Changes In Fatty Acid Profile Research Articles

Three hen strains fed photoisomerized trans,trans CLA-rich soy oil exhibit different yolk accumulation rates and source-specific isomer deposition.

Most CLA chicken feeding trials used cis,trans (c,t) and trans,cis (t,c) CLA isomers to produce CLA-rich eggs, while reports of trans,trans (t,t) CLA enrichment in egg yolks are limited. The CLA yolk fatty acid profile changes and the 10-12 days of feeding needed for maximum CLA are well documented, but there is no information describing CLA accumulation during initial feed administration. In addition, no information on CLA accumulation rates in different hen strains is available. The aim of this study was to determine a mathematical model that described yolk CLA accumulation and depletion in three hen strains by using t,t CLA-rich soybean oil produced by photoisomerization. Diets of 30-week Leghorns, broilers, and jungle fowl were supplemented with 15% CLA-rich soy oil for 16 days, and eggs were collected for 32 days. Yolk fatty acid profiles were measured by GC-FID. CLA accumulation and depletion was modeled by both quadratic and piecewise regression analysis. A strong quadratic model was proposed, but it was not as effective as piecewise regression in describing CLA accumulation and depletion. Broiler hen eggs contained the greatest concentration of CLA at 3.2 mol/100 g egg yolk, then jungle fowl at 2.9 mol CLA, and Leghorns at 2.3 mol CLA. The t,t CLA isomer levels remained at 55% of total yolk CLA during CLA feeding. However, t-10,c-12 (t,c) CLA concentration increased slightly during CLA accumulation and was significantly greater than c-9,t-11 CLA. Jungle fowl had the smallest increase in yolk saturated fat with CLA yolk accumulation.

Changes in fatty acid profiles of sea cucumber Apostichopus japonicus (Selenka) induced by terrestrial plants in diets

It has been well known that fatty acid profiles of consumers were flexible in response to the changes in the fatty acid constituents of diets due to the different feed ingredients. No previous studies, however, have been carried out focused on the changes in fatty acid profiles of sea cucumber Apostichopus japonicus (Selenka) induced by the addition of terrestrial plants in diets. In the present study, 4 experimental diets were prepared with gradually increased proportions of terrestrial plants (corn meal and soybean meal) and concurrently decreased proportions of seaweed Sargassum thunbergii. The artificial feed of sea cucumber containing 50% of S. thunbergii was used as the control diet (diet 1), and S. thunbergii were replaced by the mixture of corn meal and soybean meal with the percentages of 10%, 20% and 30% in diets 2, 3 and 4, respectively. Fatty acid profiles of feed ingredients and sea cucumbers fed with the 4 experimental diets were determined. Results showed that fatty acid compositions of sea cucumbers were remarkably affected by those of the diets. Concentrations of fatty acids 16:0, 18:2n-6, 22:6n-3 and ∑ n-6 in sea cucumbers appeared to positively correlate with those in the diets. In contrast, contents of fatty acids 20:1n-9, 22:1n-9, 20:3n-3, 20:4n-6 and 20:5n-3 in sea cucumbers showed a significant increase with the increasing levels of corn meal and soybean meal in diets, even though the contents of these fatty acids in corn meal and soybean meal were lower, even absent, compared with S. thunbergii suggesting that sea cucumbers might have the ability to synthesize these fatty acids. Data of the growth performance revealed that sea cucumbers showed the highest weight gain in diet 2 and the lowest weight gain in diet 4 while the growth of the sea cucumbers in diet 3 did not remarkably differ with those in the control group.

Glicerina bruta na dieta de ovinos confinados: Composição centesimal e perfil de ácidos graxos do longissimus dorsi

The aim was to evaluate the centesimal composition and fatty acids profile of longissimus dorsi of wethers fed diets with increasing levels (0; 2.65; 5.33 e 8.06% in dry matter) of crude glycerin (CG). Were used 20 crossbred, castrated lambs Dorper x St. Ines, with 24 ± 2.0 kg of weight, housed in individual pens. The experimental design was completely randomized with four treatments and five replications. Diet samples were collected to fatty acids profile analyses. After 84 days of assessment and data collection, the animals were slaughtered. Longissimus dorsi samples were collected and frozen for subsequent analysis of fatty acids by gas chromatography. There was no effect of treatments on the ash content and protein, however, there was influence (P<0.05) on the lipid content and moisture. The fatty acids which had the highest percentages in meat were stearic and oleic acids respectively. These acids were not influenced (P>0.05) by increasing levels of crude glycerin in the diet. There was decreased linear effect (P<0.05) for palmitic fatty acid (16:0) and quadratic effect (P<0.05) for myristic acid (14:0) as a function of increasing glycerin levels in diet. The glycerin addition in the diets affected quadratically (P<0.05) the total polyunsaturated fatty acid (PUFA) and omega 6. There was increasing linear effect (P<0.05) for the sum of total conjugated linoleic acid (CLA) and PUFA / SFA ratio. Were not affected by increasing levels of glycerin in the diet the total saturated fatty acids (SFA), monounsaturated fatty acids, omega 3 family and 6 omega/omega 3 ratio. The inclusion of glycerin yielded changes in proximate composition and fatty acid profile of the meat, but these changes did not alter the meat quality.

The effect of oxygen on fatty acid composition of soil micromycetes

The aim of this work was to describe changes in fatty acid profiles of fungi growing under artificial conditions of oxygen depletion. In total, 133 fungal strains belonging to eight orders were isolated from cattle impacted soils and tested. The analysis of the ten most frequent fatty acids revealed significant shift in fatty acids composition as a result of decreasing oxygen level. Taxonomic- as well as aeration-dependent changes in the amounts of fungal biomarker fatty acids (18:1ω9 and 18:2ω6,9) were found. Therefore, the ratio of these two fatty acids could be considered as an indicator of anaerobic, microaerobic or aerobic conditions in soil. Moreover, fatty acid-based estimation of fungal biomass in soils should be performed as a sum of both biomarker fatty acids and with respect to the soil characteristics as well as to the composition of fungal community.

Plant-assisted rhizoremediation of decabromodiphenyl ether for e-waste recycling area soil of Taizhou, China.

To develop an effective phytoremediation approach to purify soils polluted by decabromodiphenyl ether (BDE-209) in e-waste recycling area, pot experiments were conducted through greenhouse growth of seven plant species in BDE-209-polluted soils. The hygrocolous rice (Oryza sativa L.) cultivars (XiuS and HuangHZ) and the xerophyte ryegrass (Lolium perenne L.) were found to be as the most effective functional plants for facilitating BDE-209 dissipation, with the removal of 52.9, 41.9, and 38.7% in field-contaminated soils (collected directly from field, with an average pollution concentration of 394.6 μg BDE-209 kg(-1) soil), as well as 21.7, 27.6, and 28.1% in freshly spiked soils (an average pollution concentration of 4413.57 μg BDE-209 kg(-1) soil, with additional BDE-209 added to field-contaminated soils), respectively. Changes in soil phospholipid fatty acid (PLFA) profiles revealed that different selective enrichments of functional microbial groups (e.g., arbuscular mycorrhizal fungi and gram-positive bacteria) were induced due to plant growth under contrasting water management (flooded-drained sequentially, flooded only, and drained only, respectively). The abundance of available electron donors and acceptors and the activities of soil oxido-reductases were also correspondingly modified, with the activity of catalase, and the content of NO3(-) and Fe(3+) increased generally toward most of the xerophyte treatments, while the activity of dehydrogenase and the content of dissolved organic carbon (DOC) and NH4(+) increased toward the hygrophyte treatments. This differentiated dissipation of BDE-209 in soils as function of plant species, pollution doses and time, and water-dependent redox condition. This study illustrates a possibility of phytoremediation for BDE-209-polluted soils by successive cultivation of rice followed by ryegrass coupling with suitable water management, possibly through dissipation pathway of microbial reductive debromination and subsequent aerobic oxidative cleavage of benzene ring.

Effect of Roasting on Fatty Acid Profile of Brown and Yellow Varieties of Flaxseed (<i>Linum usitatissimum </i>L)

Purpose: To monitor changes in fatty acid profiles of brown and yellow varieties of flaxseeds in the raw and roasted states using gas chromatography (GC).Methods: Samples of flaxseeds were extracted with n-hexane in a Soxhlet apparatus for 8 h. Methylesterification of the samples was performed by methanolic boron trifluoride (BF3-MeOH) method according to American Oil Chemists' Society (AOCS). Fatty acid (FA), analyzed using GC equipped with a split/splitless capillary injector and flame ionization detector (FID).Results: The results indicate that lipid content varied with the type of seed. Seed oil content was 53.31 ± 0.30 and 45.20 ± 0.20 % for roasted and unroasted brown flax, respectively, and 10.25 ± 0.04 % for the yellow type. The yellow and roasted brown type, at 300oC, showed the lowest and highest oil content, respectively. The highest calculated oxidizability (COX) value was found for the unroasted brown type (13.19 ± 0.01 %) whilst the lowest amount was observed for the roasted brown seed at 350oC (12.79 ± 0.01 %). COX value for yellow type was 5.62 ± 0.01 %.Conclusion: This study shows that the fatty acids content of flaxseeds vary with roasting conditions. This is significant because flax seed fatty acid composition influences the applications of the oil.Keywords: Oil, Flaxseed, Roasting, Fatty acid, Linum usitatissimum, Calculated oxidizability value

Mobilisation of blubber fatty acids of northern elephant seal pups (Mirounga angustirostris) during the post-weaning fast

Northern elephant seal pups were longitudinally sampled at Año Nuevo State Reserve during the post-weaning fast, in order to evaluate the changes of fatty acid (FA) profiles in serum as well as in the inner and outer layers of blubber. The major FAs of inner and outer blubber layers were broadly similar to those found in NES maternal milk previously measured, suggesting a direct deposit of dietary FAs in the blubber during the suckling period. The outer blubber layer contained more medium-chain monounsaturated FAs that contribute in keeping the fluidity of this tissue at cold temperatures. It was compensated by higher proportions of saturated FAs in the inner blubber layer. The FA signature of inner blubber, the layer that is mainly mobilised during energy deprivation, slightly differed from the signature of serum. There were greater proportions of medium-chain saturated FAs and ω-6 polyunsaturated FAs, and lower proportions of long-chain saturated FAs, medium-chain monounsaturated FAs and long-chain monounsaturated FAs in serum as compared to inner blubber. We also demonstrated that lipophilicity is the main factor governing the mobilisation of FAs from blubber. The least lipophilic FAs were preferentially hydrolysed from blubber, leading to an enrichment of the more lipophilic FAs in this tissue with the progression of the fast. The expression levels of HSL and ATGL, which are two enzymes involved in the lipolytic process, remained stable during the post-weaning fast. This suggests that the pups have developed the enzymatic mechanisms for an efficient lipolysis as soon as the first week of fast.

Fatty acid changes help to better understand regression of nonalcoholic fatty liver disease.

To investigate whether liver steatosis reduction due to a six-month dietary intervention results in significant changes in the concentrations of fatty acids. A group of 35 Caucasian individuals diagnosed with different levels of steatosis were prospectively enrolled in the present study. Analysis of the fatty acid profiles was performed according to changes in liver steatosis (liver steatosis reduction by one or two degrees) after a six-month dietary intervention. The diet helped reduce body mass in obese and overweight patients, and stabilize both glycemia and dyslipidemia. Fatty acids were extracted according to the Folch method and analyzed by gas chromatography. This study showed significant changes in fatty acid profiles in patients who had reduced liver steatosis by one as well as two degrees. A reduction in liver steatosis by one degree caused a significant increase in the level of the n-3 family: eicosapentaenoic acid (P < 0.055), docosapentaenoic acid-C 22:5 (P < 0.05) and docosahexaenoic acid (P < 0.05). A reduction in liver steatosis by two degrees caused a significant decrease in serum palmitoleic acid-C 16:1 (P < 0.05). Liver steatosis reduction is associated with changes in fatty acid profiles, and these changes may reflect an alteration in fatty acid synthesis and metabolism. These findings may help better understand regression of nonalcoholic fatty liver disease.

Perturbation of a Human Gut Ecosystem by Silver Chloride Colloids

The bactericidal and fungicidal properties of silver (Ag) and Ag salt colloids make them popular choices for a variety of applications including water purification, bio-medical therapies for burns, epilepsy, mental illness, gastroenteritis, syphilis and gonorrhea, amongst other diseases. In addition, individuals deliberately drink colloidal Ag and Ag salts in the belief that this self- therapy will be beneficial. Despite this widespread usage, very little is known about the impact of this metal on human gut consortia. Here we investigated the impact of Ag chloride colloids, at several concentrations, on a defined anaerobic and facultative anaerobic gut bacterial community developed from the collected stool of a healthy donor. Defined microbial ecosystem therapeutic- 1 (MET-1) consortia were exposed to different concentrations of colloidal Ag (25-200 mg/L) for 48 hrs and compared to unamended cultures. Carbon dioxide and nitrogen gases recovered from the headspace of anaerobic cultures were analyzed by an Agilent Technologies 7890B Gas Chromatograph. Fatty acid methyl ester profiles were extracted following the MIDI Sherlock Microbial Identification System protocol and detected by gas chromatography. Colloidal AgCl toxicity was also monitored by a suite of DNA analyses including polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) and 16S ribosomal RNA gene fragment 454-pyrosequencing. Colloidal AgCl had an overall deleterious impact on MET-1 bacterial abundance and their metabolic activities as evidenced by the 20 - 78% reduction in CO2 respiration and significant (p<0.01) changes in fatty acid profiles, including a greater reduction (15 - 100%) in most Gram negative signatures compared to controls. Multidimensional scaling and cluster analysis produced from PCR-DGGE profile-based DNA analysis, as well as gene sequencing also demonstrated the negative impact of colloidal Ag on MET-1, resulting in a shift in the community structure, including the apparent elimination of some beneficial species. Together, this research suggests that deliberate or inadvertent colloidal Ag ingestion could have a potential negative impact on our overall digestive health.

Dietary sunflower oil modulates milk fatty acid composition without major changes in adipose and mammary tissue fatty acid profile or related gene mRNA abundance in sheep

There are very few studies in ruminants characterizing mammary and adipose tissue (AT) expression of genes and gene networks for diets causing variations in milk fatty acid (FA) composition without altering milk fat secretion, and even less complementing this information with data on tissue FA profiles. This work was conducted in sheep in order to investigate the response of the mammary gland and the subcutaneous and perirenal AT, in terms of FA profile and mRNA abundance of genes involved in lipid metabolism, to a diet known to modify milk FA composition. Ten lactating Assaf ewes were randomly assigned to two treatments consisting of a total mixed ration based on alfalfa hay and a concentrate (60 : 40) supplemented with 0 (control diet) or 25 (SO diet) g of sunflower oil/kg of diet dry matter for 7 weeks. Milk composition, including FA profile, was analysed after 48 days on treatments. On day 49, the animals were euthanized and tissue samples were collected to analyse FA and mRNA abundance of 16 candidate genes. Feeding SO did not affect animal performance but modified milk FA composition. Major changes included decreases in the concentration of FA derived from de novo synthesis (e.g. 12:0, 14:0 and 16:0) and increases in that of long-chain FA (e.g. 18:0, c9-18:1, trans-18:1 isomers and c9,t11-CLA); however, they were not accompanied by significant variations in the mRNA abundance of the studied lipogenic genes (i.e. ACACA, FASN, LPL, CD36, FABP3, SCD1 and SCD5) and transcription factors (SREBF1 and PPARG), or in the constituent FA of mammary tissue. Regarding the FA composition of AT, the little influence of SO did not appear to be linked to changes in gene mRNA abundance (decreases of GPAM and SREBF1 in both tissues, and of PPARG in the subcutaneous depot). Similarly, the great variation between AT (higher contents of saturated FA and trans-18:1 isomers in the perirenal, and of cis-18:1, c9,t11-CLA and n-3 PUFA in the subcutaneous AT) could not be related to differences in gene mRNA abundance due to tissue site (higher LPL and CD36, and lower SREBF1 in perirenal than in subcutaneous AT). Overall, these results suggest a marginal contribution of gene expression to the nutritional regulation of lipid metabolism in these tissues, at least with the examined diets and after 7 weeks on treatments. It cannot be ruled out, however, that the response to SO is mediated by other genes or post-transcriptional mechanisms.

Changes of Fatty Acid Profile During Gamma Irradiation of Rainbow Trout (Oncorhynchus mykiss) Fillets

Changes of Fatty Acid Profile During Gamma Irradiation of Rainbow Trout (Oncorhynchus mykiss) Fillets

LED (Light-Emitting Diode)를 이용한 미세조류 (Chaetoceros calcitrans)의 성장 및 생화학적 조성 변화

The marine microalgae Chaetoceros calcitrans was cultured under a fluorescent lamp (CON) and light-emitting diodes (LEDs) of various wavelengths (blue, LB; red, LR; green, LG; white, LW); changes in growth, fucoxanthin, chlorophyll-a, amino acid and fatty acid profiles were investigated. LR-exposed cultures exhibited the highest specific growth rate (SGR) (0.34), whereas LG-exposed cultures showed the lowest SGR (0.26). After cultivation for 10 days, the maximum dry cell weight (g/L) of LR-exposed cultures was significantly higher than that of those exposed to other light conditions (LR≧ CON>LB≧LW≧LG). Eicosapentaenoic acid (EPA) levels were significantly higher in CON-exposed cultures compared to those exposed to LW (P 0.05). The fucoxanthin content was highest in LB-exposed cultures (6.3μg/mL), whereas LW showed the lowest (3.6μg/mL; P<0.05). Chlorophyll-a content was highest in cultures exposed to LB compared to other light sources. These results suggest consistent differences in growth and biochemical composition after exposure to light of different wavelengths.

Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds.

Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. Amore detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600000 and 1500000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production.

Vliv doplňkového ruminálně chráněného lysinu, methioninu nebo obou do krmné dávky laktujících dojnic na skladbu mastných kyselin mléka

The objective of this study was to determine the effect of supplemental lysine (Lys), methionine (Met) or both added to diet of dairy cows in the form of rumen-protected (RP) tablets on changes in milk fatty acids (FA) profile. The trial was carried out on four lactating Holstein cows in the form of Latin square design and was divided into 4 periods of 14 d (10-d preliminary period and a 4-d experimental period). The four treatments were as follows: C – control without amino acids (AA) supplementation, L – supplement of RP Lys, M – supplement of RP Met and ML – supplement of RP Met and Lys. Cows were fed on a diet based on maize silage, lucerne hay and supplemental mixture. Milk yield in ML (34.18 kg/d) was higher than in L or M (32.46 kg and 32.13 kg, respectively, P &lt; 0.05) and tended to be higher than in C (33.33 kg/d, P &gt; 0.05). Protein yield in ML (1054 g / d) was higher than that found in C, L or M (990, 998 or 968 g / d, respectively, P &lt; 0.05). Milk fat content and yield in C and ML was higher in comparison to L and M (P &lt; 0.05). Content of short-chain FA (C 4:0–C 12:0) was not affected by the treatment except of L that was lower than in C (P &lt; 0.05). Content of medium-chain FA in M was lower compared to C, L or ML (P &lt; 0.05). The content of long-chain FA in M was significantly higher than in other groups (P &lt; 0.05). The total content of SFA in M was lower than in C or ML (P &lt; 0.05) and tended to be lower than in L. Contents of UFA, MUFA and PUFA in M were higher than in C and ML (P &lt; 0.05).

Comparison of total lipids and fatty acids from liver, heart and abdominal muscle of scalloped (Sphyrna lewini) and smooth (Sphyrna zygaena) hammerhead sharks.

Liver, heart and abdominal muscle samples from scalloped (Sphyrna lewini) and smooth (Sphyrna zygaena) hammerhead sharks were analysed to characterise their lipid and fatty acid profiles. Samples were compared both between and within species, but there were no significant differences in total lipids for either comparison, although much greater total amounts were found in the liver samples. Within the individual fatty acids, the only significant differences were greater amounts of 22:6n-3, total n-3 polyunsaturates and total polyunsaturates in smooth, when compared to scalloped, hammerhead liver. This may reflect the more wide spread distribution of this species into cooler waters. Within both species the liver levels of the same fatty acid fractions decreased from spring to summer, which may correlate with changes in fatty acid profile to adapt to any differences in amount or species of prey consumed, or other considerations, eg. buoyancy, however there was no data to clarify this.

Chlorpyrifos-induced changes in the antioxidants and fatty acid compositions of Chroococcus turgidus NTMS12.

This study investigated the effect of pesticide chlorpyrifos (CP) on a freshwater cyanobacterium Chroococcus turgidus NTMS12. The changes in chlorophyll-a, proline, superoxide dismutase (SOD), catalase (CAT) activities and fatty acid composition of the test organism were analysed. Organism was grown at 6, 9 and 12 mg l(-1) of CP, and based on the chlorophyll-a content, 6 mg l(-1) of CP was found to be the tolerable concentration. Hence, 6 mg l(-1) of CP was taken to evaluate the concentration of proline and activities of SOD and CAT at 48-h exposure. The changes in the fatty acid profile were analysed after 7 days of exposure. Upon pesticide exposure, increased concentration of proline and activities of SOD and CAT were found. Significant changes in fatty acid profile have also been observed. However, polyunsaturated fatty acid content was decreased in treated cultures when compared with the untreated control. Changes in biochemical activities indicate that cyanobacteria C. turgidus NTMS12 undergo adaptive changes against CP-induced oxidative stress. : Chlorpyrifos induces oxidative stress in Chroococcus turgidus NTMS12. A strong inference was made on increased activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and proline content and lowering the level of unsaturated fatty acids under the pesticide-exposed condition. These significant changes are the defence mechanisms against the oxidative stress. Thus, this organism holds great promise in resisting toxic pesticide.

High levels of whole raw soybean in diets for Nellore bulls in feedlot: effect on growth performance, carcass traits and meat quality.

The objective of this study was to evaluate the effect of whole raw soybean (WRS) in the finishing diet of Nellore cattle on productive performance, carcass traits, meat quality, fatty acid profile of meat, and blood parameters. In a completely randomized design, 52 Nellore bulls (mean body weight±SD: 380±34kg) were allotted for 84days. The animals received the following diets with a forage: concentrate ratio of 40/60: (i) WRS0: control diet without soybean grains; (ii) WRS8: diet containing 8% WRS in dry matter basis; (iii) WRS16: diet containing 16% WRS, and (iv) WRS24: diet containing 24% WRS. At intervals of 28days, the animals were weighed, muscle and adipose tissue was analysed by ultrasound, and blood samples were collected. The animals were slaughtered on day 85 and liver weight and hot carcass weight were measured during slaughter. The pH and carcass dressing were calculated at 24h after slaughter. Longissimus dorsi muscle samples were collected for the determination of fatty acid profile of meat, ether extract, tenderness and sensory analysis of meat aged for 14days. Blood cholesterol content increased linearly with increasing proportion of whole raw soybean grains. The diet did not affect performance or carcass attributes. The WRS8 had the highest shear force values. In fatty acid profile, C14:0 decreased (p=0.05), whereas 16:1, 20:0 and 20:1 fatty acids increased linearly with increasing proportion of WRS (p<0.05). However, concentration of conjugated linoleic acid cis 9, trans 11 and 17:0 increased with WRS24 and WRS16. In the sensory analysis, WRS24 was more tender with respect to the other treatments (p<0.05). Finally, the inclusion of WRS in the finishing diet of feedlot Nellore bulls only evidenced little changes in fatty acid profile and tenderness, in animals fed diets containing 16 or 24% soybean.

Effect of β-glucan supplementation on acute postprandial changes in fatty acid profile of lymph and serum in pigs.

Triglycerides are absorbed by the lymphatic system and have various functions in the body. It has been shown that some types of β-glucans have a positive effect on the systemic concentrations of cholesterol and lipid, presumably through interference with the absorption of lipid and/or reabsorption of bile acids. In the current study we investigated the acute effects of ingesting 2 g of β-glucan concentrates derived from barley β-(1→3)(1→4)-d-glucan or yeast β-(1→3)(1→6)-d-glucan on fatty acid content and composition in lymph and serum of 10 female pigs (initial weight 34.7 ± 1.1 kg) fitted with a permanent catheter in the jejunal lymphatic trunk in a cross-over design. Lymph was collected continuously for 8 h followed by a spot sample taken 24 h after. A significant effect of time after feeding was observed for all fatty acids in serum and for 18:0, 18:2ω6 and 18:3ω3 in lymph, but a significant effect of β-glucan was only observed for 14:0 (p = 0.049) and 22:6ω3 (p = 0.048) in lymph and 18:0 (p = 0.019) in serum. While the concentration of dietary fatty acids increased postprandially in lymph, the concentration of arachidonic and docahexanoic acid tended to decrease. Furthermore, there was a drop in concentration of all fatty acid in serum 1 h after the meal.

Changes in fatty acid profiles of three tissue types in channel catfishIctalurus punctatus(Rafinesque, 1818) transferred from river to pond environments

Summary Little information is available regarding the time scale over which tissue fatty acid (FA) profiles change when fish transition between prey resources with different FA profiles, specifically when fish move from a main river channel to a floodplain habitat. The objective of this study was to evaluate changes in the FA composition of muscle, liver, and adipose fin tissues of channel catfish Ictalurus punctatus transferred from the Kaskaskia River, Illinois to earthen ponds at the Center for Fisheries, Aquaculture, and Aquatic Sciences Pond Facility, Makanda, Illinois, mimicking migration from river to floodplain habitat. Over time, n-3 and C18 polyunsaturated FA (C18 PUFA) decreased in all tissues, whereas monounsaturated fatty acids (MUFA) increased with pond residence time. Liver profiles changed more rapidly than the muscle or adipose fin profiles (significant change in <2 weeks vs ~10 weeks). The results provide some insight regarding the timing of tissue FA profile change in channel catfish moving between distinct habitats with different prey resources. Results also suggest that adipose fin tissue samples may be a less invasive alternative to muscle tissue for analysis of FA profiles in channel catfish; however, issues with reclassification/identification accuracy using adipose fin tissue must be addressed in order for this approach to be fully justified.

Species-Specific Variations in the Nutritional Quality of Southern Ocean Phytoplankton in Response to Elevated pCO2

Increased seawater pCO2 has the potential to alter phytoplankton biochemistry, which in turn may negatively affect the nutritional quality of phytoplankton as food for grazers. Our aim was to identify how Antarctic phytoplankton, Pyramimonas gelidicola, Phaeocystis antarctica, and Gymnodinium sp., respond to increased pCO2. Cultures were maintained in a continuous culture setup to ensure stable CO2 concentrations. Cells were subjected to a range of pCO2 from ambient to 993 µatm. We measured phytoplankton response in terms of cell size, cellular carbohydrate content, and elemental, pigment and fatty acid composition and content. We observed few changes in phytoplankton biochemistry with increasing CO2 concentration which were species-specific and predominantly included differences in the fatty acid composition. The C:N ratio was unaffected by CO2 concentration in the three species, while carbohydrate content decreased in Pyramimonas gelidicola, but increased in Phaeocystis antarctica. We found a significant reduction in the content of nutritionally important polyunsaturated fatty acids in Pyramimonas gelidicola cultures under high CO2 treatment, while cellular levels of the polyunsaturated fatty acid 20:5ω3, EPA, in Gymnodinium sp. increased. These changes in fatty acid profile could affect the nutritional quality of phytoplankton as food for grazers, however, further research is needed to identify the mechanisms for the observed species-specific changes and to improve our ability to extrapolate laboratory-based experiments on individual species to natural communities.