• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.477-484
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• 1984

The crude lipid contents in meat, skin and viscera of eel were 24.94, 20.00 and 14.96, respectively, and higher than the other fresh water fishes. The free lipid was consisted in order of neutral lipid(86.71~94.94), phospholipid(4.13~12.74) and glycolipid(0.63~1.22), and the bound lipid in order of phospholipid(51.74~75.21), neutral lipid(14.41~36.82) and glycolipid(5.12~7.51). The neutral lipid in free lipid was mainly consisted of TG(68.51~95.22), and that in bound lipid TG(36.54~39.94), ES & HC(17.20~18.01), and MG(15.81~18.11). The phospholipid in free lipid was mainly consisted of PC (32.40~56.08) and PE(18.71~31.09), while that in bound lipid PC (<42.51~67.90) and PS (23.37~34.49). The contents of major fatty acid of polar lipid in free and bound lipids were $C_{16:0}$(16.58, 14.10, $C_{18:0}$(12.44, 7.36), $C_{18:1}$(16.01, 15.78), $C_{20:4}$(10.01, 6.11) $C_{20:5}$(4.20, 8.67) and $C_{22:6}$(10.26, 18.32) and those of nonpolar lipid in free and bound lipids were $C_{16:0}$(22.31, 18.61), $C_{18:0}$(4.36, 5.69, $C_{18:1}$(36.30, 27.20) $C_{20:5}$(2.88, 2.38) $C_{22:5}$(6.38, 5.11) and $C_{22:6}$(1.20, 5.11). The total essential fatty acid(TEFA) content of polar lipid in meat was ranged from 17.33 to 22.88, and 2.0~3.0 times higher than that of nonpolar lipid, and the TEFA content of bound lipid in meat was ranged from 11.54 to 22.88, and 1.5~2.0 times higher than that of free lipid. The w3 highly unsaturated fatty acid(w3-HUFA) content of polar lipid in meat was ranged from 8.63 to 42.85, and higer than 11.48 to 14.42 of nonpolar lipid. Also the w3-HUFA content of bound lipid in meat was ranged from 13.35 to 42.85, and higher than 11.48 to 18.63 of free lipid. The w3-HUFA content in meat was higher than that in skin and/or viscera

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.328-337
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• 1990

The incividual and combined effects of the chloroacetanilide herbicide pretilachlor and of the safener fenclorim on the growth and selected physiological processes of rice (Oryza sativa L., var 'Lemont')were evaluated under greenhouse and laboratory conditions. Fenclorim applied at rates ranging from 50 to 300 g a.i./ha antagonized the injurious effects caused by 150 to 900 g a.i./ha of pretilachlor on 15-day old wet-sown rice grown under greenhouse conditions. When used rates of 150 g/ha or higher, fenclorim reversed completely the effects of all doses of pretilachlor on rice. When the two compounds were given simultaneously, fenclorim enhanced the uptake of $^{14}C$pretilachlor into rice leaf mesophyll protoplasts measured for 1 hr, indicating that competition for uptake at the protoplast level is not involved in the protective action of this safener. The safener-induced stimulation of pretilachlor uptake was particularly evident when fenclorim was used at concentrations of 10, 20 and $40{\mu}M$. Following 4 hr of incubation, individual treatments with pretilachlor inhibited the in vitro incorporation of radiolabeled precursors into proteins, DNA, and lipids of rice leaf protoplasts only when used at the high concentration of $100{\mu}M$M. Individual treatments with high concentrations (10 or $100{\mu}M$) of the safener fenclorim inhibited the incorporation of radiolabeled precursors into proteins and lipids of rice protoplasts, but had no DNA synthesis. The combined effects of pretilachlor and fenclorim on the incorporation of radiolabeled precursors into these macromolecules of isolated rice mesophyll protoplasts appeared to be additive or slightly synergistic rather than antagonistic. Fenclorim at $1{\mu}M$ antagonized the effects of pretilachlor on total lipids of rice leaf protoplasts. In addition, individual and combined treat-menu with pretilachlor and fenclorim influenced the incoroporation of$^{14}C$acetate into polar lipids, triglycerides and steryl esters of rice leaf protoplas causing a redistribution of carbon in these lipid fractions. However, these effects were not large enough to explain the herbicidal activity of pretilachlor or to account for the protective action of the safener fenclorim. Overall, the uesults of the present study idnicate that the safener fenclorim does not seem to protect rice against pretilachlor injury by antagonizing its effects on protein, DNA, or lipid syntheses.

• Ocean and Polar Research
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• v.34 no.4
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• pp.365-384
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• 2012

Microalgae are photosynthetic microorganisms that are highly productive in the presence of basic renewable natural sources (light, $CO_2$, water and nutrients). They can synthesize lipids, carbohydrates and proteins in a small number of days. Subsequently, these carbon-captured products can be processed into both biofuels and valuable co-products. Additionally, microalgae would be an ideal feedstock for replacing land-based food crops with cellular products as high energy density transportation fuels. These microscopic organisms could contribute a significant amount of renewable energy on a global scale. In Korea, microalgae biofuel research was common in the early 1990s. The research activities were unfortunately stopped due to limited governmental funds and low petroleum prices. Interest in algal biofuels in Korea has been growing recently due to an increased concern over oil prices, energy security, greenhouse gas emissions, and the potential for other biofuel feedstock to compete for limited agricultural resources. The high productivity of microalgae suggests that much of the Korean transportation fuel requirements can be met by biofuels at a production cost competitive with the increasing cost of petroleum seen in early 2008. At this time, the development of microlalgal biomass production technology remains in its infancy. This study reviewed microalgae culture systems and biomass production, harvesting, oil extraction, conversion, and technoeconomical bottlenecks. Many technical and economic barriers to using microalgal biofuels need to be overcome before mass production of microalgal-derived fuel substitutes is possible. However, serious efforts to overcome these barriers could become a large-scale commercial reality. Overall, this study provides a brief overview of the past few decades of global microalgal research.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.17-25
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• 1981

The purpose of this study was to determine effects of thermal oxidation according to heating time and temperature, using sunflower oil from seed grown in Korea. To investigate these effects, the lipid components, fatty acid compositions, and chemical characteristics of crude oil from sunflower seed were determined. The content of nonpolar and polar in total lipids was 94.1% and 5.9%, respectively. The fatty acid compositions in the total lipids showed 6.21% palmitic, 4.50% stearic, 59.84% oleci and 29.48% linoleic acid. The concent of linoleic acid decreased during heating. However, the concent of oleic, palmitic and stearic acid increased during heating. The components of neutral lipid were found 6 fractions, including triglyceride, diglyceride and free fatty acid. The content of triglyceride decreased but diglyceride and monoglyceride increased during heating. The content of free fatty acid increased during the continuous heating period for 32 hours at $100^{\circ}C$, whereas decreased in 16 hours at $180^{\circ}C$. Iodine value decreased during heating, and peroxide value increased during the continuous heating period for 32 hours at $100^{\circ}C$, whereas decreased in 16 hours at $180^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.708-716
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• 2013

Changes in the proximate composition, lipid classes, and fatty acids were studied in chub mackerel Scomber japonicus and Japanese jack mackerel Trachurus japonicus muscles cooked using a frying pan, oven, and microwave oven. The moisture content was high in the raw samples (chub mackerel 65.5%, Japanese jack mackerel 60.5%) and decreased with cooking, especially in the frying pan method (chub mackerel 49.2%, Japanese jack mackerel 49.8%). In contrast, the protein, lipid and ash contents increased significantly with cooking in chub mackerel muscle (P<0.05). However, the lipid content of Japanese jack mackerel muscle showed no significant difference between the samples using the three cooking methods and the raw sample. The dripped lipid contents from the cooked muscles showed the highest levels in the frying pan samples and the lowest levels in the microwave oven samples. The percentage of non-polar lipid (NL) in the total lipid content was over 95% in the muscle lipids (10.43-21.86 g/100 g sample). Prominent fatty acids were 16:0, 18:1n-9, 22:6n-3 (docosahexaenoic acid, DHA), 16:1n-7 and 20:5n-3 (eicosapentaenoic acid, EPA) in both fish muscles and dripped lipids. There was no change in the EPA level in any of the fish muscles, by any cooking method. The percentage of DHA in the muscle of chub mackerel showed the lowest level in the frying pan sample and the highest level in the microwave oven and raw samples, and an intermediate level in the oven sample. However, the percentage of DHA in the Japanese jack mackerel muscle was not significantly different between the various cooking methods. From these results, the microwave oven and oven cooking methods showed relatively low levels of dripped lipid content and loss of n-3 PUFA compared with the frying pan cooking method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.5
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• pp.376-383
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• 2006

The chemical components, lipid class, and fatty acid composition of the viscera from male and female common squid, Todarodes pacificus, were examined to evaluate the possible utilization of the liver, reproductive organs, and gills. In male and female squid, the viscera comprise 21% and 27% of the body weight, respectively. The protein content of the viscera was slightly higher in females (17.7-19.5%) than in males (15.6-17.2%). This was especially marked in the female reproductive organs, while there was little difference in the gill. The liver contained the largest amounts of lipids (17.2-18.6%) and the levels were higher in males than in females (P<0.01). By contrast, the reproductive organs of females contained more lipids than did those of males (4.68% vs. 1.65%, p<0.01). The prominent non-polar lipid (NL) classes were triacylglycerol (51.9-55.4% of the NL content) and sterol ester (16.3-21.8%) in the liver, and free sterol (47.0-68.5%) and free fatty acids (31.5-41.2%) in the reproductive organs. However, there were no significant differences in the NL classes between sexes. The percentage of the most prominent phospholipid (PL) class, phosphatidylcholine (PC), was highest in the liver (78.1-79.6% of the PL content), and there was no significant difference between the sexes. By contrast, phosphatidylethanolamine (PE) was highest in the reproductive organs (33.4%), and was higher in males than in females (P<0.05). All the visceral organs contained 36.4-48.5% of n-3 polyunsaturated fatty acids (PUFA), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The DHA level was highest in female reproductive organs (32.3%), while EPA was high in male reproductive organs. These results demonstrate that the viscera of male and female common squid are a good source of DHA and EPA.

• Journal of Aquaculture
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• v.6 no.2
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• pp.89-105
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• 1993

In order to investigate the effects of dietary n-3 highly unsaturated fatty acids (n-3HUF A) levels on growth and body composition of the Korean rockfish, six experimental diets with various levels of n-3HUFA, which were adjusted by adding squid liver oil and/or soybean oil at $8\%$ dietary lipid level, were fed to the Korean rockfish (6.2g in mean body weight) for 10 weeks. Daily weight gain, feed efficiency and nutrient retention efficiency were the lowest in the fish fed a diet containing 0% n-3HUFA. These parameters were effectively improved by supplementation with n-3HUFA, and showed linear increase up to $1.2\%$ dietary n-3HUFA level (P<0.01). There was no additional response above this level. A higher concentration of nonpolar lipids in the liver was observed for the fish fed insufficient levels of n-3HUFA in the diets. However the liver glycogen content and hepatosomatic index were slightly deareased. The lipid contents of the whole body and vicera showed significantly higher in the fish fed sufficient levels of n-3HUFA in the diets (P<0.05). The fatty acid compositions of polar lipids in the whole body and liver were affected by dietary fatty acid compositions. The contents of n-3HUFA and 18:1 in the liver increased with increasing the n-3HUFA level in the diets, while the 18:2n-6 and 18: 3n-3 decreased. These results suggest that n-3HUFA plays an essential role for normal growth of the Korean rockfish, and the requirement of n-3HUF A is around $1.2\%$ of the diet.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.321-329
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• 2014

This experiment was conducted to establish an analytical method for residues of amisulbrom, as recently developed an oomycete-specific fungicide showing inhibition of fungal respiration, in crops using HPLC-UVD/MS. Amisulbrom residue was extracted with acetonitrile from representative samples of five raw products which comprised apple, green pepper, kimchi cabbage, potato and hulled rice. The extract was diluted with 50 mL of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. For the hulled rice sample, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. On an octadecylsilyl column in HPLC, amisulbrom was successfully separated from sample co-extractives and sensitively quantitated by ultraviolet absorption at 255 nm with no interference. Accuracy and precision of the proposed method was validated by the recovery test on every crop samples fortified with amisulbrom at 3 concentration levels per crop in each triplication. Mean recoveries ranged from 85.3% to 105.6% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of amisulbrom was 0.04 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring technique was also provided to clearly identify the suspected residue. The proposed method was sensitive, reproducible and easy-to-operate enough to routinely determine the residue of amisulbrom in agricultural commodities.

• Korean Journal of Environmental Agriculture
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• v.37 no.1
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• pp.57-65
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• 2018

BACKGROUND: An analytical method was developed using HPLC-UVD/MS to precisely determine the residue of flusulfamide, a benzenesulfonamide fungicide used to inhibit spore germination. METHODS AND RESULTS: Flusulfamide residue was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice, and soybean. The extract was diluted with large volume of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. On an octadecylsilyl column in HPLC, flusulfamide was successfully separated from co-extractives of sample, and sensitively quantitated by ultraviolet absorption at 280 nm with no interference. Accuracy and precision of the proposed method was validated by the recovery experiment on every crop sample fortified with flusulfamide at 3 concentration levels per crop in each triplication. CONCLUSION: Mean recoveries ranged from 82.3 to 98.2% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of flusulfamide was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring technique was also provided to clearly identify the suspected residue.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.247-254
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• 1989

In deep-fat frying, the fats and oils are used over and over again, and moisture and air are mixed in to the hot oil. Many reports related to these fats and oils have been established that thermal and oxidative decomposition products and polymers formed under the conditions of deep fat frying are harmful to health. This work was carried out with 3 domestic frying oils and 6 used oils commercially, and that there were difficulties in finding a good definition between fresh oil and used oil with adding unheated oil. As starting materials, commercially used soybean oil and rapeseed oil already passed over induction period in the lipids oxidation standard. From the qualitative point of view, they were inferior to domestic frying oils. Free fatty acid and peroxide value of heated oils were increased gradually by the time pass whereas iodine value were decreased. After adding unheated oil to the heated oil, these values were restored to that of initial levels. On the other hand, content of polar components in the heated oil were directly related to the heating time. This result showed that polar compounds may be a clear indicator of used oils. Fatty acid composition in the used oils, unsaturated fatty acids such as linoleic and linolenic acid decreased while saturated fatty acid content increased with heating.