Major Monounsaturated Fatty Acids Research Articles

Hepatic Stearoyl‐CoA Desaturase deficiency suppresses gluconeogenesis by regulating lipid profile of mitochondria

Obesity plays a central role in the metabolic syndrome, which includes hyperinsulinemia, hypertension, hyperlipidemia and an increased risk of atherosclerotic cardiovascular disease. A common health complication observed in obese patients is insulin resistance, a condition in which increased insulin levels are required to maintain normal blood glucose levels. Without proper intervention, the condition often deteriorates into type 2 diabetes mellitus, characterized by increased hepatic glucose production, and decreased glucose clearance by insulin‐responsive tissues. It has been suggested that high glucose is associated with increased oxidative stress, enhanced leukocyte‐endothelial interaction, and glycosylation of lipoproteins, apolipoproteins, and clotting factors. Identification of new therapeutic approaches to improve glycemic management via the inhibition of hepatic glucose production will be beneficial for diabetes, cardiovascular diseases and related metabolic disorders.Stearoyl‐CoA desaturase (SCD) expressed at high levels in several human tissues is required for the biosynthesis of oleate (18:1) and palmitoleate (16:1), which are the major monounsaturated fatty acids of membrane phospholipids, triglycerides and cholesterol esters. Given the multiple roles of monounsaturated fatty acids, variation in stearoyl‐CoA desaturase activity in mammals would be expected to have a major effect on lipid metabolism. We and others have reported that global deletion of SCD1 in mice dramatically increases whole body energy expenditure and the loss of SCD1 activity in the liver suppresses hepatic glucose production when mice were fed a lipogenic diet. We hypothesize that the deficiency of SCD alters energy metabolism at the cellular level via the regulation of mitochondria function. Our preliminary data suggest that hepatic SCD1 deficiency alters the lipid profile of mitochondria membrane, therefore alters the membrane potential and metabolic rate of the cell. In addition, we show that the pharmaceutical inhibition of SCD activity reduces hepatic glucose production in the cell culture conditions. These studies provide essential information on the role of SCD on energy metabolism and, at the same time validate hepatic SCD enzymes as therapeutic targets against hyperglycemia in disease conditions, such as diabetes and metabolic syndrome.Support or Funding InformationAmerican Diabetes Association 7‐13‐BS‐118

Regulation And Function Of Fatty Acid Desaturases

Stearoyl‐CoA desaturase is a central lipogenic enzyme catalyzing the synthesis of monounsaturated fatty acids mainly oleate (C18:1) and palmitoleate (C16:1) which are the major monounsaturated fatty acids of membrane phospholipids, triglycerides, wax esters and cholesterol esters. Several SCD gene isoforms (SCD1‐4) exist in the mouse. While SCD1, 2 and 4 desaturate both 16:0 and 18:0 to 16:1n7 and 18:1n9 respectively, the SCD3 isoform has a substrate specificity and prefers desaturation of 16:0 to 16:1n7. 16:1n7 has been labeled as a lipokine that represses hepatic de novo lipogenesis and improves insulin signaling in muscle. We found that mice with a targeted disruption of the SCD3 isoform (SCD3−/−) exhibit dramatic brown adipose tissue (BAT) expansion and whitening with paradoxical increase in monounsaturated fatty acids and triglyceride accumulation. The alteration in fatty acid composition and lipid metanbolism causes reduced abundance of electron transport chain components and near ablation of UCP1 in BAT. Interestingly, this decreased protein abundance is not driven by repressed gene transcription and likely stems from protein instability and degradation. Consequently, the SCD3−/− mice have impaired cold tolerance and cannot maintain core body temperature during a 4ºC cold challenge past 6 hours. Meanwhile, the subcutaneous WAT of the KO mice shows increased expression of genes associated with fatty acid oxidation and thermogenesis. These observations suggest that SCD3 expression plays distinct roles in BAT and subcuteneous fat depots and help to elucidate how changes in monounsaturated fatty acids modulate metabolic activities in adipocytes.Support or Funding InformationSupported by NIH grants RO1DK62388 and T32 GM07215.

Physicochemical and antioxidant characteristics of gingerbread plum (<em>Neocarya macrophylla</em>) kernel oils

This study examined the physicochemical characteristics and antioxidant activities of oils extracted from gingerbread plum kernels grown in two different areas (Niger and Guinea). The oil contents were found to be significantly different (P ≤ 0.05); 56% and 60% for gingerbread plum kernels originated from Niger (GPKN) and guinea (GPKG), respectively. GPKG showed the highest levels for physical parameters such as iodine, saponification, free fatty acid, acid and peroxide values when compared with GPKN. The major monounsaturated fatty acid in both GPKN and GPKG was oleic acid (42.46 and 41.43%, respectively) while the polyunsaturated fatty acids consisted of linoleic and arachidonic acid. Arachidonic acid was at higher levels (17.67 and 21.72% in GPKN and GPKG, respectively) than those in common vegetable oils. Results from antioxidant activity essays showed that GPKG is more active than GPKN in DPPH radical scavenging, β-carotene and phenolic contents while GPKN showed the highest values for reducing power and flavonoid. Of the 11 sterol compounds found in this study, 24-hydroxy-24-methyl cholesterol, clerosterol and sitosterol accounted for 68.5% and 66.33% in GPKN and GPKG, respectively. Finally, all tocopherol vitamers (except γ-tocopherol) were present in GPKN and GPKG with α-tocopherol being the main element in both samples.

Fatty Acids Analysis, Antioxidant and Biological Activity of Fixed Oil ofAnnona muricataL. Seeds

The total oil yield and the fatty acid composition were determined in theAnnona muricataL. fixed oil using organic solvent extraction and GC-FID. The seeds were found to contain about ~21.5% of crude fixed oil on a dry weight basis. The crude oil containing fatty acid was converted into methyl esters and analysed by GC-FID. Fourteen fatty acids were identified using GC-FID. The major monounsaturated and saturated fatty acids were oleic acid (39.2%) and palmitic acid (19.1–19.2%), respectively, whereas theα-linolenic acid (1.2%) and linoleic acid (34.9%) were polyunsaturated fatty acid. The other saturated acids were stearic acid (3.3%), arachidic acid (0.4%), myristic acid (0.1%), heptadecanoic acid (0.1%), behenic acid (0.1%), and lignoceric acid (0.1%). Some of the fatty acids have not been reported earlier from the oil ofAnnona muricataL. Fixed oil exhibited significant free radical scavenging activity which was measured using DPPH and is also known to inhibit the gastrointestinal motility significantly.

Fatty acid content in muscles of amago salmon homozygous or heterozygous for a growth hormone transgene

Abstract Fatty acids are a vital energy source in fish and are of significant importance to their physiological wellbeing. Amago salmon ( Oncorhynchus masou ishikawae ) transgenic for a growth hormone (GH) show both accelerated growth and altered fatty acid composition and content in liver tissues. In particular, they show a decrease in saturated fatty acids and monounsaturated fatty acids, and an increase in polyunsaturated fatty acids except for docosahexaenoic acid (22:6n− 3) and eicosapentaenoic acid (20:5n − 3). Furthermore, transgenic fish have decreased levels of serum glucose, triacylglycerol and an increase in 3-hydroxybutyric acid, generally considered a starvation marker. As liver tissue is physiologically connected to muscle tissue, here we examined the effects of GH transgenesis on fatty acid contents in muscles of homozygous and heterozygous GH transgenic fish. The major monounsaturated fatty acids oleic acid (18:1n − 9) and palmitoleic acid (16:1n − 7) were slightly higher in the control, whereas polyunsaturated fatty acids, except 22:6n − 3 and 20:5n − 3, were significantly greater in the transgenic fish ( P P

Fatty acids in female’s gonads of the Red Sea fish Rhabdosargus sarba during the spawning season

Objective: To determine the fatty acids profiles in female fish, Rhabdosargus sarba (R. sarba) from the Red Sea during the spawning season. Methods: Monthly individual R. sarba were obtained from Bangalah market in Jeddah, Red Sea and transported to the laboratory in ice aquarium. The total length, standard length and weight were measured, fishes were dissected. Ovaries were removed, weighed and 10 mL of concentrated hydrochloric acid were added to 10 g of the ovary in a conical flask and immersed in boiling water until the sample was dissolved and the fat was seen to collect on the surface. The conical was cooled and the fat was extracted by shaking with 30 mL of diethyl ether. The extract was bowled after allowing the layers to separate into a weighed flask. The extraction was repeated three times more and distilled off the solvent then the fat dried at 100 °C, cooled and weighed. Then 50 mg of lipid was put in a tube, 5 mL of methanolic sulphuric acid was added and 2 mL of benzene, the tube well closed and placed in water bath at 90 °C for an hour and a half. After cooling, 8 mL water and 5 mL petroleum were added and shaked strongly and the ethereal layer was separated in a dry tube, evaporated to dryness. The fatty acid methyl esters were analyzed by using a Hewlett Packard (HP 6890) chromatography, a split/splitless injector and flame ionization detector. Results: In female R. sarba, a total of 29 fatty acids were detected in ovaries throughout the spawning season. The main fatty acid group in total lipid was saturated fatty acid (SFA, 28.9%), followed by 23.5% of polyunsaturated fatty acids (PUFA) and 12.9% of monounsaturated fatty acids (MUFA). The dominant SFA were palmitic and stearic, the major MUFA were palmitoleic and oleic, and the major PUFA were C18:2 and C22:2. During spawning stages, there were no significant differences in total SFA, MUFA and PUFA. The highest value of SFA was in late spawning (36.78%). However, the highest value of MUFA and PUFA was in spawning (16.70% and 24.96% respectively). During spawning season there were significant differences in total SFA between March (late spawning stage) and December (nearly ripe stage), P<0.05. Conclusions: From the present study it has been shown that 29 fatty acids were detected in ovaries of R. sarba throughout the spawning season. The main fatty acid group in total lipid was SFA followed by PUFA and MUFA. The dominant SFA were palmitic and stearic, the major MUFA were palmitoleic and oleic, and the major PUFA were C18:2 and C22:2. The highest value of SFA was in late spawning. However, the highest value of MUFA and PUFA was in spawning.

南海南部悬浮颗粒物脂肪酸组成分析

Some fatty acids( FA) are specific to individual classes of organisms and attempts to trace organic materials in the ocean. Fatty acid markers have been widely used to trace or confirm predator-prey relationships so as to illustrate the key trophic linkages in the marine ecosystem. Suspended particulate matter from 0m,75 m and 150 m were collected to better understand the fatty acid composition and its fatty acid biomarkers in the southern South China Sea. The cruise was conducted by"NanFeng"RV from February 22 to March 30,initiated by South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences. The range of FA contents were 9.9—15.65 μg /L,10.45 —14.45 μg /L and 9.65—16.45 μg /L at 0 m,75 m and 150 m,respectively. FA contents indicate that vertical change of FA contents was unobvious.Deep chlorophyll a( Chl a) maximum phenomenon was popular in South China Sea,thus FA /Chl a concentration varied in the water column obviously. The ratio of FA /Chl a was higher than 70 at surface and 150m layer,while lower than 30 at75m layer( except A7). Saturated fatty acids( SFA) and mono-unsaturated fatty acids( MUFA) dominated total fatty acid contents in all SPM from each layer. Major SFA was C16: 0,C18: 0 and C12: 0. Major MUFA were C14: 1n3,C16: 1n7 and C16: 1n9,and major polyunsaturated fatty acids( PUFA) were C18: 2n6 and C22: 2n6. Principle components analysis( PCA) revealed that PC1 was positively related to C16:0,C18:0 and C20:0 concentrations,so PC1 maybe the indicator of phytoplankton and debris. PC2 may be represented the information of zooplankton. Within five FA biomarkers,C16: 1n7 /C16: 0 was positively related to C16: 1 /∑FA,while negatively related to ∑C18 /∑FA,so the combination of C16: 1n7 /C16: 0 and C16: 1 /∑FA can be considered as FA biomarker of diatoms,and ∑C18 /∑FA also can be applied to indicate dinoflagellate.

Comparative Lipid Profiles of Milk Bank Breast Milk and Infant Formulas

Lipid profiles of seven human breast milk samples obtained from milk banks and four infant formulas were compared in view of the potential food hypersensitivities of certain infants to human milk.The cholesterol (0.15-0.26 mM) content of the human samples was about 50% lower than that found in the infant formulas whereas the triglyceride (TG, 173-386 mM) contents of these products were found to be comparable.The major saturated fatty acid (SFA) and mono-unsaturated fatty acid (MUFA) were 16:0 and 18:1 respectively. The major poly-unsaturated fatty acid (PUFA) was 18:2 with other PUFA members of the C18, C20 and C22 families identified and quantified. Although conjugated linoleic acid (CLA) was not detected in any infant formulas tested, no other major differences in the fatty acid patterns were found. However, the mean (13.6) of the ratio of n-6 PUFAs/n-3 PUFAs in the human milk samples was about 50% higher than that observed in the infant formula samples.Although our results indicate that there are small yet significant differences in cholesterol and CLA content and the ratio of n-6 PUFAs/n-3PUFAs, the lipid composition of milk bank breast milk and infant formulas is quite comparable.

Total Lipid Fractions and Fatty Acids Composition of Low-Fat Beef Burger

Low-fat beef burgers were produced with four different fat replacer (carrageenan, carboxymethyl cellulose, soy flour and goat meat) which were added at three levels (0.3, 0.5 and 1%), (1.5, 3 and 4.5%), (5, 10 and 15%) and (25, 50 and 100%); respectively. Total lipid fractions were determined by using thin layer chromatography technique for beef burger in both raw and grilled state after 3 months of frozen storage. Data revealed that phospholipids contents were less and triglyc- erides contents were more in the studied beef burger. Low-fat beef burgers containing 0.3% carrageenan, 5% low-fat soy flour, 1.5% carboxymethyl cellulose, 25% goat meat + 75% beef and control sample (without any fat replacer) gained the highest sensory score, so it was important of determine the fatty acids composition of these samples by the end of frozen storage. Saturated fatty acids were C12:0, C14:0, C16:0, C17:0andC18:0. Predominated, major monounsaturated fatty acids were C16:1, C17:1, C18:1 and C20:1; and the major polyunsaturated fatty acids were descendingly: C18:2, C18:3. Among these fatty acids, the fatty acid C18:1 represented the highest relative percentage of all identified fatty acids.

Palmitoleate Is a Mitogen, Formed upon Stimulation with Growth Factors, and Converted to Palmitoleoyl-phosphatidylinositol

Controversial correlations between biological activity and concentration of the novel lipokine palmitoleate (9Z-hexadecenoate, 16:1) might depend on the formation of an active 16:1 metabolite. For its identification, we analyzed the glycerophospholipid composition of mouse Swiss 3T3 fibroblasts in response to 16:1 using LC-MS/MS. 16:1 was either supplemented to the cell culture medium or endogenously formed when cells were stimulated with insulin or growth factors as suggested by the enhanced mRNA expression of 16:1-biosynthetic enzymes. The proportion of 1-acyl-2-16:1-sn-phosphatidylinositol (16:1-PI) was time-dependently and specifically increased relative to other glycerophospholipids under both conditions and correlated with the proliferation of fatty acid (16:1, palmitate, oleate, or arachidonate)-supplemented cells. Accordingly, cell proliferation was impaired by blocking 16:1 biosynthesis using the selective stearoyl-CoA desaturase-1 inhibitor CAY10566 and restored by supplementation of 16:1. The accumulation of 16:1-PI occurred throughout cellular compartments and within diverse mouse cell lines (Swiss 3T3, NIH-3T3, and 3T3-L1 cells). To elucidate further whether 16:1-PI is formed through the de novo or remodeling pathway of PI biosynthesis, phosphatidate levels and lyso-PI-acyltransferase activities were analyzed as respective markers. The proportion of 16:1-phosphatidate was significantly increased by insulin and growth factors, whereas lyso-PI-acyltransferases showed negligible activity for 16:1-coenzyme A. The relevance of the de novo pathway for 16:1-PI biosynthesis is supported further by the comparable incorporation rate of deuterium-labeled 16:1 and tritium-labeled inositol into PI for growth factor-stimulated cells. In conclusion, we identified 16:1 or 16:1-PI as mitogen whose biosynthesis is induced by growth factors.

Effect of ground beef fatty acid composition on atherosclerotic cardiovascular disease risk factors in healthy men

Dietary fatty acids reportedly alter atherosclerotic cardiovascular disease (ASCVD) risk. Oleic acid, the major monounsaturated fatty acid (MUFA) in beef, may improve blood lipids (AJCN 70:1009, 1999). We sought to compare the effects of MUFA:SAT ratios in ground beef patties with a fixed total fat content of 24 g fat/100 g patty in 25 healthy men. Test beef patty MUFA:SAT was either 1.10 (HI) or 0.71 (LO). Subjects consumed 5 patties per week in a random test‐retest design lasting 5 weeks each separated by 4‐week wash‐out period. We measured metabolic indices and HDL functionality immediately before and at the end of each test. Increased beef consumption per se, and beef MUFA:SAT had no effect on circulating homocysteine, adipokines, or HDL3 apolipoprotein composition. Beef patty MUFA:SAT had no effect, while beef consumption per se increased total HDL (p&lt;0.001), HDL3 (p&lt;0.0001) and atheroprotective HDL3 sphingosine‐1‐phophate (S1P) (p&lt;0.05). Independent of MUFA:SAT, beef consumption also improved insulin sensitivity as judged by reduction in HOMA scores (p&lt;0.05). Interestingly, beef consumption per se caused a decrease in PON1 activity per HDL (p&lt;0.05). We conclude that increased beef consumption improved indices of HDL functionality and insulin sensitivity independent of fatty acid composition. “Funded in part by The Beef Checkoff through the National Cattlemen's Beef Association”

Abstract MP065: Genetic Loci Associated With Plasma Phospholipid Fatty Acids in the De Novo Lipogenesis Pathway: A Meta-analysis of Genome-wide Association Studies From the Charge Consortium

Background Palmitic acid (16:0), stearic acid (18:0), palmitoleic acid (16:1n-7), and oleic acid (18:1n-9) are major saturated and mono-unsaturated fatty acids that are synthesized via de novo lipogenesis (DNL) or obtained from the diet. Circulating levels of these fatty acids are linked to several diseases including diabetes and heart disease. Prior family and twin studies suggest high heritability of circulating levels, but potential genes involved are unknown. Objective To carry out a Genome-Wide Association Study (GWAS) to investigate genetic determinants of circulating levels of these fatty acids. Methods GWAS in 5 population-based cohorts (n=8,961) of European ancestry. Each study conducted linear regression analysis using an additive genetic model. All analyses were adjusted for age, sex, site of recruitment, and principal components to account for possible population genetic substructure where appropriate. Study-specific results were combined using inverse-variance weighted meta-analysis. Results We found SNPs at 7 novel loci linked at GWA significance to levels of one or more of these fatty acids ( Figure ). Directionality is reported for minor alleles. SNPs in ALG14 were associated with higher levels of 16:0 ( P =2.7x10 -11 ) and lower levels of 18:0 ( P =2.7x10 -11 ). SNPs in FADS1 /2 were associated with higher 18:1n-9 ( P =2.2x10 -32 ) and 16:1n-7 ( P =6.6x10 -13 ), and lower 18:0 ( P =1.3x10 -20 ). SNPs in LPGAT1 were associated with lower 18:0 ( P =2.8x10 -9 ). SNPs in GCKR ( P =9.8x10 -10 ) and HIF1AN ( P =5.7x10 -9 ) were associated with higher 16:1n-7, whereas those in PKD2L1 ( P =5.7x10 -15 ) and another locus on chromosome 2 (not near known genes) were associated with lower 16:1n-7. Conclusion Our findings provide novel evidence that common variations in genes with diverse functions, including protein glycosylation, polyunsaturated fatty acid metabolism, phospholipid modeling, and glucose- and oxygen-sensing pathways, are associated with circulating levels of fatty acids in the DNL pathway.

Chemical characterization of Central American pitaya ( Hylocereus sp.) seeds and seed oil

Central American red pitaya (Hylocereussp.) seeds were studied for their chemical and nutritional traits with particular reference to the fatty acid (FA) profile of the seed oil. Proximate seed composition averaged 352 g/kg, 302 g/kg, 296 g/kg, 206 g/kg, 126 g/kg, and 21 g/kg for total carbohydrates, dietary fiber, fat, protein, moisture, and ash, respectively. FA composition of pitaya seed oil determined by GC–MS and quantified by GC-FID was dominated by unsaturated FAs (753 g/kg). Interestingly, linoleic acid was found to be the only polyunsaturated and most abundant FA (466 g/kg), whereas palmitoleic (3 g/kg), oleic (239 g/kg), and cis-11-vaccenic acid (45 g/kg) were the major monounsaturated FAs. Palmitic (182 g/kg), stearic (49 g/kg), and arachidic acid (18g/kg) represented the saturated FA fraction. Iodine absorption value, saponification number and free fatty acid value amounted to 105.6 g I2/100 g, 235.7 mg KOH/g, and 1.9 mg KOH/g, respectively.

Characteristics of Fatty Acid Composition of the Deep‐Sea Vent Crab, Shinkaia crosnieri Baba and Williams

The neutral and polar lipids of the Galatheidae vent crab, Shinkaia crosnieri, with its eggs were studied to assess its lipid physiology and trophic relationship at hydrothermal vents. The vent crab obtained many of its lipids from Bathymodiolus mussels and chemosynthetic microorganisms which live on a mat of long, silky setae on the crab body as exosymbionts. In all lipid classes, the major monounsaturated fatty acids were 16:1n-7 and 18:1n-7, which originate from bacteria. The major polyunsaturated fatty acids (PUFA) in the triacylglycerols were 16:2n-4, 18:2n-4, 18:2n-7, 18:3n-4,7,10, and 16:2n-3, while those of the crab polar lipids were 16:2n-4, 18:2n-4, 18:3n-4,7,10, 20:4n-6 (arachidonic acid), 20:5n-3 (icosapentaenoic acid), and 22:6n-3 (docosahexaenoic acid) in the phosphatidylethanolamine, and 16:2n-4, 18:2n-4, and 18:3n-4,7,10, with noticeable levels of 20:4n-6, 20:5n-3, and 22:6n-3 in the phosphatidylcholine. In the crab and its eggs, TAG and phospholipid PUFA consisted primarily of n-4 family (n-4 and n-7) methylene-interrupted PUFA with n-3 and n-6 PUFA. The unique fatty acid composition mix of n-3, n-4, and n-6 PUFA in S. crosnieri lipids suggests the vent crab utilizing chemosynthetic bacteria, which produce both unusual n-4 and normal n-3 and n-6 PUFA. Such unique fatty acid composition differs from that reported for other common marine animals, which depend on organic matter derived from phytoplankton lipids.

The content of fat and fatty acids composition in chicken liver

Liver is recognized as a valuable source of nutrients in human nutrition but there are a few reports of the lipid profile of chicken liver. The aim of work was to determine fat content as well as fatty acids composition of raw chicken liver. The study was carried out on three chicken breeds (New Hampshire, Plymouth Rock, Rhode Island) obtained from National Research Institute of Animal Production in Balice. Total fat was determined by Soxhlet method and the fatty acids profile was performed with gas chromatography method on a Varian 3400. Fat content of chicken liver ranged from 2.65 to 10.07 g/100g depended on the breed. The predominant saturated acid (SFA) in all samples was palmitate (C16:0), followed by stearate (C18:0). Oleate (C18:1) was the major monounsaturated fatty acid (MUFA) in all samples, followed by palmitooleate (16:1). n-3 fatty acids in chicken liver were comparatively lower than SFA and MUFA. The predominant polyunsaturated acid (PUFA) was linoleate (C18:2). Arachidonate (C20:4) was the second most important n-6 fatty acid. Fatty acid content also varied between breeds of chicken. It has been demonstrated that conjugated linoleic acids (CLA) is found in chicken liver.

Seasonal changes on total fatty acid composition of carp (Cyprinus carpio L. ), in vriz Dam Lake, Turkey

The effects of seasonal variation on the fatty acid composition of carps Cyprinus carpio were determined. A total of 38 different fatty acids were determined in the composition of carps. There were quantitative differences between fatty acids in muscle tissue investigated, depending on the season. Oleic acid C18:1 ω9 was the major monounsaturated fatty acid (MUFA) in all seasons. Palmitic acid C16:0 was identified as the major saturated fatty acid (SFA) in four seasons. Palmitoleic acid C16:1 was the third highest fatty acid in total fatty acids. MUFAs were found to be higher than SFAs and polyunsaturated fatty acids (PUFAs) in all seasons. Docosahexaenoic acid C22:6 ω3, linoleic acid C18:2 ω6 and eicosapentaenoic acid C20:5 ω3 were the highest levels among the PUFAs. The percentages of ω3 fatty acid were higher than those of total ω6 fatty acid in the fatty acid composition of carp. In the present study, ω3/ω6 ratios were found to be 1.08, 1.43, 1.64 and 1.60 in spring, summer, autumn and winter, respectively. C. carpio may be a valuable food for human consumption in terms of fatty acids. Key words: Fatty acid composition, seasonal changes, freshwater fish, Turkey.

Lipid and DNA features of Gonyaulax fragilis (Dinophyceae) as potential biomarkers in mucilage genesis

Due to the increasing evidences on dinoflagellate contribution to mucilage phenomena in the Mediterranean Sea, this study was aimed at identifying biochemical and/or genetic markers that could help in relating Gonyaulax fragilis growth with mucilage formation when microscope identification was difficult. The biochemical characterization considered the fatty acid and sterol composition of cultured strains and mucilage samples. The cultured algae displayed the typical fatty acid pattern of dinoflagellates as the 18:0 was the prevalent saturated fatty acid (SFA), 18:1n−7 and 18:1n−9 were the major monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were dominated by 18:5n−3 and 22:6n−3. Two groups of sterols were identified in algal cells: desmethylsterols, dominated by cholesterol and β-sitosterol, and 4α-methylsterols, having dinosterol as the prevailing sterol. The mucilage lipid pattern was characterized by low amounts of PUFAs and appeared deeply influenced by environment dynamics; however, the 20:5n−3/22:6n−3 ratio <1, the low C16/C18 and 16:1/16:0 ratios evidenced a higher contribution of dinoflagellates to mucilage formation than previously observed. Mucilage sterols showed higher correspondence with those found in G. fragilis than fatty acids. As a genetic marker for G. fragilis a molecular probe that could specifically bind to its 18S rDNA was designed and assayed. The probe displayed a good specificity and sensitivity as it could recognize G. fragilis DNA in the presence of high concentrations of different species, and also in samples having a high complexity and that were partially degraded, as often occurs in field mucilage samples. The results suggest that, among lipid biomarkers, sterols have a higher specificity and persistence than fatty acids and that nucleotide probes could be useful to identify this dinoflagellate in field samples, thus representing a tool to test mucilage samples of uncertain biogenetic origin.

Effects of breed, sex and halothane genotype on fatty acid composition of triacylglycerols and phospholipids in pork longissimus muscle

The objective of this study was to estimate the effects of breed, sex, and halothane (HAL-1843) genotype on fatty acid composition of triacylglycerols (TAG) and phospholipids (PL) extracted from porcine longissimus muscle (LM). Purebred Yorkshire (n = 131), Duroc (n = 136), Hampshire (n = 49), Spotted (n = 35), Chester White (n = 74), Poland China (n = 51), Berkshire (n = 169) and Landrace (n = 82) pigs (n = 727; 427 barrows and 300 gilts) from the 1994 and 2001 National Barrow Show Sire Progeny Tests were used. For statistical analyses, a mixed model was used that included fixed effects of breed, sex, HAL-1843(TM) genotype, year, slaughter date within each year, interaction of breed x sex and random effects of sire and dam within breed. Breeds and sex were significantly associated with the percentages of the majority fatty acids in TAG. Duroc pigs had greater total saturated fatty acids (SFA) and lower total monounsaturated fatty acids (MUFA) (p < 0.05) contents than did pigs of all other breeds except Berkshire (p > 0.05). The concentration of total polyunsaturated fatty acids (PUFA) was the greatest in Hampshire pigs (p < 0.05). The content of total SFA was greater (p < 0.01), whereas the concentrations of total MUFA and PUFA were lower (p < 0.01) in barrows than those in gilts. The contents of major SFA in PL did not differ significantly among pigs from different breeds and sex groups. However, breed and sex significantly affected the concentrations of major MUFA and PUFA in PL and strong negative correlation between the total contents of MUFA and PUFA in PL was observed in the current study. Chester White pigs had greater total MUFA and lower total PUFA contents (p < 0.05) in PL than did pigs of all other breeds except Spotted (p > 0.05). In contrast to breed and sex effects, the concentrations of fatty acids in PL were more affected by HAL-1843 genotype than those in TAG. The content of C16:0, a major SFA in PL, differed significantly in pigs with different HAL-1843 genotypes. In conclusion, these results suggest that breed and sex are important sources of the variations for fatty acid composition of TAG and PL in LM.

Seasonal changes in the total fatty acid composition of Vimba, Vimba vimba tenella (Nordmann, 1840) in Eğirdir Lake, Turkey

Total fatty acid compositions and its seasonal variations in Vimba, Vimba vimba tenella (Nordmann, 1840) in Egirdir Lake, which is the second largest freshwater lake in Turkey, were investigated by a gas chromatographic method. Twenty seven different fatty acids were determined in the composition of Vimba vimba tenella. Monounsaturated fatty acids (MUFAs) were found to be in higher amounts than saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) in all seasons. Oleic acid (C18:1 n9) was the major MUFA in all seasons. Palmitic acid (C16:0) was identified as the major SFA in all four seasons. Arachidonic acid (C20:4 n6), docosahexaenoic acid (C22:6 n3), linoleic acid (C18:2 n6), and eicosapentaenoic acid (C20:5 n3) were at the highest levels among the PUFAs. In the present study, n-3/n-6 ratios were found to be 1.4,1.5,1.2 and 1.4 in spring, summer, autumn and winter, respectively. Vimba vimba tenella may be a valuable food for human consumption in terms of fatty acids.

Seasonal Variations of n-6: n-3 Ratios and Fatty Acid Compositions in Foot and Tissue of Chiton lamyi in a High Primary Productivity Area

Problem statement: Fatty acid content and composition in mollusks is a function of their feeding diversity. Chabahar bay located in the northern part of Oman sea in Indian ocean provides high rates of primary productivity and a diverse food source for mollusks in this area. Identification of fatty acid compositions of Chiton lamyi and study their seasonal changes in the intertidal zone of Chabahar bay. Study the meat quality by n-6: n-3 ratios calculation throughout the year. Approach: Chiton lamyi species analyzed seasonally for its fatty acid compositions in foot and internal tissue separately by GC/MS chromatography. Temperature and nutrients measured monthly for evaluating their effects on investigated seasonal variations of fatty acids. Pearson analysis showed effects of measured environmental factors on studied fatty acids composition. n-6: n-3 ratio calculated seasonally in order to study meat quality. Results: Thirteen fatty acids identified in foot and internal tissue of Chiton lamyi. The major Saturated Fatty Acids (SFAs) were myristic, palmitic and stearic acids. The major Mono-Unsaturated Fatty Acids (MUFAs) were palmitoleic, oleic and 11-eicosenoic acids and Poly-Unsaturated Fatty Acids (PUFAs) were linoleic, eicosapentaenoic and arachidonic acids. Palmitic acid was the most abundant in this species. Fatty acid contents of foot and internal tissue of Chiton lamyi were similar but their seasonal variations were different. Pearson analysis showed correlation among palmitic and oleic acids with silicate; oleic acid with phosphate; Linoleic and arachidonic acids with nitrate in Chiton lamyi internal tissues, but no correlation observed in foot. Although temperature showed correlation with heptadecanoic and methyl-heptadecanoic acids in Chiton lamyi foot, no correlation found in internal tissues. Also, n-6: n-3 ratio calculations showed domination of n-3 fatty acid over n-6 only in spring. Conclusion: Fatty acid variations were not same at different organs and environmental factors could have opposite effects on them in this species. Also, n-6: n-3 ratio showed the lack of food loads throughout the year except in spring for this species. These findings can lead the best exploitation periods for such marine mollusks.