• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.27-36
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• 1973

The effect of water activity on degradation of pigments in dried lavers, Porphyra tenera Kjellm. was examined when stored at room temperature for fifty days. Chlorophyll pigment was extracted with methanol-petroleum ether mixture solvent(2:1 v/v), partitioned in ether, and analysed spectrophotometrically at 662 nm as chlorophyll a. The degradation products of chlorophyll were isolated on sugar-starch column(85:15 w/w) with n-propanol-petroleum ether solution(1:200 v/v) as a developing solvent. The isolated green colored zones were analysed individually at the wavelengths of 650, 662, and 667 nm as allomerized product, chlorophyll a retained, and pheophytin formed respectively. Carotenoida were also extracted with the methanol mixture solvent, partitioned in ether, and finally redissolved in acetone after the evaporation of ether in a rotary vacuum evaporator. The total carotenoid content was measured as lutein at 450 nm. From the results, it is noted that the rate of chlorophyll degradation reached a minimum at 0.11 to 0.33 water activity while progressively increased at higher moisture levels resulting in rapid conversion of chlorophyll to pheophytin. At lower activity, autocatalysed oxidizing reaction like allomerization seemed prevailing the acid catalysed conversion reaction. The loss of carotenoid pigment was also greatly reduced at the range of 0.22 to 0.34 water activity with much faster oxidative degradation at both higher and extremely lower moisture levels. These two moisture levels indicated above at which the both pigments exhibited maximum stability are considerably higher than the BET monolayer moisture which appeared 7.91 percent on dry basis at Aw=0.10 calculated from the adsorption isothermal data of the sample at $20^{\circ}C$. The rate of pigment loss in heat treated samples at 60 and $100^{\circ}C$ for 2 hours prior to storage somewhat decreased, particularly at higher moisture levels although the final pigment retention was not much stabilized.

• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.69-79
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• 2020

In this study, the anti-inflammatory and cytotoxic effects of hot-water extracts from 10 kinds of macroalgae in Korea were investigated. It was selected materials in consideration of biological activity and industrial potential as follows: Caulerpa okamurae; Codium fragile; Ulva australis; Ishige foliacea; Saccharina japonica; Sargassum horneri; Undaria pinnatifida; Gloiopeltis tenax; Gracilaria verrucosa; Porphyra tenera. Results showed that S. japonica and G. tenax significantly decreased NO productionn in LPS-stimulated Raw 264.7 cells at concentrations of 100, 1000 ㎍/mL and 1000 ㎍/mL, respectively. However, most of the other macroalgae used in the experiment did not affect NO production. It was observed that all macroalgae extracts except for the highest concentration (1000 ㎍/mL) treatment group of P. tenera did not affect the viability in Raw 264.7 cells. In addition, there was not significant decrease in cell viability by macroalgae extracts treatment in HINAE cells. These results suggest that S. japonica and G. tenax could be used as potential safe natural anti-inflammatory agents for food and feed additives. Also, the results of this study are expected to be used as basic data for the development of functional materials for 10 kinds of macroalgae resources in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.52-56
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• 1985

For the fundamental studies of radiation breeding in edible marine algae, the biological effects on conchospores of Porphyra species by gamma-irradiation were examined. Two varieties, Keun-cham-gim (Porphyra tenera Kjell. form tamatsuensis Miura) and Saga No.5, were chosen for this study, and their conchospores after r-irradiation($5.0{\sim}20.0$ KR) were cultured for 50 days. The results obtained were summarized as follows. 1. Gamma-irradiation in less than the dose of 20KR did not affect germination of conchospores, and almost all spores grew into two cells germ in 24 hours after irradiation, but withering germs were gradually increased in number according to higher exposure within 5 days old culture. 2. High irradiation caused the induction of giant cells, abnormal useless growth of hold-fast, lumpish thalli and callus-like lumpy tissues. 3. The liberation of neutral spores from young germs and carpospores from mature thalli were observed on the frond exposed at $10{\sim}20$ KR irradiation. All spores were normal in division and its size. 4. The best irradiation effect on growth of Keun-cham-gim was observed at 10 KR dose, whose growth-rates were $140\%$ in wet weight and $108\%$ in mean frond area, but only $48\%$ was recorded in wet weight at 20 KR exposure. Saga No.5 were in contrast with Keun-cham-gim, and their most growth-rate was $400\%$ in wet weight ($258\%$ in frond area) at 10 KR irradiation and the worst was $20\%$ at the dose of 20 KR. 5. The withering phenomenon to death by treatment of gamma-ray presented substantial difference between two varieties. Survival rate compared with control in Keun-cham-gim was $70.7\%$ at 20 KR, but that in Saga No.5 recorded $47.0\%$ at same dose. 6. Synthesizing the results of high and low r-irradiation, it was suggested tat high r-irradiation in more than 5.0 KR inhibited conspicuously the growth of germs derived from conchospores, and about half of them withered at 15.0 KR dose or more.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.469-475
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• 1987

The present paper was investigated to elucidate the nitrite-scavenging ability of seaweed extracts. Seaweed extracts possessed the scavenging ability of nitrite. By fractionation of seaweed extracts, nitrite-scavenging ability of laver(Porphyra tenera), sea lettuce(Enteromorpha compresa) extracts were effective in the water-soluble fraction, but sea mustard (Undaria pinnatifida), sea staghorn (Codium fragile) extracts in the methanol-soluble fraction. Nitrite scavenging ability of seaweed extracts was also pH-dependent, highest at pH1.2 and lowest at pH6.0. Particularly, nitrite-scavenging abilities of water-soluble fractions obtained from laver and sea lettuce were similar to that of L-ascorbic acid at pHl.2. After seaweed extracts were treated with sodium borohydride, nitrite-scavenging ability was remarkably decreased at pH1.2. It is assumed that reducing powers of seaweed extracts participated in their nitrite-scavenging abilities.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.95-100
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• 2000

The effect of natural foods, utilizing the extracts or juices of teas(Green tea; Camellia sinesis, Du'chung; Eucommia ulmoides Oliver), medicinal plants(Eu sung cho; Houttuynia cordata Thunb, Sam back cho; Saurus Chinensis, Baek hwa sa seal cho; Oldenladia diffusa Roxb.) seaweeds(Laver; Porphyra tenera, Sea mustard; Undaria pinnatifida, Sea staghorn; Condium fragile) and vegetables(Sweet pepper; Capsicum annuum var. angulosum, Kale; Brassia oleracea var.. acephala, Cucumber; Cucumis sativus, Onion; Allium cepa) and fruits(Tomato; Lycopericon esculentum, Maesil; Prunus mume, Plum; Prunus saticina and Grape; Vitis spp.)on the inhibition of N-Nitrosodimethylamine(NDMA) formation was investigated from the various conditions. The inhibition effect was observed in vitro using the reaction fluids of pH 1.2, 4.2 and 6.0. From the teas and medicinal plants, there was a positive response of NDMA formation; however, From the seaweed extracts, there was a negative response of the inhibition effect of NDMA formation, and as the pH of reaction fluids and the amount of materials increase, the inhibition of NDMA formation was strengthened. The inhibition ratios by the level of pH are as follows: under pH 1.2 vegetable juice were 57.6∼99.7% and fruits were 35.9∼99.7%; under pH 4.2 vegetable juice were 55.0∼97.5% and fruits were 21.3∼96.8%. All of the materials observed has been proved and shown the inhibition effect of NDMA formation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.3081-3088
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• 2013

Phenolic contents and antioxidant activities were determined in the water and ethanol extracts from six species of edible seaweeds, Phaeophyceae (Laminaria japonica, Hizikia fusiformis and Undaria pinnatifida), Rhodophyceae (Porphyra tenera and Gracilaria verrucosa) and Chlorophyceae (Ulva lactuca). The highest extraction yield was observed in water extract (pH 8.0) of G. verrucosa (44.23 %) and phenolic content was the highest in ethanolic (75 %) extract of H. fusiformis (52.82 ${\mu}g/mg$). 25 % ethanolic extract from U. lactuca was found to have the highest DPPH radicals scavenging activity(19.29 %) and superoxide anion scavenging activitiy was higher in water extract (pH 8.0) from H. fusiformis (81.20 %) than that other seaweeds. Phenolic contents were strongly correlated with antioxidant activity in the six edible seaweeds extracts ($R^2$=0.852). Taken together, these results indicate that H fusiformis may be a excellent source for development of natural antioxidants.

• Journal of Life Science
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• v.23 no.8
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• pp.1004-1009
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• 2013

The biochemical compositions and nutritive values of six species of seaweeds were analyzed to determine their applicability in functional foods or ingredients. The biochemical compositions (moisture, ash, protein, lipid, and dietary fiber) and fatty acid contents were determined for the following seaweed extracts: Phaeophyceae (Laminaria japonica, Hizikia fusiformis, and Undaria pinnatifida), Rhodophyceae (Porphyra tenera and Gracilaria verrucosa), and Chlorophyceae (Ulva lactuca). The moisture content (% dry weight) ranged from 11.47% to 13.94%, ash from 19.15% to 26.50%, protein from 5.08% to 15.44%, lipid from 2.75% to 4.43%, and dietary fiber from 36.84% to 52.98%. C14:0, C16:0, C18:0, C16:1, C18: 1n-3, C18:2n-6, C18:3n-6, C20:4n-6, and C20:5n-3 represented the predominant proportions of fatty acids. Interestingly, docosahexaenoic acid (C22:6n-3, DHA) was either not found or only detected in trace amounts in the analyzed seaweeds. The levels of n-3 fatty acid were higher than other polyunsaturated fatty acids, and the n-6/n-3 ratio was very low. These results indicate that seaweed inhabiting Korean coastal areas will be beneficial to human health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.443-449
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• 2012

This study was conducted to investigate the antioxidant and acetylcholinesterase (AChE) inhibitory activities of extracts from various seaweed. The extracts of $Sargassum$ $thunbergii$ (91.3%), $Polysiphonia$ $morrowii$ (90.7%), $Ecklonia$ $cava$ (89.9%), and $Artemisia$ $fukudo$ (85.9%) showed over 80% high radical scavenging activities at the final concentration of 40 ${\mu}g$/mL. The $Artemisia$ $fukudo$ extract showed the highest inhibition activity of 30.2% on AChE at the final concentration of 10 ${\mu}g$/mL. The extract of $Porphyra$ $tenera$, $Costaria$ $costata$, $Monostroma$ $nitidum$, $Ecklonia$ $cava$, and $Agarum$ $clathratum$ against AChE at a concentration of 10 ${\mu}g$/mL exhibited inhibition of 26.6%, 25.3%, 23.4%, 21.7%, 20.4% and 19.9%, respectively. The bioautography results showed that the mixtures of structurally diverse compounds were thought to affect AChE inhibitory activity. These results suggest that extracts from seaweed with their high quality components may be effective in the prevention of Alzheimer's disease and may be used to develop various functional food products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.79-85
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• 1981

As one of the fundamental studies for the breeding of marine algae, the effects of several plant hormones (IAA, Gibberellin, 2.4-D, NAA, Kinetin) on the growth of Porphyra-fronds, P. tenera Kjell. form tamatsuensis Miura, were investigated from January 21 to February 21 1981. The fronds used for the experiment were dissected out at $25mm^2$ size, and cultured in modified Provasoli's ESP medium supplemented with various concentrations of each plant growth regulators. The culture was kept under constant water temperature of $5^{\circ}C$ in 14 hrs. photoperiod and illuminated with 2,400 lux by fluorescent light. Based on the results of first experiment, the culture of fronds for the secondary experiment was carried out at $5^{\circ}C\;and\;10^{\circ}C$ in medium containing various levels of Kinetin from April 6 to 24, and compared the growth of two groups at each concentrations with each other, The results obtained are summarized as follows : (1) The best growth efficiencies were observed at 5.0mg/1 of each plant hormones except Gibberellin. Among them, the highest growth-rate was $312.5\%\;(345.3\%\;in\;frond\;size)$ in contrast with control at 5.0mg/1 of Kinetin, and was followed by $257.5\%\;(236.1\%)$ in 2.4-D,$166.7\%(147.6\%)$ in IAA and $141.7\%\;(167.7\%)$ in NAA, but that in Gibberellin was $247.9\%(241.9\%)$ at 10.0mg/l. (2) Especially, the fronds cultured at 5.0mg/1 of Kinetin were deep black-brown in colour, and had vivid, healthy chloroplasts in their all cells. On the contrary, the fronds cultured in other media were discoloured to light black-brown or green-drown, and almost all cells were vacuolated or shrunk gradually into death.(3) There was an obvious difference between the best growth-rates of the fronds cultured at 5.0mg/l of Kinetin at $5^{\circ}C$ and those at $10^{\circ}C$. The former was $366.7\%$, the latter $318.8\%$ but the difference was little at lower concentrations. (4) Many abnormal cells grown up to $25.0-27.5\mu$ in diameter were found among the marginal cells of fronds which showed the best growth in Kinetin, and the fronds wire $41.0-42.0\mu$ in thickness which was thicker by $10.0\mu$ or so than the others. (5) In two fronds at 1.0mg/1 of Kinetin cell-divisions were observed, which might developed into antheridium, but it was doubtful whether due to the efficiency of Kinetin.