Fatty acid composition as a function of latitude in barnacle cyprid larvae

Downward flux of particulate fatty acids in the Central Arabian Sea

The black soldier fly (Hermetia illucens) has emerged as an interesting alternative protein source in animal feed due to its ability to grow on various substrates. Although it has many rearing benefits and possible applications, it has an unfavourable fatty acid profile if used for human consumption due to its high content of lauric acid and low content of polyunsaturated fatty acids. In order to investigate whether the lipid composition of black soldier fly larvae can be altered, the feeding media were supplemented with varying concentrations of fish, linseed or coconut oil (1, 2.5 and 5%). Two-week-old larvae were collected, measured and their tissue fatty acid composition was determined. The fatty acid profile of the larvae showed significant plasticity, depending on the life stage and the fatty acid composition of the feeding media. The addition of 2.5 and 5% of different oils significantly changed the fatty acid composition of larvae, depending on the type and percentage of oil. The n6/n3 ratio was considerably improved by supplementing fish and linseed oil. The addition of linseed oil increased the content of linolenic acid, but bioconversion to eicosapentaenoic and docosahexaenoic acids was low. In contrast, the addition of fish oil significantly increased the content of eicosapentaenoic and docosahexaenoic acids in the larvae. The content of lauric acid significantly increased after coconut addition. The trial showed that by using different oils, the lipid composition of black soldier fly larvae could be specifically changed to increase the beneficial long chain n3 polyunsaturated fatty acids, and the amount of lauric or linolenic acid.

Lipid content and fatty acid composition of larvae and adults of the velvetbean caterpillar, Anticarsia gemmatalis, as affected by larval diet

Effects of different mono, bi and trispecific microalgal diets on survival, growth, development, settlement and fatty acid composition of mussel Mytilus galloprovincialis (Lamarck, 1819) larvae

Over the past 100 years, changes in the food supply in Western nations have resulted in alterations in dietary fatty acid consumption, leading to a dramatic increase in the ratio of omega-6 (omega6) to omega3 polyunsaturated fatty acids (PUFA) in circulation and in tissues. Increased omega6/omega3 ratios are hypothesized to increase inflammatory mediator production, leading to higher incidence of inflammatory diseases, and may impact inflammatory gene expression. To determine the effect of reducing the omega6/omega3 ratio on expression of inflammatory pathway genes in mononuclear cells, healthy humans were placed on a controlled diet for 1 week, then given fish oil and borage oil for an additional 4 weeks. Serum and neutrophil fatty acid composition and ex vivo leukotriene B(4) production from stimulated neutrophils were measured at the start and end of the supplementation period and after a 2-week washout. RNA was isolated from mononuclear cells and expression of PI3K, Akt, NFkappaB, and inflammatory cytokines was measured by real-time PCR. A marked increase was seen in serum and neutrophil levels of long-chain omega3 PUFA concomitant with a reduction in the omega6/omega3 PUFA ratio (40%). The ex vivo capacity of stimulated neutrophils to produce leukotriene B(4) was decreased by 31%. Expression of PI3Kalpha and PI3Kgamma and the quantity of PI3Kalpha protein in mononuclear cells was reduced after supplementation, as was the expression of several proinflammatory cytokines. These data reveal that PUFA may exert their clinical effects via their capacity to regulate the expression of signal transduction genes and genes for proinflammatory cytokines.

Given that the effects of trans fatty acids (TFA) may be associated with the type of TFA isomer and the proportion of n‐3/n‐6/n‐9 fatty acids (FA), this work aimed to investigate the influence of different oils on the following parameters: content, incorporation, and retention of TFA; conversion of vaccenic acid (VA) to rumenic acid (RA) in different tissues; and hepatic output of TFA by VLDL. Another objective was to assess relative conversion rates of key FA and the potential alteration of FA composition induced by TFA in tissues. Male CF1 mice were fed (30‐days) diets containing 7% olive, corn or rapeseed oils either supplemented with 0.75% of TFA or without added TFA. FA composition of liver, epididymal adipose tissue, gastrocnemius muscle, brain, and serum was assessed. With the exception of the brain, TFAs were incorporated into the analyzed tissues and serum. TFA retention and RA bioconversion from VA depended on the dietary unsaturated FA proportions. The higher levels of hepatic RA in the liver of mice fed an olive oil+TFA diet could be associated with a raised Δ9‐desaturase index. The FA composition of tissues was scarcely modified by the consumption of partially hydrogenated vegetable oils containing similar proportions of t9‐, t10‐, and t11‐18:1.Practical applications: The present study evaluates the interaction of hydrogenated vegetable oils with different edible oils and the impact on the FA profile and, specifically, TFA incorporation and retention in the tissues. Since the characterization of FA present in tissues might be determining the biological effects of edible fats, this study is relevant for elucidation of existing controversial findings associated with the intake of TFA and its effects on human metabolic alterations.The levels of trans fatty acids (TFA) in a particular tissue might be related to different variables including: type and level of the dietary TFA isomer; uptake, metabolization and release from the tissue, and interference with different dietary fatty acids.

Apparent digestion and apparent retention of lipid and fatty acids in Atlantic cod ( Gadus morhua) fed increasing dietary lipid levels

Fatty acids in fresh meat contribute to palatability in many ways. However, fatty acids primarily influence flavor and juiciness. Perceived juiciness is impacted through lubrication by fatty acids and stimulation of saliva during mastication. Therefore, the content of fatty acids primarily impacts juiciness. However, for flavor, fatty acid content and composition are each important. Volatile flavor compounds have been demonstrated to have greater expression as overall fatty acid content increases. This may be through the retention of fat-soluble volatile compounds leading up to consumption. In addition to content, fatty acid composition may also be altered. Factors, such as, species, muscle, and diet dictate fatty acid composition. In general, these factors mediate proportions of major fatty acids and thus alter levels of fatty acid saturation. As fatty acid saturation is decreased, there is greater propensity towards oxidation. Greater fatty acid oxidation generally leads to negative off-flavors. During storage and handling there is opportunity for less saturated fresh meats to undergo oxidation, ultimately impacting flavor. To summarize, both fatty acid content and composition play roles in fresh meat palatability. Understanding the role of fatty acids in palatability helps equip processors and meat scientist to maintain or improve meat palatability.

To investigate the nutritional composition of fatty acids in freshwater products in Hunan Province. The edible parts of freshwater products were detected by gas chromatography, and fatty acid fingerprints were obtained by statistical analysis. A total of 18 freshwater products were monitored and 14-26 fatty acids were detected in each freshwater product. Among them, 12 were saturated fatty acids(SFA), ranging from 0. 74 to 3143 mg/100 g, 9 were monounsaturated fatty acids(MUFA), ranging from 1. 23 to 2790 mg/100 g, and 10 were polyunsaturated fatty acids(PUFA), ranging from 1. 75 to 2832 mg/100 g. The ratio of n-6 to n-3 in polyunsaturated fatty acids ranged from 0. 24∶1 to 15. 7∶1. The composition of fatty acids in freshwater products in Hunan Province is mainly unsaturated fatty acids. Most freshwater products are rich in n-3 PUFA, and the ratio of n-6 PUFA to n-3 PUFA is less than 6, which is beneficial to the nutritional balance. The composition and content of fatty acids have ideal nutritional value.

Epidemiological studies suggest that chronic consumption of trans MUFA may alter muscle insulin sensitivity. The major sources of dietary trans MUFA (dairy fat vs. industrially hydrogenated oils) have different isomeric profiles and thus probably different metabolic consequences. These effects may involve alterations in muscle mitochondrial oxidative capacity, which may in turn promote insulin resistance if fatty acid oxidation is reduced. We report that in Wistar rats, an 8 week diet enriched (4% of energy intake) in either dairy, industrial, or control MUFA did not alter insulin and glucose responses to an intraperitoneal glucose tolerance test (1g/kg). In C2C12 myotubes, vaccenic and elaidic acids did not modify insulin sensitivity compared with oleic acid. Furthermore, the ex vivo total, mitochondrial and peroxisomal oxidation rates of [1-(14)C]oleic, vaccenic, and elaidic acids were similar in soleus and tibialis anterior rat muscle. Finally, an 8 week diet enriched in either dairy or industrial trans MUFA did not alter mitochondrial oxidative capacity in these two muscles compared with control MUFA but did induce a specific reduction in soleus mitochondrial ATP and superoxide anion production (P<0.01 vs. control). In conclusion, dietary trans MUFA of dairy or industrial origin have similar effects and do not impair muscle mitochondrial capacity and insulin sensitivity.

Dietary fatty acid (FA) composition in early postnatal life can modulate growth and development and later metabolic health. Investigating programming effects of early dietary FA manipulations in rodents may be stressful and complicated due to the need of artificial feeding techniques. It is largely unknown to what extent breast milk (BM) FA composition can be directly manipulated by the diet. We exposed dams to different dietary FA compositions from postnatal day (PN) 2 until PN28. Dams with litters were randomly assigned to control (CTRL), high-medium-chain FA (MCFA), low-linoleic acid (LowLA), high-n-3 long-chain PUFA (n-3LCP) or high-n-3LCP and MCFA (n-3LCP/MCFA) diets, and diets were continued after weaning until PN28. FA compositions were determined in feeds, milk and in erythrocytes. BM MCFA content was independent from dietary MCFA intake. In contrast, the LowLA diet reduced BM LA content by about 50 % compared with the CTRL diet at PN7. BM of dams fed the n-3LCP or n-3LCP/MCFA diet contained about 6-fold more n-3 LCP than BM of the dams fed the CTRL diet at PN7. These changes in milk FA composition established after 5 d of dietary exposure did not further change over the lactation period. At PN28, the erythrocyte FA composition of the male pups correlated with analysed milk FA profiles. In conclusion, manipulation of the diet of lactating mice can strongly and rapidly affect BM FA composition, in particular of n-6 LA and n-3 LCP. Our present findings will facilitate mechanistic studies on the programming of adult metabolic health by dietary FA in the early postnatal period via direct and selective manipulation of the maternal diet.

We determined fatty acid (FA) profiles and carbon stable isotopic composition of individual FAs (δ(13)CFA values) from sea ice particulate organic matter (i-POM) and pelagic POM (p-POM) in the Bering Sea during maximum ice extent, ice melt, and ice-free conditions in 2010. Based on FA biomarkers, differences in relative composition of diatoms, dinoflagellates, and bacteria were inferred for i-POM versus p-POM and for seasonal succession stages in p-POM. Proportions of diatom markers were higher in i-POM (16:4n-1, 6.6-8.7%; 20:5n-3, 19.6-25.9%) than in p-POM (16:4n-1, 1.2-4.0%; 20:5n-3, 5.5-14.0%). The dinoflagellate marker 22:6n-3/20:5n-3 was highest in p-POM. Bacterial FA concentration was higher in the bottom 1 cm of sea ice (14-245 μg L(-1)) than in the water column (0.6-1.7 μg L(-1)). Many i-POM δ(13)C(FA) values were higher (up to ~10‰) than those of p-POM, and i-POM δ(13)C(FA) values increased with day length. The higher i-POM δ(13)C(FA) values are most likely related to the reduced dissolved inorganic carbon (DIC) availability within the semi-closed sea ice brine channel system. Based on a modified Rayleigh equation, the fraction of sea ice DIC fixed in i-POM ranged from 12 to 73%, implying that carbon was not limiting for primary productivity in the sympagic habitat. These differences in FA composition and δ(13)C(FA) values between i-POM and p-POM will aid efforts to track the proportional contribution of sea ice algal carbon to higher trophic levels in the Bering Sea and likely other Arctic seas.

Non-thermal stress-induced modifications of fatty acids profiles in rat brown adipose tissue

The effects of altering dietary carbohydrates and lipids to oocyte donors during superovulation and ovum pickup (OPU) on in vitro embryo production was reported previously (Adamiak et al. 2004 Reprod. Dev. Fert. 16, 193–194). Here we report the effects of these dietary treatments on the fatty acid (FA) composition of plasma, granulosa cells (GCs), and cumulus–oocyte complexes (COCs) from the 32 heifers used in that study. Blood samples were collected by jugular venipuncture. COCs and GCs were harvested from each heifer by OPU as described previously but were pooled between pairs of heifers within treatment to provide adequate material for FA analysis. Both GCs and COCs were washed twice in PBS supplemented with 0.3% (w/v) BSA (FA-free) before being transferred into 2 : 1 (v/v) chloroform : methanol solution for FA extraction. FA composition was determined using gas chromatography as described previously (Reis et al. 2002, Theriogenology 57, 507). Data were analyzed by ANOVA. Total plasma FA content averaged 1.12 μg/mL and was unaffected by body condition score (BCS). Low BCS heifers had more saturated (54.0 ± 1.76 vs. 49.2 ± 1.74%) and monounsaturated (22.4 ± 1.08 vs. 18.2 ± 0.69%) FA, but less polyunsaturated FA (PUFA) (23.7 ± 1.75 vs. 32.8 ± 2.21%) in plasma than moderate BCS heifers (P &lt; 0.01). Animals fed high relative to low fiber diets had greater plasma FA (1.3 ± 0.15 vs. 1.0 ± 0.12 μg/mL) and PUFA (31.2 ± 2.56 vs. 25.3 ± 2.19%), but less monounsaturated FA (18.8 ± 1.04 vs. 21.5 ± 1.09%) (P &lt; 0.01). Dietary protected lipid (Ca soaps of FA) increased plasma FA (1.6 ± 0.07 vs. 0.6 ± 0.04 μg/mL) and PUFA (30.0 ± 1.92 vs. 26.4 ± 3.03%) (P &lt; 0.05), but reduced plasma saturated FA (48.9 ± 1.12 vs. 54.2 ± 2.14%; P &lt; 0.01) in the animals fed high compared to low fiber diets, respectively. In contrast to their effects in plasma, BCS and diet had little effect on FA composition of GCs and COCs. Although low BCS and dietary lipids both increased FA in COCs (78.3 ± 2.01 vs. 69.2 ± 2.80, P &lt; 0.01; and 77.1 ± 2.96 vs. 70.5 ± 2.26 ng/COC; P &lt; 0.05, respectively), neither factor significantly altered the FA composition of COCs. Across treatments, the FA composition of GCs and COCs differed markedly from that of plasma (Table 1), confirming the presence of a selective uptake mechanism in the follicle that can moderate dietary induced fluctuations in FA supply from peripheral circulation. Table 1. Concentrations of fatty acids in plasma, GCs, and COCs expressed as mean percentages (w/w) of total fatty acids This work was supported by Defra and The Perry Foundation.

Condition indices (CI), hepatosomatic indices (HSI) and proximate, lipid and fatty acid composition of wild and laboratory-reared yellowtail flounder (Limanda ferruginea) (Storer, 1839) were compared from data taken throughout spring and summer 1996–1998. Cluster analysis was performed on the fatty acid signatures of these two groups along with a commercial diet and several invertebrate species to determine possible feeding patterns in Conception Bay, Newfoundland. HSI and levels of storage fat were significantly higher in the muscle and liver of laboratory-reared yellowtail flounder, indicating an efficient absorption of dietary lipid and an increase in fat deposition. Fatty acid analysis of the liver showed that wild fish contained significantly higher proportions of the essential fatty acids 20:4ω6, 20:5ω3 and 22:6ω3; whereas proportions of 18:1 and 18:2ω6 were significantly higher in all fractions of lipid examined from laboratory-reared fish than they were from wild fish. Polar fractions of lipid were more similar than the neutral fraction of lipid when comparing wild and laboratory-reared fish. Taken together, the differences in CI, HSI, proximate and fatty acid composition suggest that feeding commercial diets to L. ferruginea can cause changes in patterns of lipid deposition and metabolism. Cluster analysis of marine plankton, sedimenting particulate matter, wild invertebrates, the commercial diet and fish tissues showed that the fatty acid signatures of both wild and laboratory-reared yellowtail flounder closely resembled their respective food items. Fatty acid signatures from wild fish were more closely related to plankton and settling particulate matter, suggesting relatively few steps in the food web leading to yellowtail flounder. In addition to the resemblance between fatty acids in the commercial diet and the tissues of laboratory-reared yellowtail flounder, these fish had similar fatty acid signatures to those of wild invertebrates.