Properties of soaps derived from distilled palm stearin and palm kernel fatty acids

Soaps made from blends of distilled palm stearin (PS) and palm (PK) kernel fatty acids were evaluated for total fatty matter, sodium chloride content, moisture content, hardness, Hunter whiteness, foamability, iodine value, titer value, and acid value. Data showed that these soaps had properties similar to palm-based soaps made from distilled palm oil and palm kernel fatty acids. The soaps showed good whiteness (greater than 80%) and foamability. Total fatty matter ranged from 10–18%, sodium chloride content was 0.5%, and free caustic was 0.1% except for blend 8 containing 10 PS:90 PK, which had a free caustic of 0.03%. Initial penetration value, a reflection of soap hardness, ranged from 32–126 mm, with an average value of 54 mm. This value is within the range of the best blends of palm-based soaps (50–63 mm). There was no obvious trend observed. Penetration value, however was found to stabilize after a month of storage with an average value of 19.4 mm. Soap with this hardness value is relatively hard and therefore should be blended with a small amount of soft oils.     

The function of fatty acids in metallic soaps

Conclusion The above consideration of metallic soaps has been conducted from the point of view of the fatty acid used. It is evident that the fatty acid does play an important function in determining the method of preparation, the physical properties, and ultimately the use of metallic soaps. Presented at the annual Fall Meeting, American Oil Chemists’ Society, Nov. 2–4, 1953, Chicago, Ill.     

Application of urea complexes in the purification of fatty acids,esters, and alcohols. III. Concentrates of natural linoleic and linolenic acids

Summary Concentrates of natural linoleic acid (linoleic acid content, 85–95%) have been prepared in 50–72% yields from corn oil fatty acids by preferential precipitation of the saturated and monounsaturated fatty acids at room temperature as their urea complexes. By a similar procedure, concentrates of natural linolenic acid (linolenic acid content, 87–89%) have been prepared in 55–61% yields from perilla oil fatty acids by preferential precipitation of the saturated, monounsaturated, and diunsaturated fatty acids. Although concentrates of natural linolenic acid containing only 66–70% linolenic acid were obtained from linseed oil fatty acids, yields were 87–90%. A levelling-off effect has been observed in the use of the preferential precipitation technique in raising the purity of concentrates of linoleic and linolenic acid. This parallels the experience in the purification of these acids by low-temperature crystallization. The preceding papers in this series are references 12 and 13. Presented at the Fall Meeting of the American Oil Chemists' Society, Cincinnati, O., Oct. 20–22, 1952. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

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.     

The solubilization of calcium soaps by fatty acids

The solubilization of the calcium soaps of long chain fatty acids by liquid fatty acids was observed. The solubilities of calcium palmitate, calcium laurate, and calcium oleate were 15.6, 22.8, and 53.3 wt%, respectively, in oleic acid at 40°C. The formation of an acid-calcium soap complex was demonstrated by x-ray diffraction studies of calcium laurate, lauric acid, and a mixture of these compounds that had been heated. Similar evidence was obtained for a calcium oleate-oleic acid complex. The solubility of calcium oleate in a bile salt micellar system was enhanced by obeic acid. The solubilization of calcium soaps by liquid fatty acids may explain the unexpectedly high bioavailability of some calcium soaps.     

Temperature acclimation in the crayfish: Effects on phospholipid fatty acids

Acclimation to different temperatures by a poikilothermous animal must include modification of its membrane lipids to maintain the proper physical properties. The simplest way to achieve this acclimation would seem to be by modification of the phospholipid fatty acids. In a freshwater cray-fish,Procambarus clarkii, rapid changes in the degree of unsaturation of newly synthesized phospholipid fatty acids were correlated with changes in environmental temperature, both in whole animals and in slices of hepatopancreas tissue. At 5 C, the rate of fatty acid synthesis was about half that occurring at 23 C. Hepatopancreas tissue from animals acclimated to either 5 C or 23 C, when incubated for 2 hr at 5 C, incorporated a higher percentage of exogenous [1-¹⁴C] acetate into polyunsaturated acids (27–38% of the radioactivity in total fatty acids) than when incubated at 23 C (12–14%); conversely, more saturated fatty acids were synthesized at 23 C (73–80% vs 51–73%). The higher average unsaturation of the fatty acids biosynthesized at 5 C constitutes an effective response to the animal's need for modification of lipids to maintain adequate membrane function at the lower environmental temperature. Presented at the AOCS meeting in Mexico City, Mexico, April 27–May 2, 1974. Work done at the Laboratory of Nuclear Medicine and Radiation Biology, University of California, Los Angeles, CA 90024.     

Selective distribution of saturated fatty acids into the monoglyceride fraction during enzymatic glycerolysis

Four triglyceride fats and oils (beef tallow, lard, rapeseed oil and soybean oil) were reacted with glycerol while using lipase as the catalyst. For all fats examined, at reaction temperatures above the critical temperature (T_c), the fatty acid compositions of the monoglyceride (MG) and diglyceride (DG) fractions and of the original fat were similar. A relatively low yield of MG was obtained (20–30 wt%). When the reaction was carried out with beef tallow or lard at a temperature below the T_c (40°C), the concentration of saturated fatty acids in the MG fraction was 2 to 4 times greater than that in the DG fraction. Correspondingly, the concentration of unsaturated fatty acids in the DG fraction was more than two times greater than that in the MG fraction. At 5°C, a similar trend was observed for rapeseed oil and soybean oil. Direct analysis of partial glycerides during glycerolysis by high-temperature gas-liquid chromatography showed that below T_c the content of C16 MG increased relatively more than C18 MG. C36 DG and C54 TG were apparently resistant to glycerolysis. Preferential distribution of saturated fatty acids into the MG fraction was accompanied by a high yield of monoglyceride (45–70 wt%) and solidification of the reaction mixture. It is concluded that during glycerolysis below T_c, preferential crystallization occurs for MGs that contain a saturated fatty acid.     

X-Ray diffraction study of sodium soaps of monounsaturated and polyunsaturated fatty acids

X-Ray powder diffraction patterns of the sodium soaps of 14 monounsaturated and polyunsaturated fatty acids were obtained at room temperature. The patterns of the soaps of 9,12-trans,trans-octadecadienoic acid, 11,14-cis,cis-eicosadienoic acid 11,14,17-allcis-eicosatrienoic acid and 5 monounsaturated fatty acids were typical of the crystalline lamellar phase. The patterns of the soaps of 9,12-cis,cis-octadecadienoic, allcis-9,12,15-octadecatrienoic, allcis-8,11,14-eicostrienoic, allcis-5,8,11,14-eicosatetraenoic, allcis-5,8,11,14,17-eicosapentaenoic and allcis-4,7,10,13,16,19-docosahexaenoic acids were indicative of the less ordered forms reported for sodium oleate at elevated temperature. The diffraction data from the less ordered soaps are consistent with the melted form of the hydrocarbon chains of the unsaturated acids at room temperature.     

Studies in soap crystallization processes. Part III. Acid soap crystallization in the segregation of tall oil fatty acids

Tall oil fatty acids have been fractionated into 80–90% oleic acid, and 60–80% linoleic acid fractions, by precipitation of the oleic acid as acid soap from polar solvents. Sodium and potassium acid soaps are equally effective, but ammonium acid soaps require lower operating temperatures. The choice of solvent is not critical as regards degree of separation, but technically attractive filtration rates have been obtained only with methanol and acetone. Acidulation gives colorless oleic acid of very low rosin acid and unsaponifiable content, but with 5–10% of conjugated linoleic acid.     

Applications of fatty acids in metallic soaps

Summary In this discussion we have attempted to cover pertinent factors concerning the production and applications of solid fatty acid soaps, with particular emphasis on how the fatty acid characteristics come into play. We have avoided reference to specific formulations because these must be kept in the realm of metallic soap manufacturers’ “know how.” Those interested in modifiers and their effect on metallic soaps can find reference material in past issues of the Journal of American Oil Chemists’ Society (for example, reference 9) and in the patent literature. Reference to theoretical considerations of metallic soap structure has also been avoided as in this area the reader can again find reference material in the Journal of American Oil Chemists’ Society (for example, reference 10).     

The separation of solid fatty acids from liquid fatty acids by the formation of acid soaps. II. Pilot plant studies

On contemplating pilot plant scale-up of the acid soap process for separating fatty acid mixtures into low and high iodine value fractions, improvements were desirable in acidifying agent used, and the method of separating the solid acid soaps. A further objective was to determine the range of applicability of the process. Studies indicated that CO₂ can be replaced by mineral acids, or by the fatty acids themselves. A continuous precoat vacuum filter is suitable for the separation of the solid acid soaps. The process is applicable to refinery foots as well as to distilled and undistilled fatty acids.     

Cyclic fatty acids: Separation from straight-chain fatty acids by urea adducting

A mixture containing 37% cyclic and 63% straight-chain fatty acids, made by high-temperature treatment of linseed oil fatty acids with alkali, was separated by the urea adduct method to give unsaturated cyclic fatty acids (nonadduct) in 95% purity and 90–95% yeild. Previous reports from this Laboratory describe a process for separating cyclic fatty acids from stearic acid by hydrogenation followed by crystallization at −40C. The urea adduct method avoids hydrogenation and low-temperature crystallization, and furthermore, unsaturated cyclic and unsaturated straight-chain products can be recovered as individual fractions. Then, by readducting the unsaturated straight-chain fatty acid fraction, the small amounts of palmitic and stearic acids are removed leaving an unsaturated fraction containing oleic, nonconjugated and conjugated linoleic and some unsaturated cyclic fatty acids. Presented at AOCS Meeting, Los Angeles, April 1966. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Viscosities of fatty acids and methylated fatty acids saturated with supercritical carbon dioxide

The viscosities of several types of lipids saturated with supercritical carbon dioxide (SC-CO₂) were measured with a high-pressure capillary viscometer. Oleic acid and linoleic acid were evaluated from 85 to 350 bar at 40 and 60°C. The more SC-CO₂-soluble methylated derivatives of these fatty acids were evaluated from 90 to 170 bar at 40 and 60°C. The complex mixture of anhydrous milk fat (AMF) was evaluated from 100–310 bar at 40°C. The viscosities of the methylated fatty acids saturated with SC-CO₂ decreased between 5 and 10 times when the pressure increased from 1 to 80 bar, followed by a further decrease by a factor of 2 to 3 when the pressure was increased from 80 to 180 bar. The viscosities of the fatty acids and AMF saturated with SC-CO₂ had viscosity reduction similar to the methylated fatty acids between 1 and 80 bar, but they decreased much less between 80 and 350 bar. At constant pressure, the viscosity of the fatty acids and AMF decreased with increasing temperature, whereas the viscosity of the methylated fatty acids increased with increasing temperature. The lipid/SC-CO₂ mixtures were Newtonian, and their viscosities were best interpreted by using the mass concentration of dissolved SC-CO₂ in the lipids and the pure component viscosities.     

Tall oil fatty acids

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.     

Comparative value of fatty acids and resin acids of tall oil in soaps

Summary A study has been made of the detergency and foaming power of soaps made from a typical acid-refined American tall oil. Sodium soap of tall oil, straight tall oil fatty-acid soap, and straight tall oil resin-acid soap were evaluated. The effect of fatty acid-resin acid ratio was determined by using mixtures of those soaps. Sodium rosinate, sodium oleate, and mixtures of these soaps were used as comparison standards. Curves plotted show wash-test data and foaming values as functions of the ratio of fatty soap to resin soap. The data indicate in terms of detergency: a) tall oil soap has a higher value than sodium rosinate; b) sodium oleate is better than tall oil fatty-acid soap, but the latter is approximately equivalent to soaps from various unsaturated vegetable oils; c) both tall oil resin-acid soap and rosin soap have low detergency on cotton; d) the detergency of most mixtures of tall oil fatty-acid and resin-acid soaps at lower concentrations is greater than would be predicted from the individual soaps, indicating a synergistic effect. As a rough approximation, tall oil soap without unsaponifiables is equivalent to a corresponding mixture of sodium oleate and sodium rosinate. The presence of unsaponifiables lowers both detergency and foaming. Tall oil soap is somewhat less sensitive to hard water than sodium oleate. Significant differences between detergencies of soaps, and especially between soap mixtures, are obscured when launderometer tests are run at moderate soap concentrations. These differences are readily detected at lower concentrations. Presented at 113th meeting of the American Chemical Society, Chicago, Ill., April 14–23, 1948.     

New developments in synthetic fatty acids

New developments in synthetic fatty acids have occurred in the last few years in Russia, Japan, the United States and Canada. In 1959 Russia decided to replace 40% of natural fatty acids in soaps with synthetic fatty acids. In 1966, 548 million pounds of C₅–C₃₀ synthetic fatty acids were produced including 288 million pounds of C₁₀–C₂₀ fatty acids. Forty million pounds of fatty acids are converted directly to the fatty alcohols for detergent use. A conservative estimate predicts that one billion pounds of synthetic fatty acids will be produced in Russia by the end of the current five-year program. Reports say that the Japanese have been interested in the oxidation of not only paraffin hydrocarbons but naphthenic petroleum hydrocarbons as well. Production of lower homology fatty acids up to butyric acid is being seriously considered in Japan. In America the most likely syntheses aside from “oxo” syntheses being considered for the manufacture of products like lauric acid is the carboxylation of the Ziegler intermediates prepared from ethylene polymerization. Some data on the current and future coconut oil consumption by major end-use for Canada and the United States are presented. Synthetic lauric acid is predicted for 1970 in the United States. Prepared from an address given at a meeting of the Northeast Section, New York, June 1968.     

Chemical and physical characteristics of soap made from distilled fatty acids of palm oil and palm kernel oil

Manufacture of soaps from distilled fatty acids of palm oil (PO) and palm kernel oil (PK) is a well-established technology in Malaysia. Data on quality and characteristics of various blends of PO/PK fatty acid-based (palm-based) soaps made in Malaysia are not available, however. In view of this, the study described in this paper was undertaken. Eleven blends of palm-based bar soaps were made, and their properties were evaluated. There was an increase in the acid value of blended raw materials with increasing amounts of PK fatty acids. The iodine value and titer (°C) of blended raw materials, however, bear an inverse relationship with the amount of PK fatty acids. As expected, the hardness of the soap bars from the various blends increased with increasing PK fatty acid. Total fatty matter ranged from 76–85%, free caustic content was 0.1%, and sodium chloride content was 0.3–0.4%. Characteristics of soap blends made for this study were comparable with those from other countries. Quality of the soap obtained was comparable to those produced commercially.     

Trans-monoenoic and polyunsaturated fatty acids in phospholipids of aVibrio species of bacterium in relation to growth conditions

AVibrio species of bacterium known to contain the polyunsaturated fatty acid 20∶5n−3 was grown in both freshwater and seawater media at 5 and 20°C and examined for adaptive changes in lipid composition. Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG), together with a smaller proportion of nonesterified fatty acids (NEFA), comprised almost all the lipid under all growth conditions examined. Temperature had a more pronounced effect than the salinity of the medium on lipid composition. The proportion of PE in total lipid was always higher at 5 than at 20°C. Conversely, the proportion of NEFA was lower at 5 than 20°C whereas that of PG was not altered. The levels of saturated fatty acids in total lipid, PE and PG were all decreased by growth at 5°C. No differences were observed with respect to growth temperature in the levels ofcis 16∶1n−7, the principal monoenoic fatty acid in both PE and PG.Trans 16∶1n−7 was found to comprise 12.8–15.2% of fatty acids in PE and PG of bacteria grown at 5°C but only 4.4–8.5% of phospholipid fatty acids in bacteria cultured at 20°C. Regardless of medium composition, a reduction in growth temperature from 20 to 5°C also caused the proportions of 20∶5n−3 to increase from around 0.8 to 4.4% in PE and from around 4 to 20% in PG. The simultaneous occurrence oftrans 16∶1n−7 and 20∶5n−3 is unique to thisVibrio species of bacterium. The increased proportions of both these fatty acids with decreasing temperature suggest that they have a role in retailoring biomembrane phospholipids during temperature acclimation of the bacterium.     

The fractionation of marine-oil fatty acids with urea

Summary In two series of experiments, marine-animal-oil fatty acids were fractionated with urea using methanol as solvent. In the first series, menhaden-oil fatty acids were fractionated at 1°C. Almost all the saturated and monoenoic fatty acids were removed at mole ratios of 12∶1 to 13∶1. At higher ratios increasing amounts of the less stable dienoic fatty acids were precipitated. By the use of the appropriate ratio, fractions having iodine values above 300 were prepared. In the second series, fatty acids from the oils of menhaden, herring, tuna, seal, salmon eggs, and salmon heads and viscera were fractionated at a mole ratio of urea to fatty acid of 9.2∶1. At 25° and 1° the complexes were composed almost entirely of saturated and monoenoic fatty acids, but as the temperature was lowered to −30°, the content of dienoic fatty acids in the precipitates increased. Presented at the Regional American Chemical Society Meeting, Richland, Wash., June 11–12, 1954. One of the laboratories of the Branch of Commercial Fisheries, Fish and Wildlife Service, U. S. Department of the Interior.     

Composition of fatty acids and structure of triglycerides in medium and low erucic acid rapeseed

Total triglycerides in medium (MEAR) and low (LEAR) erucic acid cultivars of rapeseed were fractionated by argentation chromatography into twelve and ten fractions, respectively. Gas liquid chromatography of the fatty acids in the triglyceride fractions and their 2-monoglycerides was used to evaluate the structural characteristics of the individual fractions. Fractionation occurred on the basis of degree of unsaturation, molecular weight and positional characteristics. The most mobile fractions contained 34–50% of saturated fatty acids while the less mobile had 59–65% of polyunsaturated fatty acids. In the medium erucic acid oil, long chain fatty acids (C20–C22) were found in all fractions, but four fractions of low erucic acid oil were essentially free of long chain acids. Two of these fractions in the latter oil, which represented 44% of the total triglycerides, were glycerol trioleate and dioleoyllinoleoylglycerol. The majority of the 2-positions were occupied by unsaturated C18 fatty acids, generally in the order of linoleic ≥linolenic> oleic acids. The saturated and long chain fatty acids occurred predominantly in the 1-and 3-positions. The various fractions of medium and low erucic acid oils were similar in structural composition except that eicosenoic and erucic acids substituted for oleic acid in some external positions. Erucic acid did not appear to substitute directly for oleic acid in the 2-position.