Effect of Fish Oil on (-Adrenoceptors and the Activity of Adenylate Cyclase on Myocardial Membrane in Rats

Effects of fish oil on β-adrenoceptors as well as the activity of adenylate cyclase (AC) on rat myocardial membrane were investigated.Supplementation with fish oil had no significant effect on basal activity of AC on myocardial membrane whereas it could markedly inhibit the AC activity stimulated by isoproterenol (ISO). Radioligand binding assays showed that supplementation with fish oil had no effect on Bmax and Kd, compared with saline control. However, supplementation with sheep oil could markedly reduce both the Kd and Bmax, compared with saline control. And the Kd of sheep oil group was greatly decreased than that of fish oil group. The results suggested that supplementation with fish oil mainly affected the activation of AC, not β-adrenoceptor itself.

Replacement of Dietary Fish Oil with Vegetable Oils Improves the Growth and Flesh Quality of Large Yellow Croaker(Larmichthys crocea)

We investigated the effect of the replacement of dietary fish oil with vegetable oils on the growth and flesh quality of large yellow croaker(Larmichthys crocea). The basal diet(FO) was formulated to contain 66.5% fish meal and 6.4% menhaden fish oil; whereas the other 3 experimental diets were formulated by replacing the fish oil with 50% soybean oil(SO50), 100% soybean oil(SO100) and 100% palm oil(PO100), respectively. The 4 diets were randomly assigned to 4 floating sea cages(3.0 m × 3.0 m × 3.0 m), and each was stocked with 250 fish individuals with an initial average weight of 245.29 g ± 7.45 g. The fish were fed to apparent satiation twice a day at 5:00 and 17:00, respectively, for 12 weeks. Experimental analysis showed that the specific growth rate of fish fed SO50 or PO100 were significantly higher than that of fish fed FO or SO100(P<0.05), and crude lipid contents of ventral muscle and viscera were significantly lower in fish fed FO than in those fed the other 3 diets(P<0.05). No significant differences in condition factor, viscerosomatic index, hepatosomatic index, gutted yield and colorimetric values of fish among the dietary treatments were observed(P>0.05). Compared to FO diet, SO50, SO100 and PO100 diets led to substantial decreases in the liquid loss and water loss from fresh fillets(1 d, 4℃)(P<0.05). Similarly, thiobarbituric acid reactive substance(TBARS) values of fillets under different storage conditions(1 d, 4℃; 7 d, 4℃; 4 weeks,-20℃; 8 weeks,-20℃) decreased significantly after partial or complete replacement of fish oil with vegetable oils. These findings indicated that the growth performance and selected flesh quality properties(liquid holding capacity and TBARS value) of large yellow croaker were substantially improved by replacing dietary fish oil with vegetable oils.

Liver-protecting effects of omega-3 fish oil lipid emulsion in liver transplantation

AIM:To investigate the liver-protecting effect of parenteral nutrition(PN) support with omega-3 fatty acids in a randomized controlled clinical trial.METHODS:Sixty-six patients with the diagnosis of end-stage liver disease or hepatic cellular carcinoma were admitted to the Affiliated Drum Tower Hospital,Nanjing University,China for orthotopic liver transplantation.The patients were randomly divided into two groups:PN group(n = 33) and polyunsaturated fatty acid(PUFA) group(n = 33).All patients received isocaloric and isonitrogenous PN for seven days after surgery,and in PUFA group omega-3 fish oil lipid emulsion replaced part of the standard lipid emulsion.Liver function was tested on days 2 and 9 after surgery.Pathological examination was performed after reperfusion of the donor liver and on day 9.Clinical outcome was assessed based on the post-transplant investigations,including:(1) post-transplant mechanical ventilation;(2) total hospital stay;(3) infectious morbidities;(4) acute and chronic rejection;and(5) mortality(intensive care unit mortality,hospital mortality,28-d mortality,and survival at a one-year post-transplant surveillance period).RESULTS:On days 2 and 9 after operation,a significant decrease of alanine aminotransferase(299.16 U/L ± 189.17 U/L vs 246.16 U/L ± 175.21 U/L,P = 0.024) and prothrombin time(5.64 s ± 2.06 svs 2.54 s ± 1.15 s,P = 0.035) was seen in PUFA group compared with PN group.The pathological results showed that omega-3 fatty acid supplement improved the injury of hepatic cells.Compared with PN group,there was a significant decrease of post-transplant hospital stay in PUFA group(18.7 d ± 4.0 d vs 20.6 d ± 4.6 d,P = 0.041).Complications of infection occurred in 6 cases of PN group(2 cases of pneumonia,3 cases of intra-abdominal abscess and 1 case of urinary tract infection),and in 3 cases of PUFA group(2 cases of pneumonia and 1 case of intra-abdominal abscess).No acute or chronic rejection and hospital mortality were found in both groups.The one-year mortality in PN group was 9.1%(3/33),one died of pulmonary infection,one died of severe intra-hepatic cholangitis and hepatic dysfunction and the other died of hepatic cell carcinoma recurrence.Only one patient in PUFA group(1/33,3.1%) died of biliary complication and hepatic dysfunction during follow-up.CONCLUSION:Post-transplant parenteral nutritional support combined with omega-3 fatty acids can significantly improve the liver injury,reduce the infectious morbidities,and shorten the post-transplant hospital stay.

EFFECTS OF FISH OIL, DHA OIL AND LECITHIN IN MICROPARTICULATE DIETS ON STRESS TOLERANCE OF LARVAL GILTHEAD SEABREAM (SPARUS AURATA)

The effects of natural fish oil, DHA oil and soybean lecithin in microparticulate diets on stress tolerance of larval gilthead seabream ( Sparus aurata ) were investigated after 15 days feeding trials. The tolerance of larval gilthead seabream to various stress factors such as exposure to air ( lack of dissolved oxygen), changes in water temperature (low) and salinity ( high) were determined. This study showed that microparticulate diet with natural fish oil and soybean lecithin was the most effective for increasing the tolerance of larval gilthead seabream to various stresses, and that microparticulate diet with natural fish oil and palmitic acid (16:0) was more effective than microparticulate diet with DHA oil and soybean lecithin.

Total Replacement of Fish Oil with Vegetable Oils in the Diet of Juvenile Jade Perch Scortum barcoo Reared in Recirculating Aquaculture Systems

To determine the replacement of fish oil with vegetable oils in the diet of juvenile Jade perch Scortum barcoo, four feeds with each a different oil （fish, sunflower, linseed and a mixture of 75% canola and 25% linseed oil）, were fed to Jade perch reared in recirculating aquaculture systems （RAS）. The trial lasted for 10 weeks and the fatty acid （FA） profile of both feed and fish muscle tissue were examined. There was no difference in growth, feed conversion rate （FCR） and mortality. The fish grew from 10 g to 110 g with a FCR of 1.25 and 0 mortality. The FA profile of the fish muscle tissue reflected the FA profile of the feed. The flesh of the fish that were fed the linseed oil diet, were extremely high in omega-3 （n-3） polyunsaturated FA （n-3 PUFA） with 3.75% of wet weight. This is one of the highest concentrations of n-3 PUFA ever recorded in fish flesh. In a finishing feeding test, the remaining vegetable oil fed fish were fed the fish oil diet for another two weeks immediately after the 10 weeks trial, to check for a possible recovery of n-3 highly unsaturated fatty acids （HUFA）. The wash out rate of FA towards n-3 HUFA in the muscle tissue was about 25% over this two weeks period.

Effect of Fish Oil on Left Ventricular Function in Anes-thetized Rats

The effect of fish oil on the basal left ventricular function and changes of left ventricular function induced by isoproterenol(ISO)were demonstrated in our study. The detennina-tion of cardiac perfonnance in vivo showed that supplementation with fish oil(EPA and DHA,70%,1.4 ml / kg) had no significant effect on basal cardiac perfonnance,while it could significantly inhibit changes of+ dp / dt_(max),V_(pm) and HR induced by ISO(0.4μg/ kg,4.0μg/ kg,40μg/ kg)intrave-nously.The results suggested that supplementation with fish oil perhaps affected the function of β-adrenoceptors on rat myocardial membrane.

Regulation of ω-3 Fish Oil Emulsion on the SIRS during the Initial Stage of Severe Acute Pancreatitis

The aim of this study was to explore the effects of parenteral supplementation with ω-3 fish oil emulsion （Omegaven） on systemic inflammatory response syndrome （SIRS） during the initial stage of severe acute pancreatitis （SAP）. In a prospective, randomized and controlled trial, 60 patients with SAP were randomized either to treat with conventional therapy （Con group, n=30） or conventional therapy plus intravenous supplementation with ω-3 fish oil emulsion 0.2 g/kg every day （FO group, n=30）. The effects were analyzed by the SIRS-related indexes. The results showed that APACHE-Ⅱ scores in FO group were significantly lower, and the gap increased much farther after the 4th day than those in Con group （P〈0.05）. Fluid equilibrium time became shorter markedly in FO group than in Con group （5.1±2.2 days vs 8.4±2.3 days）. In FO group, SIRS scores were markedly decreased and the SIRS state vanished after the 4th day; Plasma level of TNF-α was significantly reduced, while IL-10 decreased markedly, most prominently between the 4th and 7th day, and the ratio of IL-10/TNF-α raised as compared with Con group （P〈0.05）. During the initial stage of SAP, parenteral supplementation with ω-3 fish oil emulsion could efficiently lower the magnitude and persistence time of the SIRS, markedly retrieve the unbalance of the pro-/anti-inflammatory cytokines, improve severe condition of illness and may provide a new way to regulate the SIRS.

Decreased Sperm Quality in Mice Fed a Diet with Fish Oil

Polyunsaturated fatty acids （PUFAs） play an important role in sperm quality and fertility. This study was conducted to investigate the effect of dietary supplementation with PUFAs on male mice reproductive capacity. Mice were fed a diet of 4% soybean oil （SO） ,4% fish oil （FO） ,or 4% conjugated linoleic acid （CLA） for 30 days. Litter sizes and sperm quality were measured during the study. Litter size decreased in females mated with FO group males. Although sperm total number,motility,and in virto fertilization did not differ among treatments,the proportion of intact sperm membrane decreased in the FO group compared to other groups. This was supported by the increased proportion of damaged sperm membrane inthe FO group. Furthermore,the percentage of high mitochondrial membrane potential （MMP） declined,but the percentage of low MMP was increased by dietary FO and CLA supplementation compared to the SO group. Sperm membrane phospholipid in mice receiving the FO diet had a higher concentration of docosapentenoic acid （C22 ∶ 5n-3,DPA） ,docosahexaneoic acid （C22∶ 6n-3,DHA） ,and n-3 PUFAs,but lower levels of arachidonic acid （C20 ∶ 4n-6,AA） and n-6 PUFAs compared to those receiving the SO diet. These data suggest that decreased sperm quality in mice fed a FO diet may be due to excessive DPA and DHA in the membrane.

^1H NMR Quantification of DHA and EPA in Fish Oil

Fish oil is a popular nutritional product consumed in China. The beneficial effects of fish oil have been attributed to docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA). Hence, it is crucial to develop a rapid and precise method to determine the contents of EPA and DHA in fish oil. In this study, a rapid and accurate proton nuclear magnetic resonance method for the quantification of DHA and EPA was developed. Dimethyl terephthalate was selected as an internal standard, and the signals at 2.391 ppm for DHA and at 1.697 ppm for EPA were chosen for the quantification. Validation of the method was performed in terms of specificity, precision, and stability. The results indicated that the method was precise and in line with the China Food and Drug Administration guidance. The method has been successfully applied to characterize fish oil capsules obtained from four pharmaceutical companies. This study indicated that the rapid ~1H NMR method is suitable for the quality control of fish oil.

Increasing Conjugated Linoleic Acid Content in Milk and Cheese after Supplementing a Blend of Crude Soybean Oil Sediment Combined with Fish Oil to Grazing Dairy Cows

The aim of the work was to improve the healthy value of milk and cheese fatty acids (FA) by feeding a mix of crude soybean oil sediment (CSOS) combined with fish oil (FO) to grazing dairy cows. The CSOS is a by-product commonly discarded after oil extraction containing 3.3% moisture, 6% total ash and 70.7% oil, locally available, comparatively economic and easy to mix with other feed ingredients. The experiment lasted 55 days from September 30th to November 23th 2018 and was carried out at the dairy farm “Gacef” provider of milk to the dairy industrial plant “Capilla Del Señor” (CDS) located at the Villa María City, Córdoba Province, Argentine. A herd of 80 multiparous Holstein cows producing 24 kg-1 milk·cow-1·day-1 was used. The cows grazed an alfalfa and an oat pasture that represented about 47% of total dry matter (DM) intake supplemented at 8.5 kg DM·cow-1·day-1 with a total mixed ration (TMR) composed (DM basis) by cracked corn grain (35.18%), whole plant corn silage (31.98%), pelletized soyben meal (17.99%), the CSOS supplement (13.85%) and FO (0.99%). The TMR was supplied by halves after each milking time in groupal feeders yielding 1.4 kg·cow-1·day-1 of the CSOS and 0.1 kg·cow-1·day-1 of FO. Before the start of lipid supplementation, milk samples (5) were obtained from the farm-tank representing the standar or reference milk (Ref-Milk). After 21 days of supplementary lipid supply, additional milk samples (5) were obtained representing the modified milk (Mod-Milk). Milk samples were analyzed for chemical composition and milk FA profile. At each time, sufficient quantities of both (Ref- and Mod-Milk) were collected for manufacturing six types of cheeses. The results were analyzed through the Student-T test for independent observations. Oil supplementation did not modify (P > 0.05) the chemical composition of milk. Concentration of butyric acid (C4:0) in milk was not affected (P < 0.858). Concentration of total saturated FA (SFAs) in Ref-Milk averaged 58.83 g 100 g-1 FA and was decreased to 49.67 g 100 g-1 FA in Mod-Milk (P < 0.0001). Monounsaturated FA (MUFAs) increased (P < 0.001) from 32.03 g 100 g-1 FA in Ref-Milk to 38.13 g 100 g-1 FA in Mod-Milk (+19.07%) whereas polyunsaturated FA (PUFAs) increased (+36.1%) from 4.71 to 6.41 (P < 0.004). The Mod-Milk showed a significant (P < 0.002) reduction (-15.3% or 5.9 g 100 g-1 FA) for the total concentration of the potentially atherogenic fraction of milk FA (C12:0 to C16:0). The atherogenic index (AI) also decreased (P < 0.012) from 1.98 in Ref-Milk to 1.42 in Mod-Milk (-28.4%). Concentration of vaccenic acid (VA, trans-11 C18:1) in Mod-Milk averaged 7.77 g 100 g-1 FA which represented a 162 % increase (P < 0.0001) over that observed in Ref-Milk (2.95 g 100 g-1). Concentration of conjugated linoleic acid (CLA, cis-9, trans-11 C18:2) in Ref-Milk averaged 1.47 g 100 g-1 FA and showed an important increase (P < 0.002) in the Mod-Milk (3.86 g 100 g-1 FA, +163%). The omega 6/3 ratio resulted lower (P < 0.012) in the Ref-Milk (2.28) compared to the Mod-Milk (2.83). Milk and cheese FA composition were highly correlated (R2 = 0.99, P < 0.0001). The Mod-Cheeses showed similar results in AI, total concentration of SFAs, MUFAs and PUFAs compared to the milk of origin. Differences in FA composition between the cheeses made with the Ref- and Mod-Milk were equivalent to those described for milks. It is concluded that supplementation with a blend of CSOS supplement and FO was an effective way to improve the healthy value of dairy products by reducing contents of SFAs, atherogenic FAs and the atherogenicity index with a concomitant increase in VA and CLA. Modifications induced in the Mod-Milk were recovered in the Mod-Cheeses. The results obtained may help to reduce saturated fat intake and fight or prevent incidence of non-communicable, cardiovascular and chronic diseases.

Using Green Cold Pressing to Produce High Quality Fish Oil From Industrial Salmon Waste

The main objective of this research was to determine the amount of oil fish were extracted from fish west resulted from butchering,cutting and splitting processes before salmon smoking by using cold pressing methods.The amount and the characteristics of extracted of oil were tested at Regional Centre for food and feed the USDA Agricultural Research Center laboratory.The samples were used from fresh Salmon waste about 1000g from each of the(head,skin,viscera,backbone,frames and cuts off).This waste recorded more than 22%of the total mass from salmon fish with used modern extract machine.in this experiment the results revealed the fresh salmon waste have more than 16%of oil fish per one kg of salmon waste.The oil weight from Salmon waste for(head,skin,viscera,backbone,frames and cuts off).was increased with pressing time increase as well as oil productivity increased.The optimum conditions at pressing time was 200 min,for all salmon waste components.Oil productivity fluctuated according to waste sources was 190,210,86,188,178 and 90 g.oil/1000 g.by head,skin,off cuts,terming,,viscera,and backbone frames,Salmon by-products,oil productivity was ranged between 8.60 to 21.00%at constant pressure.High contents of functional EPA(20:5ω3)and DHA(22:6ω3)for oil fish.

Fish oil alleviates liver injury induced by intestinal ischemia/reperfusion via AMPK/SIRT-1/autophagy pathway

AIM To evaluate whether fish oil(FO) can protect liver injury induced by intestinal ischemia/reperfusion(I/R) via the AMPK/SIRT-1/autophagy pathway.METHODS Ischemia in wistar rats was induced by superior mesenteric artery occlusion for 60 min and reperfusion for 240 min. One milliliter per day of FO emulsion or normal saline was administered by intraperitoneal injection for 5 consecutive days to each animal. Animals were sacrificed at the end of reperfusion. Blood andtissue samples were collected for analyses. AMPK, SIRT-1, and Beclin-1 expression was determined in lipopolysaccharide(LPS)-stimulated HepG2 cells with or without FO emulsion treatment.RESULTS Intestinal I/R induced significant liver morphological changes and increased serum alanine aminotransferase and aspartate aminotransferase levels. Expression of p-AMPK/AMPK, SIRT-1, and autophagy markers was decreased whereas tumor necrosis factor-α(TNF-α) and malonaldehyde(MDA) were increased. FO emulsion blocked the changes of the above indicators effectively. Besides, in LPS-stimulated HepG2 cells, small interfering RNA(siRNA) targeting AMPK impaired the FO induced increase of p-AMPK, SIRT-1, and Beclin-1 and decrease of TNF-α and MDA. SIRT-1 siRNA impaired the increase of SIRT-1 and Beclin-1 and the decrease of TNF-α and MDA.CONCLUSION Our study indicates that FO may protect the liver against intestinal I/R induced injury through the AMPK/SIRT-1/autophagy pathway.

High-Lard and High-Fish Oil Diets Differ in Their Effects on Insulin Resistance Development, Mitochondrial Morphology and Dynamic Behaviour in Rat Skeletal Muscle

Fish oil (mainly omega 3 polyunsaturated fatty acids), differently from lard (mainly saturated fatty acids) has been suggested to have anti-inflammatory effects associated with amelioration of insulin sensibility. An important role in skeletal muscle insulin resistance development has been recently attributed to mitochondrial dynamic behavior. Mitochondria are dynamic organelles that frequently undergo fission/fusion processes and a shift toward fission process has been associated with skeletal muscle mitochondrial dysfunction and insulin resistance development. The present work aimed to evaluate if the replacement of lard with fish oil in high-fat diet positively affect skeletal muscle mitochondrial dynamic behavior in association with the improvement of insulin-resistance. Body weight gain, systemic insulin-resistance (glucose/insulin ratio), serum TNFα levels and skeletal muscle lipid content were assessed in rats fed a high-lard or high-fish-oil diet for 6 weeks. In skeletal muscle sections, immunohistochemical analysis were performed to detect the presence of insulin receptor substrate 1 (IRS1) and tyrosine phosphorylated IRS1 (key factor in insulin signalling pathway) as well as to detect the main proteins involved in mitochondrial fusion (MFN2 and OPA1) and fission (DRP1 and Fis1) processes. Skeletal muscle mitochondrial ultrastructural features were assessed by electron microscopy. High-fish oil feeding induced lower body weight gain, systemic inflammation and insulin-resistance development as well as skeletal muscle lipid accumulation compared to high-lard feeding. Skeletal muscle sections from high-fish oil fed rats exhibited a greater number of immunoreactive fibers for MFN2 and OPA1 proteins as well as weaker immunostaining for DRP1 and Fis1 compared to sections from high-lard fed rats. Electron microscopy observations suggested a prominent presence of fission events in L rats and fusion events in F rats. The positive effect of the replacement of lard with fish oil in high-fat diet on systemic and skeletal muscle insulin sensibility was associated to changes in mitochondrial dynamic behavior.

Is there a role for fish oil in inflammatory bowel disease?

A number of animal and human studies suggest omega3-fatty acids are anti-inflammatory. As a result they may have a therapeutic role in inflammatory bowel disease(IBD). The aim of this review is to briefly assess the literature about the utility of poly-unsaturated fatty acids(PUFAs) in the management of IBD. Taken together, almost all studies suggest some beneficial effects of n-3 PUFAs in IBD but the mechanism remains controversial. In addition, clinical benefit seems to be largely confined to ulcerative colitis. However all studies have concluded that these compounds have no potential for a steroid/aminosalicylic acid sparing effect or to maintain remission. Now the question arises as to whether this treatment is of real value to IBD patients?Clearly they have some therapeutic potential but further work is needed.

The Protective and Recovery Effects of Fish Oil Supplementation on Cedar Pollen-Induced Allergic Reactions in Mice

Obesity is associated with the production of pro-inflammatory cytokines and therefore can lead to worsening of allergic reactions. Thus, there is cross-talk between obesity and allergic reactions. In this study, we investigated whether the anti-obesity action of fish oil supplementation is involved in the anti-allergic action also induced by fish oil. We observed attenuation of cedar pollen-induced IgE serum increases in two experimental protocols: 15% fish oil supplementation for 8 weeks, which attenuated body weight increases compared with 15% soybean supplementation, and 4% fish oil supplementation for 2 weeks, which did not affect body weight increases compared with 4% soybean or 4% lard supplementation. The former but not the latter protocol attenuated sneezing after pollen challenge. Gene expression of TNF-α and IL-13, a Th2 cytokine, was moderately reduced in the trachea and nasal mucosa in mice fed fish oil supple- ments. In a third protocol, fish oil was administered for up to 15 weeks after a cedar pollen sensitization and challenge-induced increase in IgE levels. These levels decreased following fish oil supplementation but were almost unaffected by soybean oil supplementation. Surprisingly, the IL-13 gene expression level in the nasal mucosa and trachea was higher in the fish oil group than in the soybean oil group. These results suggest that fish oil supplementation before, during, or after antigen sensitization and challenge in mice helped to reduce cedar pollen-induced allergic reactions in- dependent of its anti-obesity action. Fish oil supplementation can also exhibit pro- or anti-inflammatory action against IL-13 expression depending on the experimental protocol.

Dietary Combination of Fish Oil and Hemoglobin Hydrolysates Alters Serum and Liver Lipid Contents in Rat

Fish oil has been shown to have anti-inflammatory and anti-cancer effects, and to reduce serum triacylglycerol (TAG) levels by stimulating lipid oxidation and inhibiting lipogenesis in the liver. A small number of studies have demonstrated the synergistic effect of fish oil and other bioactive components. This study examined the effect of fish oil in combination with porcine hemoglobin (Hb) hydrolysates on serum and liver lipid contents in rats. Male Wistar rats were divided into four groups;one group was fed a casein and soybean oil-based semi-purified basal diet and other three groups were fed the basal diet supplemented with 2% fish oil, 0.175% Hb hydrolysates, and 2% fish oil plus 0.175% Hb hydrolysates, respectively, for 4 weeks. The fish oil diet decreased serum and liver TAG contents but did not change serum and liver cholesterol levels. The dietary combination of fish oil and Hb hydrolysates decreased serum and liver TAG and cholesterol contents owing to the additive effect of both compounds, and this diet reduced the serum non-high-density lipoprotein cholesterol content as a result of a synergistic effect. This hypolipidemic effect was in part caused by enhanced excretion of fecal fatty acids, neutral steroids, and acidic steroids. The results of this study suggest that the combined intake of fish oil and Hb hydrolysates may play beneficial roles in the prevention of cardiovascular disease as compared with fish oil alone.

Comparative Assessment of Low-Concentration Ethanol and Waste Fish Oil Biodiesel Blends on Emission Reduction and Performance Improvement in Variable Compression Ratio Engine

The costs of conventional fuels are rising on a daily basis as a result of technical limits,a misallocation of resources between demand and supply,and a shortage of conventional fuel.The use of crude oil contributes to increased environmental contamination,and as a result,there is a pressing need to investigate alternate fuel sources for car applications.Biodiesel is a renewable fuel that is derived chemically by reacting with the sources of biodiesel.The present research is based on analyzing the effect of fish oil biodiesel-ethanol blend in variable compression engine for variable compression ratio(VCR).The processed fish oil was procured and subjected to a transesterification process to convert fatty acids into methyl esters.The obtained methyl esters(biodiesel)were blended with ethanol and diesel to obtain a ternary blend.The ternary blend was tested for its stability,and a stable blend was obtained and tested in VCR engines for its performance,combustion,and emission characteristics.In the second phase,experiments are conducted in the diesel engine by fueling the fish oil methyl ester and ethanol blended with diesel fuel in the concentration of 92.5 vol%of Diesel+7.5 vol%of Fish oil+1.25vol%ethanol,92.5 vol%of Diesel+7.5 vol%of Fish oil+5 vol%ethanol,87.5 vol%of Diesel+12.5 vol%of Fish oil+1.25 vol%ethanol,87.5 vol%of Diesel+12.5 vol%of Fish oil+5 vol%ethanol,82.5 vol%of Diesel+17.5vol%of Fish oil+1.25 vol%ethanol,82.5 vol%of Diesel+17.5 vol%of Fish oil+5 vol%ethanol to find out the performance parameters and emissions.Because the alternative fuel performs better in terms of engine performance and pollution management,the percentage chosen is considered the best mix.The results showed that the use of a lower concentration of ethanol in the fish oil biodiesel blend improved the engine thermal efficiency by 5.23%at a higher compression ratio.Similarly,the engine operated with a higher compression ratio reduced the formation of HC and CO emissions,whereas the NOxand CO_(2)emissions increased with an increased proportion of biodiesel in diesel and ethanol blends.

Preservation Potentials of Essential Oils of Ocimum basilicum and Ocimum gratissimum from Two Agro-Ecological Zones on Freshwater Smoke-Dried Oreochromis niloticus Fish Sold in Some Local Markets in Cameroon

Dried fish are susceptible to bacteria and fungi attack and are liable to chemical changes which cause losses in quality and reduction of shelf-life. It is important therefore to maintain the quality of fish because continuous consumption of contaminated fish and their products may predispose consumers to health hazards. Maintenance of high quality fish therefore calls for adequate and effective preservation techniques. The study examined the effectiveness of essential oils of Ocimum basilicum and Ocimum gratissimum from two Agro-ecological zones of Cameroon in limiting the microbial proliferation and preserving the quality of smoke-dried Oreochromis niloticus fish stored at 25˚C for two months. The plant materials were harvested from the Western Highlands and Monomodal Humid Forest agroecological zones of Cameroon. Extraction of the essential oil from the plants was done by hydro-distillation. The fish species (Oreochromis niloticus) used in this study was chosen based on a survey study on the most consumed species of freshwater smoke-dried fish in the Western Highlands and Monomodal Humid Forest Agro-ecological zones of Cameroon. Heterotrophic bacteria counts, fungi counts and Enterobacteriaceae counts were used to assess the level heterotrophic bacteria, fungi and Enterobacteriaceae respectively in the fish samples during storage and were done by culture techniques using total plate count agar, potato dextrose agar and violet red bile glucose agar respectively. Total volatile basic nitrogen, peroxide value, and thiobarbituric acid reactive substance assays were used as spoilage indices to assess the nutritional quality of the fish during storage. From the survey study, Oreochromis niloticus was the most consumed smoke-dried fish in the Western Highlands (35.45%) and Monomodal Humid Forest (34.55%) agroecological zones. All the EOs caused a significant reduction in the microbial loads, total volatile basic nitrogen, peroxide value, and thiobarbituric acid reactive substance of smoke-dried Oreochromis niloticus as storage progressed. However, the reduction in these values was more pronounced in samples treated with essential oils of O. gratissimum from the Western Highlands, with heterotrophic bacteria, fungi and Enterobacteriaceae counts being 5.89, 6.97 and 4.59 log10 cfu/g respectively at the end of the storage period. This was followed by essential oils of O. gratissimum from the Monomodal Humid Forest with heterotrophic bacteria, fungi and Enterobacteriaceae counts being 6.11, 7.79 and 4.86 log10 cfu/g respectively at the end of the storage period. Also, essential oils of O. gratissimum from the Western Highlands was more effective in preserving the fish quality as lowest total volatile basic nitrogen (12.29 mg/100g), peroxide value (2.79 mEq O2·Kg−1) and thiobabituric reactive substance (1.695 mg MDA/Kg) values were observed for fish samples treated with this extract at the end of the storage period. This was followed by essential oils of O. gratissimum from the Monomodal Humid Forest with total volatile basic nitrogen (14.95 mgN/100g), Peroxide value (3.23 mEq O2·Kg−1) and thiobabituric reactive substance (2.354 mg MDA/Kg) at the end of the storage period. From the results obtained, essential oils from O. gratissimum were more effective than that from O. basilicum in the two agroecological zones and should be considered as natural alternative to chemical preservatives for further application in food preservation.

Characterization of refined fish oil from small fish in Mauritania

In this study,the effects of chemical refining on the physicochemical indices,environmental pollutants,lipid functional groups,relaxation characteristics,fatty acid profiles,and triglyceride(TG)molecular species in crude oil extracted from small fish in Mauritania were evaluated.The acid,peroxide,and iodine values of crude oil were identified as 5.52 mg KOH/g,1.73 meq/kg,and 200.78 g/100 g oil,respectively.After refining,these values were determined to be 0.29 mg KOH/g,0.76 meq/kg,and 210.80 g/100 g oil,respectively.The polychlorinated biphenyls and arsenic content of crude oil were identified as 32.30μg/kg and 1.00 mg/kg,respectively.After refining,these were not detected.The content of eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)accounted for as much as 87.55%of the polyunsaturated fatty acids in the refined oil,indicating that high-quality fish oil is suitable as a food supplement.The correlation coefficient of the infrared spectra before and after refining was 0.968,and the relaxation time and peak shape data were almost similar before and after purification.Meanwhile,there were no significant differences(P≥0.05)in fatty acid profiles between the crude and refined oils,except for C16:0(P<0.01).Based on UPLC-Q E-MS/MS detection,137 TG molecules were identified in both crude and refined oils.Among the detected TG molecular species,64 contained EPA or DHA,which accounted for 46.83%and 46.00%of the total TG content in crude and refined oils,respectively.After refining,the content of the molecular species decreased by 31.95 mg/10 g,among which the three most variable molecular species were TG(16:0/18:1/22:6),(16:1/16:2/18:1),and(18:4/16:0/20:5),accounting for 29.26%of the decline of the molecular species.Overall,the refining process had little effect on the fatty acid profile and distribution of TG molecular species in fish oil.

Impact of fish oil enriched total parenteral nutrition on elderly patients after colorectal cancer surgery

Background Polyunsaturated omega-3 fatty acids may beneficially influence healing processes and patient outcomes.The aim of this research was to study the clinical efficacy of fish oil enriched total parenteral nutrition in elderly patients after colorectal cancer surgery.Methods Fifty-seven elderly patients with colorectal cancer were enrolled in this prospective,randomized,double-blind,controlled clinical trial.All patients received isocaloric and isonitrogenous total parenteral nutrition by continuous infusion （20-24 hours per day） for seven days after surgery.The control group （n=28） received 1.2 g/kg soybean oil per day,whereas the treatment group （n=29） received 0.2 g/kg fish oil and 1.0 g/kg soybean oil per day.Blood samples were taken pre-operatively,and at days one and eight after the operation.The plasma levels of CD4,CD8,CD4/CD8,interleukin 6 （IL-6） and tumor necrosis factor a （TNF-a） were measured.Clinical outcomes were then analysed.Results Patient characteristics were comparable between the two groups.At day eight post-surgery,IL-6,TNF-α and CD8 titres were lower in the treatment group when compared to the control group; these results reached statistical significance.In the treatment group,there were fewer infectious complications and incidences of systemic inflammatory response syndrome （SIRS）,and shorter lengths of hospital stay were observed.The total cost of medical care was comparable for the two groups.No serious adverse events occurred in either group.Conclusions Fish oil 0.2 g/kg per day administrated to elderly patients after colorectal surgery was safe and may shorten the length of hospital stay and improve clinical outcomes.