• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1477-1483
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• 1999

In order to retain or remove the flavor components of onions, this study was performed to investigate the effect of seaweeds and adsorbents on volatile flavor components of onion juice by testing a sensory evaluation, measuring the amount of pyruvate and thiosulfinate, and investigating the changes of volatile components by SPME/GC. The main flavor compounds in raw onion juice were dipropyl tetrasulfide, 1-propenyl propyl trisulfide, methyl propyl trisulfide, dipropyl trisulfide. Volatile flavor compounds in onion juice treated with tangleweed, brown-seaweed, laver and celite showed a relatively decreasing tendency compared to untreated onion juice, but most of volatile flavor compounds in onion juice treated with activated charcoal and ${\beta}-cyclodextrin$ were removed. The result of the sensory evaluation with various materials for masking onion flavor showed a significant difference at the p<0.05 level. The amount of pyruvate and thiosulfinate treated with tangleweed, brown-seaweed, laver and celite showed little difference compared to untreated onion juice, but the amount of pyruvate and thiosulfinate treated with activated charcoal and ${\beta}-cyclodextrin$ decreased largely compared to untreated onion juice. As a result of the study, onion juice treated with tangleweed, brown-seaweed, laver and celite showed the effect of preserving the pungent taste and masking the onion flavor. Activated charcoal and ${\beta}-cyclodextrin$added to onion juice might have a role in removing the onion flavor by adsorbing volatile flavor compounds in onion.

• 한국해양학회지
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• v.10 no.1
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• pp.25-32
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• 1975

Continued to the previous paper, the present investigation deals with stronitium-90 activities and calcium contents among 54 samples of edible marine algae collected along the coast of Korea during September, 1973 and April, 1974. The calcium contents are variable 2.0-17.8%, and 6.38% on an average. Most of the members investigated contain 2-4% in green and red algae, and 8-10% in brown algae. Strontium-90 activities are 0.32-0.37 pCi/l in sea-water, and 0.80-28.66 pCi$\^$90/Sr/g Ca in edible seaweeds. Among the algal phyla, they are 12.49 in green, 3.34 in brown, and 9.39 pCi$\^$90/Sr/g Ca in red algae, while they are 6.25 pCi$\^$90/Sr/g Ca on an average. In a single species collected at the same season, the highest activities appear mostly from the eastern coast, and from the western and southern coasts, in turn. The green algae, Capsosiphon- Enteromorpha complex show about 3 times higher activities, 28.66 pCi$\^$90/Sr /g Ca compared with the other members showing rather higher activities, and would be an indicator plant of strontium-90 activities of the marine algae along the coast of Korea.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1008-1013
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• 2004

Effects of extraction conditions and molecular fractionation on anticoagulant activities of major brown seaweeds in Korea were investigated. Hot water extracts of C. costata, U. pinnatifida (Sporophyte), L. japonica, K. crassifolia, E. stolonifera, E. bicyclis, S. horneri, and E. kurome increaced activated partial thromboplastin time (APTT) over 190 seconds, which may be related to intrinsic pathway of blood coagulation. Hot water extract of E. Kurome (EKJ) was further fractionated by ethanol precipitation. EKJ-eim, ethanol-insoluble material of EKJ, showed higher anticoagulant activity than EKJ. EKJ-eim was further fractioned with ultrafiltration. EKJ-eim 1, (over 100 kDa) fraction showed higher APTT activity than EKJ-eim. A EKJ-eim 1 was sulfated polysaccharide consisting of fucose, xylose, mannose, galactose, glucose and, sulfate at molar ratio of 1 : 0.05 : 0.10 : 0.15 : 0.17 : 1.46. The anticoagulant activity increased as sulfate content and molecular weight increased.

• Korean journal of food and cookery science
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• v.28 no.5
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• pp.549-557
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• 2012

In this study, the FFQ-50 questionnaire which composed of 50 food items frequently eaten as sources of dietary fiber, was developed and used to estimate the dietary fiber intake of middle school students in the Chungbuk province. According to the survey, the average daily intakes of dietary fiber for the boys and girls were $23.3{\pm}12.3$ g (93.2%) and $20.8{\pm}11.5$ g (104.0%), respectively, showing a significant difference between the gender. The proportions of boys and girls who did not reach to the sufficient dietary fiber intake were 66.2% and 53.9% respectively. The major sources of dietary fiber were grain foods and vegetables, which measured at 77.24%, followed by fruits, seaweeds, tofu and tofu products, potato and starch, and mushrooms. The cooked white rice contributed the highest (17.81%), followed by baechu-kimchi, cooked brown rice, ramyeon (instant noodle), tangerine, sesame leaf jangajji (pickled sesame leaf), topokki (spicy rice cake stir-fry), blanched and seasoned bean sprouts, bread, and radish kimchi. The study showed that the cooked white rice was the major source of dietary fiber in the boys' diet followed by baechu-kimchi, ramyeon, cooked brown rice, tangerine, bread, strawberry, blanched and seasoned bean sprouts, sesame leaf jangajji, radish kimchi. Girls were taking in dietary fiber mostly from boiled white rice followed by baechu-kimchi, boiled brown rice, tangerine, ramyeon, sesame leaf jangajji, topokki, blanched and seasoned bean sprouts, radish kimchi, and boiled barley.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1226-1232
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• 2004

Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them, Ecklonia stolonifera OKAMURA (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract of E. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 1~5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$ values of 92.8, 126, 33.2, 177, and 2.16 ${\mu}g$ /mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with $IC_{50}$ values of 6.32 and 112 ${\mu}g$ / mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds 1 and 2 to be competitive inhibitors with $K_i$ of $2.3{\times}10^{-4}\;and\;3.1{times}10^{-4}$ M, and compounds 3~5 to be noncompetitive inhibitors with $K_i$ of $1.9{\times}10^{-5},\;1.4{\times}10^{-3}\;and\;1.5{\times}10^{-5}$ M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.8-16
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• 2014

Macroalgae has been strongly touted as an alternative biomass for biofuel production due to its higher photosynthetic efficiency, carbon fixation rate, and growth rate compared to conventional cellulosic plants. However, its unique carbohydrate composition and structure limits the utilization efficiency by conventional microorganisms, resulting in reduced growth rates and lower productivity. Nevertheless, recent studies have shown that it is possible to enable microorganisms to utilize various sugars from seaweeds and to produce some energy chemicals such as methane, ethanol, etc. This paper introduces the basic information on macroalgae and the overall conversion process from harvest to production of biofuels. Especially, we will review the successful efforts on microbial engineering through metabolic engineering and synthetic biology to utilize carbon sources from red and brown seaweed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.291-296
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• 1997

The dietary fiber contents of seaweeds including Drown algae (Undaria pinnatifida, Laminaria japonica, Hizikia fusiforme), red algae (Gelidium amansii, Gracilaria verrucosa) and green algae (Ulva lactuca) and the extraction condition of the fiber was investigated. The dietary fiber contents of Undaria pinnatifida, Laminaria japonica, Hizikia jusiforme, Gelidium amansii, Gracilaria verrucosa and Ulva lactuca were $47.2\%,\;50.7,\;42.6\%,\;48.8\%,\;44.5\%\;and\;40.0\%$, respectively. It was effective to extract soluble dietary fiber with sodium salts such as disodium carbonate and disodium EDTA in brown algae. In red algae, it was effective to extract soluble dietary fibre with disodium EDTA. Also, the extraction time and temperature affected the yields of dietary fiber.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.274-282
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• 2014

We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.878-885
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• 2013

Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Heuksando and Hongdo, Shinan, Korea, from July 2008 to May 2009. In total, 86 macroalgal species were identified, including 12 green, 19 brown, and 55 red algae; 67 species at Heuksando and 70 species at Hongdo, were observed. Annual seaweed biomass was 252.44 g dry $wt/m^2$ at Heuksando and 217.67 g dry $wt/m^2$ at Hongdo. The dominant seaweed in importance value (IV > 15) differed between the sites: Sargassum thunbergii at Heuksando and Corallina pilulifera at Hongdo. The vertical distribution pattern of seaweeds from the upper to lower intertidal zones at Heuksando was Gloiopeltis spp., Ulva spp. - S. thunbergii, S. fusiforme, Hildenbrandia rubra - S. thunbergii, C. pilulifera. On the rocky shore of Hongdo, seaweed zonation was distinct: Porphyra yezoensis, Gloiopeltis spp., Ulva spp. - C. pilulifera, S. fusiforme, Myelophycus simplex - Chondrus ocellatus, C. pilulifera, and Carpopeltis affinis. Annual seaweed coverage, richness index (R), evenness index (J'), and diversity index (H') values were greater at Hongdo (41.35%, 12.82, 0.59, and 2.50 respectively) than at Heuksando (31.54%, 11.93, 0.44, and 1.87 respectively), which may indicate that the seaweed community at Hongdo is more stable relative to the one at Heuksando.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1336-1347
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• 2013

The marine algal flora assemblages settled on the artificial seaweed reefs in Jeju-do before and after rocky cleaning were investigated during summer and the early succession of seaweeds attached to the test panels on the structures of the artificial reef after rocky cleaning were observed by visual observations and under the dissecting microscope in order to evaluate the effects of this rocky cleaning operation. Species composition and algal biomass on the Bboolsamgak-typed seaweed artificial reefs before and after rocky cleaning were measured and compared before and after rocky cleaning. Before rocky cleaning in July 2012, only nine algal species had existed on the Bboolsamgak-typed seaweed artificial reefs, however, twenty algal species occurred on the seaweed artificial reefs after rocky cleaning in July 2013. Particularly, 15 species among them in July 2013 were not found in July 2012 and they seemed to occur newly on the artificial reefs. A large quantity of algal biomass increased in July 2013 after rocky cleaning. Based on the importance value, there was a drastic change in the dominant species between July 2012 and July 2013 after rocky cleaning. By dissecting micrographs, an epiphytic diatom, Licmophora sp. and flagellates, were observed on the 9th day. A chlorophyte, Ulothrix flacca was observed after 14 days, Ulva pertusa, Bryopsis pulmosa, crustose coralline algae, and Cladophora spp. were after one month. After two months, a significant species succession was observed from three previous chlorophyte species to crustose coralline algae existed as a dominant species on the panels. In this study, however, any brown algae were not found until three months in the early seaweed succession. All above results indicates that the rocky cleaning is a very efficient method for the establishment of macroalgal assemblages on the artificial reefs.