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.     

Solvent Crystallization of the Fat and Fatty Acids of Schleichera trijuga Seed

The crystallizations of the kusum oil and the mixed fatty acids thereof were studied from several solvents at various temperatures (+10° C to ?60° C). The results indicate in general that in the range of temperatures studied, petroleum ether as a single solvent is comparable in efficiency to methanol and superior to both acetone and ethanol in respect of separation of the saturated and unsaturated components of the fatty acid mixture. The saturated and unsaturated fractions of the oil also are better separated by petroleum ether than acetone. Further, oleic acid essentially free from linoleic acid is obtainable by a preliminary crystallization of the fatty acid mixture from petroleum ether at ca. ?12° C, followed by two additional crystallizations from acetone at ca. ?55° C.     

Measurement oftrans and other isomeric unsaturated fatty acids in butterand margarine

A procedure is described for gas liquid chromatographic determination of cis andtrans isomers of unsaturated fatty acids after fractionation of the saturated, monenoic, dienoic, and polyenoic fatty acid methyl esters by argentation thin layer chromatography. To test its reliability, the procedure was used for quantitative measurement of transisomers of unsaturated fatty acids in a known mixture of simple triglycerides containing saturated fatty acids from 4:0 to 24:0 andcis andtrans isomers of 14:1. 16:1, 18:1, and 18:2. Results of the analyses of five margarine and five butter samples are presented, together with results of infrared spectrophotometric analyses fortrans fatty acid concentrations, ultraviolet spectrophotometric analyses for conjugated fatty acid concentrations, and enzymatic analyses forcis-cis-methylene interrupted fatty acid concentrations. The combined argentation thin layer and gas Chromatographic procedure is suitable for determination of the principal fatty acids in complex food lipids such as milk fat.     

Untersuchungen zur Beeinflussung des Fettstoffwechsels bei Schweinen nach Gabe von ungeradzahligen Fettsäuren

Investigations on the Influence of Odd-Numbered Fatty Acids on the Lipid Metabolism in Pigs Two groups of piglets (n=3) with life weights of 12.0 ± 1.4 kg were given feedstuff containing different mixtures of odd-numbered fatty acids. For comparison, a control group was given feedstuff of customary lipid composition. At the end of the test period, spinal fat, cardiac lipids, cerebral lipids, muscular lipids and hepatic lipids were analyzed. Contingent on the mixtures of odd-numbered fatty acids given, an enrichment of C18:2 was determined in the organic lipids as well as in the depot fat of the animals. In addition to saturated odd-numbered fatty acids, the corresponding unsaturated acids were also produced. Hence the enzymic system of pigs is capable of desaturating odd-numbered fatty acids. The determined concentrations of n-3 fatty acids were partly higher, partly lower.     

Δ9 desaturase activity in bovine subcutaneous adipose tissue of different fatty acid compositiondesaturase activity in bovine subcutaneous adipose tissue of different fatty acid composition

Two experiments were conducted to investigate the relationship between Δ⁹ desaturase (stearoyl-coenzyme A desaturase) activity and fatty acid composition in subcutaneous adipose tissue from cattle of different backgrounds. In Experiment 1, subcutaneous adipose tissue samples were taken from carcasses of pasture-fed cattle and feedlot cattle fed for 100, 200, or 300 d. Adipose tissue from pasture-fed cattle had significantly lower total saturated fatty acids and higher total unsaturated fatty acids than feedlot cattle. Desaturase activity correspondingly was 60–85% higher in pasture-fed cattle than in feedlot cattle. There was no difference in the fatty acid composition or desaturase activity among samples from the 100-, 200-, and 300-d feedlot cattle. In Experiment 2, adipose tissue samples were collected from carcasses of feedlot cattle fed for 180 d with either a standard feedlot ration (control group), or a ration containing rumen-protected cottonseed oil (CSO) for the last 70–80 d. Adipose tissue from the CSO-fed cattle was more saturated than that from the control group, having significantly more 18∶0 and less 16∶1 and 18∶1. Correspondingly, adipose tissue from the CSO group had significantly lower desaturase activity. The elevated 18∶2 in adipose tissue from the CSO group confirmed that unsaturated fatty acids (including cyclopropenoid fatty acids) were protected from biohydrogenation. Further studies are needed to determine whether the repression of desaturase activity results from direct inhibition by cyclopropenoic acids or by higher dietary contents of 18∶2.     

Ethoxylation of Fatty Acids Fractions of Overused Vegetable Oils

Unsaturated and saturated fatty acids fractions were separated from overused sunflower and olein oils, which are considered to be a waste, in order to use them in the preparation of valuable ethoxylated fatty derivatives with low cost of preparation. Fatty acid fractions were ethoxylated using ethylene oxide gas in the presence of 1% K₂CO₃ catalyst at 120 and 180 °C for 5, 6 and 7 h. Also fresh stearic acid and a fresh mixture of stearic acid:sunflower oil (1:1 wt/wt) were ethoxylated at 180 °C for 6 h for comparison. Results showed that effective fatty derivatives could be obtained from overused oils which may give an economic retrieval. Also, reaction conditions have different effects on the properties of the produced derivatives where the best results were obtained for samples prepared at 180 °C for 6 and 7 h. Ethoxylating the saturated fatty acids fraction of both overused oils especially olein oil gave better results than those of the unsaturated fraction, the ethoxylated fresh stearic acid and the ethoxylated fresh mixture of stearic acid:sunflower oil (1:1 wt/wt).     

Identification of methyl-branched fatty acids from the triacylglycerols of subcutaneous adipose tissue of lambs

A concentrate of branched chain fatty acids (as methyl esters) was prepared from the triacylglycerols of subcutaneous adipose tissue lipids of lambs receiving a carbohydrate-rich (cereal) diet. This was accomplished by procedures which allowed the removal of unsaturated components by peroxidation and straight chain saturated components by urea-adduct formation. The concentrate was analyzed by high resolution gas chromatography in combination with mass spectrometry and was shown to consist of a complex mixture of saturated methyl-substituted fatty acids. Methyl substitution occurred on even-numbered carbon atoms (relative to the carboxyl group) and the chain lengths of the acids ranged from 10 to 18 carbon atoms. Acids with one methyl substituent in the fatty acyl chain were most abundant; di-, tri- and tetramethyl-substituted acids were also present. The biosynthesis of these methyl-substituted acids is discussed briefly.     

Effect of vacuum‐packaging on the changes of Russian sturgeon muscle lipids during frozen storage

The changes in fatty acid composition, non‐polar (triglycerols) and polar lipids (phospholipids), total free fatty acids and total cholesterol of Russian sturgeon (Acipenser gueldenstaedtii) were studied during 360 days of storage at ?18°C. It was established that total neutral lipids and phospholipids content decreased and total free fatty acids concentration increased significantly during the frozen storage. Lower non‐polar and polar lipids content and higher free fatty acids concentration of vacuum‐packaged samples in comparison with air‐packaged samples were found. The changes in total cholesterol concentration and phospholipid classes of frozen stored sturgeon were not influenced by the frozen storage period and the type of packaging. It was established that the sturgeon polar lipids consisted mainly of phosphatidylcholine – 54.98 ± 0.85%, phosphatidylethanolamine – 28.42 ± 0.61%, and phosphatidylserine – 8.64 ± 0.45%. The increase of the total free fatty acids concentration was associated with the free n ? 3 PUFA accumulation as a result of hydrolysis of non‐polar and polar lipids. During the frozen storage DHA percentage of non‐polar lipids and phospholipids decreased approximately 3 and 1.75%, respectively. After 360 days of storage at ?18°C the n ? 3/n ? 6 PUFA ratio of total lipids decreased 4.9%.     

Zur Umweltvariabilität der Fettsäure-Zusammensetzung von Galaktolipiden in Rapsblättern

The Variability of the Fatty Acid Composition of Galactolipids from Leaves of Oil-Seed Rape as Affected by Environmental Factors The influences of light (500 Lux, 20 000 Lux), temperature (5°C, 15°C, 25°C) and nitrogen-nutrition (2 mval N, 4 mval N, 16 mval N) treatments on the fatty acid composition of galactolipids from old and young leaves of oil-seed rape (Brassica napus) were tested. The linolenic acid (18:3) content of lipids from young leaves mainly was effected by light and temperature. However, older leaves principally reacted on light and nitrogen-nutrition. With young leaves a significant light/temperature interaction was obvious. The highest level of linolenic acid (72%) was observed at 5°C/500 Lux. In relation to older leaves the changes in the fatty acid composition pointed at a retarded senescence by an increased nitrogen supply. The 16 mval N/20 000 Lux treatment resulted in the highest percentages of unsaturated fatty acids. In lipids from young leaves linolenic and hexadecatrienoic (16:3) acids increased together. In older leaves, however, the high level of linolenic acid caused by increased nitrogen-nutrition was accompanied by a decrease of hexadecatrienoic acid.     

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.     

Characterization of Free and Bound Lipids among Four Corn Genotypes as Affected by Drying and Storage Temperatures

For whole grains, the most sensitive components to the environmental changes are the lipids. In the current study, the effects of drying temperature (27 and 93 °C) and storage temperature (4 and 27 °C) on the fatty acid (FA) levels and lipid classes of endosperm lipids on four selected corn genotypes were investigated during a 12-month storage period. Storage temperature indicated greater impact on the FA composition than did the drying temperature. The ratio of saturated to unsaturated fatty acids, which was around 0.20–0.22 levels in the free lipid (FL) fractions of all corn types studied here, did not change significantly due to the drying and storage temperatures. However, in the bound lipid (BL) fractions, it was changed by a change in the drying and storage temperature in some of the corn types. Some changes were also found in the lipid classes within the FL and BL fractions of the studied corn samples. No lysophosphatidylcholine (LPC) was found in the FL fractions. In the BL fractions of two of the corn samples, the level of free fatty acids (FFA) increased more likely due to the deterioration of LPC. The results of the current study indicated a possible migration of triglycerides and FFA between the FL and BL fractions due to drying and storage at higher temperatures.     

Effects of lipid oxidation on fish lipids — amylopectin interactions

The results of studies on fish lipid oxidation effects on lipid‐amylopectin starch interactions are presented. Particular attention is paid to fish lipid availability (extractability from the system) and fatty acid contributions to individual lipid groups after mixing‐provoked interaction and after a 30‐day storage at —18 °C. The study involved model systems containing fish lipids at different levels of oxidation, lipids containing an antioxidant (BHA), and gelatinised amylopectin starch in a 10% aqueous solution. The lipid to starch ratio was 1:1. The test systems were subjected to selective extraction. The extracts were assayed for lipid content, peroxide value, anisidine value, fluorescence, and fatty acid composition. Compared to fresh fish lipids, those lipids, which were oxidised to a higher extent were shown to be more amenable to complexing with amylopectin, but they were also more readily released during frozen storage. On the other hand, addition of BHA stabilised the lipid‐amylopectin starch interaction during storage at —18 °C. In the entire systems tested, polyunsaturated fatty acids, eicosapentaenoic and docosahexaenoic acids in particular, proved to be most susceptible to binding, up to 90% of the latter being complexed.     

Isolation and Evaluation of Stearin and Olein Fractions from Rice Bran Oil Fatty Acid Distillate by Detergent Fractionation and Conversion into Neutral Glycerides by Autocatalytic Esterification Reaction

Detergent fractionation (Lanza process) offers a valuable separation process for edible oils that contain varying amounts of saturated and unsaturated fatty acids. The rice bran oil fatty acid distillate (RBOFAD), obtained as a major byproduct of rice bran oil deacidification refining process, was fractionated by detergent solution into a fatty acid mixture as follows: low-melting (19.00 °C) fraction of fatty acids as olein fraction (44.50 g/100 g) and high-melting (49.00 °C) fatty acids as stearin fraction (37.15 g/100 g). A high amount of palmitic acid (42.75 wt%) is present in stearin fraction, while oleic acid is higher (48.21 wt%) in the olein fraction. The stearin and olein fractions of RBOFAD with very high content of free fatty acids are converted into neutral glycerides by autocatalytic esterification reaction with a theoretical amount of glycerol at high temperatures (130–230 °C) and at a reduced pressure (30 mmHg). Acid value, peroxide value, saponification value, and unsaponifiable matters are important analytical parameters to identity for quality assurance. These neutral glyceride-rich stearin and olein fractions, along with unsaponifiable matters, can be used as nutritionally and functionally superior quality food ingredients in margarine and in baked goods as shortenings.     

Studies on characterization and variation in triglyceride fatty acids from punt/us sarana body lipids

Body lipids of P. sarana of four different sizes were fractionated into phospholipids, neutral lipids, nonsaponifiables, total fatty acids, polyunsaturated, monounsaturated and saturated fatty acid fractions. Percentage composition of each fraction was determined. The triglyceride fatty acids were identified by thin layer and gas liquid chromatography. C₈ to C₂₃ fatty acids including both odd numbered and branched chain acids were detected. The major constituents were C₁₄, C₁₅, C₁₆, C_16:1, C₁₈ C_18:1, C_18:2, C_18:3; forty-three other acids were detected in lower proportions. Composition of each fatty acids and their variation with size have been discussed.tP. sarana body lipids in general showed a behavior typical of fresh water fish by having a higher percentage of saturated C₁₆ and unsaturated C₁₈ acids and a lower percentage of unsaturated C₂₀ acid.     

Enzymatic interesterification of lard and high-oleic sunflower oil with Candida antarctica lipase to produce plastic fats

Lard and high-oleic sunflower oil (Trisun® Extra) were interesterified at 55°C for 24 h with SP435 lipase from Candida antarctica to produce plastic fats. As the amount of trisun increased, percentage free fatty acid, unsaturated fatty acid/saturated fatty acid value, oxidizability, and the amount of 18:1 found at the sn-2 position of triglyceride products increased. Differential scanning calorimetry showed that the low-melting components in the product contained more 18:1 than the high-melting components. A 60:40 (w/w) ratio of lard to trisun had the widest plastic range (3–26°C). The scaled-up reaction to produce this blend resulted in a product that had 60.1% 18:1 at the sn-2 position compared to 44.9% for the physical blend. The solid fat content of the 60:40 interesterified mixture resembled soft-type margarine oil.     

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.     

Headspace Volatile Oxylipins of Eastern Himalayan Moss Cyathophorella adiantum Extracted by Sample Enrichment Probe

Cyathophorella adiantum (Griff.) M. Fleisch. (Division-Bryophyta, Family-Daltoniaceae), an Eastern Himalayan moss was studied for the first time to identify the volatiles derived from cellular and membrane bound fatty acids. A high capacity sample enrichment probe (SEP) was used for extraction of headspace volatile (HSV) molecules followed by GC–MS analysis. Different short-chain oxylipins like alkenes, alkanes, saturated and unsaturated alcohols, saturated and unsaturated aldehydes, ketones were identified along with free and esterified fatty acids, cyclo compounds and some by-products of secondary metabolites. Fatty acid analysis of neutral lipids (NL) and phospholipids (PL) of this plant exhibits the predominance of C16 and C18 fatty acids. It also reveals some interesting information that might indicate the possible fatty acid precursors for volatile generation and their sources in this plant.     

Different metabolism of saturated and unsaturated long chain plasma free fatty acids by intestinal mucosa of rats

During fat absorption, unsaturated long chain fatty acids are esterified at a higher rate than saturated fatty acids of similar chain length. This phenomenon has been attributed to differences in the binding affinity of fatty acids to a cytosolic fatty acid-binding protein. As intestinal mucosa utilizes plasma free fatty acids as well, we investigated whether long chainplasma free fatty acids of different degree of saturation are metabolized also at different rates.³H-Palmitic and¹⁴C-linoleic acid complexed to rat serum were injected rapidly into a tail vein of fasting rats. One, 2 and 4 min later there was no difference between³H and¹⁴C-radioactivity in intestinal mucosa, suggesting equal initial uptake of the two labeled fatty acids from plasma. Despite their equal uptake, the incorporation of the isotopes into ester lipids was significantly different, however: at 2 min, 53.1±3.9% of³H and 73.8±4.6% of¹⁴C were recovered in ester lipids. Phospholipids and triglycerides accounted for most of the mucosal³H and¹⁴C. At 4 min, a similar distribution of isotopes in intestinal mucosal metabolites was found. These data show that despite equal initial uptake by intestinal mucosa unsaturated long chain fatty acids taken up from plasma are esterified to a higher and oxidized to a lower extent than saturated plasma free fatty acids. Unsaturated plasma free fatty acids, therefore, may provide a more important source of fatty acids for endogenous intestinal lipoprotein lipids than saturated plasma free fatty acids. It is speculated that the fatty acid binding protein might be operative not only in the intracellular transport and metabolism of luminal fatty acids but of plasma free fatty acids as well.     

Lipids of Haliphthoros philippinensis: An oomycetous marine microbe

Lipids of the marine oomycetous microbe Haliphthoros philippinensis were characterized by chromatographic and spectroscopic techniques. Total lipid content of this organism was relatively low and not very responsive to manipulation of the culture conditions. Neutral lipid comprised 21% of the total lipid and the polar lipids were mainly phosphatidylcholine (44%), phosphatidylethanolamine (15%), and a ceramide-phosphorylethanolamine (19%). Palmitic (16:0) was the primary saturated fatty acid at 25% of the total fatty acids, and arachidonic acid (20:4n-6, ARA) and eicosapentaenoic acid (20:5n-3, EPA) were the major unsaturated fatty acids at 19 and 21%, respectively. Fucosterol was the principal sterol at 59% of the total sterols. The effects of several cultivation variables on growth and EPA production by this species were investigated. Among those tested, glucose and sodium glutamate were the most efficient carbon and nitrogen sources for growth, respectively. When the mycelium was cultivated for 6 d to produce biomass under optimal growth conditions, and then transferred to low temperature for an additional 13 d without glucose, the EPA content reached 31% of the total fatty acids and the yield was 203 mg/L. When the same experiment was performed with glucose supplementation during the low-temperature phase, EPA composed 27% of total fatty acids and yield reached 316 mg/L, or a 285% increase over that from mycelium cultured for 6 d at 24°C, and 56% over that cultured at 16°C for 13 d. ARA production did not respond accordingly.     

Origin of the high saturated fatty acid content of rat fecal lipids

The biohydrogenation of unsaturated fatty acids and the preferential absorption of unsaturated fatty acids over long chain saturated fatty acids from the gut have been investigated to find the origin of the high saturated fatty acid content of the facal lipids of rats fed soybean oil. Label from dietary (1-¹⁴C)-linoleic acid was recovered in the saturated and monounsaturated fatty acids of the fecal lipid. However, when (9,10-³H)-stearic acid and (1-¹⁴C)-linoleic acid were fed together, the isotope ratio (³H/¹⁴C) of the fecal lipid was 1.9 times that of the diet. It is concluded that both processes occur.