Solvent-Assisted Crystallization of Fatty Acid Alkyl Esters from Animal Fat

An easy and efficient method for the separation of saturated and unsaturated fatty acid mono alkyl esters, prepared from animal fat, was developed. The most efficient separation was achieved by the use of solvents such as methanol and acetone at low temperatures. The dilution of the alkyl esters with 10 times the amount of solvent (10:1 v/w) and storage of the mixture for 4 h at ?22 °C could be defined as optimum conditions. After filtration of the saturated fraction at the corresponding temperature very pure fractions were obtained. For fatty acid methyl esters deriving from tallow, with an initial content of saturated fatty acids of almost 50 %, a saturated ester fraction with only 5 % unsaturated fatty acids and an unsaturated ester fraction with about 9 % of saturated fatty acids could be obtained. The solvent easily could be recovered by distillation. In addition fatty acid ethyl, 1‐propyl, 2‐propyl, 1‐butyl, tert‐butyl and 3‐methyl‐1‐butyl esters were prepared and separated into saturated and unsaturated fractions. All fractions were analyzed according to the fatty acid compositions and showed similar or slightly worse results compared to the methyl esters. The cold filter plugging points of the unsaturated fractions were measured, showing the lowest value for the unsaturated methyl ester fraction at ?26 °C. The fractionation with the use of solvents is an easy tool in order to obtain fatty acid alkyl esters with excellent cold temperature behavior out of animal fat.     

Spurennachweis von mehrfach verzweigten Fettsäuren in Fetten

Detection of Traces of Polybranched Fatty Acids in Fats A method for the detection and quantitative determination of saturated polybranched fatty acids in animal and vegetable fats is described. The method is based on gas-chromatographic determination of polybranched fatty acid methyl esters in the methyl esters which do not form urea adducts. The following amounts of polybranched fatty acids were determined in animal fats: whale oil 15 000 ppm., fish oil 6000 ppm., butter fat 4000 ppm., beef tallow 2000 ppm. and lard 110 ppm. In different vegetable oils and fats upto 200 ppm. of polybranched fatty acids were found. Not only the difference in total content of polybranched fatty acids but also differences in their percentage composition and retention volumes in gas-chromatograms were found. This method therefore offers the possibility of identification of some of the animal fats.     

Fettsäure-Spektren wichtiger Nahrungsfette

Fatty Acid Composition of Important Dietary Fats The recommendations issued by the German Nutrition Association (DGE) include both total fat quantities and the distribution of fatty acids in daily food intake. It is recommended that fats should account for 30% of the daily energy intake, comprising 10% each of saturated, mono-unsaturated and polyunsaturated fatty acids. An increasing number of scientific studies are quoted according to which the chain lengths of saturated fatty acids and the stereoisomers of unsaturated fatty acids play a part in raising the blood cholesterol level. Examples are given of both vegetable oils and fats and a animal and “hidden” fats. Recommendations from DGE for fat intake and fatty acid composition in fat in Germany are not reached yet. The fat intake has to be reduced.     

Composition of liver fats of mature and embryo sharks (galeocerdo tigrinus)

1. Two liver fats, one from the “mother” and the other from the “embryo” shark (Galeocerdo tigrinus), have been studied. Their component fatty acids are reported.
2. The mixed fatty acids from each of the fats were first resolved into groups of acids of varying unsaturation by the lithium salt acetone and/or lead salt alcohol methods. The methyl esters of each of these groups of acids were fractionated through the Longenecker's E.H.P. column.
3. The two fats are found to belong to the fourth group of Tsujimoto's classification of the Elasmobranch fish liver fats. The “mother” shark liver fat contains 43.3% saturated and 56.7% unsaturated acids. The “embryo” shark liver fat contains 39.1% saturated and 60.9% unsaturated acids. Palmitic acid was about 25% in both of the fats.
4. A possible explanation for the less unsaturation and the absence of higher polyethenoids in the “embryo” liver fat is given.

     

Trans-Fettsäuren in Lebensmitteln

Trans Fatty Acids in Foods The fatty acid compositions of the fat in 196 german food samples were analyzed with emphasis on trans components by gas liquid chromatograghy. The range of trans fatty acids (weight percent of methyl esters) in several foods was: margarines 0.6 - 23.5%, shortenings 0.1 - 31.8%, french fried potatoes 508 - 32.8%, cakes and cookies 0 - 15.5%, candies and frostings 0.2 - 15.7%, Crisps and other snacks 0.1 - 20.2%, animal and dairy fats from ruminants. 1.5 - 10.6%, other meat products animals and sausages less than 1%. Teh composition of trans fatty acids differed between hydrogenated fats and ruminant fats. Food processing (except hydrogenation) did not substantially alter the fatty acid composition. The daily intake of trans fatty acids in Germany was estimated by the National Consumption Assay. women consumed 3.4 g/day and men 4.1 g/day. Hydrogenated fats and ruminant fats contributed to the consumption nearly equally. Trans fatty acids influence the plasma lipoprotein levels similarly to saturated fatty acids. The trans fatty acids appear mostly as monounsaturated fatty acids in food composition tables. It seems necessary to distinguish between cis and trans isomers.     

Evaluation of Some Egyptian Animal Fats and their Use in Shortenings

Physical and chemical constants of some Egyptian animal fats, e. i. from camel hump and buffalo caul in comparison with imported beef tallow were investigated. Camel hump fat revealed different characteristics from buffalo caul and imported beef tallow in melting point, iodine value, saponification value and unsaponifiable matter. Fatty acid composition by GLC for the three extracted fats indicated the presence of large amounts of saturated fatty acids in comparison with unsaturated acids. Oleic acid was found to be the only unsaturated acid which has been in considerable amount especially in camel hump. Small amounts of palmitoleic and myristoleic acid were found in camel hump and buffalo caul while imported beef tallow contains more of myristopalmitic and palmitostearic acid. Sensory evaluations of shortenings prepared by incorporation of three different concentrations (5, 10, 15%) of the three extracted fats revealed that Egyptian animal fats can be used successfully as a substitute of imported fat. On the other hand 10% incorporation was found to be the most suitable concentration to obtain a good quality of the shortenings in colour, odor and consistency. Statistical analysis confirmed the above mentioned results.     

Synthesis and Surface Active Properties of Sulfonated Acrylate Esters Based on Al‐Cedre Oil

Sulfonated acrylate esters have been synthesized by using renewable raw materials such as fatty alcohols of Al‐Ceder oil. Mixed fatty acids were isolated from Al‐Ceder oil by hydrolysis; both saturated and unsaturated fatty acids were isolated from the mixed fatty acids. The methyl esters of mixed fatty acid, saturated and unsaturated acids of Al‐Cedre oil were subjected to reduction with (LiAlH4) to give the corresponding fatty alcohols. The products of the reduction process were saponified and the hydroxyl values were estimated to further confirm the reduction occurrence. The acrylate esters were synthesized by esterification of acrylic acid with fatty alcohols of C_16:0, C_18:0, C_18:1, and C_18:2 mixed saturated, mixed unsaturated and mixed fatty acids of Al‐Cedre oil, respectively. This esterification was followed by addition of NaHSO₃ to form bisulfite adducts. The structures of the prepared surfactants were characterized by IR and ¹HNMR spectroscopy. A series of useful surface parameters, stability towards acids and base hydrolysis and calcium stability have been determined.     

Gas chromatographic analysis of the dimethylhydrazones of long chain aldehydes

Long chain saturated and unsaturated aldehydes, prepared by the partial reduction of the corresponding fatty acid phenyl esters with lithium tri-t-butoxyhydroaluminate, were converted quantitatively to their dimethylhydrazones. Dimethyl acetals and 1,3-dioxolanes were prepared from the dimethylhydrazones. The dimethylhydrazones were then separated from the corresponding aldehydes by gas liquid chromatography on a semipolar column. Fatty acids were readily separated quantitatively from fatty aldehydes by formation of dimethylhydrazones of the aldehydes followed by an alkaline extraction of the reaction mixture prior to gas chromatography. A method for analysis of fatty acids and aldehydes from plasmalogens is described. Presented at the AOCS Meeting, Chicago, October 1967. Michigan Agricultural Experiment Station Journal Article No. 5104.     

Die unterschiedliche Bedeutung der Fettsäuren in ihrer fungistatischen Wirkung

Significance of Fatty Acids in Their Fungistatic Action The fungistatic action of saturated and unsaturated fatty acids, halogenated fatty acids and esters as well as sulfurcontaining derivatives is reviewed. Fungistatic agents, known since a long time, are propionic acid, caprylic acid and its salts as well as undecylenic acid and its salts. The recently known fatty acid derivatives having fungistatic action are morpholine and piperidine compounds of long chain fatty acids and the new class of aminimides of fatty acids with 14–16 C atoms.     

Highly unsaturated fatty acids. II. Fractionation by urea inclusion compounds

Summary 1. Urea segregation has been found to be a useful tool in concentration of highly unsaturated acids and esters. Fatty acids and esters derived from fish oils and methyl esters of hog adrenal fatty acids have been fractionated, and the polyunsaturated acids have been enriched. 2. The tendency for fatty acids and esters to combine with urea decreases with increasing unsaturation. Combination is favored by lowered temperature. Polyunsaturated acids are concentrated in the final filtrate whereas esters of these acids appear in the final inclusion compound fractions. Fatty acid concentrates have been obtained with iodine values ranging from 294 to 356. Bound esters exhibited iodine values as high as 338. 3. The increased chain length brought about by esterification has a minor role in increasing the yield of inclusion compounds. Likewise, shifting of the terminal polar group in an acid toward the center of the molecule by esterification does not explain the higher yield of inclusion compound from esters. 4. The improved tendency of esterified acids to form urea inclusion compounds is probably due to blocking of association of acid groups. This effect is found in unsaturated acids and in short chain saturated acids. In long chain saturated acids and esters this effect is not noticed. Both give high yields of inclusion compounds because the effect of the carboxyl group is overshadowed by the high energy of formation contributed by the long carbon chain. Taken from a dissertation presented by A. M. Abu-Nasr to the Graduate School of Texas Agricultural and Mechanical College in partial fulfillment for the requirements of the Ph.D. degree, May, 1953. Supported in part by contract N8onr-66218 of the Office of Naval Research. Hormel Institute publication No. 93.     

Untersuchungen über die Entstehung von Kohlenwasserstoffen in UV-bestrahlten Fettsäuren und Fettsäure-Estern

Studies on the Formation of Hydrocarbons in Fatty Acids and Fatty Acid Esters Irradiated with UV Rays The investigation of volatile compounds in unsaponifiable matter and in steam distillates of UV-irradiated saturated fatty acids and fatty acid esters has shown that by irradiation in the presence of air as well as under vacuum, along with other substances, unsaturated hydrocarbons are formed. They are most probably 1,2 alkenes whose chains are shorter than the corresponding fatty acids by 2 C-atoms. The volatile compounds in the unsaponifiable matter of the UV-irradiated oleic acid comprise predominantly of carbonyle compounds.     

Distribution and identification of the fatty acids from the coho salmon,Oncorhynchus kisutch (Walbaum)

To study the fatty acids of the coho salmon, entire fish were homogenized and the total lipids extracted with methanol-chloroform. The fish ranged in size from 75 to 85 mm total length and contained from 2.1%–6.9% lipid in the tissues. Methyl esters of the fatty acids were produced with anhydrous methanol and HCl. Qualitative identification of the fatty acid methyl esters was accomplished by gas-liquid chromatography. Thin layer silver nitrate-silicic acid plates were used to separate the component methyl esters according to the number of double bonds. Location of the ethylenic groups of the unsaturated fatty acid methyl esters was established by reductive ozonolysis and identification of the aldehydes and aldehyde-esters produced. The number of carbons in the unsaturated fatty acid methyl esters was determined by hydrogenation of each of the fractions. Fatty acids found in the highest concentrations were: 16∶0, 16∶1, 18∶0, 18∶1, 18∶4, and 22∶6. Fatty acids 16∶0, 18∶1, 18∶2, 20∶5, and 22∶6, differed markedly from concentrations found in tubificid worms, the exclusive diet of the fish during the experiment. Technical Paper No. 2059, Oregon Agricultural Experiment Station Work supported in part by research Grant No. EF105, U.S.P.H.S.     

Analysis of fatty acid methyl esters with high accuracy and reliability. IV. Fats with fatty acids containing four or more carbon atoms

Those aspects of the quantitative methanolysis of fats with fatty acids containing four or more carbon atoms and the gas liquid chromatographic analysis of the methyl esters which have not been adequately dealt with to date were investigated. Accurate analysis of the esters requires the optimization of the total chromatographic system using a carefully prepared methyl ester primary standard and applying, as the only correction factors, the theoretical flame ionization detector response factors of Ackman and Sipos. These factors now have also been shown to be highly accurate for short chain saturated fatty acid methyl esters, in particular methyl butyrate and methyl caproate. Under the conditions specified by the international methods for the methylation (methanolic KOH) of fats with fatty acids containing four or more carbon atoms, saponification of the esters, once formed, proceeds much more rapidly for short chain than for long chain esters. This problem is easily overcome by neutralizing the catalyst, which then leads to very stable solutions and contributes to column life. This step should be mandatory in the international procedures. Tristearin methylated more slowly than other triacylglycerols under the standard conditions, but there was no difficulty in the case of unsaturated fatty acids of this chain length. Satisfactory results could not be obtained when sodium methoxide was the catalyst. The optimum procedure rendered unnecessary the use of methyl pentanoate as an internal standard for the accurate quantitation of methyl butyrate.     

Empirical relationships between iodine value and polyunsaturated fatty acid content in marine oils and lipids

From data obtained in this laboratory two empirical formulas have been developed which correlate polyunsaturated fatty acids indicated by GLC analyses with iodine values of marine oils or their fatty acid methyl esters. These formulas have been applied to data from the literature with good agreement. It is suggested that these formulas function only with fats having the basic composition of marine lipids, which consist principally of saturated, monounsaturated and very highly unsaturated fatty acids. The presence of modest amounts of dienoic and trienoic fatty acids such as are found in freshwater aquatic life and in land animals makes the formulas inapplicable, suggesting their use to distinguish marine fish oils and lipids from other types. The formulas could be particularly useful in technological applications of marine oils where a rapid and approximate knowledge of amount of polyunsaturated fatty acids is desirable.     

Selektive Härtung mehrfach ungesättigter Fettsäuren in der Flüssigphase

Selective Hydrogenation of Multi-Unsaturated Fatty Acids in the Liquid Phase Fatty acids and esters which contain only one double bond have interesting properties such as high oxidation stability or favourable pour points. For these reasons such products find a broad field of application for instance in the sections cosmetics, textile finishing agents or oilfield chemicals. However, natural fats and oils contain often multi-unsaturated fatty acids such as linoleic and linoleinic acid which are able - even in minor amounts - to change substantially the physical and chemical properties of the fatty material. Therefore, a hydrogenation procedure is needed which enables the selective conversion of multi-unsaturated into mono-unsaturated fatty acids without formation of completely saturated compounds. After a review of the general possibilities in selective hydrogenation a new method is described to hydrogenate with solvent-stabilized palladium colloid catalysts. A remarkable high selectivity was obtained applying very mild reaction conditions. By use of the liquid-liquid two phase technique an easy and complete catalyst recycle is possible.     

Fatty acid compositions of lipids from corn and grain sorghum kernels

Summary Characteristics and fatty acid compositions of the lipid components of the main fractions (germ, starch, gluten, and fiber) obtained in the wet milling of corn and grain sorghum kernels have been determined. The various lipids exhibited differences in chemical characteristics and fatty acid composition. These differences were found to be similar in both grains. Germ fats were the most unsaturated, contained the least free fatty acids and the least unsaponifiable matter. Starch fats were 70 to 90% free fatty acids and contained large amounts of palmitic acid. Gluten and fiber fats contained up to 32% unsaponifiables and about 20% free fatty acids.     

Studies on the fatty acid composition of crayfish lipids

The fatty acid composition of carcass and exoskeleton lipids was determined for the freshwater crayfishOrconectes rusticus. Lipid fractions were isolated by column and thin-layer chromatography. Fatty acid methyl esters and alcohol acetates were then prepared and analyzed by gas-liquid chromatography. Peak identities were established from retention time data for methyl esters, hydrogenated methyl esters, and saturated, monoene, diene, and polyene methyl esters separated as acetoxy-mercuri-methoxy derivatives. Minor component acids were estimated from their relative compositions in these fractions. Presented at the symposium honoring J. B. Brown, AOCS meeting in Chicago, 1964.     

Produkte der Dimerisierung ungesättigter Fettsäuren III: Trennung dimerer Fettsäuren mittels GC und HPLC — Nachweis aliphatischer und verzweigter Dicarbonsäuren

Products of the Dimerisation of Unsaturated Fatty Acids III: Separation of Dimeric Fatty Acids with the Aid of GC and HPLC — Identification of Branched Aliphatic Dicarboxylic Acids From dimers produced by dimerisation of pure oleic acid we obtain by freezing small amounts of compounds, which can be separated further by GC. The separated compounds are isomers with a molecular weight of 594. They are saturated branched aliphatic dicarboxylic acid esters. They are obviously produced by en-reaction followed by hydrogenation. A much more effective separation than by GC is possible by HPLC, using a detector based on light scattering. Thus the dimeric fatty esters can be separated into four fractions: the first fraction consists of aromatics, the second obviously of alicyclic and unsaturated dicarboxylic acids, the third and fourth consist of aliphatic dicarboxylic acid esters of MW 594. Fatty acids obtained by dimerisation of a starting material rich in linoleic acid contain large amounts of aromatic compounds, those which are obtained by dimerisation of starting material rich in oleic acid contain rather high amounts of aliphatic dicarboxylic acids and practically no aromatic compounds.     

Effects of ionizing radiation on some vegetable fats

The volatile compounds produced by irradiation, under vacuum at 6 megarads, in five vegetable fats were analyzed qualitatively and quantitatively by gas chromatography and mass spectrometry. A series of compounds,n-alkanes, 1-alkenes, internally unsaturated alkenes, alkadienes, alkatrienes, alkanals and methyl and ethyl esters of fatty acids, were identified in each of the fats studied. A wide variation occurs in the amounts of the volatiles produced from each fat. The major radiolytic products were few in number and were found to depend largely on the fatty acid composition of the fat. These compounds were essentially the hydrocarbons containing one or two carbon atoms less than the component fatty acids. This relationship was found consistent if radiolytic products of fats with different fatty acid compositions are compared or if the fatty acid composition of the same fat is altered by hydrogenation. The results correlate well with those of earlier studies on simple triglycerides.