, and less stearic acid in small fat globules compared to large fat globules in milk obtained in both winter and spring. The relative content of oleic and linoleic acids were found to depend on fat globule size and season. Results are interpreted on the basis of the relative content of milk fat globule membrane depending on fat globule size, and on consequences of compositional variations on milk fat globule melting behavior.     

Minor Seed Oils II: Fatty Acid Composition of Some Seed Oils

Three seed oils, Achyranthes aspera, Cucumis callosus and Aberia caffra were examined and were found to contain the following acids (wt%): lauric (0.4,-, 0.2), myristic (1.2, 0.6, 0.9), palmitic (18.6, 10.6, 25.9), stearic (4.4, 10.0, 3.9), arachidic (1.6, 1.6, 1.2), behenic (1.8, 0.6, 0.5), oleic (22.6, 17.5, 19.3), linoleic (49.4, 59.1, 48.1) respectively.