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The objective of this study was the effectiveness of using activated earth, activated alumina, and/or chitosan, either separately or in combination, as adsorbents to remove free fatty acids (FFA) and peroxides from unpurified menhaden oil (MO). Thermal and rheological properties of MO were also evaluated. Five different combinations of absorbents were used to purify MO: Processes 1–3 involved purifications of MO by 5% chitosan (wt/wt of oil), 5% activated earth, and 5% activated alumina, respectively, process 4 involved MO purification with a combination of 6.5% chitosan, 3.5% activated earth, and 5% activated alumina, and process 5 involved MO purification process with a combination of adsorbents of 9% chitosan, 1% activated earth, and 5% activated alumina. All the adsorption processes were conducted at 25°C. Purified MO and MO were evaluated for their fatty acid profile, FFA, peroxide value (PV), moisture content (MC), minerals, and color. Triplicate experiments were conducted, and data were statistically analyzed using α = 0.05. Processes 4 and 5 were effective in reducing PV, FFA, and MC in MO. Thermal properties indicated processes 4 and 5 produced purer MO than processes 1–3. All the oil samples became less viscous, and the flow behavior index of MO was close to 1 after the adsorption processes. This study demonstrated that adsorption processes that include chitosan, activated earth, and activated alumina could effectively improve MO quality. [ABSTRACT FROM AUTHOR]

Menhaden oil was enzymatically modified with caprylic (8:0) and/or stearic acid (18:0) to produce structured lipids (SL). The goal was to produce SL with high amounts of polyunsaturated fatty acids (PUFA), a low level of saturation, and a melting point of 25–35 °C. Substrate (menhaden oil to acyl donor) molar ratios were 1:1, 1:3, and 1:5 for 8:0, and 1:1, 1:2, and 1:3 for 18:0. Enzyme load was 10% of the total weight of substrates. Time course study determined optimal time for maximum acyl donor incorporation. Linear interpolation estimated molar ratios that yielded SL with 20 or 30 mol% incorporation of 8:0 or 18:0. Enzymatic reactions were also conducted with molar ratios of menhaden oil to acyl donors:8:0:18:0 (1:1:3, 1:2:2, and 1:3:1). Lipases from Candida antarctica, Lipozyme® 435, and Rhizomucor miehei, Lipozyme® RM IM (Novozymes North America, Inc., Franklinton, NC, USA), were compared for all reactions. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, volatile lipid oxidation products, solid fat contents, and oxidative stability were compared. When 8:0 was the acyl donor, the 1:3.03 and 1:4.58 ratios resulted in incorporation of 20 and 30 mol% 8:0, respectively. With 18:0 as the acyl donor, the 1:1.32 and 1:2.41 ratios led to incorporation of 20 and 30 mol% 18:0, respectively. The 1:3:1 ratio SL had a crystallization onset (C0) of 15.3 °C and a melting completion (Mc) of 33.1 °C. The physicochemical properties of these SL suggest that some may be useful in formulating food products such as margarines and spreads. [ABSTRACT FROM AUTHOR]

Oleogels were produced using a phytosterol blend of β‐sitosterol/γ‐oryzanol or a blend of sucrose stearate/ascorbyl palmitate (SSAP) as oleogelators. Four lipid phases were compared in oleogel formation for each oleogelator blend: menhaden oil, structured lipid (SL) of menhaden oil and 30 mol% caprylic acid (SL‐C), SL of menhaden oil and 20 mol% stearic acid (SL‐S), and SL of menhaden oil and 14 mol% each of caprylic and stearic acid (SL‐CS). All SLs were produced enzymatically using a recombinant lipase from Candida antarctica as the biocatalyst. Menhaden oil, SL, phytosterol, or SSAP oleogels were evaluated as alternatives to shortening in the preparation of yellow cake in terms of batter and cake physicochemical properties. The shortening, phytosterol, and SSAP oleogel batters exhibited statistically similar specific gravities (0.85). The shortening, and menhaden oil phytosterol and SSAP oleogel batters, exhibited similar Power‐Law values (n: 0.78, k: 31 Pa sn), while all SL (and respective oleogels) batters typically had lower flow index values (n: 0.68 to 0.72), and higher consistency index values (k: 45 to 79 Pa sn). All SL (and respective oleogels) cakes exhibited lower hardness (5 to 8 N) and chewiness (4 to 6 N) than the shortening cake (12 N, 9 N). Menhaden oil and SL‐S phytosterol oleogel cakes, and SL‐CS SSAP oleogel cake, showed similar textural properties to the shortening cake. Both phytosterol and SSAP oleogels were acceptable as zero trans‐fat substitutes for shortening in yellow cake. Practical Application: The oleogels in this study may be a suitable replacement for shortening in yellow cake. These oleogels, which contain health beneficial omega‐3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have the potential to lower consumer consumption of total saturated fat when used in foods. [ABSTRACT FROM AUTHOR]

The goal of this study was to improve the chemical stability of menhaden oil and control the lipolysis in emulsions with whey protein during in vitro digestion through EGCG conjugation and genipin-mediated interfacial cross-linking (CL). WPI-EGCG conjugate was successfully synthesized, confirmed by SDS-PAGE, ESI-MS, and phenolic group quantifications (125.3 mg/g), and characterized with far UV CD and ATR-FTIR. Emulsion particle diameter with WPI-EGCG is lower than with WPI. Compared to the native emulsion, WPI CL increased particle diameter and physical stability. Higher oxidative stability was observed for emulsions stabilized with WPI-EGCG conjugate than that with interfacial cross-linking due to the great antioxidant activity. Whereas, WPI CL is more effective than WPI-EGCG conjugate in hindering the rate and extent of lipolysis. The combination of EGCG conjugation and interfacial CL showed both the highest protection of menhaden oil against degradation and highest inhibition on the rate and extent of lipolysis of menhaden oil. [ABSTRACT FROM AUTHOR]

Abstract: Structured lipids (SL) were produced using menhaden oil and capric acid or ethyl caprate as the substrate. Enzymatic reaction conditions were optimized using the Taguchi method L9 orthogonal array with three substrate molar ratio levels of capric acid or ethyl caprate to menhaden oil (1:1, 2:1, and 3:1), three enzyme load levels (5, 10, and 15% [w/w]), three temperature levels (40, 50, and 60 °C), and three reaction times (12, 24, 36 hours). Recombinant lipase from Candida antarctica, Lipozyme® 435, and sn‐1,3 specific Rhizomucor miehei lipase, Lipozyme® RM IM (Novozymes North America, Inc., Franklinton, NC, USA), were used as biocatalysts in both acidolysis and interesterification reactions. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability were compared. Optimal conditions for all reactions were 3:1 substrate molar ratio, 10% [w/w] enzyme load, 60 °C, and 16 hours reaction time. Reactions with ethyl caprate incorporated significantly more C10:0, at 30.76 ± 1.15 and 28.63 ± 2.37 mol% versus 19.50 ± 1.06 and 9.81 ± 1.51 mol%, respectively, for both Lipozyme® 435 and Lipozyme® RM IM, respectively. Reactions with ethyl caprate as substrate and Lipozyme® 435 as biocatalyst produced more of the desired medium‐long‐medium (MLM)‐type TAGs with polyunsaturated fatty acids (PUFA) at sn‐2 and C10:0 at sn‐1,3 positions. [ABSTRACT FROM AUTHOR]

We have previously demonstrated that enalapril, α-lipoic acid and menhaden (fish) oil has potential as a treatment for diabetic peripheral neuropathy. In this study we sought to determine the efficacy of these treatments individually or in combination on multiple neuropathic endpoints in a high fat fed low dose streptozotocin treated mouse, a model of type 2 diabetes, following early or late intervention. Four or twelve weeks after the onset of hyperglycemia, diabetic mice were treated with enalapril, α-lipoic acid, menhaden oil or their combination for 12 weeks. Afterwards, endpoints including glucose tolerance, motor and sensory nerve conduction velocity, thermal nociception, and intraepidermal and cornea nerve fiber density was determined. Glucose clearance was impaired in diabetic mice and significantly improved only with combination treatment and early intervention. Diabetes caused steatosis, slowing of motor and sensory nerve conduction velocity, thermal hypoalgesia and reduction in intraepidermal and cornea nerve fiber density. Treating diabetic mice with enalapril, α-lipoic acid or menhaden oil partially protected diabetic mice from these deficits, whereas the combination of these three treatments was more efficacious following early or late intervention. These studies suggest that a combination therapy may be more effective for treating neural complications of type 2 diabetes. [ABSTRACT FROM AUTHOR]

We have previously demonstrated that treating diabetic rats with enalapril, an angiotensin converting enzyme (ACE) inhibitor, α-lipoic acid, an antioxidant, or menhaden oil, a natural source of omega-3 fatty acids can partially improve diabetic peripheral neuropathy. In this study we sought to determine the efficacy of combining these three treatments on vascular and neural complications in a high fat fed low dose streptozotocin treated rat, a model of type 2 diabetes. Rats were fed a high fat diet for 8 weeks followed by a 30 mg/kg dose of streptozotocin. Eight weeks after the onset of hyperglycemia diabetic rats were treated with a combination of enalapril, α-lipoic acid and menhaden oil. Diabetic rats not receiving treatment were continued on the high fat diet. Glucose clearance was impaired in diabetic rats and significantly improved with treatment. Diabetes caused steatosis, elevated serum lipid levels, slowing of motor and sensory nerve conduction, thermal hypoalgesia, reduction in intraepidermal nerve fiber profiles, decrease in cornea sub-basal nerve fiber length and corneal sensitivity and impairment in vascular relaxation to acetylcholine and calcitonin gene-related peptide in epineurial arterioles of the sciatic nerve. Treating diabetic rats with the combination of enalapril, α-lipoic acid and menhaden oil reversed all these deficits to near control levels except for motor nerve conduction velocity which was also significantly improved compared to diabetic rats but remained significantly decreased compared to control rats. These studies suggest that a combination therapeutic approach may be most effective for treating vascular and neural complications of type 2 diabetes. [ABSTRACT FROM AUTHOR]

This study investigated the effect of blueberry juice on menhaden oil lipid oxidation during microencapsulation. Oil in water emulsions containing menhaden oil with 0, 5, or 10% blueberry juice were spray dried to produce control-M, 5% BJ-M, and 10% BJ-M microencapsulated powders, respectively. All microencapsulated powders had similar encapsulation efficiencies with low surface oil content. Peroxide value (meq/kg of oil) was 4.50, 4.31, and 3.38 for control-M, 5% BJ-M and 10% BJ-M, respectively. Ten percent BJ-M had lower (P < 0.05) anisidine value, and totox values than 5% BJ-M and control-M. This indicated that 10% blueberry juice reduced lipid oxidation in menhaden oil during microencapsulation to a greater extent than the other formulations. [ABSTRACT FROM AUTHOR]

The effects of xanthan gum (XG)–locust bean gum (LBG) mixtures (0.05, 0.1, 0.15, 0.2 and 0.5 wt%) on the physicochemical properties of whey protein isolate (WPI) stabilised oil-in-water (O/W) emulsions containing 20% v/v menhaden oil was investigated. At higher concentrations, the apparent viscosity of the emulsions containing XG/LBG mixtures was significantly higher ( p < 0.05) than the emulsions containing either XG or LBG alone. Locust bean gum showed the greatest phase separation, followed by XG. Microstructure images showed depletion flocculation at lower biopolymer concentrations, and thus led to an increase in creaming instability and apparent viscosity of the emulsions. Addition of 0.15, 0.2 and 0.5 wt% XG/LBG mixtures greatly decreased the creaming of the emulsions. The rate of lipid oxidation for 8-week storage was significantly lower ( p < 0.05) in emulsions containing XG/LBG mixtures than in emulsions containing either of the biopolymer alone. [ABSTRACT FROM AUTHOR]

Purpose: 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. [ABSTRACT FROM AUTHOR]

The fatty acids contained in marine oils or products are traditionally analyzed by gas chromatography using capillary columns coated with polyethylene glycol phases. Recent reports indicate that 100 % cyanopropyl siloxane phases should also be used when the analyzed samples contain trans fatty acids. We investigated the separation of the fatty acid methyl esters prepared from menhaden oil using the more polar SLB-IL111 (200 m × 0.25 mm) ionic liquid capillary column and the chromatographic conditions previously optimized for the separation of the complex mixture of fatty acid methyl esters prepared from milk fat. Identifications of fatty acids were achieved by applying Ag +-HPLC fractionation and GC-TOF/MS analysis in CI + mode with isobutane as the ionization reagent. Calculation of equivalent chain lengths confirmed the assignment of double bond positions. This methodology allowed the identification of 125 fatty acids in menhaden oil, including isoprenoid and furanoid fatty acids, and the novel 7-methyl-6-hexadecenoic and 7-methyl-6-octadecenoic fatty acids. The chromatographic conditions applied in this study showed the potential of separating in a single 90-min analysis, among others, the short chain and trans fatty acids contained in dairy products, and the polyunsaturated fatty acids contained in marine products. [ABSTRACT FROM AUTHOR]

Abstract: 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 60cm 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. [Copyright &y& Elsevier]

Abstract: Surimi-based seafood products are widely accepted and enjoyed worldwide. The U.S. 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). Protein endothermal transitions, heat-induced gelation (elastic modulus, G′), and fundamental texture properties (shear stress) of Alaska pollock surimi nutrified with ω-3 PUFAs-rich oils (flaxseed, algae, menhaden, krill, and blend) were determined and compared to Alaska pollock surimi without oil (control). Differential scanning calorimetry showed that oil addition enhanced thermal transition of actin and did not compromise the transition of myosin. The addition of oil improved heat-induced protein gelation as demonstrated with dynamic rheology. Elastic modulus increased when oil was added. There were no differences (P > 0.05) in shear stress between surimi gels with and without oil, indicating that nutrification with ω-3 PUFAs-rich oils within the ranges tested did not alter gel strength. This study demonstrates that the nutritional value and gelation of surimi seafood can be enhanced without altering texture properties by addition of ω-3 PUFAs-rich oils. [Copyright &y& Elsevier]

Abstract: 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 (P <0.05) 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 (P <0.05) 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. [Copyright &y& Elsevier]

Abstract: Purified menhaden oil (PMO) was characterized and microencapsulated. Baby foods containing PMO and microencapsulated purified menhaden oil (MPMO) were evaluated and compared. PMO had higher total omega-3, total saturated, total monounsaturated, DHA, and EPA contents than MPMO. Emulsion containing PMO (EPMO) exhibited viscoelastic characteristic and droplet size of EPMO was around 2–10 μm. The DHA and EPA in the PMO were reduced in MPMO. All baby-food samples with added fish oils had similar FFA values and color. DHA and EPA of baby food were significantly increased by adding PMO and/or MPMO. Total percent values for omega-3 fatty acids of extracted fat from commercial baby food (CB), commercial baby food containing PMO (BPMO), and commercial baby food containing MPMO (BMPMO) were 4.5, 9.8 and 10.1%, respectively. [ABSTRACT FROM AUTHOR]

A study was conducted to determine the effects of different sources of dietary lipid that differ in fatty acid (FA) composition on growth, feed conversion ratio (FCR), survival, and whole-body proximate and FA composition of juvenile red claw. Juvenile red claw (0.55 ± 0.02 g) were reared over a 12-week period. Five practical diets were supplemented with 70 g kg oil (by weight) from either linseed oil (LO), canola oil (CAO), corn oil (CO), beef tallow (BT) or menhaden oil (MO) and formulated to contain 400 g kg crude protein. Red claw were fed three times daily (800, 1200 and 1600) to controlled excess. At the conclusion of the experimental period, there were no significant differences ( P > 0.05) found in percentage survival and FCR among dietary treatments and values averaged 85.4% and 3.4, respectively. However, final mean weight and specific growth rate of red claw fed Diet 1 (LO) was significantly higher (16.44 g and 3.95% day, respectively) compared with that of red claw fed Diet 4 (BT; 12.24 g and 3.43% day, respectively), but not different from red claw fed the other three diets. Likewise, red claw fed Diets 1 (LO) and 2 (CAO) had significantly higher percentage weight gain (2990 and 2880%, respectively) compared with the BT diet (2124%), but not different from red claw fed Diets 3 (CO) and 5 (MO). Whole-body fat and ash composition was significantly affected ( P < 0.05) by source of added lipid, but no differences were found in whole-body moisture and protein. Moreover, whole-body FA composition showed differences among the varying oil sources and primarily reflected the FA in the diets. Results of the present study indicate that plant oils LO, CAO and CO rich in linolenic acid (18:3 n-3), linoleic acid (18:2 n-6) and oleic acid (18:1 n-9) perform as well as MO containing high levels of n-3 highly unsaturated fatty acids eicosapentanoic acid (20:5 n-3) and docosahexaenoic acid (22:6 n-3) for juvenile red claw crayfish grown indoors lacking natural food items. Further, red claw fed a diet containing BT, which has a high percentage of saturated FA, performed poorly compared with LO and CO in regards to weight gain. It appears that juvenile red claw can be fed diets containing less expensive plant-based oils with high levels of 18-carbon unsaturated fatty acids. This could reduce diet costs for producers and allow for profitability. [ABSTRACT FROM AUTHOR]

Unrefined menhaden oil was evaluated for thermal and rheological properties and its temperature-dependent viscosity and lipid oxidation rate were determined. Peroxide value, free fatty acids, density, specific gravity, water activity, moisture content, and enthalpy of the unrefined menhaden oil were 5.70 meq/kg, 3.80%, 0.93 g/mL, 0.93%, 0.52%, 0.15%, and 20.2 kJ/kg, respectively. The melting point range of unrefined menhaden oil was found to be −69.5 to 27.21 °C. The menhaden oil exhibited non-Newtonian fluid behavior at lower temperatures (5 to 25 °C), while it behaved like a Newtonian fluid at 30 °C. The oil apparent viscosity at 5 °C (0.22 Pa.s) was significantly higher ( P < 0.05) than that at 30 °C (0.033 Pa.s). The average magnitude of activation energy for viscosity of the unrefined menhaden oil was 50.37 kJ/mol. The predicted apparent viscosity agreed ( R2= 0.9837) satisfactorily with the experimental apparent viscosity. The minimal lipid oxidation rate of the oil was found at 25 and 35 °C for 6 h, higher lipid oxidation rates were observed when the oil was heated for 6 h at 45 to 85 °C. The rate of lipid oxidation for unrefined menhaden oil was temperature dependent ( R2= 0.9425). This study showed that the magnitude of the apparent viscosity and oxidation rate of the unrefined menhaden oil was greatly influenced by temperature. [ABSTRACT FROM AUTHOR]

Abstract: The effect of xanthan gum (XG) addition on physicochemical properties of 2wt% whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20% v/v menhaden oil was investigated by measuring droplet size, viscosity, microstructure, creaming profile and oxidative stability. In fresh emulsions, addition of XG at different concentrations did not show any significant effect on the surface-area-average droplet size (d 32). However, emulsion microstructure and creaming profile indicated that the degree of flocculation is a function of XG concentration: when XG=0%, there was no flocculation; when XG=0.02–0.15wt%, there was limited flocculation; when XG=0.2wt%, there was extensive flocculation leading to the formation of an emulsion gel; and when XG=0.5wt%, there was little or no flocculation. Lipid oxidation of the emulsions was inhibited by the addition of 0.15 or 0.2wt% XG. In the presence of 0.5wt% XG, the emulsion exhibited a high yield stress, which appreciably inhibited creaming. Nevertheless, addition of 0.5wt% XG was believed to have interacted with unadsorbed WPI in the aqueous phase, which inhibited the antioxidant property of WPI. Thus, addition of 0.5wt% XG had a net prooxidant effect in the 2wt% WPI stabilized emulsions containing 20% v/v menhaden oil. [Copyright &y& Elsevier]

The effect of long-chain n-3 polyunsaturated fatty acid (PUFA) on bone measurements was evaluated in gonad-intact middle-aged male rats. Seven rats were killed on day 0 of dietary intervention to determine bone parameters at baseline. Experimental rats (7/group) were fed one of the following lipid treatments (g/kg diet): 167 g safflower oil + 33 g menhaden oil (N6+N3 diet, control), 200 g safflower oil (N6 diet), or 190 menhaden oil + 10 g corn oil (N3 diet). After 20 weeks of dietary treatment, all groups had lower values for peak load and ultimate stiffness in femurs compared to baseline values. Rats fed the N3 diet had the highest values for peak load, ultimate stiffness, and Young’s modulus compared with those fed the N6 and control diets. Compared to baseline, all dietary treatment groups had significantly lower values for trabecular thickness and number in proximal tibia but higher values for trabecular separation and formation rate in proximal tibia and endocortical bone formation rate in tibial shaft. Compared with the control group, rats fed the N3 diet had lower values for formation rate, osteoclast number, and eroded surface in proximal tibia but higher values for periosteal mineral apposition and formation rates in tibia shaft. These findings indicate that a diet rich in long-chain n-3 PUFA mitigate aging-induced loss of bone integrity in intact middle-aged male rats through reducing bone turnover rate by suppressing both bone formation and resorption as a result of a larger net bone volume and modulating endocortical and cancellous bone compartments. [ABSTRACT FROM AUTHOR]

Abstract: We conducted a 12-week feeding trial with largemouth bass (LMB) to examine the interactive effects of non-fish dietary proteins with different lipid sources on the performance of LMB (3.4 g±0.05 g). Practical diets contained poultry by-product meal (PBM) in place of fish meal on a digestible-protein basis, and 12% blood meal (BM). Diets were supplemented with 10% lipid as canola (CAN), chicken (CHK), CHK+MFO (50:50), menhaden fish oil (MFO) or CHK+CAN (50:50). A commercial trout diet (SC) was included as a positive control. Growth, survival, feed intake (FI), feed conversion ratio (FCR), protein efficiency ratio (PER), body composition, fatty acid composition of liver and muscle, hematological parameters and lysozyme and alternative complement activity (ACH50) were measured to assess diet effects. Weight gain (23.8±1.8 g), survival (92±4%), FI (44.3±4.1 g), FCR (2.1±0.1) and PER (1.3±0.04) of LMB did not differ among the replacement diets. However, weight gain (38.5±1.5), FI (53.9±1.1), and PER (1.6±0.1) of LMB fed the SC diet was higher and FCR (1.4±0.1) was lower than that of fish fed the test diets. No signs of essential fatty acid deficiency were observed, although tissue concentrations of n-3 highly unsaturated fatty acids declined markedly in LMB fed diets without fish oil. Lymphocytes were elevated in fish fed diets with ≥7% n-3 fatty acids. Fish fed diets with 10% MFO or CHK+MFO had higher ACH50 than fish fed the diet with 10% CHK. There were no differences in serum lysozyme activity among fish fed the test diets. Hematocrit, hemoglobin, ACH50, and lysozyme activity were higher in fish fed the SC diet than in those fed the test diets. Regardless of lipid source, the ACH50 and lysozyme activity were greatly reduced in LMB fed PBM diets compared to LMB fed diets with 30% fish meal in a previous trial. The amino acid composition of the PBM was similar to that of fish meal. However, the availability of some essential amino acids from PBM to LMB may have been limited, and poor diet palatability caused by BM also may have reduced feed intake and performance of LMB. [Copyright &y& Elsevier]

Abstract: We conducted a 12-week feeding trial with LMB fed practical diets differing primarily in lipid source. We reduced the fish oil content of commercially solvent-extracted menhaden fish meal to 0.5–1.2%, and used it as the primary protein source in all test diets. Diets were supplemented with 10% lipid as canola (CAN), chicken (CHK), menhaden fish oil (MFO) or CHK+MFO (50/50%). An additional diet contained non-extracted fish meal and 10% CHK (NEF+CHK), and a commercial trout diet (SC) was also included. Growth, survival, feed utilization, body composition and health parameters were measured to assess diet effects. Weight gain, survival, feed intake, feed conversion ratio, and protein efficiency ratio of LMB fed the test diets did not differ. Weight gain of LMB fed the SC diet was higher than that of LMB fed the test diets. Muscle lipid of fish fed the diet with 10% MFO was higher than that of fish fed diets with an equal mixture of CHK+MFO or NEF+CHK, and muscle lipid of LMB fed the SC diet was higher than that of fish fed the test diets. The n-3 to n-6 fatty acid ratio of the test diets was lower than expected because the poultry meal contained 16% lipid (high in 18:2n-6). The ratio of n-3 to n-6 fatty acids was higher in muscle and liver of fish fed the SC diet than those of fish fed the test diets. Docosahexaenoic acid (22:6n-3) and 20:4n-6 were conserved in fish fed diets without HUFA, but 20:5n-3 declined sharply from initial values. The index of atherogenicity (IA) and the index of thrombogenicity (IT) of LMB fed the test or SC diets were below 1.0 (considered healthful). Lymphocytes were higher in fish fed diets with >4% n-3 fatty acids, including the CAN diet without HUFA. There were no differences in the Hk, Hb, MCHC, or serum lysozyme of LMB fed the test diets, but lysozyme was lower in LMB fed the SC diet than those fed the CHK+MFO diet. Fish fed diets with 10% MFO or CAN had higher alternative complement activity than fish fed diets with CHK. Tissue concentrations of HUFA (especially 20:4n-6 and 22:6n-6) were not depleted in 12 weeks, possibly due to conservation of initial HUFA, synthesis of HUFA from 18:3n-3 and 18:2n-6, or both. Therefore, non-fish oils might reduce diet cost with few deleterious effects for at least a quarter of the production cycle of LMB. [Copyright &y& Elsevier]

This study evaluated the effect of a fat blend containing long-chain (LC) n-3 PUFA on bone mineral density (BMD) and bone metabolism in gonad-intact middle-aged male rats (12 months old, n 28). Seven rats were killed on day 0 of dietary intervention to determine the baseline BMD. The remaining rats (seven per group) were fed a diet with one of the following dietary lipid treatments (g/kg diet): 167g safflower oil+33g menhaden oil (N6+N3 diet, control), 200g safflower oil (N6 diet, almost devoid of LC n-3 PUFA), or 190g menhaden oil+10g corn oil (N3 diet, rich in LC n-3 PUFA) for 20 weeks. After 20 weeks, all dietary treatment groups had a lower BMD compared with the baseline reference. However, rats fed the N3 diet had the highest bone mineral content and cortical+subcortical BMD compared with those fed the N6 and control N6+N3 diet. Compared with the control (N6+N3) group, rats fed the N3 diet had higher values for serum insulin-like growth factor-I, parathyroid hormone, 1, 25-(OH)2 vitamin D3 and bone-specific alkaline phosphatase activity, but lower bone NO production and urinary Ca, whereas rats fed the N6 diet had higher bone prostaglandin E2 production and serum pyridinoline. These findings indicate a protective action of LC n-3 PUFA on ageing-induced bone loss in gonad-intact middle-aged male rats through a modulation of local factors and systemic calcitrophic hormones. [ABSTRACT FROM PUBLISHER]

Lipase-catalyzed acidolysis of menhaden oil with a pinolenic acid (PLA) concentrate, prepared from pine nut oil, was studied in a solvent-free system. The PLA concentrate was prepared by urea complexation of the FA obtained by saponification of pine nut oil. Eight commercial lipases from different sources were screened for their ability to catalyze the acidolysis reaction. Two different types of structured lipids (SL) were synthesized. The first type, which has PLA residues as a primary FA residue at the sn-1,3 positions of the TAG, was synthesized using a 1,3-regiospecific lipase, namely, Lipozyme RM IM from Rhizomucor miehei. The second type of SL, which has PLA residues as a primary FA residue at both the sn-1,3 and sn-2 positions of the TAG, was synthesized using a nonspecific lipase, namely, Novozym 435 from Candida antarctica. The effects of variations in enzyme loading, temperature, and reaction time on PLA incorporation into the oil were monitored by GC analyses. The optimal temperature and enzyme loading for synthesis of the two types of SL were 50°C and 10% of the total weight of substrates for both enzymes. The optimal reaction time for the synthesis with Lipozyme RM IM was 16 h, whereas the optimal reaction time for the synthesis mediated by Novozym 435 was 36 h. Pancreatic lipase-catalyzed sn-2 positional analyses were also carried out on the TAG samples. [ABSTRACT FROM AUTHOR]

The suitability of soybean/corn lecithin and poultry fat as partial replacements for menhaden oil in feeds for post-juvenile rainbow trout (initial weight 46.0 g) was investigated. For 16 weeks, fish were fed experimental diets in which either 10% menhaden oil (FO), 10% poultry fat (PF), 10% lecithin (soybean/corn, L10), or 15% lecithin (soybean/corn, L15), plus 5% supplemental menhaden oil was added to fish meal-based diets. There were no significant differences in body weight gain among all treatments (328–347 g/fish), although fish fed the L15 diet consumed significantly more feed (299 g/fish) than fish fed the PF diet (269 g/fish). Sensory analysis indicated that raw L10 fillets stored for 4 and 12 weeks at -20 °C were significantly more yellow than raw FO fillets. Raw and cooked L15 fillets stored for 1 and 8 days at 5 °C, or for 17 days, 4 weeks, and 12 weeks at -20 °C had significantly higher colorimetric b* values (more yellow) than raw and cooked FO, PF, and L10 fillets. There was a trend for FO fillets to have higher TBARS values compared to fillets of the other treatments when stored under all time/temperature conditions tested. Although fillets of fish fed diets containing soybean/corn lecithin were more yellow in color, either lecithin (soybean/corn) or poultry fat was a nutritionally suitable substitute for most of the fish oil added to fish feeds. [Copyright &y& Elsevier]

The thermal degradation (weight loss) of individual FA and of catfish and menhaden oils collected from different refining steps was investigated by thermogravimetric analysis. The heat resistance of FA was partially dependent on chain length and degree of unsaturation. The weight loss of catfish and menhaden oils increased with increased heating temperatures, regardless of the oil refining process. All oil samples (except crude catfish oil) were decomposed after the heating temperature reached 550°C. Based on the thermogravimetric curves, the following thermal stability sequence at different refining steps for both catfish and menhaden oils was proposed: crude > degummed > neutralized > bleached > deodorized oils. [ABSTRACT FROM AUTHOR]

The present study investigated the influence of dietary omega-3 fatty acid supplementation on the growth of human colon carcinoma xenograft in athymic nude mice. Four diets were fed to evaluate the effect of levels and types of fat on colon tumor growth. Animals were maintained on a standard diet modified by addition of fats containing omega-3 and omega-6 fatty acids to represent high and low fat intakes for 53 days. The final mean estimated tumor weight for the high fat corn oil (24%) fed group was 2302 mg, whereas the low fat (8% corn oil) group was 1681 mg. The final mean tumor weight of the high fat menhaden oil fed group was 782 mg representing a 66% decrease in growth compared to the high fat corn oil group and a decrease of 54% compared to the low corn oil fed group. The high fat golden algae oil fed group resulted in a mean final tumor weight of 223 mg representing a 90% inhibition of tumor growth relative to the high fat corn oil fed group and 87% inhibition of growth compared to the low fat corn oil fed group. These findings indicate that dietary omega-3 fatty acids possess significant tumor suppressing properties and that the primary tumor suppressing fatty acid is docosahexaenoic acid. Histopathologic examination of control and treated tumors and expression array analyses (human cytokine and apoptosis arrays) support the tumor growth inhibition data and provide evidence for discussion of possible mechanisms for the observed growth inhibition. [Copyright &y& Elsevier]

Weanling rats fed a lipotropic-deficient diet (LDD) may develop acute renal failure with morphological features that vary from focal tubular necrosis to widespread cortical necrosis and eventually reparative changes. The type of lipid in the diet influences the development of renal necrosis. The aim of this work was to study the effect of dietary menhaden oil on the development of acute renal failure induced in weanling rats fed a methyl-deficient diet. Experiment I: 40 weanling Sprague-Dawley male rats were allotted to 4 different groups and fed as follows: group 1, LDD with hydrogenated vegetable oil and corn oil as lipids; group 2, LDD with menhaden oil as lipid; group 3 and 4, similar to groups 1 and 2 plus choline. Rats were fed ad libitum until they died; surviving animals were killed on day 21. Mortality in the 4 groups was 60, 0, 0, and 10% respectively. Rats from groups 2, 3 and 4 did not show renal damage. Rats from group 1 showed tubular or cortical necrosis in dead rats and reparative changes in those killed on the 21st day. Experiment II was similar to experiment I, except that 45 weanling Wistar male rats were used and they were killed on the 7th day. All rats from group 1 showed renal necrosis; no renal damage was found in rats from groups 2, 3 and 4. Urea and creatinine alterations corroborated the renal changes. We conclude that menhaden oil displays a protective effect for renal necrosis induced by methyl-deficient diets in weanling rats. [Copyright &y& Elsevier]

The effect of dietary fats with varying degrees of unsaturation in the presence of different concentrations of vitamin E on tissue lipid levels was studied in rats. Rats were fed either menhaden oil, olive oil or coconut oil at 15% levels with either 0.1, 0.3 or 0.6 mg/g of vitamin E as α-tocopherol for four weeks. Rat serum and liver were analyzed for total cholesterol, HDL-cholesterol, triacylglycerol and phospholipids. In addition, fatty acid composition of serum lipids was also analyzed. Serum total cholesterol and triacylglycerol were significantly lower in rats fed menhaden oil than in those fed olive or coconut oil, while the HDL-cholesterol was significantly higher in serum of rats fed menhaden and olive oil than in those fed coconut oil. Levels of vitamin E in the diet had only a significant effect on serum cholesterol and liver phospholipids. The Pearson correlation coefficient showed a significant positive relationship between serum triacylglycerol and total cholesterol, and a negative correlation between triacylglycerol and HDL-cholesterol, and between total and HDL-cholesterol.In the liver, total cholesterol was significantly higher in rats fed coconut oil than in rats fed menhaden oil. Total liver phospholipids were lower in rats fed either coconut oil or olive oil compared to those fed menhaden oil, especially with higher levels of vitamin E intake. Higher levels of vitamin E in the diet appear to increase triacylglycerol and phospholipids in livers of rats fed menhaden oil. In the liver a significant negative correlation was observed between phospholipids and cholesterol. The type and degree of unsaturation (polyunsaturated fatty acids in menhaden oil, monounsaturated fatty acids in olive oil and saturated fatty acids in coconut oil) significantly affected plasma and tissue lipids. [ABSTRACT FROM AUTHOR]

Oils containing both n−3 and n−6 fatty acids have important clinical and nutritional applications. Lipase-catalyzed acidolysis of seal blubber (SBO) and menhaden oils (MO) with γ-linolenic acid (GLA) was carried out in hexane. The process variables studied for lipase-catalyzed reaction were concentration of enzyme (100–700 units/g of oil), reaction temperature (30–60°C), reaction time (0–48 h), and mole ratio of GLA to triacylglycerols (TAG) (1∶1 to 5∶1). Two lipases chosen for acidolysis reaction were from Pseudomonas species (PS-30) and Mucor miehei. Lipase PS-30 was chosen over Mucor (also known as Rhizomucor) miehei to catalyze the acidolysis reaction owing to higher incorporation of GLA. For the acidolysis reaction, optimal conditions were a 3∶1 mole ratio of GLA to TAG, reaction temperature of 40°C, reaction time of 24 h, and an enzyme concentration of 500 units/g of oil. Under these conditions, incorporation of GLA was 37.1% for SBO and 39.6% for MO. [ABSTRACT FROM AUTHOR]

European eels ( Anguilla anguilla, L.) were fed on a commercial diet supplemented either with 15% by dry feed weight of menhaden oil (MO), an oil rich in highly unsaturated fatty acids of the n-3 series (n-3 HUFA), or with 15% by dry feed weight of coconut oil (CO), an oil composed primarily of saturated fatty acids (SFA). Following 90 days of feeding, the mean final masses of eels fed the two different oil supplements were similar, and higher than the mean final mass of a group fed the commercial diet alone. The diets created two distinct phenotypes of eels, distinguished by the fatty acid (FA) composition of their tissue lipids. Eels fed MO had significantly more total n-3 FA and n-3 HUFA in muscle and liver lipids than did eels fed CO, leading to higher n-3/n-6 and eicosapentaenoic acid/arachidonic acid ratios in the MO group. Measurements of O2 uptake (MO2) revealed that the MO group had a significantly lower routine metabolic rate (RMR) than the CO group. When exposed to progressive hypoxia, both groups regulated MO2 at routine normoxic levels until critical water O2 partial pressures that were statistically similar (9.62±1.08 kPa in MO versus 7.57±1.07 kPa in CO), beyond which they showed a reduction in MO2 below RMR. The MO group exhibited a significantly lower MO2 than the CO group throughout hypoxic exposure, but the percentage reductions in MO2 below their relative RMR were equal in both groups. During recovery to normoxia, both groups exhibited an increase in MO2 to rates significantly higher than their RMR. Throughout recovery, MO2 was significantly lower in the MO group compared with the CO group, but the percentage increases in MO2 relative to RMR were equal in both. During progressive hypoxia, neither group exhibited a marked ventilatory reflex response, both showed similar reductions in blood O2 partial pressure and content, and similar increases in plasma lactate. The results indicate that, although the n-3 HUFA-enriched MO group had a significantly lower routine metabolic rate than the CO group, the difference in aerobic metabolism did not influence the European eel's homeostatic regulation of MO2 in hypoxia. [ABSTRACT FROM AUTHOR]