• The Korean Journal of Food And Nutrition
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• v.10 no.1
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• pp.14-24
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• 1997

The seasonal variation in lipids, and fatty acid composition of neutral lipid(NL) and phospholipid(PL) contained in the muscles of hibernant fish(loach) were investigated. In the investigation, four groups of wild loaches ere used, those caught May, 1993(before spawning period), August, 1993(after spawning period), November, 1993(just before hibernation) and March, 1994(just after hibernation). The NL was the most abundant in muscle lipid, followed by PL and glycolipid(GL), and also the composition and variation patterns were almost similar between female and male throughout all the periods. NL content began to increase gradually after March and came to the maximum in August(under 90%) ; hereafter got to decrease gradually again and came to the minimum in March of the next year(under 60%). While the variation-pattern of GL and PL was in inverse proportion with that of NL and their content came to the maximum in March of the next year. The NL and PL fractions were mainly consisted of triglyceride and phosphatidyl choline respectively, and both of the contents showed the highest value in August, the lowest in March of the next year. The major fatty acids in NL fraction were 16:0, 16:1, 18:1, 18:2 and 18:3($\omega$3). In particular, the ratio of 16:1 was much higher than that in PL, while those of highly unsaturated fatty acids(HUFAs) such as 20:4($\omega$6), 20:5($\omega$3) and 22:6($\omega$3) were much lower. The ratio of 16:0 in NL was almost constant through the year, however those of 16:1, 18:1, 18:2 and 18:3($\omega$3) showed a tendency to increase after March and were about 2~4% higher in May, compared with that in March, while those of HUFAs were about 2~4% lower. In particular, the ratio of 16:1 in NL continuously decreased after May and markedly decreased in March of the next year, but those of 18:1, 18:2 were almost constant until November. In August, saturates and monoenes were higher levels due to the slight increase of 18:0, 14:1 and 17:1 than in the other periods, while those of HUFAs decreased and the unsaturation(TUFA/TSFA) of NL showed the lowest value in August. On the contrary, saturates and monoenes gradually decreased after November and the most of them including 18:0, 16:1, 18:1 and 18:2 rapidly decreased in March of the next year, while 20:1, 20:4(~6), and 20:5(~3), and 22:6(~3) were in inverse proportion. PL consisted mainly of 16:0, 16:1, 18:1, 18:2, 20:4(~6), and 20:5(~3). Saturates and monoenes-composition showed almost no difference in March and May, while polyene acids ratio showed similar changes with that of NL. In August, the ratio of saturates(16:0, 18:0) were high but that of HUFAs were low, and after November 16:0, 18:0, 18:1, 18:2 and 18:3($\omega$3) began to decrease, while most of HUFAs increased in their composition-ratio until the marking increase of their unsaturation and the big changes of 18:2, 18:3($\omega$3), 20:4($\omega$6), 22:6($\omega$3) in March of the next year.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.659-666
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• 2005

The purpose of this study was to compare the intake status of calcium, phosphorus, iron, and zinc of Korean adults residing in different regions. Subjects were recruited and divided into three groups according to the districts where they lived, which included rural (n=137), coastal (n=100), and urban district (n=117). Subjects were interviewed using a general questionnaire and 24-hour recall method for dietary intake. The average age of the subjects were 58.1 years for rural district, 57.7 years for coastal district, and 48.6 years for urban district. There was no significance in total food intake by regions. The food intakes from cereals, mushrooms, vegetables of rural district, that from fishes of coastal district, and those from sugars, milks, oils of urban area were the highest among three districts. The calcium, phosphorus, iron, and zinc intakes were $60.1\%,\;123.9\%,\;95.2\%,\;and\;73.1\%$ of RDAs, respectively. The calcium intakes as percentage of RDA in rural and coastal district were significantly (p<0.01) lower than that in urban district. A larger number of subjects from coastal or urban district ate under $75\%$ of zinc RDA compared to those from rural village. Major sources of dietary calcium in total subjects were anchovy, kimchi, milk, soybean curd, rice, ice cream, sea mustard, yogurt, loach, and welsh onion. Rice supplied $15.5\%$ for phosphorus, $22.1\%$ for iron, and $35.9\%$ for zinc of total intake. Except for rice, major sources of dietary zinc were pork, beef, small red bean, dog meat, chicken, jacopever, soybean curd, glutinous millet, and kimchi. In conclusion, the food and mineral intakes of adults differed according to the regions in which they resided. The food and nutrient intakes of coastal district were not satisfactory, and calcium and zinc intakes of three regions did not meet RDAs. Therefore, it is required unique and discriminatory nutritional education with each region for increasing intakes of calcium and zinc.

• Korean Journal of Community Nutrition
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• v.26 no.3
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• pp.188-199
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• 2021

Objectives: The purpose was to identify the ingredients that are usually surveyed for assessing real prices and to present the demand for such surveys by nutrition teachers and dietitians for ingredients used by school foodservice. Methods: A survey was conducted online from December 2019 to January 2020. The survey questionnaire was distributed to 1,158 nutrition teachers and dietitians from elementary, middle, and high schools nationwide, and 439 (37.9% return rate) of the 1,158 were collected and used for data analysis. Results: The ingredients which were investigated for price realities directly by schools were industrial products in 228 schools (51.8%), fruits in 169 schools (38.4%), and specialty crops in 166 schools (37.7%). Moreover, nutrition teachers and dietitians in elementary, middle, and high schools searched in different ways for the real prices of ingredients. In elementary schools, there was a high demand for price information about grains, vegetables or root and tuber crops, special crops, fruits, eggs, fishes, and organic and locally grown ingredients by the School Foodservice Support Centers. Real price information about meats, industrial products, and pickled processed products were sought from the external specialized institutions. In addition, nutrition teachers and dietitians in middle and high schools wanted to obtain prices of all of the ingredients from the Offices of Education or the District Office of Education. Conclusions: Schools want to efficiently use the time or money spent on research for the real prices of ingredients through reputable organizations or to co-work with other nutrition teachers and dietitians. The results of this study will be useful in understanding the current status of the surveys carried out to determine the real price information for ingredients used by the school foodservice.

• Journal of Aquaculture
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• v.11 no.4
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• pp.475-485
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• 1998

To clarify annual reproductive cycle of Koran dark sleeper, odontobutis platycephala, we examined the seasonal changes of gonadosomatic index(GSI), testicular development stages and sex steroid hormones in blood from December 1995 to November 1997. Testis was podlike shape from July to October, and tadpole-like shape from November because of its expanded posterior part. GSI was 0.14~0.18 from July to September and increased to $0.43{\pm}0.04$ in October and then was not changed significantly until February. GSI was reincreased to $0.52{\pm}0.09$ from March and then was kept at similer levels until May, but fell down to $0.28{\pm}0.05$ in June. As results of histological observation, testis was divided into 3 parts(anterior, boundary, posterior) in the development progress of germ cells. In July, the testis was composed of only spermatogonia without seminiferous tubules in most fishes. In the anterior part of testis, the ferquency of spermatogenesis stage seminiferous tubules appearing in August was more than 80% from September to December. decreased gradually from January to March and drastically in April, and then disappeared in June. The frequency of spermiogenesis stage seminiferous tubules appearing in December, increased gradually from January to March and drastically to 80% in April, and reached to 90% the highest levels of the year in June. Post-spawning stage seminiferous tubules did not appear throughout the year. The frequency of spermatogonia was 100% and 65% in July and August, and less than 20% in the rest period of the year. In the boundary part, the frequency of spermatogenesis stage seminiferous tubules appearing in August increased from September and reached to 82% in November, decreased from December, adn disappeared in March. The frequency of spermiogenesis stage seminiferous tubules appearing in November was less than 18% until February, and increased to 29%~57% from March to June. The frequency of post-spawning stage seminiferous tubules appeared 12%~25% only from March to June. The frequency of spermatogonia was 100% in July, decreased to 85% in August and 10% in November, and increased gradually from December to 50% in April, and decreased again from May to June. In the posterior part, seminiferous tubules with some seminiferous tubules increased drastically 80%~85% in August and September, decreased drastically from October to November and remained below 10% until February, and disappeared after March. The frequency of spermiogenesis stage seminiferous tubules appearing in August increased sharply from October and reached to 75% in November. decreased to 15% in December and no significant changes until March, and disappeared after April. The frequency of post-spawning stage seminiferous tubules appearing very early in November increased to 82% in December and 85%~95% until June. The frequency of spermatogonia was 100% in July, decreased drastically to 15% in August, disappeared from October to Mrch, but reappeared from April and kept at less than 10% until June. The blood level of testosterone (T) increrased gradually from August was $0.61{\pm}0.09 ng/m\ell$ in November, increrased drastically to $3.99{\pm}1.22 ng/m\ell$ in December and maintained at in similar level until March, and decreased to $0.25{\pm}0.14 ng/m{\ell} ~ 0.17{\pm}0.13ng/m{\ell}$ in April and May and no significant changes until July (P<0.05). The blood level of 17, 20 -dihydroxy-4-pregnen-3-one $ng/m{\ell}$in the rest of year without significant changes(P<0.05). Taken together these results, the germ cell development of testis progressed in the order of posterior, boundary, anterior part during annual reproductive cycle in Korean dark sleeper. The testicular cycle of Korean dark sleeper was as follows. The anterior part of testis : i.e. spermatogonial proliferation period (July), early maturation period (from August to November), mid maturation period (from December to March), late maturation period (from April to May) and functional maturation period (June) were elucidated. The boundary of testis, i.e. spermatogonial proliferation period (July), early maturation period (from August to October), mid maturation period (from November to February) and the coexistence period of late maturation, functional maturation and post-spawn (from March to June) were elucidated. The posterior of testis, i.e. spermatogonial proliferation period (July), mid maturation period (from August ot September), late maturation period (October), functional maturation period (November) and post-spawn period (from December to June) were elucidated. It was showed that the changes of sex steroid hormone in blood played a important roles in the annual reproductive cycle of Korean dark sleeper.

• Journal of Fisheries and Marine Sciences Education
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• v.4 no.1
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• pp.30-46
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• 1992

Korea's first exploratory tuna fishing was done with a used longliner in 1957. Then the commercial fishing has been made steady headway since the 1960's and grown up to one of major tuna fishing countries in 1970's. The tuna fishing aimed primarily at acquiring foreign currency, then tuna was exported directly from the overseas fishing base. Tuna, however, has been gradually favored by Koreans as high-proteined foods according to the growth of GNP since the 1970's. In 1980, the canned tuna began to be produced and sold at home. And so the demand of raw tuna for cannaries has steeply increased not only for home but also for abroad, and stimulated the development of tuna purse seine fishery. The author carried out a study on the development of tuna purse seine fishery in Korea and countries concerned-the United States and Japan-because it is recognized to be significant for the further development of this fishery. Just as purse seining was originated in the United States, so tuna purse seining was also pioneered by Californian fishermen in the west coastal waters of the United States (Eastern Pacific Ocean). They started to produce the canned tuna in the early 1900's, and the demand for raw tuna began to be increased rapidly. In those days, tuna was mostly caught by pole-and-line, but the catch amount was far away from the demand. To satisfy this demand, they began to try out fishing tuna by the use of purse seine which had been born in the eastern waters in the 1820's and applied to catch white fishes in the western waters of the United States in those days. Even though their trial was technically successful through severe trial and error, a new problem was raised on the management of tuna resource and the preservation of porpoise which was occassionally caught with tuna. Then the Inter-American Tropical Tuna Commission (IATTC) was established by countries neighboring to the United States in 1950 and they set up the Commission's Yellowfin Regulatory Area (CYRA) and regulated the annual quota for yellowfin. Then, American owners tried to send their seiners to the Western African waters to expand the fishing ground in 1967 and to the Centeral-Western Pacfic in 1974, and the fishing ground was widely expanded. The number of the United States' purse seiners amounted to about 150 in 1980, but the enthusiasm was gradually cooled thereafter and the number of seiner was decreased to 67 in 1986. The landing of tuna by purse seiners in the United States after 1980 maintains 200 thousands M/T or so with a little increase despite the decreasing of domestic seiners. This shows that the landing by foreign seiners are increasing, compared with the landing by domestic seiners are decreasing. In Japan, even though purse seining was introduced in 1880, they had fished tuna by longline and pole-and -line until the tuna purse seining was introduced from the United States again. In the 1960's, Japanese tuna seiners made the exploratory fishing in the South-western Pacific and West African waters with a limited success. In 1971, the government-funded research center "JARMRAC" conducted the exploratory fishing which extended to the Central American waters, the Asia-Pacific Region and the South-western Pacific. It had also much difficulties, till they improved the fishing gear adaptable to the new fishing condition in the South-western Pacific. Japanese government has begun to licence 32 single seiners and 7 group seiners since 1980 and their standard has lasted up to now. The catch in the Pacific Islands Region amounted to 160 thousands M/T in 1986. Korea's tuna purse seine fishery was originated in 1971 by Jedong Industrial Co., Ltd. with three used tuna purse seiners purchased from the United States, and they began to fish in the Eastern Pacific, but failed owing to the superannuation of vessel and the infancy of fishing technique. The second challenge was done by Dongwon Industrial Co., Ltd. in 1979, with one used seiner purchased from the United States, and started to fish in the Eastern Pacific. Even though the first trial was almost unsuccessful but they could obtain the noticeable success by removing the vessel to the South-western Pacific in 1980. This success stimulated the Korean entherprisers to take part in this fishery, and the number of Korean tuna purse seiners has been increased rapidly in accordance with the increased demand for raw tuna. The number of vessels actually at work amounted to 36 in 1990 and they operate in the South-western Pacific. The annual catch of tuna by purse seiners amounted to 170 thousands M/T in 1990 and ranked to one of the major tuna purse seining countries in the world.