• Preventive Nutrition and Food Science
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• v.8 no.4
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• pp.315-320
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• 2003

Headspace volatile compounds of oxidized fish oil were analyzed by the combination of hexane solvent or solid phase microextraction, gas chromatography and mass selective detector. The optimum condition of headspace analysis by hexane trapping was 23 min absorption time, 96$^{\circ}C$ sample temperature and 20 mL/min air flow rate. The numbers of volatile compounds identified by solvent trapping and SPME were 35 and 14, respectively. Groups having the largest amount and many kinds were hydrocarbons and aldehydes, respectively. The numbers of aldehydes were 15 and 6 for solvent trap and SPME, respectively. These basic data could be used as indicators for the quality changes of fish oil.

• Journal of the Korean Home Economics Association
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• v.18 no.3
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• pp.13-19
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• 1980

To study the rancidity of dried file fish oil by Oxidation during the storage period, general properties of the oil and composition of its fatty acids were analysed qumtitatively with gas-chromatography. The results indicated that; 1) The dried file fish oil was involved in drying oil of heigh degree of unsaturation with IV 158., and consisted of higher-fatty acid with SV 190. 2) The composition of the fatty acids were composed of 18 fatty acids involving 6 unknown fatty acids, and polyunsaturated fatty acid with docosapentaenoic acid(20 weight%). 3) Changes of malonaldehyde content during the storage of dried file fish were about 5.0 mg/kg after 10day, 3.4 mg/kg after 40 days.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.85-89
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• 2016

Omega-3 rich fish oils are extremely labile, thus requiring control of oxidation and off flavor development. A recently proposed emulsification method, layer-by-layer (LbL) deposition, was found to be a plausible method to enhance the characteristics of bioactive ingredients, especially lipids. The present work was designed to test the possibility of enhancing the uptake and utilization of omega-3 fatty acids present in fish oil. The bioavailability of nano-emulsified fish oil was monitored in terms of intestinal absorption as well as skin permeability by using the everted intestinal sac model and Franz cell model. The skin permeability and intestinal absorption characteristics was significantly improved by LbL emulsification with lecithin/chitosan/low methoxypectin. Multilayer encapsulation along with nano-emulsification can be a useful method to deliver biologically active lipids and related components, such as fish oil. The protective effect of this tool from lipid oxidation still needs to be verified.

• Journal of Nutrition and Health
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• v.16 no.1
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• pp.10-20
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• 1983

In order to establish tissue lipid status in animal on feeding of various dietary fat and oils, each group of rats was fed a semisynthetic diet containing 10%(w/w) mackerel oil (MO), eel oil (EO), soybean oil (SO), rapeseed oil (RO) or beef tallow (BT) for 1, 2 and 4 weeks, After each feeding period, levels of cholesterol, triglyceride and phospholipid were measured in serum. Fatty acid ${\leftarrow}$ composition was also investigated in serum and tissue lipids. Levels of total serum cholesterol were lower but HDL-cholesterol were higher in fish oil groups, which resulted in significantly higher ratio of HDL to total cholesterol in the fish oil groups. Fish oil groups, in general, also had lower levels of serum triglyceride and phospholipid than other groups, but S0 group maintained as low phospholipid levrl as fish oil groups. Fatty acid composition of dietary fat was reflected in all the tissues investigated but with varying degrees. Very long chain fatty acids, specific components exclusively found in fish oils were most well reflected in liver and relatively well in serum, whereas linoleic acid and erucic acid of SO and RO in the diet were better shown up in heart and adipose tissue. It attracted a particular attention that major proportions of long chain monoenoic acids $(C_{22:1})$ occurring both in MO and RO were detected separately in liver and heart plus adipose tissue, the result of which strongly indicates that there is a significant difference in metabolism between isomers $(C_{22:1}\;w\;11\;and\;C_{22:1}\;w\;9,\;respectively)$. It is suggested from this study that differences in lipid status as well as in the levels of serum lipids result from uniqueness in metabolism of each different fatty acid and give rise to distinguishable change in serum lipoprotein pattern, followed by diet with different fat sources.

• Nutritional Sciences
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• v.4 no.2
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• pp.73-78
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• 2001

This study investigated the effect of different dietary fats and fibers on colon tumor incidence and cell proliferation, the levels of eicosanoids and polyamines in colonic mucosa of DMH-treated rats. The experiment was conducted on male Sprague Dawley rats using a 2 $\times$3 factorial design with two fats (corn oil and DHA-rich fish oil) and two fibers (cellulose and pectin) and a fiber-free control. The rats were find an experimental diet containing 15% (w/w) dietary fat and 6% (w/w) fiber for 25 weeks. Tumor incidence was Bower in rats fed fish oil as opposed to corn oil. The levels of arachidonic acid (AA) and eicosanoids ($PGE_2, and TXB_2$) in normal colonic mucosa were significantly lower in rats fed fish oil and there was a concomitant increase of docosahexaenoic acid (DHA). The levels of eicosanoids and AA in tumor tissues were significantly higher than those of normal colonic mucosa. The level of polyamines in normal colonic mucosa was not affected by dietary fats but was significantly lower than that in rumor tissues. Dietary fiber did not have a significant effect on rumor incidence and the levels of AA, eicosanoids and polyamines. Overall, fish oil rich in DHA reduced cell prolifiration and thus inhibited colon carcinogenesis through its effect on the distribution of AA and production of eicosanoids in normal colonic mucosa. However, its effect on colon carcinogenesis revealed a lack of consistency depending on the type of dietary fiber in diet.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.558-565
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• 1993

This study was carried out to observe the effects of dietary n-6, n-3 fatty acids and vitamin A levels on serum lipid contents and hepatic tissues in rats. Sixty eight male Sprague-Dawley rats were fed 6 different experimental diets for 6 weeks. The diets were composed of 10% of either corn oil or fish oil with three levels of vitamin A ; defient (1240IU/kg diet), adequate (4000IU/kg diet), excess(400,000IU/kg diet). It was observed that triglyceride content and lipoprotein ratio in serum were not affected by dietary fat types and vitamin A levels. However, total serum cholesterol contents were significantly lower in fish oil groups than in corn oil groups, which were not affected by vitamin A levels. Under light microscope, vitamin A excess groups showed pathological abnormalites, such as fatty change and inflammation of the hepatic tissues. There abnormalities were less severe in fish oil groups. These results suggested that fish oil could be a dietary factor lowering the serum lipid contents, and it seems to relieve the abnormal changes in liver induced by excess vitamin A.

• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.310-321
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• 2014

Change in fish species composition after the Hebei Spirit oil spill in December 2007 off Taean were determined by analysis of samples collected in Mailpo beach, 10 km south from the oil spill site and polluted by the crude oil. Fish samples were collected by a beach seine in the shallow water at Malipo beach during the low tide of the new moon from February 2008 to December 2009. Five seine hauls were made during the day and the night in each sampling time. Monthly day and night samples did not show the significant differences in species composition. A total of 21 species, 1,032 individuals and 6,544 g of fish were collected in 2008, and 31 species, 4,206 individuals and 35,659 g of fish in 2009. The species collected were composed of the small-sized fish or juveniles. Abundant fishes were the resident species in coastal water, and the migrants were low in abundance. Among the fish occurred, Chelon haematochelius, Sebastes schlegelii, Takifugu niphobles and Pleuronectes yokohamae were predominated in abundance of both years. Monthly fish abundance and species diversity in 2008 were significantly lower than those in 2009. A few number of resident fish were collected from February to June 2008 showing the lowest in May 2008, and fish abundance increased from July 2008. The number of species and abundance of fish in 2009 were increased in spring as the temperature raised, showed a peak in summer and decreased in autumn. This monthly variation in fish species composition and abundance was similar to those in the non-polluted water in other temperate waters. Low fish abundance during several months after oil spill was considered to be related to the residual oil in the water and habitat disturbance due to oil cleaning activity in the beach. Monthly fish species compositions after September 2008 were similar to those of 2009 suggested that the impact on the shallow water fish by the oil residuals was not too significant at least to the fish species composition after September 2008.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.367-374
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• 2001

Conjugated linoleic acid(CLA) is a naturally occuring group of derivatives of linoleic acid found in beef and dairy products. CLA has reported to reduce body fat. This study was designed to observe the effect of CLA supplementation on fat accumulation and degradation in male Sprague Dawley rats. Seventy two rats, weighing 150-180g, were divided into 2 groups according to the types of dietary fat(beef tallow or fish oil) and then each group was divided into 2 groups depending on CLA supplementation, i.e., BT, BT-CLA, FO, FO-CLA. All rats were fed experimental diet containing total fat at 12%(w/w) including CLA at 1% for 30 weeks. At 30 weeks, rats were sacrificed to measure TG, free fatty acid level in plasma, TG, lipogenic enzymes in lever and fat cell size, LPL and HSL activities in epididymal fat fad. Fish oil supplemented with CLA diet showed significant reduction in the food efficiency and weight in 30 weeks-fed rats. CLA supplement did not effect on plasma TG, hepatic TG levels and lipogenic enzymes activities in rats, but, fish oil significantly reduced, The LPL and HSL activities did not affected by CLA supplement and n-3 fatty acid rich fish oil. In conclusion, the results suggest that CLA supplement was not a proper way to reduce the fat accumulation in Sprague Dawley rats. Fish oil supplemented with CLA might better way to reduce the body fatness than fish oil itself. Therefore, It is recommended that further study be performed related to physiological and biochemical effects of CLA supplementation and n-3 fatty acid in rats for the reduction of body fatness.(Korean J Nutrition 34(4) : 367∼374, 2001)

• KSBB Journal
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• v.13 no.1
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• pp.90-95
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• 1998

Experiments on the process development for the concentration of polyunsaturated fatty acid (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil by using acyl chain specificity of Candida cylindracea lipase were performed. Five kinds of oils were hydrolyzed with Candida cylindracea lipase. Among then, Candida cylindracea lipase just had low activity on the PUFAs-rich fish oil. After the hydrolysis of fish oil, free fatty acid was removed and fatty acid components of glyceride mixtures were analyzed. When the hydrolysis was about 70%, the DHA content in the glyceride mixture was about three times more than that in the original fish oil. The EPA and stearidonic acid contents in the glyceride mixtures, however, were similar to that of the original fish oil. In this work, these results showed that the concentration process of PUFAs by using the acyl chain specificity of Candida cylindreacea lipase was effective in producing glycerides that contained a high concentration of PUFAs in good yield.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.445-450
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• 2010

This study investigated the effects of dietary lipid sources on growth performance and body composition of juvenile far eastern catfish, Silurus asotus. Three replicate groups of fish (average weight 3.6 g) were fed with one of the following experimental diets containing 10% beef tallow (BT), 5% BT plus 5% corn oil (CO), 5% BT plus 5% linseed oil (LO), or 5% BT plus 5% squid liver oil (SO) as the lipid source for 5 weeks. No significant difference was observed in the survival among groups. The weight gain of fish fed the LO (high in 18:3n-3) and SO (high in n-3 highly unsaturated fatty acid) diets was significantly higher than that of the fish fed the CO (high in 18:2n-6) and BT diets (P<0.05). The feed efficiency of fish fed LO and SO diets was significantly higher than that of the fish fed the BT diet (P<0.05), but not significantly different from that of the fish fed the CO diet. The protein efficiency ratio of fish fed the SO diet was significantly higher than that of fish fed the CO and BT diets (P<0.05), but not significantly different from that of fish fed the LO diet. The 18:1n-9 of whole-body polar lipid fraction in fish fed the BT diet increased compared to that of fish fed the other diets. Fish fed the CO and LO diets had significantly higher contents of 18:2n-6 and 20:4n-6, and 18:3n-3, than the fish fed the other diets in polar and non-polar lipid fractions, respectively (P<0.05). Significantly higher contents of 20:5n-3 and 22:6n-3 were observed in the whole-body polar lipid fraction of fish fed the SO diet compared with fish fed the other diets (P<0.05). The study results indicate that linseed oil and squid liver oil containing n-3 fatty acids are good dietary lipid sources for the growth of far eastern catfish.