Comparison of Free Fatty Acids Composition of Cuticular Lipids of <Emphasis Type="Italic">Calliphora vicina</Emphasis> Larvae and Pupae

The chemical characterization of the free fatty acid (FFA) fractions of the cuticular lipids of Calliphora vicina larvae and pupae was performed by separating the FFA fraction using high-performance liquid chromatography with laser light scattering detection (HPLC–LLSD) and quantitatively analyzing the FFA using gas chromatography–electron impact mass spectrometry (GC–MS). Thirty-two saturated and unsaturated FFA were identified and quantified in the insect lipids. Cuticular FFA profiles of C. vicina larvae and pupae were compared. Cuticular FFA of larvae and pupae accounted for 70.8 and 77.8 % of the total lipids, respectively. The cuticular lipids of C. vicina larvae contained 24 FFA ranging from 8:0 to 24:0, whereas the cuticular lipids of pupae contained 32 FFA ranging from 6:0 to 26:0. The cuticular lipids of the larvae contained 16 saturated, five monounsaturated, one diunsaturated, and two polyunsaturated FFA. The cuticular lipids of the pupae contained 18 saturated, nine monounsaturated, two diunsaturated, and three polyunsaturated FFA. The major cuticular FFA in C. vicina larvae and pupae was 18:1 (47.6 and 41.7 %, respectively). The highest amounts of total cuticular FFA were detected in larvae of C. vicina (1.7 mg/g of the insect body). The quantities of total cuticular FFA in pupae were smaller (1.4 mg/g of the insect body).     

Total,polar and neutral lipids ofRhizopus arrhizus fischer

The changes in total lipid content, neutral and polar lipids, total fatty acids, and free fatty acids were investigated over a 4 day period in the zygomycete,Rhizopus arrhizus Fischer. The highest concentration of lipids occurred at the 72 hr period. The degree of unsaturation in the total fatty acid fraction increased during the growth period, whereas the degree of unsaturation decreased in the free fatty acid fraction during the same time period. The ratios of neutral to polar lipids over the 4 day period were: 0.75, 0.22, 1.94 and 0.94. The major components of polar lipids were phosphatidyl ethanolamine, lecithin, lysolecithin, and fatty acids. The fatty acids in the mono- and diglycerides were predominately saturated (67–96%). The fatty acids in the triglycerides shifted from a predominately unaturated (69%, 24 hr) to a more saturated pattern (62%, 96 hr).     

Characteristics and composition of libyan olive oil

Chemical and physical characteristics of local olive oil (both virgin and refined) were determined. The moisture levels in olive fruit, cake and oils were 11.77, 12.7 and 0.16% respectively. The total crude fat on dry basis was: fruit, 39%; and cake, 7%. The free fatty acids (FFA) in both virgin and refined oils were high (4.4 and 4.3%). The samples of virgin as well as refined oil were found to have relatively low oleic acid contents (43.7 and 46.4%). However, linoleic acid was found to be higher than expected and the total of oleic and linoleic acids was more than 75% in the fraction of neutral lipids. The total saturated and unsaturated fatty acids in olive oil samples was ca. 20 and 80%, respectively.     

Cholesterol,Lipid Content,and Fatty Acid Composition of Different Tissues of Farmed Cobia (<Emphasis Type="Italic">Rachycentron canadum</Emphasis>) from China

Marine fishes are rich in n-3 polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are extremely important for human health. The objective of our work was to determine the content and composition of lipids and fatty acids in the different tissues of cobia from China and to evaluate their nutritional value. The results showed that cobia from China was rich in lipids; the neutral lipid content was above 82%; the content of cholesterol and phospholipid was low. Eighteen fatty acids were identified. Myristic (C14:0), palmitic (C16:0), and stearic acids (C18:0) were the main saturated acids; palmitoleic (C16:1n-7) and oleic acid (C18:1n-9) were the main monounsaturated fatty acids. EPA and DHA were the main PUFA; n-3 and n-6 PUFA were present as 12–18% and 2.6–3.2% of the total fatty acids, respectively. The n-6/n-3 ratio was in the range from 0.18 to 0.22, which was far lower than that (5:1) recommended by WHO/FAO. Therefore, cobia lipids from China have a high nutritional value.     

Characterization of Oil Precipitate and Oil Extracted from Condensed Corn Distillers Solubles

Oil extracted from condensed corn distillers solubles (CCDS) can form a semi-solid and waxy precipitate at the bottom of containers during storage. CCDS is a good source to recover oil, and such oil can be converted to biodiesel. Precipitate formation in the extracted oil is mainly a physical stability problem, but it may become a performance problem for biodiesel. The objective of the present work was to determine the composition of the CCDS oil precipitate and also determine if valuable phytosterols were present in high concentration. The free fatty acid (FFA) content was very high, 35.7%, and fatty acid composition of the FFA fraction was predominantly palmitic acid, 70.3%. The solid appearance was mainly due to a high percentage of high-melting point free saturated fatty acid. The total unsaponifiable matter was 2.0%, and total phytosterol content was 8.6 mg/g of CCDS oil precipitate. Therefore, CCDS oil precipitate is a not an enriched source of phytosterols compared to total sterols present in crude corn oil (15.6 mg/g oil). The wax content was high, 2.5 mg/g of CCDS oil precipitate compared to 0.5 mg/g of crude corn oil. CCDS oil that is uncentrifugable but polar solvent extractable (trapped oil fraction) was also characterized and found to contain more polar lipids than those in the free oil fraction (centrifugable oil).     

Monitoring of Fat Content,Free Fatty Acid and Fatty Acid Profile Including <Emphasis Type="Italic">trans</Emphasis> Fat in Pakistani Biscuits

The fat contents of 12 brands of biscuits were extracted and evaluated for free fatty acids (FFA) and their fatty acid composition (FAC). The oil content and FFA varied from 13.7 to 27.6% and 0.2 to 1.0%, respectively. The FAC was analyzed by gas chromatography–mass spectroscopy with particular emphasis on trans fatty acids (TFA). Total saturated, unsaturated, cis-monounsaturated and polyunsaturated fatty acids were determined in the range of 37.9–46.9, 53.0–62.0, 12.3–43.7 and 0.1–9.2%, respectively. The high amount of TFA was observed in all biscuit samples and varied from 9.3 to 34.9%. The quantity and quality of the lipid fraction of the biscuits indicated that the all analyzed biscuits are a rich source of fat, saturated fatty acids and trans fatty acids, consequently not suitable for the health of consumers. The high content of trans fatty acids and palmitic acid also indicated that blends of RBD palm oil and partially hydrogenated oil had been used in the biscuit manufacturing.     

Lipid components of borage (Borago officinalis L.) seeds and their changes during germination

The changes in composition of total and neutral lipids (NL) as well as glycolipids (GL) and phospholipids (PL) of borage (Borago officinalis L.) seeds, germinated in the dark at 25^°C for 10 d, were studied. Total lipids constituted 34.0% of the dry matter of borage seeds. During germination, the content of total lipids was decreased by 95%. NL accounted for 95.7% of total lipids prior to germination and were composed of triacylglycerols (TAG; 99.1%), diacylglycerols (DAG; 0.06%), monoacylglycerols (MAG;0.02%), free fatty acids (FFA;0.91%), and sterols (0.02%). The content of TAG was significantly (P≤0.05) decreased, while that of other components, such as MAG and FFA, significantly (P≤0.05) increased during germination. However, the content of DAG did not change. GL and PL accounted for 2.0 and 2.3% of total lipids, respectively, and their contents significantly (P≤0.05) increased as germination proceeded. The thin layer chromatography-flame-ionization detection studies showed that phosphatidylcholine (PC; 69.7%) was the major PL present. The total content of phosphatidylserine (PS) and phosphatidylethanolamine (PE), which were coeluted, was 18.2%; phosphatidic acid (PA) was present at 11.2% of the total PL fraction. Lysophosphatidylcholine was detected at 0.9%. The proportion of PC, PS, and PE significantly (P≤0.05) decreased during germination, but that of PA increased (P≤0.05) markedly. The fatty acid composition of lipid fractions changed as germination proceeded. The predominant fatty acids of total lipids, NL, and GL were linoleic and linolenic acids, while those of PL were linoleic and palmitic acids. The present study demonstrated that the overall changes of lipids seen in borage seeds during germination agree well with results for other oilseeds. Changes in lipid compositions during germination result from the formation of tissues and metabolic interconversion of lipid classes. Rapid changes in lipid composition during seed germination may enhance the nutritional value of the sprouts.     

Lipid Content and Fatty Acid Composition of 15 Marine Fish Species from the Southeast Coast of Brazil

Lipid content and fatty acid composition were determined in edible meat of fifteen marine fish species caught on the Southeast Brazilian coast and two from East Antarctic. Most of the fish had lipid amounts lower than 10% of their total weight. Palmitic acid (C16:0) predominated, accounting for 54–63% of the total amount of saturated fatty acids. Oleic acid (C18:1n-9) was the most abundant (49–69%) monounsaturated fatty acid, and docosahexaenoic acid (DHA) was the predominant polyunsaturated fatty acid (PUFA), accounting for 31–84% of n-3 PUFA. n-3 PUFA level were highest in Antarctic fish meat, comprising 45% of the total fatty acid content, which consisted of mainly EPA (16.1 ± 1.5 g/100 g lipids) and DHA (24.8 ± 2.4 g/100 g lipids). The amounts of EPA + DHA in g/100 g of lipids on the Southeast Brazilian coast and Antarctic fish species investigated were found to be similar: 42.0 ± 1.7 for Bonito cachorro, 41.0 ± 2.3 for Atum, and 39.4 ± 1.8 for peixe porco, respectively. All the studied species exhibited an n-3/n-6 ratio higher than 3, which confirms the great importance of Southeast Brazilian coast fish as a significant dietary source of n-3 PUFA.     

Enzymatic enrichment of arachidonic acid from Mortierella single-cell oil

An attempt was made to enrich arachidonic acid (AA) from Mortierella single-cell oil, which had an AA content of 25%. The first step involved the hydrolysis of the oil with Pseudomonas sp. lipase. A mixture of 2.5 g oil, 2.5 g water, and 4000 units (U) Pseudomonas lipase was incubated at 40°C for 40 h with stirring at 500 rpm. The hydrolysis was 90% complete after 40 h, and the resulting free fatty acids (FFA) were extracted with n-hexane (AA content, 25%; recovery of AA, 91%). The second step involved the selective esterification of the fatty acids with lauryl alcohol and Candida rugosa lipase. A mixture of 3.5 g fatty acids/lauryl alcohol (1:1, mol/mol), 1.5 g water, and 1000 U Candida lipase was incubated at 30°C for 16 h with stirring at 500 rpm. Under these conditions, 55% of the fatty acids were esterified, and the AA content in the FFA fraction was raised to 51% with a 92% yield. The long-chain saturated fatty acids in the FFA fraction were eliminated as urea adducts. This procedure raised the AA content to 63%. To further elevate the AA content, the fatty acids were esterified again in the same manner with Candida lipase. The repeated esterification raised the AA content to 75% with a recovery of 71% of its initial content.     

Fatty acid compositions of lipid fractions from vegetative cells and mature sorocarps of the cellular slime moldDictyostelium discoideum

A wild-type strain ofDictyostelium discoideum was grown uponAerobacter aerogenes. Fatty acid compositions of lipid fractions and of total lipids obtained from vegetative amoebae and mature sorocarps were compared. Fatty acids isolated from vegetative cells were found to include large quantities of 17- and 19-carbon cyclopropane fatty acids while straight-chain, saturated fatty acids represented only 10% (w/w) of total fatty acids. These cyclopropane fatty acids appear to be derived from ingested bacteria and are preferentially incorporated into neutral lipids of the slime mold. Development of amoebae to mature sorocarps is accompanied by a substantial decrease in cyclopropane fatty acid content and a concomitant increase in unsaturated fatty acids, mostly as octadeca-5,11-dienoic acid. The †-22 stigmastenyl ester fraction is the richest source of this acid. Fully 65% of the fatty acids in this fraction are the octadecadienoate.     

Enzymatic enrichment of arachidonic acid from Mortierella single-cell oil

An attempt was made to enrich arachidonic acid (AA) from Mortierella single-cell oil, which had an AA content of 25%. The first step involved the hydrolysis of the oil with Pseudomonas sp. lipase. A mixture of 2.5 g oil, 2.5 g water, and 4000 units (U) Pseudomonas lipase was incubated at 40°C for 40 h with stirring at 500 rpm. The hydrolysis was 90% complete after 40 h, and the resulting free fatty acids (FFA) were extracted with n-hexane (AA content, 25%; recovery of AA, 91%). The second step involved the selective esterification of the fatty acids with lauryl alcohol and Candida rugosa lipase. A mixture of 3.5 g fatty acids/lauryl alcohol (1:1, mol/mol), 1.5 g water, and 1000 U Candida lipase was incubated at 30°C for 16 h with stirring at 500 rpm. Under these conditions, 55% of the fatty acids were esterified, and the AA content in the FFA fraction was raised to 51% with a 92% yield. The long-chain saturated fatty acids in the FFA fraction were eliminated as urea adducts. This procedure raised the AA content to 63%. To further elevate the AA content, the fatty acids were esterified again in the same manner with Candida lipase. The repeated esterification raised the AA content to 75% with a recovery of 71% of its initial content.     

Isolation of tocopherol and sterol concentrate from sunflower oil deodorizer distillate

The isolation of tocopherols and sterols together as a concentrate from sunflower oil deodorizer distillate was investigated. The sunflower oil deodorizer distillate was composed of 24.9% unsaponifiable matter with 4.8% tocopherols and 9.7% sterols, 28.8% free fatty acid (FFA) and 46.3% neutral glycerides. The isolation technology included process steps such as biohydrolysis, bioesterification and fractional distillation. The neutral glycerides of the deodorizer distillates were hydrolyzed byCandida cylindracea lipase. The total fatty acids (initial FFA plus FFA from neutral glycerides) were converted into butyl esters withMucor miehei lipase. The esterified product was then fractionally distilled in a Claisen-vigreux flask. The first fraction, which was collected at 180–230°C at 1.00 mm of Hg for 45 min, contained mainly butyl esters, hydrocarbons, oxidized products and some amount of free fatty acids. The fraction collected at 230–260°C at 1.00 mm Hg for 15 min was rich in tocopherols (about 30%) and sterols (about 36%). The overall recovery of tocopherols and sterols after hydrolysis, esterification and distillation were around 70% and 42%, respectively, of the original content in sunflower oil deodorizer distillate.     

The distribution of lipids in the germ,endosperm, pericarp and tip cap of amylomaize,LG-11 hybrid maize and waxy maize

The quantitative distribution of 23 acyl lipid classes and unsaponifiable matter in kernels of amylomaize, LG-11 hybrid maize and waxy maize is described. LG-11 and waxy maize were normal (oil content) varieties, containing 4.9% and 5.1% lipid, respectively, while amylomaize (9.3% lipid) was a high oil variety. The distribution of kernel lipids was 76–83% in germ, 1–2% in pericarp, 1% in tip cap, 1–11% in starch, and 13–15% in aleurone plus the nonstarch fraction of the starchy endosperm. Germ contained 39–47% lipid, which was nostly triglyceride (TG), with some steryl esters (SE) and diglycerides (DG), and small amounts of glycolipids (GL) and phospholipids (PL). Aleurone lipids appeared to be TG with some free fatty acids (FFA) and SE. The other nonstarch lipids in starchy endosperm were FFA with very small amounts of SE, DG, GL and PL. The starches had a little surface lipid (FFA) and true (internal) starch lipid (FFA, lyso-PL) in quantities roughly related to amylose content (amylomaize =ca. 73% amylose, 1.0% lipid; LG-11=23% amylose, 0.7% lipid; waxy maize =<5% amylose, 0.2% lipid). Pericarp lipids (0.8–2.5%) were mainly unsaponifiable matter, the acyl lipids being TG, SE, DG and FFA. Tip cap lipids (2.5–2.9%) had more TG, GL and PL than pericarp lipids, but were otherwise similar. Pericarp lipids and endosperm nonstarch lipids appeared to have suffered extensive degradation at some time during kernel development or after harvesting, while lipids in starch, germ and tip cap were evidently unaffected. FFA and lyso-PL are regarded as normal components of maize starch (rather than degradation products) and may occur as amylose inclusion complexes.     

Isolation of erucic acid from rapeseed oil by lipase-catalyzed hydrolysis

Three lipases were compared for their ability to hydrolyze high erucic acid rapeseed oil, with the objective of concentrating the erucic acid in a single glyceride fraction. Lipase fromPseudomonas cepacia released all fatty acids rapidly and did not result in selective distribution of erucic acid.Geotrichum candidum lipase released C20 and C22 fatty acids extremely slowly, resulting in their accumulation in the di- and triglyceride fractions. Less than 2% of the total erucic acid was found in the free fatty acid (FFA) fraction. Lipase fromCandida rugosa released erucic acid more slowly than C20 and C18 fatty acids at 35°C but only resulted in a limited accumulation of the erucic acid in the di- and triglyceride fractions. However, when hydrolysis catalyzed byC. rugosa lipase was carried out below 20°C, the reaction mixture solidified and was composed solely of FFAs and diglycerides. The diglyceride fraction contained approximately 95% erucic acid while about 20% of the total erucic acid was found in the FFA fraction. It is concluded that hydrolysis at low temperature withC. rugosa lipase results in a higher purity of erucic acid in the glyceride fraction than can be obtained withG. candidum lipase, but with considerable loss of erucic acid to the FFA fraction.     

Variation in fatty acid composition of the different acyl lipids in seed oils from fourSesamum species

Seeds from different collections of cultivatedSesamum indicum Linn. and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum and Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil content and fatty acid composition of the total lipids. The wild seeds contained less oil (ca. 30%) than the cultivated seeds (ca. 50%). Lipids from all four species were comparable in their total fatty acid composition, with palmitic (8.2–12.7%), stearic (5.6–9.1%), oleic (33.4–46.9%) and linoleic acid (33.2–48.4%) as the major acids. The total lipids from selected samples were fractionated by thin-layer chromatography into five fractions: triacylglycerols (TAG; 80.3–88.9%), diacylglycerols (DAG; 6.5–10.4%), free fatty acids (FFA; 1.2–5.1%), polar lipids (PL; 2.3–3.5%) and steryl esters (SE; 0.3–0.6%). Compared to the TAG, the four other fractions (viz, DAG, FFA, PL and SE) were generally characterized by higher percentages of saturated acids, notably palmitic and stearic acids, and lower percentages of linoleic and oleic acids in all species. Slightly higher percentages of long-chain fatty acids (20∶0, 20∶1, 22∶0 and 24∶0) were observed for lipid classes other than TAG in all four species. Based on the fatty acid composition of the total lipids and of the different acyl lipid classes, it seems thatS. radiatum andS. angustifolium are more related to each other than they are to the other two species.     

Brain mitochondrial incorporation of elongated fatty acids into phospholipids

The characteristics patterns and asymmetric distribution of phospholipid fatty acids suggest precise control mechanisms. Our investigations were designed to assess mitochondrial fatty acid elongation and their pattern of incorporation into complex lipids. Fatty acid chain elongation in the total lipid fraction occurred primarily with the more abundant fatty acids present. Elongation patterns in free fatty acids were similar to the total lipid fraction except C_20:4 and C_22:4 were formed to slightly greater extent. Choline glycerophosphatide and ethanolamine glycerophosphatide displayed different patterns of elongation. Choline glycerophosphatide contained more elongated longer chain polyunsaturated fatty acids, while ethanolamine glycerophosphatide contained greater amounts of elongated shorter chain saturated and monounsaturated fatty acids. These results suggest that fatty acid elongation may play a specific role in fulfilling mitochondrial phospholipid fatty acid requirements.     

Lipid metabolism in germinating flaxseed

Flaxseed was germinated in the dark at 25C for 90 hr and the amt of triglycerides, free fatty acids (FFA) and phospholipids, as well as the fatty acid composition of each, were determined at 18-hr intervals. The amt of FFA increased greatly during germination. There was no preferential metabolism of any particular fatty acid in either the triglyceride or FFA fractions. The percentage of linolenic acid in the phospholipids increased as germination progressed. Behenic, lignoceric and cerotic acids were observed in the FFA fraction after 54 hr of germination. Odd-numbered saturated and unsaturated acids, indicative of ana-oxidation mechanism, were observed in the FFA fraction at 54 hr and in the triglyceride fraction at 72 hr. Cooperative investigations of the Dept. of Agricultural Biochemistry, North Dakota State University. Fargo, and Crops Research Div., ARS, USDA. Published by permission of the Director, North Dakota Agricultural Experiment Station. Journal No. 54. Crops Research Div., ARS, USDA. This paper is taken in part from the dissertation for the degree of Doctor of Philosophy of D.C.Z., 1964.     

Characteristics of Oil from Hulless Barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) Bran from Tibet

The bran of hulless barley (Hordeum vulgare L.) from Tibet was investigated. This paper reports on the physicochemical characteristics, lipid classes and fatty acids of the oil from the bran. The petroleum (60–90 °C) extract of hulless barley bran was found to be 8.1%. The investigated physiochemical parameters included density at 40 °C (0.96 g/cm³), refractive index at 40 °C (1.41), melting point (30.12 °C), acid value (11.6 mg KOH/g), peroxide value (19.41 μg/g), saponification value (337.62 mg KOH/g), iodine value (113.51 mg iodine/g) and unsaponifiable matter (4.5% of total lipids).The amount of neutral lipids in the crude oil was the highest (94.55% of total lipids), followed by glycolipids (4.20% of the total lipid) and phospholipids (1.25% of the total lipid). Linoleic acid (75.08% of total fatty acids) followed by palmitic acid (20.58% of total fatty acids), were the two major fatty acids in the oil. The results show that the oil from the hulless barley bran could be a good source of valuable essential fatty acids.     

<Superscript>1</Superscript>H- and <Superscript>13</Superscript>C-NMR Characterization of the Molecular Components of the Lipid Fraction of Pecorino Sardo Cheese

In this work the molecular fatty components of Pecorino Sardo Protected Designation of Origin (PS PDO) cheese were characterized through an exhaustive investigation of the ¹H- and ¹³C-NMR spectra of the extracted lipids. Several fatty acids (FA), such as long chain saturated, oleic, linoleic, linolenic, butyric, capric, caprylic, caproic, trans vaccenic, conjugated linoleic acid (cis9, trans11–18:2), and caproleic (9–10:1) were unambiguously detected. The positional isomery of some acyl groups in the glycerol backbone of triacylglycerols (TAG) was assessed. Furthermore, the NMR signals belonging to sn-1,2/2,3, sn-1,3 diacylglycerols (DAG), and free fatty acids (FFA) were analysed as a measure of lipolytic processes on cheese. Lastly, ¹H-NMR resonances of saturated aldehydes and hydroperoxides were detected, their very low intensity indicating that the lipid oxidation process can be considered to be of minor relevance in Pecorino Sardo cheese.     

Phospholipid Composition of <Emphasis Type="Italic">Jatropha curcus</Emphasis> Seed Lipids

Jatropha curcus L. oil has emerged as one of the most important raw materials for biodiesel production. However, no detailed study has been reported on characterizing the lipid constituents of jatropha oil. The present study revealed that the total oil content of jatropha seeds was 32% with a composition of 97.6% neutral lipids, 0.95% glycolipids and 1.45% phospholipids. The fatty acid composition of total lipids, neutral lipids, phospholipids and glycolipids was also determined and found to contain oleic acid (18:1) and linoleic acids (18:2) as major fatty acids. The phospholipids fraction was further characterized and quantified and found to contain phosphatidyl choline (PC) 60.5%, phosphatidyl inositol (PI) 24% and phosphatidyl ethanolamine (PE) 15.5%. The fatty acid composition and the positional distribution of the fatty acids of individual phospholipids were also reported.