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The influence of menhaden fish oil and other oils on the fatty acid composition of the egg was studied. Diets containing 1.5% menhaden oil, 1.5% corn oil and no oil added were fed to 50 hens. The menhaden oil diet increased the composition of C 14:0 ' C 16:1 ' C 18:1 ' C 18:3a3 ' C 20:5a3 and C 22:6a3 was found in eggs but decreased C 18:3a6 and C 20:4a6 compared with the corn oil diet. The concentration of C 10:5a3 was greater than C 22:6a3 in menhaden oil, but more C 22:6a3 was found in eggs than C 22:6a3 . A significant increase in total w-3 PUF As (polyansaturated fatty acids) occured in the eggs after feeding the menhaden oil diet for 5 days and the concentration continued to increase through day 15. Dietary fats tend to produce a fatty acid patern in eggs similar to that of the diet and varies with the oil source concentration. Most fatty acid profiles in egg yoilds were altered within 15 days after hens began to consume test diets

The effects of feeding different sources of brine shrimp nauplii with different fatty acid compositions on growth, survival, and fatty acid composition of striped bass, Morone saxarilis and palmetto bass (M. saxatilis x M. chrysops) were determined. The sources of brine shrimp were Chinese (CH), with a high percentage of 20:5(n-3), eicosapentaenoic acid (EPA), and Colombian (COL), San Francisco Bay (SFB), and Great Salt Lake (GSL), with low percentages of EPA but high percentages of 18:3(n-3), linoienic acid. None of the brine shrimp sources contained a measurable amount of 22:6(n-3), docosahexaenoic acid (DHA). After enrichment with menhaden oil to increase the content of EPA and DHA, the GSL brine shrimp nauplii were also fed to hybrid striped bass.Growth and survival of fish larvae fed brine shrimp nauplii with high percentages of EPA and DHA (CH and GSLE) were higher (P < 0.05) than those of fish fed brine shrimp with a low percentage of EPA (COL, SFB, and GSL). The ratio of 20:3(n-9) eicosatrienoic a...

Simultaneous, 6-week feeding trials were conducted in which diets containing menhaden, corn, coconut and hydrogenated menhaden oil at 7.0%, plus a diet containing 14% menhaden oil, were fed to triplicate groups of juvenile red drum (Sciaenops ocellatus) at two different salinities (5 and 32%.). Weight gain was significantly (p < 0.05) affected by diet and salinity. Fish fed the diet containing 14% menhaden oil had the greatest weight gain; whereas, fish fed the diet containing coconut oil gained the least weight. Fish in brackish water had significantly greater weight gain than fish in full-strength seawater over the 6-week period, although fish fed coconut and saturated menhaden oil in brackish water had reduced survival. Dietary lipid also significantly affected muscle and liver total lipid, hepatosomatic index (HSI), and intraperitoneal fat (IPF) ratio, as fish fed the diets containing 14% menhaden oil had higher values for all of these body condition indices. After the feeding trial, fish were subjected to a chronic cold tolerance assay. In the chronic trial, where temperature was gradually reduced over a 3-week period, fish fed the diets containing menhaden oil had significantly lower median lethal temperatures (MLT) than those fish fed the diets containing coconut, corn and saturated menhaden oils. No significant effects of cold exposure were observed on muscle and liver total lipid. Cold exposure prompted a modification in lipid metabolism by lowering total saturated fatty acids and raising (n − 3) highly unsaturated fatty acids (HUFA) in the neutral lipid of liver. Fish with the lowest MLT in the chronic assay exhibited signs of conserving (n − 3) HUFA and depleting (n − 6) fatty acids [primarily 18:2 (n − 6)], resulting in higher (n − 3)/(n − 6) ratios in the polar lipid of liver. These data suggest that the lower lethal temperature of juvenile red drum can be reduced through dietary manipulation involving the inclusion of high levels of dietary lipid rich in (n − 3) HUFA.

Larvae of red drum (Sciaenops ocellatus) were reared from first feeding to 18 d posthatching at 26°C under a feeding protocol that combined artificial diets with live food (rotifers). Semipurified microparticulate test diets were formulated with graded levels (13.0, 18.3, 22.7, and 27.1 %) of total lipid (menhaden oil and red drum muscle lipid). Growth of larvae fed the test diets was compared with that of larvae fed a commercial microparticulate diet (Kyowa-A) containing 24.8% crude lipid. In separate, repeated feeding trials, standard length and dry weight of 18-d-old larvae fed the Kyowa-A diet were significantly greater than lengths and weights of larvae fed the test diets. However, dry weight of larvae fed the diet containing 18.3% total lipid was significantly greater than weights of larvae fed the other test diets. Additionally, the semipurified diets were readily accepted and ingested by larvae. Digestion of the diets was evident in the significant growth of the larvae.

Eggs from hens fed n‐3 fatty acids (n‐3FA) may provide a means for increased marketing of these healthful fatty acids. Eggs from hens fed graded levels (0, 0.5, 1.5, 3.0%) of menhaden oil (MO) were evaluated for fatty acid composition, sensory characteristics, and headspace volatiles. Eggs from hens fed 1.5% and 3.0% MO contained the greatest n‐3 FA content and were not different. A linear increase in fishy notes occurred as level of dietary MO increased from 0 to 1.5%; however, these notes were not different between 1.5% and 3.0% eggs. Changes in headspace volatile profiles were quantitative. No unique volatiles characterized eggs from hens fed MO; however, concentration differences were noted between eggs from hens fed all levels of dietary MO. Changes in volatile profiles in response to dietary MO may be responsible for perception of fishy notes in such eggs.

The aim of this work was to investigate the potential protective effects of fish oil on the basis of kidney transcriptomic data on a nutritional experimental model. Methods Male weanling Wistar rats were divided into four groups and fed choline-deficient (CD) and choline-supplemented (CS) diets with vegetable oil (VO) and menhaden oil (MO): CSVO, CDVO, CSMO and CDMO. Animals were killed after receiving the diets for 6 days. Total RNA was purified from the right kidney and hybridized to Affymetrix GeneChip Rat Gene 1.0 ST Array. Differentially expressed genes were analyzed. Results All CSVO, CSMO and CDMO rats showed no renal alterations, while all CDVO rats showed renal cortical necrosis. A thorough analysis of the differential expression between groups CSMO and CDMO was carried out. There were no differential genes for p < 0.01. The analysis of the differential expression between groups CSVO and CSMO revealed 32 genes, 11 were over-expressed and 21 were under-expressed in CSMO rats. Conclusions This work was part of a large set of experiments and was used in a hypothesis-generating manner. The comprehensive analysis of genetic expression allowed confirming that menhaden oil has a protective effect on this nutritional experimental model and identifying 32 genes that could be responsible for that protection, including Gstp1. These results reveal that gene changes could play a role in renal injury. Fil: Denninghoff, Valeria Cecilia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ossani, Georgina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Uceda, Ana Margarita. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Rugnone, Matias Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina Fil: Fernandez, Elmer Andres. Area de Ciencias Agrarias, Ingeniería, Ciencias Biológicas y de la Salud de la Universidad Católica de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina Fil: Fresno Rodríguez, Cristóbal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Area de Ciencias Agrarias, Ingeniería, Ciencias Biológicas y de la Salud de la Universidad Católica de Córdoba; Argentina Fil: González, German. Area de Ciencias Agrarias, Ingeniería, Ciencias Biológicas y de la Salud de la Universidad Católica de Córdoba; Argentina Fil: Díaz, Maria Luisa. Hospital Británico de Buenos Aires; Argentina Fil: Avagnina, Alejandra. Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno”; Argentina Fil: Elsner, Boris. Centro de Educación Médica e Investigaciones Clínicas “Norberto Quirno”; Argentina Fil: Monserrat, Alberto Juan. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The health benefits of omega-3 polyunsaturated fatty acids (n.3 PUFA) are generally recognized. Unfortunately, in most western countries, the recommended daily intake of these compounds is rarely met. Therefore, enrichment of commonly occurring foods can boost intake of these fatty acids. In this regard, eggs are an interesting target, as they form an integral part of the diet. Their n.3 PUFA profile can bemodified through feed supplementation. A traditional n.3 PUFA source to be added to hens' diet is flaxseed, a plant source rich in á-linolenic acid. Alternatively, hens are often fed fishoil,which is rich in long chain n.3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A more recent trend is feed supplementation with microalgae as a source of EPA and/or DHA. In this paper, recent scientific literature concerning n.3 PUFA enrichment in eggs is reviewed, giving an overview of advantages and disadvantages of the different approaches. ispartof: Food Research International vol:48 issue:2 pages:961-969 status: published

Emulsion (EFMO) containing purified menhaden oil (PMO) and soluble rice bran fiber (SRBF) was dried in a pilot scale spray dryer and produced microencapsulated PMO with SRBF (MFMO). EFMO had well isolated spherical droplets with the size of 1 to 10 μm and showed pseudoplastic fluid and viscoelastic characteristics. EFMO had lower lipid oxidation than the emulsion containing PMO without SRBF when both emulsions were stored at 20 and 40 °C for 88 h, which indicated that the SRBF reduced the lipid oxidation in the EFMO. The estimated MFMO production rate (3.45 × 10(-5) kg dry solids/s) was higher than the actual production rate (2.31 × 10(-5) kg dry solids/s). The energy required to spray dry the EFMO was 12232 kJ/kg of emulsion. EPA and DHA contents of MFMO were 11.52% and 4.51%, respectively. The particle size of 90% MFMO ranged from 8 to 62 μm, and the volume-length diameter of MFMO was 28.5 μm.

A non-aqueous reversed phase high performance liquid chromatography method was developed, and optimized for triacylglycerol analysis in a Brevoortia tyrannus (menhaden) oil sample. Four columns were serially coupled to tackle such a task, for a total length of 60 cm of shell-packed stationary phase, and operated under ultra high pressure conditions. As detection, positive-ion atmospheric pressure chemical ionization mass spectrometry was used to attain identification of the analyzed sample components. A number of 137 triacylglycerols containing up to 19 fatty acids, with 14–22 carbon atom alkyl chain length and 0–6 double bonds, were positively identified in the complex lipidic sample. This is the first work that reports an extensive characterization of the triacylglycerol fraction of menhaden oil.

Fingerling channel catfish were fed practical-type diets supplemented with 2% catfish offal oil, beef tallow, or menhaden oil for 8 or 10 weeks at 24±1°C under laboratory conditions in two separate experiments. At the end of the feeding period, fish were exposed to live Edwardsiella ictaluri by immersion and mortalities were recorded daily for 3 weeks. Growth, feed efficiency, and survival rate of channel catfish at the end of the feeding period were not significantly different among dietary treatments in either experiment. Fish fed a diet supplemented with menhaden oil had significantly higher levels of 20:5n−3, 22:6n−3, and total n−3 HUFA (highly unsaturated fatty acids), and lower levels of 20:4n−6 and total n−6 HUFA in liver polar lipids than fish fed the other two diets. Average mortality of fish exposed to E. ictaluri was 21 and 15% higher for fish fed supplemental menhaden oil than for fish fed supplemental catfish offal oil in Experiments 1 and 2, respectively. Antibody titers were not different among fish regardless of diet, 3 weeks after exposure to E. ictaluri. The results of this study indicate that channel catfish fed practical diets containing 2% menhaden oil are more susceptible to E. ictaluri. These results do not preclude the use of menhaden fish oil in catfish diets, but it may be prudent to use a mixture of menhaden oil and other animal and/or plant lipids in commercial catfish feeds to provide a balance in the dietary n−3 n−6 ratio.

The effect of 8 weeks of feeding diets enriched with corn oil, linseed oil, or menhaden oil on endotoxin- and calcium ionophore (A23187)-induced tumor necrosis factor (TNF) and eicosanoid synthesis by rat peritoneal macrophages was determined. The fatty acid composition of macrophage phospholipids and TNF activity and eicosanoid synthesis in response to endotoxin and A23187 were determined. The ratio of omega-6/omega-3 fatty acids in macrophages from linseed oil or menhaden oil-fed rats decreased approximately 24- and 55-fold, respectively. Basal and endotoxin-induced synthesis of TNF was increased by ingestion of the menhaden oil diet but not by the linseed oil diet. Ingestion of the menhaden oil and linseed oil diets significantly reduced basal, endotoxin-, and A23187-induced synthesis of eicosanoids compared with the corn oil group. Ingestion of the menhaden oil diet resulted in a greater decrease in eicosanoid synthesis than the linseed oil diet.

Separate and combined effects of dietary fatty acids and water temperature on the production of leukotriene B (LTB) by the head kidney of channel catfish Ictalurus punctatus were investigated. Fish were fed semipurified diets containing 7% lipid as beef tallow, corn oil, linseed oil, menhaden oil, or a mixture (1:1:1) of menhaden oil, beef tallow, and corn oil. At 28°C, fish fed corn oil produced the greatest amount of LTB, and fish fed beef tallow produced the least. At 17°C, production of LTB by fish fed the beef tallow diet was again lowest; production of LTB by fish fed the corn oil diet was highest but was not significantly different from that obtained with the mixed-oil or menhaden oil diet. Production of LTB for the other diets was intermediate. This is the first report that the head kidney of channel catfish produces LTB; this production was affected by dietary lipid sources but not by the two water temperatures tested. Production of LTB was not related to weight gain. Moreover, the patte...

Female miniature swine, 4–11 yr, were fed 15% fat diets containing n-3 and/or n-6 polyunsaturated fat for 6 months, at 1.95 g fat/kg body weight. Liver lipids from menhaden oil-fed minipigs were elevated in the n-3 fatty acids: 20:5, 22:5 and 22:6, but heart lipids only in 20:5 and 22:6. Liver cell plasma membrane was elevated in 20:5, 22:5 and 22:6 and lowered in the n-6 acids 18:2 and 20:4 in menhaden oil-fed animals, to a greater extent than in the total tissue lipids. Liver α-tocopherol tended to decrease upon feedin menhaden oil, but heart α-tocopherol concentrations were not affected.

The goal of the present study was to determine the effectiveness of linolenic acid for enriching docosahexaenoic acid (DHA) in infant rats. Seven-day-old rat pups were artificially reared and fed intragastrically for 8 d a milk substitute containing either 1) corn oil, high in linoleic acid (35.6 g/100 g fatty acids, 775 kJ/L); 2) menhaden oil, high in DHA (3 g/100 g, 67 kJ/L) and eicosapentaenoic acid (EPA, 6 g/100 g, 132 kJ/L); or 3) linseed oil, rich in linolenic acid (34 g/100 g, 750 kJ/L). Growth rates were comparable among the artificially fed pups and those raised by lactating dams. Feeding the DHA precursor linolenic acid enriched EPA in plasma, erythrocytes and liver, but enriched DHA only in the liver, compared with feeding corn oil. The proportion of liver DHA in the pups fed the linolenic acid-rich substitute was twice that detected in the corn oil-fed pups and 60% of the level found in the pups fed the preformed DHA. The significant elevation of hepatic DHA indicates active desaturation and elongation in the developing rat liver. The failure to enrich erythrocyte DHA suggests the need for caution in the use of erythrocytes as an index of DHA status in tissues capable of in situ synthesis. The artificial rearing of rat pups was proven suitable for studying the interaction of dietary manipulation and tissue accretion of essential fatty acids during the postnatal development.

Menhaden oil is highly susceptible to oxidation due to a high concentration of n-3 polyunsaturated fatty acids, leading to objectionable off-odors and off-flavors. The purpose of this study was to investigate if the enzyme lipoxygenase is present in menhaden gill tissue and if its activity on n-3 fatty acid esters can be detected by a sensory panel. Lipoxygenase activity was found in the crude enzyme extract from menhaden gill tissue. The enzyme exhibited its highest activity at pH 9–10, and was inhibited by esculetin. Panelists judged the smell of n-3 fatty acid ethyl ester concentrates that were incubated with the enzyme extract to be significantly stronger than that of untreated controls. It can be concluded that menhaden gill tissue contains an active lipoxygenase which possibly contributes to the peroxidation of menhaden oil.

Clinical and epidemiological investigations have indicated that there may be substantial human cardiovascular benefits associated with increased consumption of n-3 fatty acids commonly found in fish oils. Recent studies have indicated that egg yolk n-3 fatty acid content is significantly increased when hens are fed diets enriched with selected fish oils such as menhaden oil (MO). In the present study, reproductively active females but not males exhibited increased hepatic lipidosis following 6 mo of feeding 3% MO. Hens fed 3% animal-vegetable oil (AV) did not exhibit hepatic lipid accumulation. Serum triglyceride and cholesterol concentrations were reduced (P < or = .05) in hens fed MO. Subsequently, yolk and total egg weights of hens fed MO were decreased as compared with those of hens fed AV. A significant interaction of dietary MO and exogenous 17 beta-estradiol was noted among chick liver and gallbladder weights. These data suggest that dietary MO and estradiol may interact in a manner that enhances the lipogenic activity of the liver, thereby inducing hepatic lipidosis in laying hens.

The effect of feeding a whole-egg diet or one matched in protein and fat content on gluconeogenesis by isolated hepatocytes was studied. BHE/cdb male weanling rats were fed one of five diets, which differed in source of protein and/or fat: casein/lactalbumin with corn oil, casein/lactalbumin with menhaden oil + corn oil, egg white with corn oil, egg white with menhaden oil + corn oil, or whole egg. At 74 ± 14 days of age, the rats were killed and isolated hepatocytes were prepared. The cells were incubated with 10 m m lactate, 10 m m pyruvate, 10 m m ethanol and 10 m m lactate, 10 m m lactate and 5 m m NH4Cl, or 10 m m glutamate. The hepatocytes from the rats fed menhaden oil differed little in glucose production from the hepatocytes isolated from rats fed corn oil, regardless of protein source. Glucose production from lactate, pyruvate, lactate + ethanol, and lactate + ammonium chloride was significantly lower in hepatocytes from rats fed whole egg, compared with cells from rats fed the other diets. These data suggest that certain components of whole egg have effects on the control of gluconeogenesis.

Three enrichment techniques were evaluated for their efficiency in improving the dietary value of Artemia nauplii to striped bass larvae. Newly hatched Artemia nauplii from the Great Salt Lake (GSL) were enriched for 24 h using the following diets: 1) gelatin-acacia microcapsules containing menhaden oil rich in omega-3 polyunsaturated fatty acids (PUFA), primarily 20:5ω3 eicosapen-taenoic acid; 2) an emulsion of Baker's yeast and menhaden oil; and 3) marine Chlorella sp. Unfed San Francisco Bay (SFB) and GSL nauplii were used as controls. Enriched GSL (all three diets) and unfed SFB nauplii had significantly higher (P < 0.05) levels of 20:503 than the unfed nauplii from GSL. Seven days post-hatched (day 0) striped bass larvae were reared for 21 d on enriched or unfed nauplii. On day 21, wet weight and total length of striped bass larvae fed enriched GSL nauplii and unfed SFB nauplii were significantly greater (P < 0.05) than those fed unenriched GSL nauplii. The enrichment of the GSL nauplii appeared to increase the eicosapentaenoic acid content and enhance the growth of the striped bass larvae.

Two experiments were conducted to evaluate the effect of feeding various lipid sources at high and low water temperatures on responses of channel catfish to challenge (25°C) with Edwardsiella ictaluri. Semipurified diets were fed which contained 7% beef tallow, corn oil, linseed oil, menhaden oil or a 1:1:1 mixture of beef tallow, corn oil and menhaden oil. In Experiment 1, fish (14.3±0.3 g average initial weight) fed the menhaden oil and linseed oil diets for 13 weeks at 28°C had lower survival than fish fed the other diets (P

Rats were fed a semisynthetic diet containing 14% of either beef fat, safflower oil, or menhaden oil plus 2% corn oil for 7 weeks, and three tissues, diaphragm, heart, and skeletal muscle, were examined for fatty acid composition in their phospholipids and triglycerides. In addition, the lipid concentrations in these tissues were examined. The in vitro oxidation and incorporation of glucose into lipids of these tissues were also examined. Skeletal muscle showed the greatest change in phospholipid composition with diet. All tissues were responsive to changes in diet in regards to the triglyceride fraction. Dietary alteration of tissue phospholipid composition did not alter lipid concentration in these tissues. However, in diaphragm tissue, rats fed the beef fat diet had lower phospholipid and higher triglyceride synthesis compared with those fed either menhaden oil or safflower oil. In addition, triglyceride synthesis was higher in the diaphragm of animals fed the menhaden oil diet as compared with the safflower oil diet. Therefore, dietary fatty acid composition may play a role in the triglyceride and phospholipid metabolism of rat diaphragm.

Background/Aims: Adaptive hyperplasia of the small intestine is important in the outcome of short bowel syndrome. Previous studies have shown that long-chain fats stimulate this process. In the present study, the trophic effects of dietary menhaden oil, a highly unsaturated fat source, on mucosal adaptation following small bowel resection in rats was evaluated. Methods: Thirty weanling Sprague-Dawley rats and their controls were fed diets containing fats provided primarily as menhaden oil, safflower oil, or beef tallow. After 4 weeks, animals underwent a 70% jejunoileal resection. Mucosal mass, DNA, protein, and sucrase levels were assessed 14 days after a 70% jejunoileal resection or control feeding. Serum fatty acid composition and several gastrointestinal hormone levels were measured. Results: Resected animals fed menhaden oil showed a marked increase in mucosal weight, DNA, and protein levels compared with rats fed the other fat sources. Enteroglucagon level was increased in all resected groups, but least increased in the menhaden-fed animals. In contrast, peptide YY concentrations were most increased in animals fed menhaden oil. Conclusions: Menhaden oil appears more effective in inducing intestinal adaptation than less highly unsaturated fats. Analysis of gastrointestinal hormones revealed no clear-cut explanation for this finding, other than a modest but associated increase in peptide YY levels.

The purpose of this work was to evaluate the use of antioxidants in extending the shelf-life of mayonnaise constantly exposed to air in which all of the oil ingredient was fish oil. Mayonnaise prepared without antioxidants had a shelf-life at room temperature of approximately 1 day. Citric acid or sodium citrate and propyl gallate in the oil phase and EDTA and ascorbic acid in the aqueous phase increased the shelf-life to an average of 49 days at room temperature as judged by sensory evaluation. With refrigeration, the number of days to off-odor development was increased to 89. With the addition of an oxygen scavenging system of glucose oxidase-catalase-glucose, the shelf-life increased to an average of 132 days. Both oxygen and light were shown to be detrimental to the stability of the product. Considerable variation was observed between batches of menhaden oil, the primary fish oil used in formulating the mayonnaise in these studies.

The balance of putative pro- and antiinflammatory lipoxygenase (LOX)-derived S-hydroxyeicosatetraenoic acids (S-HETEs) in colon mucosa is a potential target for modulating colon cancer risk and progression. The biological effects of S-HETEs and R-hydroxyeicosatetraenoic acids (produced by distinct pathways) may differ, but levels of these compounds in the colon are unknown. The objective of this study was to develop chiral methods to characterize hydroxyeicosatetraenoic (HETE) enantiomers in colonic mucosa and evaluate the effects of fish oil on HETE formation. C57BL/6 mice (COX-1 null, COX-2 null, wild-type) were fed a diet supplemented with either olive oil or menhaden oil for 11 wk, and R-/S-HETEs in colonic mucosa were quantified by chiral LC-MS/MS. The R-enantiomer comprised 60-72% of 5-HETE, 18-58% of 15-HETE, and 1-16% of 12-HETE in colonic mucosa, suggesting that non-LOX sources contribute to HETE profiles. Fish oil reduced levels of both R- and S-HETEs, and increased the preponderance of the R-enantiomers (particularly 12- and 15-HETEs). There was apparent shunting of arachidonic acid to 12-/15-LOX in the COX-1 null animals. This is the first report of the enantiomeric composition of HETEs in the colon in vivo and shows large effects of fish oil in the normal colon.

Two separate feeding trials were conducted to assess different aspects of lipid nutrition of juvenile red drum. In the first 8-week trial, growth, survival, feed efficiency, total lipid and fatty acid composition of whole-body, muscle and liver tissues were used to establish the nutritional efficacy of different triglycerides for this species. Semipurified diets contained 7% total lipid from tristearin, triolein, linseed oil or menhaden fish oil, sources rich in 18:0, 18:1, 18:3 n −3 and n −3 highly unsaturated fatty acids (HUFA), respectively. Fish were maintained in a recirculating system containing brackish water (5 ± 2 ppt) with a temperature of 25 ± 2°C. Growth was influenced by dietary lipid, with progressive increases in weight gain of fish fed linseed oil and menhaden oil. The latter contains substantial amounts of the n −3 HUFA that are necessary to satisfy the essential fatty acid (EFA) requirements of this species. Elevated monoenes were present in tissue lipids of fish fed tristearin and triolein, and n −3 HUFA were conserved in the polar lipid fractions. The second 6-week feeding trial was conducted to assess the quantitative EFA requirements of red drum in relation to total dietary lipid. Diets contained 7 or 14% total lipid from menhaden oil, or linseed oil with or without supplemental n −3 HUFA in the form of ethyl esters. Quantitative EFA requirements increased with dietary lipid, and growth was best in fish fed 20:5 n −3 plus 22:6 n −3 at 10% of dietary lipid.

Twenty-four growing pigs (18.3 kg body weight) were used in 19-day metabolism trial to determine the effect of n-3/medium-chain triacylglyceride (MCT)-structured triacylglyceride on plasma and tissue lipid profiles. Pigs were allotted to four liquid diets, each providing 19.5% protein (dry matter basis) as Na- and Ca-caseinate + soybean protein isolate. Lipid composition (percentage by weight of total lipid) by treatment was as follows: (I) corn oil:soybean oil:MCT oil (40:10:50), (II) MCT oil:menhaden oil (60:40 as structured triacylglyceride), (III) MCT oil:menhaden oil (60:40 non-structured, physical mixture), and (IV) structured triacylglyceride (as in II):safflower oil:canola oil (80:10:10). Blood samples were obtained on days 0, 12, and 19 with liver and muscle samples obtained on day 19. With the exception of arachidonic acid, plasma fatty acid profiles reflected dietary fatty acid profiles. Plasma arachidonic acid percentage was higher (P

The effects of feeding a 1% corn oil-9% menhaden oil or beef tallow diet on the early phase of diabetic nephropathy in BHE/cdb rats was studied. The diet groups were subdivided into rats with or without impaired glucose tolerance. Those fed menhaden oil had renal hypertrophy, mild albuminuria, decreased creatinine clearance, increased urea clearance, and more severe lesion scores than rats fed beef tallow. No differences in glomerular filtration rate, Na+,K+-ATPase activity, sorbitol dehydrogenase, or inositol 1,4,5-phosphate were observed. Beef tallow-fed rats had higher serum triglyceride levels and renal cholesterol levels. Renal and hepatic fatty acid profiles reflected the fatty acid profile of the dietary fat. These results suggest that beef tallow conferred a protective effect on the renal tissues of these diabetes-prone rats.

Dietary omega-3 fatty acids are currently being investigated for their beneficial effects, including their benefit form immunity. Because aging is associated with immunodeficiency, we have investigated whether diets rich in omega-3 fatty acids will improve immunity in the aged. Young and old mice were fed basal diets supplemented with menhaden oil (rich in omega-3 fatty acids) or hydrogenate4d coconuts oil. Splenocytes from these animals were tested for increased cytosolic free calcium and proliferation after stimulation with concanavalin A. Our results show that menhaden oil-rich diets did not alter splenocytes from old, menhaden oil-fed mice displayed a lower magnitude oil-fed mice was consistently lower than for all other splenocytes, including splenocytes from old, hydrogenated coconut oil fed mice. Lipid peroxidation in old, men haden oil-fed livers was lower than in young, menhaden oil-fed livers, suggesting that lipid peroxidation was not the cause of the poor responded associated with menhaden oil...

Dose-related effects of long-chain highly unsaturated n-3 fatty acids on the development of N-nitrosomethylurea (NMU)-induced rat mammary tumors were assessed in female F344 rats. Four test groups (36 rats/group) were fed the following high-fat (HF) diets (23% fat, w/w): Group 1, 18% menhaden oil (MO) and 5% corn oil (CO); Group 2, 11% MO and 11.8% CO; Group 3, 5% MO and 18% CO; Group 4, CO alone. A fifth group, serving as an internal control, was fed a low-fat diet containing 5% CO alone. Experimental diets were begun after initiation with NMU, and the experiment was terminated 31 wk later. Total tumor numbers in the five groups were 28, 16, 32, 26 and 11, respectively, indicating that the promotion phase of NMU-induced carcinogenesis was significantly suppressed only when equal parts of CO and MO (Group 2) were fed or when CO alone was fed at 5% (w/w). At high (Group 1) or low (Group 3) levels of MO, tumor numbers were indistinguishable from the HF CO group (Group 4). The same pattern was observed when assessed in terms of cumulative tumor incidence and multiplicity. However, when expressed in terms of final tumor incidence, dietary MO did not suppress tumor promotion in a statistically significant fashion at any concentration. Animals fed MO gained weight at the same rate as those fed CO, indicating that the presence of MO in the diet did not result in food avoidance behavior. Measurement of total serum cholesterol indicated an inverse trend with respect to the MO content of the diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Surimi-based seafood products are widely accepted and enjoyed worldwide. The US consumption increased in 1980s; however, it leveled thereafter. Food products nutrified with ω-3 polyunsaturated fatty acids (PUFAs) are in increasing demand due to demonstrated health benefits. Currently, surimi seafood is not nutrified with ω-3 PUFAs. In the present study, surimi seafood was nutritionally-enhanced with ω-3 PUFAs-rich oils (flaxseed, algae, menhaden, krill, and blend). The objectives were (1) chemical characterization of FA composition and oxidation, and (2) determination of physicochemical properties (colour and texture) of the nutritionally-enhanced surimi seafood. Oil addition resulted in increased (P0.05) concentration of total ω-3 FAs in surimi seafood; however, the concentration of α-linolenic (ALA, 18:3ω-3), eicosapentaenoic (EPA, 20:5ω-3) and docosahexaenoic (DHA, 22:6ω-3) acids depended on which oil was added. Although the ω-3 PUFAs nutrification resulted in increased (P0.05) susceptibility of surimi seafood to lipid oxidation, it was within ranges acceptable to consumers. Texture analysis (texture profile analysis, Kramer shear and torsion test) showed that ω-3 PUFAs nutrification did not affect texture. Colour properties of ω-3 PUFAs nutrified surimi seafood were generally improved except when krill oil or blend was added. This study demonstrates that nutritional value of surimi seafood can be enhanced with concurrent improvement of colour and without affecting texture.

To evaluate the influence of dietary supplementation of omega-3 polyunsaturated fatty acids (n-3 PUFA) on storage of boar semen, three experiments were conducted: two involved long-term, fresh semen storage (Exp. 1 and Exp. 2), whereas the other involved cryopreservation (Exp. 3). Boars were allocated randomly to three dietary treatments (for 6-7 mo). In addition to a daily allowance of 2.5 kg of a basal diet, they received: 1) 62 g of hydrogenated animal fat (AF); 2) 60 g of menhaden oil (MO), containing 18% docosahexanoic acid (DHA) and 15% eicosapentanoic acid (EPA); or 3) 60 g of tuna oil (TO), containing 33% DHA and 6.5% EPA. In Experiment 1 (n = 26) and Experiment 2 (n = 18), semen was cooled and stored in vitro for several days at 17 °C before assessment, whereas in Experiment 3 (n = 18), viability, motility, acrosomal integrity, susceptibility to peroxidation (LPO), and DNA fragmentation were determined in fresh and frozen-thawed sperm. In Experiment 1, sperm from boars fed TO had better resistance to fresh storage; even after 7 or 9 d of storage at 17 °C, there were more (P = 0.03) motile sperm in boars fed TO (60%) than in those fed AF or MO. In Experiment 2, fish oil supplementation did not influence any aspect of sperm quality during semen storage (P0.10). In Experiment 3, cryopreservation decreased the proportion of motile and viable frozen-thawed sperm as well as acrosomal integrity and increased DNA fragmentation and LPO (P0.01) relative to fresh semen, although sperm quality was unaffected by treatments (P0.09). In conclusion, although adding fish oil to the diet failed to significantly improve the quality of cryopreserved boar sperm, inconsistent responses of long-term storage of cooled sperm to dietary n-3 PUFA supplementation warrant further investigation.

Three groups of Artemia , of brine shrimp, nauplii were tested for their effect on growth and survival of hybrid striped bass larvae during a 23-day feeding period (day 5 through day 28 post-hatch). The groups of brine shrimp were a Chinese strain (CH) that had been shown to be sufficient in n -3 highly unsaturated fatty acids (HUFAs) and produced good growth in striped bass larvae, a strain from the Great Salt Lake, UT (GSL) that had been shown to be insufficient in n -3 HUFAs and produced poor growth in striped bass larvae, and the GSL strain enriched with menhaden oil (GSLE) to increase the content of n -3 HUFAs (20:5 and 22:6). The enrichment process involved holding the nauplii for 3 to 9 h in a suspension of menhaden oil in water using gum xanthum as an emulsifier. The growth and survival of larvae fed the GSLE nauplii were equal to those of larvae fed the CH nauplii and significantly greater than those of larvae fed the GSL nauplii. The polar lipids in the larvae fed GSL brine shrimp contained only trace amounts of n -3 HUFAs while the larvae fed the GSLE and the CH brine shrimp contained significant amounts of n -3 HUFAs. The larvae fed GSLE nauplii had higher amounts of n -3 HUFAs in the polar lipids than the larvae fed CH nauplii. These results indicate that brine shrimp which may have desirable hatchability, size or economic traits but are deficient in essential fatty acids can be improved nutritionally by a simple enrichment process using menhaden oil.

Hypertriglyceridemia and fatty liver are common lipid abnormalities associated with Gram-negative sepsis. Fish oils have been shown to have beneficial effects in reducing plasma triglycerides (TG). This study was designed to investigate whether fish oils would prevent the elevation of plasma TG and the accumulation of liver lipids during sepsis. One group of rats was fed a 10% menhaden oil diet and the other group was fed a 10% corn oil diet for 14 days. On the 14th day, sepsis was induced by injecting the rats with 8 x 10(7) live Escherichia coli colonies/100 g of body weight and the rats were fasted for 22 hours. The liver composition of total lipids and TG in the septic rats prefed the fish oil was lower than in the septic rats prefed the corn oil. In the rats adapted to the corn oil diet, lipids accumulated in the livers of the septic rats in comparison with the control rats. Hepatocytes isolated from the septic rats adapted to the corn oil diet showed an increased esterification of [1-14C]palmitate into TG and phospholipids than hepatocytes from the control rats. Feeding the fish oil diet instead of the corn oil diet before inducing sepsis reduced TG, cholesterol, and phospholipid synthesis by 58%, 79%, and 71%, respectively. The rise in TG synthesis in the septic rats prefed the corn oil diet was associated with an 89% increase in the activity of phosphatidate phosphohydrolase. There was no significant difference in the activities of glycerol-3-phosphate acyltransferase and phosphatidate phosphohydrolase between control and septic rats.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of dietary lipids and spice principle curcumin on kidney microsomal lipids, Na + , K + -ATPase activity and serum lipid levels were studied. Rats were fed a diet containing either coconut oil, safflower oil or menhaden oil for 8 weeks. Safflower oil and menhaden oil feeding resulted in the accumulation of n-6 polyunsaturated fatty acids (PUFA) and n-3 PUFA respectively in the kidney microsomes. The specific activity of Na + , K + -ATPase was higher by 26% in animals fed safflower oil when compared to animals fed coconut oil or menhaden oil. Supplementation of curcumin in the diets containing different lipids did not affect either the kidney microsomal fatty acid profiles or Na + , K + -ATPase activity. However, dietary curcumin reduced the serum triglyceride level by 44% in safflower oil fed animals and serum cholesterol levels by 24% and 31% in animals fed safflower oil and menhaden oil respectively. These studies indicated that dietary lipids and curcumin differentially affect membrane fatty acid composition, Na + , K + -ATPase activity and serum lipids.

The objective of the present study was to compare the incorporation of different types of n-3 polyunsaturated fatty acids into thigh muscle lipids of poultry. Nine groups of broiler chicks were fed diets supplemented with three levels (1.0, 2.5, and 5.0%) of either corn, linseed, or menhaden oil. Birds supplemented with linseed oil, rich in linolenic acid (C18:3n-3), had significantly higher levels of n-3 fatty acids and higher n-3:n-6 ratios than those supplemented with the same level of menhaden oil, primarily due to an accumulation of C18:3n-3. Levels of eicosapentaenoic acid (C20:5n-3) were increased (P less than .05), compared with the controls fed the same level of corn oil, in the groups fed the two higher levels of linseed oil, and in all the groups fed menhaden oil. Linolenic acid is less susceptible to auto-oxidation, and is less likely to impart an off-flavor to the muscle. Thus, if it is desirable to increase the n-3:n-6 ratio in poultry, seed meals or oils with a high content of C18:3n-3 could be used in poultry feeds.

The polyunsaturated fatty acid composition of dietary fat has been associated with increased oxidant stress in tissues. We previously showed that antioxidant mechanisms in colon mucosa are affected by dietary fat. In this study, the colonic antioxidant response to treatment with the colon-specific carcinogen 1,2-dimethylhydrazine (DMH) was determined. Sprague-Dawley rats were fed one of four AIN-76A-based diets with varied fat content. The basal diet contained 5% corn oil, the menhaden oil diet contained 19% menhaden oil and 1% corn oil, the corn oil diet contained 20% corn oil and the beef tallow diet contained 19% beef tallow and 1% corn oil. Animals were given one or two intraperitoneal injections of either DMH (20 mg/kg) or 1 mmol/L EDTA. Homogenates of colon mucosa were assayed to determine activity of catalase, glutathione peroxidase, total superoxide dismutase, manganese superoxide dismutase, glutathione reductase and glutathione-S-transferase, as well as total glutathione concentration, thiobarbituric acid-reacting substances and nuclear aberrations. Total glutathione concentration was greater in rats fed all diets following two injections of DMH, whereas glutathione reductase activity remained unchanged relative to controls. Lipid peroxidation was highest in the group fed menhaden oil; nuclear aberrations were greatest in the corn oil-fed group. In conclusion, both type and amount of dietary fat modified the response of colon tissue to genotoxic challenge, but none of the diets seemed more protective than the others.

The effect of dietary n−3 fatty acids on prostaglandin E2 (PGE2) and leukotriene C4 (LTC4) levels in rat salivary glands and gingiva was examined in two separate nutritional studies. In the first set of experiments, two groups of male weanling Sprague-Dawley rats were fed semipurified diets containing 10% corn oil (control group) or 10% menhaden oil (experimental group). Rats were killed after 8 wk on the diets; the fatty acid composition of total phospholipids and the concentrations of PGE2 and its precursor, arachidonic acid, were measured in gingiva and submandibular salivary glands (SMSG). Dietary n−3 fatty acids were incorporated into the tissue phospholipids. Arachidonic acid levels were reduced by 56% in gingiva and SMSG of rats fed menhaden oil compared with the control rats fed the diet containing corn oil. The concentrations of PGE2 in SMSG and gingiva of rats fed the diet containing menhaden oil were reduced by 74% and 83%, respectively. In a subsequent nutritional study, we tested whether the diet-induced reduction in tissue arachidonic acid levels would also result in a corresponding decrease in LTC4 production. Three groups of rats were fed diets containing 5% corn oil (group 1), 4% ethyl ester concentrate of n−3 fatty acids plus 1% corn oil (group 2), or 5% ethyl ester concentrate of n−3 fatty acids (group 3). After 6 wk of feeding, gingiva and SMSG were analyzed for arachidonic acid content andin vitro production of LTC4. Arachidonic acid content of total phospholipids was about 60% lower in gingiva and 69% lower in SMSG of rats fed the ethyl ester concentrate of n−3 fatty acids (groups 2 and 3) than those of the control group fed the corn oil diet (group 1). Upon incubation with calcium ionophore, gingiva and SMSG from rats fed the n−3 fatty acids rich diet produced significantly less TLC4 than those from rats of the control group. Because PGE2 and LTC4 are believed to be important biochemical mediators of periodontal disease, one may speculate that a diet-induced reduction in their levels may have a beneficial effect upon the course of the disease. The function of salivary glands may also be altered because of the role of these eicosanoids in salivary secretions.

The relative capacities of n-3 and n-6 polyunsaturated fatty acid-containing diets (PUFA) to modify chemical composition in plasma lipoproteins, liver membrane, and heart phospholipids and to thereby modulate lipoprotein and membrane fluidity were studied in the rabbit. Stock diet-fed New Zealand rabbits were made hypercholesterolemic by feeding a casein-based, semi-purified diet containing coconut oil. Subsequent replacement of the coconut oil with corn or menhaden oil caused reduction or elevation, respectively, of blood cholesterol levels. Very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) became progressively less fluid following transfer from the PUFA containing low fat stock diet to the coconut oil diet. Subsequent corn oil feeding induced significant increases in VLDL and LDL, but not HDL, fluidities. Menhaden oil feeding did not affect lipoprotein fluidity. Liver membranes were less fluid in corn oil-fed and menhaden oil-fed than in coconut oil-fed rabbits. Despite these differences in lipoprotein and membrane fluidity the amount of rabbit 125I-LDL capable of binding to liver membranes from the animals was not affected by the dietary fat modifications. Fatty acyl compositions were affected by the diets. Heart and liver phospholipids showed extensive incorporation of n-3 fatty acids and deletion of linoleate in the menhaden oil-fed animals. Dietary effects on lipoprotein phospholipid fatty acids were statistically significant but not as pronounced as in these tissues.

The effects of dietary fat on antioxidant mechanisms in colon mucosa were examined using male Sprague-Dawley rats. Animals were fed one of four AIN-76A-based test diets differing in amount and type of fat. The basal diet (BD) contained 5% corn oil; the menhaden oil diet (MO) contained 1% corn oil and 19% menhaden oil; the corn oil diet (CO) contained 20% corn oil; and the beef tallow diet (BT) contained 1% corn oil and 19% beef tallow; all were adjusted to provide equal amounts of other nutrients per kilojoule. Homogenates of colon mucosa were assayed after 2 wk and 1, 3, 6 and 9 mo for activities of catalase (CAT), glutathione peroxidase (GSHPx), superoxide dismutase (SOD), glutathione-S-transferase, glutathione reductase (GSSGRx), and total glutathione (GSH) content. Activity of GSHPx was depressed in rats fed high fat diets compared with rats fed the low fat BD. Animals fed the BD and MO diets had higher levels of CAT and GSSGRx as compared with rats fed the CO and BT diets. Activities of SOD, GSSGRx and GSHPx, as well as GSH concentration, decreased over time. Ornithine decarboxylase activity was not induced by the high fat diets. Thiobarbituric acid-reacting substances were virtually undetectable. Thus, both type and amount of fat affected antioxidant mechanisms in colon mucosa without producing overt oxidative damage in the tissue.

A 12-week feeding experiment was conducted to investigate the growth and compositional responses of channel catfish fry (Ictalurus punctatus) fed practical diets containing 7.6% fish meal supplemented with 0, 1.5, 3, or 6% menhaden fish oil. Weight gain significantly improved with increasing levels of supplemental menhaden oil up to 3% of diet; fish fed the diet containing 6% fish oil had depressed weight gain. Whole-body dry matter and lipid increased and protein decreased with increasing levels of menhaden oil. Ash content was not affected by dietary treatment. Fatty acid composition of polar lipids from whole-body tissue showed that supplementation of menhaden fish oil at a rate of 1.5% was sufficient to satisfy the essential fatty acid (EFA) requirement of young channel catfish based on the ratio of 20:3 n-9 to 22:6 n-3 fatty acids. Results from this study indicate that practical diets containing fish meal, but without supplemental fish oil, did not meet the n-3 EFA requirement of young chann...

The present work tests the hypothesis that high fat/low carbohydrate diets elevate the level of liver microsomal cytochrome P450IIE1. Male Sprague-Dawley rats were fed liquid diets containing varied ratios of corn oil/carbohydrate for 4 d. Rats fed diets with higher fat/carbohydrate ratios produced higher serum acetone levels and higher hepatic microsomal P450IIE1 content and N-nitrosodimethylamine demethylase activity than those fed diets with lower fat/carbohydrate ratios. This dietary fat/carbohydrate effect on P450IIE1 also was observed with modified semipurified AIN-76A diets. In addition, both the quantity and the extent of unsaturation of dietary lipids affected P450IIE1 regulation. At moderate fat levels (5 and 20% diet), rats fed corn oil and menhaden oil diets produced higher P450IIE1 activity than those fed lard and olive oil diets. Rats fed a diet containing 20% corn oil or an amount of linoleic acid equivalent to the 20% corn oil diet showed twofold to threefold increases in the level of P450IIE1 over those fed a fat-free diet. Rats fed a 25% corn oil diet showed twofold higher enflurane metabolism in vivo than those fed a 0.5% corn oil diet. The present results suggest that the constitutive P450 enzyme level is regulated by dietary fat/carbohydrate ratios.

We fed juvenile channel catfish Ictalurus punctatus purified diets containing different lipid sources for 90–110 d to examine the influence of dietary lipids on intracellular killing of Edwardsiella ictaluri by pronephros macrophages. The diets contained either menhaden oil, soybean oil, beef tallow, or a combination ofall three lipids. We performed the study with nonimmune and immunized fish acclimated to optimal (28°C) and suboptimal (19°C) temperatures. In both temperature trials, bactericidal activity was positively correlated with the level of n-3 fatty acids in the diet (particularly long-chain highly unsaturated fatty acids). Vaccination resulted in substantially enhanced bactericidal activity, except at suboptimal temperature in fish fed the diet containing beef tallow (primarily saturated and monoenoic fatty acids). Overall results were similar at optimal and suboptimal temperatures. This study demonstrates the potential for nutritional manipulation of disease resistance in fish and illu...

The objective of the present studies was to find out whether the lipemic effect of dietary fish oil versus corn oil would be affected by the background composition of the diet. For this purpose, a total of 192, male Wistar rats (Hsd/ Cpb:WU) three weeks of age were used in a series of four experiments. In each experiment, 48 rats were divided randomly 12 rats each. The rats were fed diets containing either fish oil or corn oil but different background compositions. The variables of the background diet were: the amount of fat (low versus high), the type of carbohydrate (glucose versus sucrose), the amount of cholesterol (low versus high), and the type of protein (casein versus soy protein). Each experiment consisted of four dietary groups, two of which received either fish oil or corn oil in the diets. The diets contained either 12% (w/w) of menhaden oil or corn oil. The menhaden oil contained approximately 14% eicosapentaenoic and 8% docosahexaenoic acid and the corn oil contained about 56% linoleic acid. The experimental diets were given for two weeks in each experiment. It was found that the hypotriglyceridemic effect of fish oil versus corn oil was not influenced by the background composition of the diet. The hypocholesterolemic effect of fish oil versus corn oil did depend on the background composition of the diet. Addition of coconut fat to the diet at the expense of an isocaloric amount of sucrose resulted in a diminished hypocholesterolemic effect of fish oil. The hypocholesterolemic effect of fish oil versus corn oil was not influenced by the type of carbohydrate (glucose versus sucrose) in the background diet. Upon the addition of 1% (w/w) of cholesterol to the diets, irrespective of whether casein or soy protein was the protein source, no cholesterol lowering effect of fish oil versus corn oil was observed. It can be concluded that the lipemic effect of fish oil versus corn oil can be influenced by the background composition of the diet. This conclusion should be qualified it holds for the hypocholesterolemic but not for the hypotriglyceridemic effect of fish oil.; This implies that the composition of the background diet should be considered when comparing the cholesterolemic effects of fish oil in various experiments

The purpose of this study was to determine the feasibility of increasing the consumption of dietary ω-3 fatty acids by incorporating menhaden oil into a French-type salad dressing. Menhaden/soybean oil blends of 10, 20 and 30% menhaden oil (w/w) were used to prepare an emulsified French salad dressing. The oil blends and salad dressings were stored at 22°C in the dark for 20 wk. The fatty acid profile, peroxide value, and anisidine value were determined. The salad dressings also were evaluated by a sensory panel for flavor, aroma, and aftertaste. The ω-3 fatty acids were stable over time under these storage conditions. Peroxide values rose slowly and consistently over time reaching higher values when more menhaden oil was added. Peroxide values were also higher in the oil blends which were stored with air in the headspace and not flushed with argon. Anisidine values also were higher with each addition of menhaden oil but did not change over time except for the 100% menhaden oil which was stored in air. After eight weeks the sensory panel rated the salad dressing which contained menhaden oil as lower than the ones which did not contain menhaden oil. While a significant amount of ω-3 fatty acids may be incorporated into foods by the addition of menhaden oil, the development over time of off-flavors must be controlled.

Studies of the utilization of fatty acids were undertaken to compare the effects of chain length and the degree of unsaturation on the accumulation of energy and of fatty acids in growing rats. Rats were fed either 17% corn oil, 17% medium chain triglyceride oil (MCT), or 17% menhaden oil in addition to 3% safflower oil. The deposition of individual fatty acids in the carcass was measured and compared with the amount of the fatty acid that was consumed during the 6 weeks of diet treatment. In all groups the percent of dietary linoleic acid in the carcass was similar with 29.2 ± 2.7, 33.0 ± 1.9, and 43.7 ± 3.8 found for the corn oil, MCT, and menhaden oil groups, respectively. In contrast, only 7.7 ± 0.9% of the dietary eicosapentaenoic acid (EPA) and 14.3 ± 1.5% of the dietary docosahexaenoic acid (DHA) were found in the carcasses of the animals fed menhaden oil. There were indications of reduced energy accumulation in the menhaden oil group, although reduced dietary consumption was also seen in this group. A paired feeding study of corn oil and menhaden oil also suggested reduced energy deposition per gram of diet in the menhaden oil group. A fat balance study comparing corn oil and fish oil showed the absorption of both fats to be essentially complete and ruled out malabsorption of the menhaden oil as a contributor to the reduced accumulation of the EPA and DHA.

The predominant polyunsaturated fatty acids of the n-6 family found in corn oil (CO) are crucial for normal mammary duct formation when fed to animals. However, as shown here, not all polyunsaturated fatty acids are equally effective in stimulating mammary gland development. The n-3 fatty acids in a 10% menhaden oil (MO) diet fed to mice effectively reduced both the diameter and the length of the growing mammary ducts. Previously, we demonstrated a similar reduction in duct growth by feeding a 10% fat diet high in those saturated fats found in hydrogenated cotton seed oil. The inhibited rate of duct maturation caused by hydrogenated cotton seed oil was reversed when the mice were allowed to mature on a diet containing n-6 fatty acids prior to feeding the saturated fat diet. The addition of 1% CO to a 9% hydrogenated cotton seed oil diet fed to immature mice was also sufficient to restore duct growth. Mice fed menhaden oil diets, on the other hand, continued to show impaired ductal growth well into adulthood. Examination of the ovaries from MO-fed mice as compared with CO-fed mice revealed significantly fewer corpora lutea. When exogenous progesterone was given to MO-fed mice, ductal growth was partially restored, but not to the extent seen in mice fed corn oil diets. Investigation of the fatty acid contents of livers of these mice revealed reduced amounts of arachidonate (20:4) in MO-fed mice when compared with CO-fed animals. The addition of 1% CO to the 9% MO diets did not alter the arachidonate content, indicating a block in the conversion of linoleate (18:2) to 20:4 by the n-3 fatty acids. Hence, dietary n-6 fatty acids are essential for normal mammary ductal development when fed prior to maturation. Although saturated rats are ineffective, n-3 fatty acids can partially substitute for the required n-6 fatty acids in both ductal and ovarian development.

The type of dietary fat has been shown to modulate the initiation stage of mammary tumorigenesis, with saturated fat fed before and/or during carcinogen treatment resulting in increased tumor incidence. This study was designed to determine whether different types of dietary fat alter the initiation stage of skin carcinogenesis by use of the initiation-promotion mouse skin carcinogenesis model. Sencar mice were divided into three groups and maintained on one of the experimental diets. The AIN-76-based diets consisted of 10% total fat with various types of fat: 8.5% menhaden oil plus 1.5% corn oil, 8.5% coconut oil plus 1.5% corn oil, and 10% corn oil. After three weeks mice were initiated with 10 nmol dimethylbenz[a]anthracene (DMBA). Two weeks later, all mice were switched to a diet containing 5% corn oil. Promotion began four weeks after initiation with twice-weekly application of 1 microgram 12-O-tetradecanoylphorbol-13-acetate and continued for 12 weeks. No statistically significant differences in kilocalories of food consumed or body weights were observed between diet groups during the study. The final papilloma incidence, yield, and size were not significantly different among the diet groups. In a parallel study, [3H]DMBA binding to epidermal DNA showed no dietary differences. Unlike the mammary carcinogenesis model, these data suggest that the type of fat fed during DMBA initiation had minimal effects on this stage of skin carcinogenesis.