Fatty acid composition,cholesterol and fat‐soluble vitamins of wild‐caught freshwater spiny eel,Mastacembelus simack (Walbaum, 1792)

Because of its local commercial value, the proximate nutritional composition, fatty acid composition, cholesterol and fat‐soluble vitamins of spiny eel (Mastacembelus simack Walbaum, 1792) were determined in 20 specimens caught in Keban Dam Lake, Elaz??, Turkey in September 2009. Moisture, protein, lipid, ash and cholesterol contents of the spiny eel were 75.9, 17.1, 10.9, 1.0% and 52.6 mg per 100 g, respectively. Fatty acid composition showed that total polyunsaturated fatty acids (PUFA) were the highest (37.1%), followed by monounsaturated fatty acids (MUFA, 35.5%) and saturated fatty acids (SFA, 27.4%). The relation between PUFA and SFA (1.35) was comparable to that of some fish species, and PUFA : MUFA : SFA ratio (1.35 : 1.29 : 1) was very close to that recommended by nutritionists. Among the vitamins (A, D, E and K) analyzed, the vitamin E content was highest followed by D, K and A. In conclusion, M. simack is rich in proteins, unsaturated fatty acids and vitamins and low in cholesterol, with a reasonable PUFA : SFA and PUFA : MUFA : SFA ratio as recommended by nutritionists. M. simack can therefore be recommended for human consumption as a good source of nutrition.     

Comparison of fatty acids and some mineral matter profiles of wild and farmed snails,Cornu aspersum Müller, 1774

ABSTRACT

The fatty acid and mineral matter compositions of the visceral mass and pedal mass of wild and farmed Cornu aspersum were compared. The relative fatty acid amounts of the visceral and pedal masses of wild and farmed snails are: polyunsaturated fatty acid (PUFA) > saturated fatty acid (SFA) > monounsaturated fatty acid (MUFA), PUFA?>?SFA?>?MUFA, MUFA?>?PUFA?>?SFA and PUFA?>?MUFA?>?SFA, respectively. Wild snails had a higher concentration of iron and zinc than farmed snails. Selenium was 2.82 times higher in the pedal mass of farmed snails than the pedal mass of wild snails. Ca:P ratios in the visceral mass of wild snails, visceral mass and pedal mass of farmed snails were 1.76:1, 1.12:1 and 3.87:1 respectively. Both wild and farmed snails have high contents of oleic, linoleic, eicosapentaenoic and docosahexaenoic fatty acids and are a good source of minerals. Careful attention should be paid, however, as to which diet will be used during farming because the composition of fatty acid in the snail is affected by diet.     

Oil and Seed Meal Quality Indices of Indian Rapeseed-Mustard Varieties

Variation in oil, protein, fatty acid profile, oil stability index, PUFA to SFA, MUFA to PUFA, ω-6 to ω-3 fatty acid ratio and glucosinolate content and their relationships were studied in 50 rapeseed-mustard (Brassica species) varieties. Variability was low for protein and oil content with CV 4.2% and 5.1%, respectively. The highest variation was recorded for oil stability index followed by oleic acid content. Erucic acid ranged from 0.4 % [TERI (00) R- 9903] to 55.3% (NDYS-2). The saturated fatty acids showed a range of 2.5–8.6% and most of the varieties had < 6 %.The maximum (3.05) and minimum (0. 59) ω-6 to ω-3 fatty acid ratio was recorded for TERI (00) R-9903 a variety of gobhi sarson and RTM-314 of taramira, respectively. The highest MUFA to PUFA ratio (3.19) was recorded for variety Parbati of toria. Twelve varieties had PUFA to SFA ratio of > 10.0. All the varieties, in general had high glucosinolate content except GSC- 5, TERI (OE) R-03 and TERI (00) R-9903. Oil stability index had highly significant and positive correlation with oleic acid and MUFA to PUFA ratio. The relationship of oil content was significantly positive with ω-6 to ω-3 fatty acid ratio (r = 0.377**). Protein content and SFA were positively correlated (r = 0.314 *). Erucic acid exhibited negative and significant association with SFA (r = ? 0.293*) and oleic acid (r = ? 0.863**).     

Acute ingestion of different dietary fatty acid species modulates postprandial lipid responses in New Zealand white rabbits

Although several investigations have linked the degree of fatty acid saturation to plasma lipid responses in the postprandial state, further evaluation is necessary. In this study, we compared the effect of saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids on postprandial lipid metabolism using complementary in vivo and in vitro approaches. Fat (10 g) cholesterol (0.5 g) test meals that provided either lard (SFA), olive oil (MUFA), or sunflower oil (PUFA) were ingested by chow-fed New Zealand white rabbits (n = 8). In addition, hepatic uptake of triglyceride-cholesterol-rich lipoproteins (TCRL) isolated from rabbits chronically ingesting SFA, MUFA, or PUFA diets was measured using freshly isolated chow-fed rabbit hepatocytes. Whatever dietary fatty acids ingested, postprandial triglyceridemia and occurrence of radiolabelled dietary lipids in plasma were not markedly different. Conversely, SFA induced higher postprandial cholesterolemia and phospholipemia than MUFA (P < 0.05) whereas PUFA prevented postprandial cholesterol increase. TCRL disappearance from cultured liver cell media was delayed with SFA-rich TCRL and faster with PUFA whereas MUFA-rich TCRL showed an intermediate figure. From these data, we conclude that SFA, MUFA, and PUFA elicited different postprandial plasma and lipoprotein lipid responses. The fatty acid composition of TCRL had a major impact on their subsequent metabolism, especially uptake by cultured hepatocytes. The SFA-induced hypercholesterolemia could be related to an altered hepatic uptake whereas a faster clearance and hepatic uptake could explain the cholesterol-lowering effect of PUFA in rabbits. MUFA, like PUFA, accelerate uptake by hepatocytes but favor cholesterol ester enrichment of TCRL.     

Fatty acid composition of particulate matter and photosynthetic products in subarctic and subtropical Pacific

The fatty acid composition of lipid materials in particulate matter and photosynthetic products was determined using ¹³C gas chromatography-mass spectrometry methodology in the subarctic and subtropical Pacific. Polyunsaturated fatty acids (PUFA) were measured as one of the major constituents of particulate and photosynthetically produced lipids in the subarctic Pacific. In the subtropical Pacific, on the other hand, a quite simple fatty acid composition was found, consisting mainly of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA); the production rate of PUFA could not be determined due to the low concentration in the subtropical area. The relationship between the fatty acid composition of particulate lipids and photosynthetically produced lipids indicated that PUFA observed in particulate lipids were mainly associated with phytoplankton. Non-living lipids, on the other hand, could be mainly constituted by SFA, due to the lability of PUFA to degradation. The difference in the contribution of phytoplankton lipids to particulate lipids is considered as an important factor affecting the difference in the fatty acid composition of particulate lipids between subarctic and subtropical Pacific.      

Phospholipid and Fatty Acid Composition of Phosphatidylcholine and Phosphatidylethanolamine in the Black Plaice <Emphasis Type="Italic">Pleuronectes obscura</Emphasis> during Thermoadaptation

The phospholipid (PL) and fatty acid (FA) composition of major membrane lipid constituents, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), as well as the cholesterol/phospholipid (CL/PL) ratio were assayed in the muscles, gills and liver of the black plaice Pleuronectes (Liopsetta) obscura at different ambient temperatures (18, 9 and 0°C). PL and CL were shown to be actively involved in adaptation of the fish to changes in the seawater temperature. As temperature declines, the monounsaturated FA (MUFA) level increases while the polyunsaturated FA (PUFA) fraction in gills and liver PC and PE, on the contrary, decreases, resulting in diminished functional activity of the fish. However, in muscles this correlation is lacking. The PC and PE composition was shown to be organ- and ambient temperature-dependent. Major PC forms are saturated FA (SFA)/PUFA and MUFA/PUFA composed of a relatively small number of major molecular species. A temperature drop results in an increased SFA/PUFA level and decreased MUFA/PUFA and PUFA/PUFA levels in muscles and gills, and this may promote a drop in the viscosity of the outer lipid monolayer of membranes and in their functional activity. In contrast to PC, the PE composition in all organs tested is characterized by a decrease in the SFA/ PUFA level and an increase in MUFA/PUFA and PUFA/PUFA levels. Such changes promote the retention of functional activity of the inner lipid monolayer of membranes and are not synchronized with rearrangements in their outer monolayer. Due to intermolecular transfer of acyl radicals at a constancy of their composition, functional rearrangement of the lipid matrix appears to be achieved through changes in the membrane viscosity. Our data support the idea that different adaptation strategies in fish are driven by certain sets of PL molecular species.     

Effect of weight at slaughter and breed on beef intramuscular lipid classes and fatty acid profile

The effect of slaughter weight and breed on the composition of intramuscular fat (IMF) of seven Spanish cattle breeds was studied. Lipid classes and fatty acids were evaluated in young bulls of seven local Spanish cattle breeds, Asturiana, Avileña, Morucha, Parda Alpina, Pirenaica, Retinta and Rubia Gallega, slaughtered at a live weight of 320 kg (veal type) and 550 kg (yearling bull type). Higher slaughter weight and early maturating breeds produced higher IMF content in the longissimus muscle (P < 0.001), which was linked to a reduction in phospholipids, monoglycerides, diglycerides, cholesterol and free-fatty acids content, but an increase in triacylglycerols. Besides, heavier animals displayed a higher percentage of saturated and monounsaturated fatty acids (MUFA), but a lower polyunsaturated fatty acids (PUFA) percentage (P < 0.001). The increase in triglycerides (TG), saturated fatty acids (SFA) and MUFA illustrates the increasing importance of lipid storage as fattening proceeds and the acquisition of ruminal functionality. The feeding system based on cereals had a strong influence on the fatty acid profile, giving the studied beef a relatively high PUFA/SFA and n-6/n-3 ratios.     

Effects of boiling,deep‐frying,and microwave treatment on the proximate composition of rainbow trout fillets: changes in fatty acids,total protein,and minerals

This study was conducted to investigate the differences in the proximate composition (moisture, fat, protein and ash), cholesterol content, energy, mineral composition (Na, Ca, Mg, K, P, Fe and Zn) and fatty acid profile of rainbow trout, Oncorhynchus mykiss, after frying, boiling, or microwaving. Results showed that all cooking methods reduced moisture and increased total protein, fat and ash contents. Also all minerals increased significantly during the microwave and frying methods. Statistical results showed that the major fatty acids among the saturated and monounsaturated fatty acids in each fish were palmitic (C16:0) and oleic (C18:1) acids, respectively. In addition, linoleic acid (C18:2) was predominant in the n‐6 polyunsaturated fatty acids (PUFA) in both cooked and raw trout. The EPA (eicosapentaenoic acid; C20:5 ω3) and DHA (docosahexaenoic acid; C22:6 ω6) acids were the major fatty acids among total n‐3 acids in fish samples. The fatty acids profile of the cooked fish showed a saturated (SFA) and monounsaturated (MUFA) decrease and an increase in PUFA contents. However, the ω‐3 fatty acids content increased in microwaved samples but decreased in the fried samples. Moreover, the PUFA/SFA and Hypocholesterolaemic/Hypercholesterolaemic (HH) ratios increased in both fried and microwaved trout, whereas significant increases in ω3/ω6 as well as EPA + DHA/C16 content were observed only in microwaved samples. A significant increase in energy content was observed in all cooked samples, whereas the cholesterol decreased. Research results show that microwaving is recommended as the best cooking method for a healthy consumption of rainbow trout.     

Genetic correlation estimates between beef fatty acid profile with meat and carcass traits in Nellore cattle finished in feedlot

The objective of this study was to estimate the genetic–quantitative relationships between the beef fatty acid profile with the carcass and meat traits of Nellore cattle. A total of 1826 bulls finished in feedlot conditions and slaughtered at 24 months of age on average were used. The following carcass and meat traits were analysed: subcutaneous fat thickness (BF), shear force (SF) and total intramuscular fat (IMF). The fatty acid (FA) profile of the Longissimus thoracis samples was determined. Twenty-five FAs (18 individuals and seven groups of FAs) were selected due to their importance for human health. The animals were genotyped with the BovineHD BeadChip and, after quality control for single nucleotide polymorphisms (SNPs), only 470,007 SNPs from 1556 samples remained. The model included the random genetic additive direct effect, the fixed effect of the contemporary group and the animal’s slaughter age as a covariable. The (co)variances and genetic parameters were estimated using the REML method, considering an animal model (single-step GBLUP). A total of 25 multi-trait analyses, with four traits, were performed considering SF, BF and IMF plus each individual FA. The heritability estimates for individual saturated fatty acids (SFA) varied from 0.06 to 0.65, for monounsaturated fatty acids (MUFA) it varied from 0.02 to 0.14 and for polyunsaturated fatty acids (PUFA) it ranged from 0.05 to 0.68. The heritability estimates for Omega 3, Omega 6, SFA, MUFA and PUFA sum were low to moderate, varying from 0.09 to 0.20. The carcass and meat traits, SF (0.06) and IMF (0.07), had low heritability estimates, while BF (0.17) was moderate. The genetic correlation estimates between SFA sum, MUFA sum and PUFA sum with BF were 0.04, 0.64 and ?0.41, respectively. The genetic correlation estimates between SFA sum, MUFA sum and PUFA sum with SF were 0.29, ?0.06 and ?0.04, respectively. The genetic correlation estimates between SFA sum, MUFA sum and PUFA sum with IMF were 0.24, 0.90 and ?0.67, respectively. The selection to improve meat tenderness in Nellore cattle should not change the fatty acid composition in beef, so it is possible to improve this attribute without affecting the nutritional beef quality in zebu breeds. However, selection for increased deposition of subcutaneous fat thickness and especially the percentage of intramuscular fat should lead to changes in the fat composition, highlighting a genetic antagonism between meat nutritional value and acceptability by the consumer.     

Uterine lipid alterations during early pseudopregnancy and following the artificial induction of decidualization by concanavalin A in QS mice

Lipid extracts of whole uterine tissue from mice were examined by gas chromatography-mass spectrometry during days 2, 3, and 4 of pseudopregnancy (day 1 = copulatory plug) and following the artificial induction of the decidual cell reaction (DCR) on day 4. The range of lipids identified during pseudopregnancy and their percentage composition on day 2 included saturated fatty acids (SFA, 38%), monounsaturated fatty acids (MUFA, 20%), polyunsaturated fatty acids (PUFA, 17%), sterols (25%), long chain alcohols (0.12%), and alkylglycerols (0.11%). Of these, the main components were the fatty acids 16:0 (21%), 18:0 (14%), cis18:1n-9 (14%), 18:2n-6 (8.5%), and cholesterol (24%). Although only subtle changes in the composition of uterine lipids occurred through days 2 and 3 of pseudopregnancy, more substantial changes were detected on day 4, at a time when the uterus normally initiates its transient “window of receptivity.” Following induction of the DCR with the lectin Concanavalin A (Con A) at this time, even greater alterations in uterine lipid composition were observed. From 20 to 1,280 min post-Con A-treatment the percentage composition of SFA in the treated left uterine horn changed from 43% to 64%, sterols from 19% to 4%, PUFA from 15% to 10%, while MUFA remained unchanged at 23%. The lipid profile of the untreated right uterine horn of these animals was similar to that of the Con A-treated left uterine horn during the early stages. However, by 1,280 min substantial differences were observed, at a time corresponding with Con A-induced uterine growth. In contrast, differences in the lipid profile of Con A- and saline-treated uteri were observed at 320 min post-treatment, a time preceding Con A-induced uterine growth. Furthermore, the tissue concentration (nmol/mg dry weight) of SFA and sterols in uterine tissue decreased significantly following Con A treatment. The results suggest that uterine lipid changes are implicated in the development of uterine receptivity, and in the remodeling of uterine tissue for successful embryonic invasion and the establishment of pregnancy. © 1996 Wiley-Liss, Inc     

Effect of sex,dietary glycerol or dietary fat during late fattening,on fatty acid composition and positional distribution of fatty acids within the triglyceride in pigs

The effect of sex, source of saturated fat (lard v. palm oil) and glycerol inclusion in the fattening diet on composition and fatty acid positional distribution in the triglyceride molecule was studied in pigs from 78 to 110 kg BW. Average daily gain and carcass characteristics, including ham and loin weight, were not affected by dietary treatment but sex affected backfat depth (P<0.01). A significant interaction between sex and glycerol inclusion was observed; dietary glycerol increased lean content in gilts but not in barrows (P<0.05 for the interaction). Individual and total saturated fatty acid (SFA) concentrations were greater in barrows than in gilts. In contrast, the concentration of total polyunsaturated fatty acids (PUFA) and of C18:2n-6, C18:3n-3, C20:3n-9 and C20:4n-6 in the intramuscular fat (IMF) was higher (P<0.05) in gilts than in barrows. Sex did not affect total monounsaturated fatty acids (MUFA) concentration in the IMF. The proportion of SFA in the subcutaneous fat (SF) was higher in barrows than in gilts (P<0.001). Within the individual SFA, sex affected only the concentrations of C14:0 and C16:0 (P<0.001). Dietary fat did not affect total SFA or PUFA concentrations of the IMF but the subcutaneous total MUFA concentration tended to be higher (P=0.079) in pigs fed lard than in pigs fed palm oil. Dietary glycerol increased total MUFA and C18:1n-9 concentration in the IMF and increased total MUFA and decreased C18:2n-6, C18:3n-3 and total PUFA concentrations in the SF. The data indicate that altering the fatty acid composition of the triglyceride molecule at the 2-position, by dietary intervention during the fattening phase, is very limited.     

Dietary fatty acids modulate antigen presentation to hepatic NKT cells in nonalcoholic fatty liver disease

Dietary fatty acids are major contributors to the development and progression of insulin resistance and nonalcoholic fatty liver disease (NAFLD). Dietary fatty acids also alter hepatic NKT cells that are activated by antigens presented by CD1d. In the current study, we examine the mechanism of dietary fatty acid induced hepatic NKT cell deficiency and its causal relationship to insulin resistance and NAFLD. We discover that dietary saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA), but not polyunsaturated fatty acids (PUFA), cause hepatic NKT cell depletion with increased apoptosis. Dietary SFA or MUFA also impair hepatocyte presentation of endogenous, but not exogenous, antigen to NKT cells, indicating alterations of the endogenous antigen processing or presenting pathway. In vitro treatment of normal hepatocytes with fatty acids also demonstrates impaired ability of CD1d to present endogenous antigen by dietary fatty acids. Furthermore, dietary SFA and MUFA activate the NFκB signaling pathway and lead to insulin resistance and hepatic steatosis. In conclusion, both dietary SFA and MUFA alter endogenous antigen presentation to hepatic NKT cells and contribute to NKT cell depletion, leading to further activation of inflammatory signaling, insulin resistance, and hepatic steatosis.     

Fatty acid composition of wild and cultured northern pike (Esox lucius)

The aim of the study was to determine the effect of diet on the fatty acids composition of cultured northern pike (Esox lucius) fillet (mean body weight, 620 g; age, 2.5 years; commercial feed) profiles when compared with wild pike caught in Lake Dga? Wielki in northern Poland (mean body weight, 570 g; age 3.5 years). Cultured pike fillets contained several times more fat (2.40%) compared with wild fish (0.19%, P < 0.01). The total relative quantity of saturated fatty acids (SFA; % of total fatty acids) and unsaturated fatty acids (USFA) in cultured and wild pike were similar. Monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) content differed in wild and cultured fish. Cultured pike contained nearly two times more MUFA (30.90% compared with 15.97%; P < 0.01) but less PUFA (42.04% compared with 58.33%; P < 0.01), n‐3 PUFA (32.42% compared with 41.26%; P < 0.01), and n‐6 PUFA (6.47% compared with 15.79%; P < 0.01). The largest differences were noted with regard to docosahexaenoic acid (DHA) and arachidonic acid (AA), the levels of which in cultured and wild pike were 18.93% vs 27.96% and 0.73% vs 8.60%, respectively (P < 0.01). Quality compositions of the commercial feed and the cultured pike fillets were identical.     

Effects of conjugated linoleic acid or betaine on the growth performance and fatty acid composition in backfat and belly fat of finishing pigs fed dried distillers grains with solubles

The objectives of this study were to determine the effects of conjugated linoleic acid (CLA) or betaine on the growth performance, carcass characteristics and fatty acid composition in backfat and belly fat of pigs fed distillers dried grains with solubles (DDGS). Thirty-two (60±2 kg) crossbred barrows (Duroc×Landrace×Yorkshine) were assigned to one of four diets randomly: (1) the control diet containing no corn DDGS (control group); (2) the diet containing 30% corn DDGS (DDGS-fed group); (3) the diet containing 30% corn DDGS and 10 g/kg CLA (CLA-fed group); (4) the diet containing 30% corn DDGS and 1 g/kg BET (BET-fed group). The pigs fed DDGS showed that the percentages of C18:2, polyunsaturated fatty acid (PUFA) and iodine value (IV) increased, while C18:1, saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) decreased. Pigs fed the DDGS+CLA or DDGS+betaine diets showed the increased percentage of SFA, and the decreased percentage of C18:2, PUFA and IV. In conclusion, results confirmed that the diets containing 30% DDGS had no detrimental effects on growth performance, but increased the percentage of PUFA and IV and decreased the percentage of SFA and MUFA in the backfat and belly fat. However, supplementation with CLA or BET can part reverse these effects on carcass fat in finishing pigs.     

Effect of Mediterranean and Occidental diets, and red wine, on plasma fatty acids in humans. An intervention study

The type of diet consumed by individuals has been associated with the development of some chronic diseases, including cardiovascular disease (CVD), cancer, diabetes, and others. Populations that consume diets rich in fruits and vegetables and drink wine in moderation, as the Mediterranean, have a higher life expectancy and less chronic diseases than other occidental populations. We carried out an intervention study in humans to evaluate the effect of a Mediterranean diet (MD), an Occidental diet (OD) and their supplementation with red wine, on biochemical, physiological and clinical parameters related to atherosclerosis and other chronic diseases. For 3 months, two groups of 21 male volunteers each, received either a MD or an OD; during the second month, red wine was added isocalorically, 240 ml/day. At days 0, 30, 60 and 90, clinical, physiological and biochemical evaluations were made. In this article we report on the results obtained in plasma fatty acids profile that includes saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), omega-6 fatty acids, omega-3 fatty acids and omega-6/omega-3 ratio. Other results have been published previously. Plasma fatty acid percentages in the OD group, compared to the MD group, did not show differences in SFA, but the OD group showed lower levels of MUFA and omega-3 fatty acids, and higher levels of PUFA and omega-6 fatty acids, with a higher omega-6/omega-3 ratio than the MD group. Wine supplementation reduced MUFA and increased PUFA in both dietary groups, suggesting that wine could improve a diet with a good omega-6/omega-3 ratio. Volunteers on MD showed a better fatty acid profile than those on OD, suggesting a lower cardiovascular risk. Moderate consumption of wine improves this profile in the MD group.     

Seasonal variation in fatty acid composition of silver pomfrets,Pampus argenteus (Euphrasen), in Kuwait waters

Proximate and fatty acid composition of wild silver pomfrets, Pampus argenteus, were studied in Kuwait waters for a period of 1 year (November 2007–October 2008) to see whether there were any seasonal compositional differences between males and females. Ten adults (five males, five females) were sampled each month during (i) Pre‐spawning (March–May), (ii) Spawning (June–August), (iii) Post‐spawning (September–November), and (iv) Winter (December–February). Both sexes had significantly (P < 0.05) higher whole body moisture and lower crude protein and lipid contents in winter compared to the respective males and females sampled in other seasons. However, females had significantly higher (9.1%) lipid content during the pre‐spawning season than females in other seasons (7.0–8.2%). The most abundant fatty acid in whole body lipid in both sexes was C16 followed by C18:1n‐9, which accounted for about 31–35% and 22–24% of total lipids, respectively. Males in the pre‐spawning and spawning seasons had significantly higher total monosaturated fatty acids (MUFA) than males and females in post‐spawning and winter. Males had significantly higher total polyunsaturated fatty acids (PUFA) during post‐spawning seasons than females in pre‐spawning and winter seasons. However, there were no significant differences (P > 0.05) in total saturated fatty acids (SFA), PUFA, EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) or n‐3/n‐6 ratios between respective males and females in different seasons. Livers in males had significantly (P < 0.05) higher MUFA, SFA, PUFA, EPA and DHA than respective females in all months during the spawning season. Female gonads had significantly (P < 0.05) higher MUFA and PUFA but lower SFA content than males in different months during the spawning season. In contrast to the liver, the gonad DHA content and n‐3/n‐6 ratios in females were significantly higher than in males. The gonads from both sexes contained more than double the amount of EPA present in liver; in the case of DHA this was more than three‐fold higher in female gonads, but not in males. Thus, the presence of higher proportions of PUFA, EPA and DHA in gonads, particularly in eggs of silver pomfret, indicates their need for these fatty acids, which may be used as a guideline for dietary essential n‐3 fatty acid requirements for feed formulation of this species. A higher content of DHA in eggs also indicates the higher requirement for DHA in the broodstock diet of silver pomfret.     

Fatty acid-related modulations of membrane fluidity in cells: detection and implications

Abstract

Metabolic homeostasis of fatty acids is complex and well-regulated in all organisms. The biosynthesis of saturated fatty acids (SFA) in mammals provides substrates for β-oxidation and ATP production. Monounsaturated fatty acids (MUFA) are products of desaturases that introduce a methylene group in cis geometry in SFA. Polyunsaturated fatty acids (n-6 and n-3 PUFA) are products of elongation and desaturation of the essential linoleic acid and α-linolenic acid, respectively. The liver processes dietary fatty acids and exports them in lipoproteins for distribution and storage in peripheral tissues. The three types of fatty acids are integrated in membrane phospholipids and determine their biophysical properties and functions. This study was aimed at investigating effects of fatty acids on membrane biophysical properties under varying nutritional and pathological conditions, by integrating lipidomic analysis of membrane phospholipids with functional two-photon microscopy (fTPM) of cellular membranes. This approach was applied to two case studies: first, pancreatic beta-cells, to investigate hormetic and detrimental effects of lipids. Second, red blood cells extracted from a genetic mouse model defective in lipoproteins, to understand the role of lipids in hepatic diseases and metabolic syndrome and their effect on circulating cells.     

Spatial and temporal variation of the fatty acid composition of Patella spp. (Gastropoda: Prosobranchia) soft bodies and gonads

This study evaluated the effects of season and spatial distribution on the fatty acid composition of Patella depressa gonads and Patella spp. soft body tissue. The results show that the quantitatively most important fatty acids were the saturated fatty acids (SFA) 16:0, 14:0 and 18:0; the monounsaturated fatty acids (MUFA) 18:1(n-7), 18:1(n-9), 16:1(n-7) and 20:1(n-9) and the polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA 20:5(n-3)), and arachidonic acid (ARA 20:4(n-6)). P. depressa and P. ulyssiponensis soft body fatty acid profiles revealed significant differences between sexes; males showed significantly higher percentages of PUFA, highly unsaturated fatty acids (HUFA), (n-3) fatty acids and ARA, while in females significantly higher proportions of MUFA were found. Analysis of variance on the fatty acid composition of P. depressa gonads revealed significant differences between sexes, which were more marked than when the whole body was analysed. Males showed a significantly higher percentage of PUFA, HUFA, fatty acids from the (n-3) and (n-6) series, ARA and EPA, while females were seen to have higher proportions of SFA, MUFA and total fatty acid methyl esters (FAME). Some variability was seen to occur due to shore location and seasons, but these effects were not so obvious.     

Rearing system and oleic acid supplementation effect on carcass and lipid characteristics of two muscles from an obese pig breed

Quality of pork depends on genotype, rearing and pre- and post-slaughter conditions. However, no information is available on rearing system changes and oleic acid supplementation on carcass characteristics and fatty acid (FA) profile of pork from the Alentejano (AL) pig, an obese breed. This study evaluates the effects of feeding low (LO) or high oleic acid diets (HO) to AL pigs reared in individual pens (IND) or outdoor (OUT) with access to pasture. Carcass composition was obtained and longissimus dorsi and semimembranosus samples were collected to analyse chemical composition and neutral and polar intramuscular lipids FA profile by gas chromatography. Statistical analysis was performed by a two-way ANOVA for rearing system and diet effects. OUT-reared pigs presented leaner carcasses than IND-reared ones. Both muscles presented lower intramuscular lipid content in OUT-reared pigs. Treatments affected the FA profile of muscles. Overall, OUT-reared pigs presented lower n-6/n-3 FA ratios, whereas pigs fed the HO diet exhibited lower saturated fatty acids (SFA), higher monounsaturated fatty acids (MUFA) levels and lower thrombogenic indexes on neutral intramuscular lipids than LO-fed pigs. On the polar fraction, OUT-reared pigs presented lower SAT and n-6/n-3 FA ratio, and higher polyunsaturated fatty acids (PUFA) levels on both muscles. Pigs fed the HO diet exhibited higher MUFA and lower PUFA levels on both muscles, and lower SAT levels on semimembranosus. This study shows rearing system and oleic acid supplementation have complementary effects and influence carcass composition and the nutritional quality of meat.