• Journal of Fisheries and Marine Sciences Education
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• v.29 no.1
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• pp.108-117
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• 2017

Laver, Porphyra, is distinctive for its high content of proteins and polysaccharides such as porphyran and hemicellulose. The chemical properties of the polysaccharides extracted with different extraction methods such as hot water, dilute acid(pH 4.0) or alkali solution(2N NaOH) were examined to investigate the suitable extraction conditions for porphyran and hemicellulose from laver. For porphyran extraction, dilute acid solution was more preferable to hot water and alkali solution because of its higher 3,6-anhydrogalactose content and lower protein content. However, alkali solution was more suitable to extract the hemicellulose because of higher mannose content indicating the extraction of mannan. To decrease contamination of the polysaccharides with protein, the dried lavers were pretreated with enzymes (Protamex, Flavourzyme, Alcalase, Viscozyme) before hot water extraction. All enzyme pretreatments increased the yield of polysaccharides by compared with control (enzyme unpretreated) and Flavourzyme pretreatment was most effective to decrease protein contamination in the polysaccharide. All viscosities of porphyran solutions pretreated by enzymes were lower compared to the control porphyran solution and showed pseudoplastic behavior with yield stress. In case of alkali extraction of residues obtained after enzyme hydrolysis and hot water extraction, protease pretreatment increased the mannose contents in the polysaccharide while the xylose content was increased by Viscozyme pretreatment.

• Journal of the Korean Applied Science and Technology
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• v.30 no.3
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• pp.504-517
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• 2013

The purpose of this study was to process extraction and separation for polyglucose porpyran from pophyra yezoensis as high yield. The acidic porphyran solution was extracted with 0.1~1N of ${\alpha},{\beta}$-dichloromaleic acid or ${\alpha}$-chloromaleic acid of 2% solution as organic acid instead of inorganic acid at $60^{\circ}C$ and then porphyran was collection of high yield to acidic solution and it was neutralization treated with 0.1N of $d-Ca(OH)_2$ solution and the mixture was conversion to porphyran salt form and treated with a shell powder of ouster and then added of ethanol as precipitator. It recovery porphyran contained of violet purple laver coloring matter was obtained as a crystalline and used for the next step without future purification to prepare of porphyran laver jam. so, The resulting porphyran and porphyran jam was characterized by it component and physical properties.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.328-340
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• 1987

In order to clarify major reasons of a poor harvest, the Porphyra-cultivation ground was investigated in Kwangyang Bay in terms of the laver production per unit area, diseases, and fouling organisms from January to April in 1986. The laver production per unit area of the control station was more than that of the study area at 'Soppal' cultivation ground, while the difference at the cultivation groud using 'nets' seemed to be insignificant. The vertical attachment range of laver was directly associated with the production per unit area at 'Soppal' cultivation ground. The number of young thalli of 1-3 mm length was almost similar between control and study sites at 'nets' cultivation ground. Two kinds of diseases in cultured laver, the crape and shot hole, were prevalent during the study period. However, the affected thalli were gradually decreased at the end of the study period. Major fouling organisms attached to 'Soppal' were Balanus albicostatus, Enteromorpha prolifera, Capsosiphon fulvescens, and Scytosiphon lomentaria. In conclusion, the poor harvest of laver in 1986 may result from such following problems as the decrease in vertical attachment range of laver and fouling problems as the decrease in vertical attachment range of laver and fouling organisms at 'Soppal' cultivation ground, prevalence of certain diseases, changes in environmental conditions, arrangement and maintenance of facilities for laver cultivation.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.503-515
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• 2012

${\alpha},{\beta}$-Dichlorosuccinic acid was synthesized through the reaction of maleic anhydride with $Cl_2$(g) and ultra violet(200~300nm) wavelength in the presence of $CCl_4$. The second reaction of N-(${\alpha},{\beta}$-dichloro)succinic acid contained glucosamine derivatives(I) was accomplished by a modification of the general acylation using excess ${\alpha},{\beta}$-dichlorosuccinic anhydride in the presence of 2% acetic acid with methanol as a solvent at elevated temperature($70^{\circ}C$). We considered organic acid derivatives were useful especially of treatment for the cultivating porphyra and skin beauty culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.1
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• pp.1-7
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• 2007

The chemical and rheological properties of deproteinated porphyrans from laver Porphyra yezoensis were investigated to obtain basic data for the production of food materials with biological functionality. Deproteinated porphyran was prepared by acid extraction (pH 4.0, $80^{\circ}C$, 4 hr) and successive hydrolysis with 0.5% Alcalase and 0.5% Flavourzyme. The porphyran constituted 10.7% of the dry laver and consisted of 0.6% protein, 14.8% ester sulfate, 3.2% 6-O-methyl galactose, 16.0% 3,6-anhydro-L-galactose, and 67.3% galactose. The effects of concentration and temperature on the apparent viscosity were examined by applying the power law and Arrhenius equations. The porphyran solution showed the typical behavior of a pseudoplastic liquid and the flow behavior index decreased with increasing concentration. The activation energy of the deproteinated porphyran solution at a 1,000 L/s shear rate also increased from $1.4954{\times}10^{4}\;to\;1.9544{\times}10^{4}\;J/kg$ mol with the concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.49-59
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• 1995

Nine species of edible seaweed [green laver (Monostroma nitidium) and sea staghorn ( Codium fragile) of green algae; sea mustard (Undaria pinnatifida), seaweed fusiforme(Hizikia fusiforme), gulf weed (Sargassum fulvellium), and sea tangle (Laminaria japonica) of brown algae; seaweed dilatata (Halimeniopsis dilatata), seaweed furcata (Gloiopeltis furcata), and laver (Porphyra tenera) of red algae] collected from Kijang, Chungmu, and Yosu in Korea, were examined and compared on their chemical and mineral composition depending on their harvesting season. Crude protein $(N\pm6.25)$ showed about $45\%$ on moisture free basis (the contents of every components described below are shown as moisture free basis) for laver and $30\%$ for green laver collected from ever seasons and sites. Sea tangle showed the highest content in crude lipid $(10\%)$ among brown seaweeds and green laver had $6\%$ of crude lipid regardless their habitats. Ash and carbohydrate in sea staghorn hold about $90\%$ of total solids but those levels were only $50\%$ in laver. The relationship between ash and carbohydrate content showed a tendency with reverse correlation. Mineral compositions were examined on green laver, sea mustard, and seaweed furcata collected from Kijang. Sodium was eminent element (1,798-7,334mg/l00g) followed by potassium. Magnesium and calcium content were low level compared with sodium and potassium. As a micro-element iron was appraised the highest status (165-330mg/100g) in green laver, however, iron in sea mustard and seaweed furcata was comparatively low amount (2.7-47.4mg/100g). The level of zinc was also comparatively high and that was varied on habitats. In conclusion, chemical compositions of these algae were distinctively varied on species and habitats, and mineral compositions were notably changed by the harvesting season.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.476-483
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• 1993

The moisture sorption characteristics of commercially produced seasoned dried layer (Porphyra yezoensis) was investigated by measuring sorption isotherms. The laver and two kinds of desiccant (silica gel and zeolite based desiccant) were used at temperatures of 30, 40 and 5$0^{\circ}C$ respectively using the method of saturated salt solution. Time to reach the equilibrium moisture content at each temperature and relative humidity varied from 4~6hr for the laver to 20~25hr for the silica gel and 43~46hr for the zeolite. The isotherms of the layer and the desiccants showed the characteristic sigmoidal curve. Monomolecular layer moisture content calculated using the BET equation at each temperature (30, 40, 5$0^{\circ}C$) were 5.26, 4.46 and 3.49% (d.b.) for the laver, 17.32, 15.24 and 12.89% (d.b.) for the silica gel, 16.89, 14.92 and 14.44% (d.b.) for the zeolite, respectively, Both desiccants showed higher values of the monomolecular layer moisture content than the laver. In all cases, the monomolerular layer moisture contents were decreased linearly as the temperature was increased in the experimental ranges. Water vapor transmission rate of the packaged material was also influenced by the temperature, which could be explained by the Arrhenius equation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.433-438
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• 1985

Lipids extracted from two kinds of sun-dried laver samples, wild Porphyra suborbiculata and cultured Porphyra tenera, produced at Wan-do in Korea were studied. Dried P. suborbiculata contained $0.8\%$ total lipid(TL) which consisted of $21.4\%$ neutral lipid(NL), $53.4\%$ glycolipid(GL) and $25.2\%$ phospholipid(PL), and dried P. tenera contained $1.2\%$ TL which consisted of $30.5\%$ NL, $50.3\%$ GL and $19.2\%$ PL. Among the NL of dried P. suborbiculate and P. tenera, free fatty acid ($41.4\%,\;39.0\%$), triglyceride($25.6\%,\;28.8\%$) and free sterol ($22.1\%,\;16.7\%$) were predominant. Digalactosyl diglyceride ($34.7\%,\;46.6\%$) and monogalactosyl diglyceride ($19.2\%,\;18.0\%$) were the major components among the GL. Sulfoquinovosyl digylceride ($4.2\%$) was also identified in P. tenera only. And main lipids in the PL of P. suborbiculata and P. tenera were phosphatidyl ethanolamine ($40.3\%,\;35.7\%$) and phosphatidyl choline ($28.6\%,\;30.7\%$) and followed by phosphatidyl serine($15.1\%,\;19.2\%$) and phosphatidyl inositol ($16.0\%,\;14.4\%$). The major fatty acids in the TL of the dried P. suborbiculata were 20:5 ($29.4\%$), 16:0 ($23.4\%$) and 20:4 ($13.0\%$), and those of the dried P. tenera were 20:5 ($36.7\%$), 16:0 ($16.2\%$), 16:1 ($10.7\%$) and 18:1 ($9.7\%$). The fatty acid composition of the both samples in the NL fraction were similar to the pattern in those of the TL. The abundant fatty acids in the PL of the both dried laver were 20:5, 16:0 and 18:1. In case of the GL fraction, the main fatty acids of the dried P. suborbiculata were 16:0, 20:5, 18:1 and 20:4, while those of the dried P. tenera were 20:5, 16:0 and 18:1.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.185-187
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• 2001

해조류는 다른 수산생물에 비해 그 용도가 상대적으로 낮고 과학적인 연구가 부족한 실정이다. 그러나 최근 구미선진국 및 일본 둥지에서는 해조류가 건강식품 생리활성 물질의 원료로서도 각광을 받고 있으며, 식량자원으로서도 재평가되고 있다. 이 같은 해조류는 비타민 A, B$_1$, B$_2$, C, D, E와 많은 미네랄이 함유되어 있으며 특히, 칼슘, 요오드, 철, 아연 등과 같은 필수 미량 원소의 함량이 높고, 특징적인 생리활성을 나타내는 성분들을 포함하고 있다. 이들 중 김(Laver)은 알래스카만에서 캘리포니아주까지 북동부에 자라고 전 세계 50여종 정도 분포하며, 그 중 한국의 남해안 일대에는 10여종 정도가 분포하교 있다. (중략)

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.633-640
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• 2001

This study investigated the effects of lipid metabolism on male Sprague Dawley rats given porphyran diet extracted from Porphyra yezoensis for 4 weeks. We divided into 5 diet groups which were normal diet, control diet fed high fat, cholesterol and sodium cholate, control and 1% porphyran diet (1% PD), control and 5% porphyran diet (5% PD), control and 10% of porphyran diet (10% PD). Feed intake and weight gain were not significantly different between control and porphyran diet. Serum triglyceride, total cholesterol and LDL-cholesterol contents were significantly (p<0.05) lower in porphyran diet groups than control group. However, serum HDL-cholesterol contents increased by the addition of porphyran in experimental diet. Hepatic triglyceride and total cholesterol concentrations were proportionally decreased by the addition of porphyran in control diet compared to control diet. A number of lipid particles were shown in liver tissue of control group and the same appearance was shown in the group fed with 1% porphyran diet, whereas lipid particles was reduced in the group fed with 5% and 10% porphyran diet compared to control group. Especially, liver tissue of 10% porphyran diet group was shown similar appearance to normal diet group. These results indicated that supplementation of porphyran in hyperlipidemic rats has an effect on the improvement of serum lipids.