• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.4
• /
• pp.366-373
• /
• 2019

The objective of this study was to investigate the utilization of diacylglycerol (DAG) as a new dietary ingredient replacing fish oil in feed for juvenile olive flounder Paralichthys olivaceus. Fish oil based control diet (CON) was prepared and four other diets were formulated by replacing 50% of the fish oil in CON with one of five DAG: DAGL (1,3-lauryl glycerol) or DAGP (1,3-palmityl glycerol) in low or high concentrations (designated as DAGLL, DAGLH, DAGPL and DAGPH). Another diet was prepared replacing 100% of the fish oil in CON with a 1:1 mixture (DAGLP) of DAGL and DAGP. Olive flounder (13.4 g) were fed to apparent satiation, twice a day, for 12 weeks. Following the feeding trials, no significant differences were observed in growth performance, blood parameters and non-specific immune responses between CON and any of the DAG groups. Polyunsaturated fatty acid levels were not significantly affected by the inclusion of DAGs. Thus, DAGL or DAGP could be used to replace up to 50% of fish oil in fish feed without reducing growth performance, health or innate immunity. The replacement of up to 100% of dietary fish oil in olive flounder feed by DAGLP is also feasible.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.769-772
• /
• 2000

Fish oil has abundant highlly unsaturated fatty acids such as EPA and DHA. Therefore, fish oil is very susceptible to peroxidation. Adding any antioxidants to fish oil is acceptable to prevent the peroxidation. However, nontoxic and strong naturally occurring antioxidants for fish oil was not developed. ${\alpha}-tocopherol$ is one of useful natural antioxidants, but it is not good to prevent the fish oil peroxidation. In this study, we examined the development of microencapsulated squid liver oil product to prevent effectively peroxidation of the fish oil. The acceptable materials for encapsuling the squid liver oil were gum arabic and gelatin. The ultimate encapsulation rate of squid liver oil was 45.5%.

• Journal of Nutrition and Health
• /
• v.27 no.9
• /
• pp.901-909
• /
• 1994

The effects of sardine oil(high in eicosapentaenoic acid : EPA) and tuna oil(high in docosahexaenoic acid : DHA, also high in EPA) on fatty acid composition of brain and learning ability were evaluated in male weanling Sprague-Dawley rats and compared with the effects of corn oil and beef tallow. Animals assigned by randomized block design to one of the four experimental diet groups containing dietary lipid at 15%(w/w) level were given ad libitum for 7 weeks. Food intake and body weight gain of the fish oil groups were significantly lower than those of the corn oil and beef tallow groups. However, brain weights of the groups were not significantly different. In the brain fatty acid composition, the corn oil group showed high concentrations of n-6 fatty acids, the fish oil groups of n-3 fatty acids, and the beef tallow group of saturated fatty acids. Brain EPA and DHA contents of the fish oil groups showed significantly higher than the other groups while the brain ratio of saturated/monounsaturated/polyunsaturated fatty acid was controlled in a narrow range. In a maze test, the fish oil groups appeared to arrive at the goal faster than the corn oil and beef tallow groups. It explained that EPA in diets might efficiently convert to DHA resulting in DHA accumulation in brain tissue and might increase the learning performance as DHA did.

• Journal of Nutrition and Health
• /
• v.17 no.4
• /
• pp.290-296
• /
• 1984

In order to evaluate the effect of fish oil on lipogenesis, activities of glucose-6-phosphate dehydrogenase ( G6PDH ) and malic enzyme (ME) were measured in liver of rats fed mackered oil(MO) or eel oil (EO) for 10 to 14 days, at the various levels of 0 to 10% (w/w ). In addition to two kinds of fish oil, soybean oil (SO), lard (L), and beef tallow (BT) were fed to the different groups of rats. When fish oil was below 10%(w/w ), soybean oil, lard, or beef tallow was mixed with fish oil to maintain constant 10% (w/w) fat level. Three days of feeding MO brought a marked decrease$({\sim}{50}%)$ both in G6PDH and ME activity, the former of which maintained during 13 days of feeding. L group had highest levels of both enzymes. G6PDH activity of MO was lower than SO, but ME activity was not different between MO and SO. G6PDH activity was decreased with increasing content of fish oil (MO, EO), starting at the 2%(w/w) level of fish oil, when L or BT was used as filler oil. But ME activity was significantly reduced when fish oil content was at least 5%(w/w). Difference between the effects shown by two kinds of fish oil and animal species were also found. The present study suggests that fish oil can suppress hepatic lipogenesis by reducing activities of lipogenic enzymes with the same or higher degree than vegetable oil can exert.

• Journal of Nutrition and Health
• /
• v.29 no.2
• /
• pp.192-198
• /
• 1996

This experiment was conducted to examine the effects of fish oil supplementation with low does on the lipid concentration and fatty acid composition of plasma and the fatty acid composition of plasma phospholipid and erythrocyte of infants. Among 18 breast-fed infants, 6 were in control group and 12 were in fish oil groups. The subjects in fish oil groups were nursed by their mothers who supplemented with fish oil 1.96g/d or 3.92g/d, respectively for 2 weeks from 10 to 12 weeks postpartum. The nursing mothers consumed their usual diets at home. Blood samples were collected at the final day of experiment. There were no significant changes in daily intakes of total lipid, triglyceride, free fatty acid, phospholipid and cholesterol of infants by fish oil supplementation. However, the content of EPA (eicosapentaenoic acid)increased and that of ARA (arachidonic acid) decreaed significantly in plasma PC(phophatidylchline). And also, there were tendencies to increase triglyceride concentration and to decrease cholesterol and phopholipid concentrations of plasma. As the above results, atherogenic index (AI) showed a tendency to decrease, but not significant. DHA (docosahexaenoic acid) and EPA contents in plasma PC and PE (phosphatidylethanolamin) as well as those of erythrocyte tended to increase. In these results, we concluded that fish oil supplementation with low dose to lactating women does not obviously affect of the plasma lipid concentrations and fatty acid composition of plasma PC and PE as well as erythrocyte. However the increase of EPA content of plasma PC and the tendency to increase DHA and EPA contents of plasma as well as erythrocyte membrane indicate that there may be some beneficial effect on infant lipid metabolism of fish oil intake of nutsing mother were increased.

• Journal of Nutrition and Health
• /
• v.29 no.2
• /
• pp.166-176
• /
• 1996

Effect of fish oil feeding was investigated on morphological changes of thoracic aora in female rats after bilateral oophorectomy(OVX). Fifty four healthy female rats of Spraque-Dawley strain, were divided into sham group, OVX group and , OVX and fish oil feeding, group. Experimental animals were sacrificed at the end first, eighth week and sixteenth week after operation, thoracic aorta blood sample were collected. The results obtained were as follows ; 1) Total cholesterol and LDL-cholesterol contents in serum were significantly higher in the sham and OVX groups than fish oil feeding group. Serum HDL-cholesterol levels among three exjperimentnal group were lowest in the OVX group. 2) In the sham operation group, as experimental period prologed the endothelial cells were distorted round shape and enlarged, and the subendothelial layer was widened in tunical intima. The elastic lamina were disrupted in tunica group. In the fish oil feeding group, the endothelial cells and subendothelial layer in tunica intima, and the elastic lamina in tunica media were intance. From the present results, it was suggested that fish oil feeding may prevent the atherosclerotic changes in thoracic aorta and serum cholesterol induced by oophhorectomy in the rats.

• Development and Reproduction
• /
• v.23 no.2
• /
• pp.183-191
• /
• 2019

The objective of this study is to evaluate the anesthetic effects of clove oil and tricaine methanesulfonate (MS-222) on the Far Eastern catfish, Silurus asotus, by measuring the times to anesthesia and recovery. Each anesthetic effect of clove oil and MS-222 was tested in two groups of fish with different body sizes: a group of small fish (mean body length: $15.5{\pm}1.58cm$, mean body weight: $50.1{\pm}5.91g$, n=20) and a group of large fish (mean body length: $31.5{\pm}4.19cm$, mean body weight: $302.1{\pm}15.22g$, n=20). The anesthetics were used at concentrations of 200, 300, 400, 500, and 600 ppm. The results showed significant relationships between the concentration of the anesthetic and the body size of the fish. Each of these variables showed statistical significance (p<0.05). The time to anesthesia decreased linearly with increasing concentration in the large fish for both clove oil and MS-222 (p<0.05). Based on an optimal anesthetic time of approximately 1 min, the preferred concentrations of the anesthetics were 500 ppm for clove oil and 600 ppm for MS-222. Both the anesthetic time and the recovery time were shorter for the small fish than for the large fish (p<0.05). Our study showed that the smaller-sized Far Eastern catfish was more easily anesthetized and recovered more rapidly from anesthesia than the larger-sized fish.

• Food Science of Animal Resources
• /
• v.39 no.2
• /
• pp.309-323
• /
• 2019

Fish oil consists of omega-3 fatty acids which play an important role in human health. Its susceptibility to oxidation causes considerable degradation during the processing and storage of food products. Accordingly, encapsulation of this ingredient through freeze drying was studied with the aim of protecting it against environmental conditions. Gum arabic (GA) was used as the wall material for fish oil nanoencapsulation where tween 80 was applied as the emulsifier. A water-in-oil (W/O) emulsion was prepared by sonication, containing 6% fish oil dispersed in aqueous solutions including 20% and 25% total wall material. The emulsion was sonicated at 24 kHz for 120 s. The emulsion was then freeze-dried and the nanocapsules were incorporated into probiotic fermented milk, with the effects of nanocapsules examined on the milk. The results showed that the nanoparticles encapsulated with 25% gum arabic and 4% emulsifier had the highest encapsulation efficiency (EE) (87.17%) and the lowest surface oil (31.66 mg/100 kg). Using nanoencapsulated fish oil in fermented milk significantly (p<0.05) increased the viability of Lactobacillus plantarum as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents. The fermented milk sample containing fish oil nanoencapsulated with 25% wall material and 4% emulsifier yielded the greatest probiotic bacterial count (8.41 Log CFU/mL) and the lowest peroxide value (0.57 mEq/kg). Moreover, this sample had the highest EPA and DHA contents. Utilizing this nanoencapsulated fish oil did not adversely affect fermented milk overall acceptance. Therefore, it can be used for fortification of low fat probiotic fermented milk.

• Journal of Nutrition and Health
• /
• v.36 no.8
• /
• pp.785-792
• /
• 2003

This study is conducted to determine the effects of dietary source of $\omega$3 fatty acids on preneoplastic foci and the glutathione dependent enzymes in rat hepatocarcinogenesis initiated by diethylnitrosamine (DEN). Male Sprague-Dawley rats were fed one of three diets containing 10% (w/w) fats fixed p/s = -1.0 and $\omega$6/$\omega$3 ratio = -0.4 or 4.0 ; fish oil-com oil blended (FC), com oil-beef tallow-fish oil blended (CF), com oil-beef tallow-perilla oil blended (CP), from gestation period. At 10 weeks, animals of experimental groups were injected intraperitoneally with DEN (200 mg/kg body weight) and two-thirds partial hepatectomy was carried out 3 weeks later and were sacrificed 8 weeks after DEN initiation. The area and number of glutathione S-transferase placenta (GST-P) positive foci were significantly decreased in rats fed diets containing fish oil (FC and CF) than those fed perilla oil diet (CP). Fish oil feeding significantly increased the activities of glutathione dependent enzymes. Rats fed diets containing fish oil (FC and CF) significantly increased the glutathione (GSH) content and the activities of glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST). Glutathione dependent enzymes had significantly negative correlation with GST-P positive foci. Glucose 6-phosphatase (G6Pase) was increased in rats feeding fish oil. Thiobarbituric acid reactive substances were not different among groups. Therefore, the preventive effect against hepatocarcinogenesis might be explained by induction of the glutathione dependent enzymes and G6Pase. (Korean J Nutrition 36(8): 785∼792, 2003)

• Journal of Nutrition and Health
• /
• v.26 no.5
• /
• pp.566-577
• /
• 1993

The study was to compare the effect of dietary fatty acids on fatty acid profile in tissue and the status of tocopherol and lipid peroxidation, and superoxide dismutase and glutathione peroxidase activities at two fat levels. Male Sprague Dawley rats weighing average 350g(17 weeks) were fed either low fat(LF, 4.3% w/w, 10% kcal) or high fat(HF, 20.8%, w/w, 40% kcal)diet for 6 weeks. The fats used were beef tallow as a source of saturated fatty acid, corn oil for n-6 linoleic acid, perilla oil for n-3 $\alpha$-linolenic acid and fish oil for n-3 eiocosapentatenoic acid(EPA) and n-3 docosahexaenoic acid(DHA). Palsma tocopherol was significantly reduced by fish oil compared to beef tallow at body fat level. However, there was no significant effect on the levels of plasma MDA, RBC MDA and tocopherol, and RBC hempolysis by the type and amount of dietary fat. The peroxidizibility index of fatty acid profile in plasma and liver was increased and liver MDA level was significantly increased by fish oil when dietary fat level was increased. The activities of SOD and GSHPx tended to be increased by perilla oil and fish oil at both fat oil significantly reduced the incorpration of c20:4 and increased the incorporation of c20:5 into liver compared to corn oil. The incorporation of n-3 fatty acids into tissue by perilla oil rich in $\alpha$-linolenic acid was significantly higher tan corn oil and its effect was improved with higher amount of perilla oil in diet by high fat diet. Overall, the lipid peroxidation of tissue could be prevented by tocopherol supplementation when dietary fat level was low in diet. However, at high fat diet, tocopherol supplementation might not be enough to prevent the lipid peroxidation in tissue since the potential for lipid peroxidation was tended to be increased with higher incorporation of higher unsaturated n-3 fatty acids into tissue. Therefore, it could not be recommended to consume large amount of fish oil even with excess amount of tocopherol supplemented to the high fat diet.