• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.1078-1082
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• 2010

The substantial trace mineral usabilities of seven seaweeds for nutrient evaluation have been studied. As the neutral detergent fiber (NDF) bound trace minerals have been known to be indigestible, these contents were excluded in the digestible trace mineral contents evaluation. Therefore, those four trace mineral contents in seven seaweeds and their NDF-bound contents were estimated. Consequently, the NDF-bound Zn, Cu and Mn contents, except Fe, in seven seaweeds were between 10 and 20% of total trace mineral contents, thus 80~90% of seaweeds trace minerals were observed to be substantially digestible. Although the average estimated availability of Fe in the seaweeds were relatively low, those Zn, Cu and Mn were high in relative to those total contents. Thus, even with consideration of their digestibility, seaweeds could be one of good sources of trace minerals for human nutrition because of their high availabilities of Zn, Cu and Mn.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1143-1150
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• 2005

Antioxidative activities of 5 common edible seaweeds in Korea, three brown algae (seaweed fusiforme, sea mustard, sea tangle), one green algae (sea lettuce) and one red algae (laver), were examined. The antioxidative activities of ethanol extracts from these seaweeds were examined by measuring of inhibition rates against iron-induced linoleate peroxidation, DPPH (1,1-diphenyl -2-picrylhydrazyl) radical generation and MDA-BSA (malondialdehyde-bovine serum albumin) conjugation. Sea lettuce ethanol extract showed the strongest anti-oxidative activity among them, especially in inhibition against conjugation of lipid peroxide and protein. Second to sea lettuce, laver and sea tangle ethanol extracts showed high DPPH radical scavenging activity and inhibition against MDA-BSA conjugation. However, seaweed fusiforme and sea mustard ethanol extracts did not show antioxidative activities. Sea mustard contained the highest total flavonoids (11.33 mg/g dry wt) and sea lettuce contained the highest total polyphenol (8.97 mg/g dry wt) among these seaweeds. In addition, there was strong positive correlation between the antioxidative activity and total polyphenol content in these seaweeds, suggesting polyphenol compounds may contribute to antioxidative effect of seaweeds. From these data, it is suggested to consume much of seaweeds such as sea lettuce, laver and sea tangle to prevent age-related chronic diseases, and also develope neutraceutical products using polyphenol rich fraction from sea lettuce.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.19-31
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• 2021

Seaweeds are a potential source of minerals, essential amino acids, fatty acids, proteins, and various bioactive compounds such as antioxidants. The higher water content of seaweeds reduces the shelf life and this requires the appropriate drying method. The drying conditions play a major role in the conservation of nutrient composition in dried seaweeds. In recent years, the seaweed industry has used many different drying methods with advantages and limitations. Hybrid hot-water Goodle dryer (HHGD) which is a special dryer mixed with hot-water and a Korean traditional heating system (Goodlejang) might be a solution to avoid these limitations. The present study evaluated the effect of drying conditions in HHGD on nutrient composition and bioactivities of brown seaweeds. Moreover, freeze-dryer (FD) and HHGD were employed in this study to compare the dried outputs obtained from four brown seaweed species. The present study aims to evaluate the effect of the hybrid hot-water Goodle drying method (HHGDM) on the nutritional composition and antioxidant activity of dried seaweeds. AOAC standard methods were used to analyze the proximate composition of dried samples and their 70% ethanol extract. The intracellular and extracellular antioxidant activities were evaluated using Vero cells and electron spin resonance (ESR) spectrometer respectively. High performance liquid chromatography, apoptotic body formation, and in-vivo experiments were used for further confirmation of the quality of dried output. The proximate composition results obtained from drying in HHGD and FD did not exhibit any significant difference. Moreover, the seaweed extracts from the dried seaweeds by HHGD and FD dryings were also not different and both significantly down-regulated in-vivo and in-vitro oxidative stress. Furthermore, the high performance liquid chromatography results revealed that the two dryers did not make the major peaks different in the chromatograms. Freeze-drying method (FDM) provides elevated quality for dried output, but there are limitations such as high cost and low capacity. The results from a novel HHGD did not provide any significant difference with the results in FD and expressed a potential to avoid the limitations in FD. Overall, these findings solidified the applicability of HHGD over FD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1041-1051
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• 2005

In order to assure the safety of the seaweeds, we measured the contents of the trace metals in the seaweeds harvested from Korean coastal area. We collected 620 marine algal samples from fourteen areas, and then analyzed the trace metals such as Hg, Cd, Cr, Cu, Mn, Ni, Pb and Zn. The contents of Hg, Cd, Ni and Mn were higher in the seaweeds collected from Chungnam Taean area. The contents of Cr and Cu were higher in the seaweeds collected from Yeongdeok and Tongyeong area, respectively. And Pb and Zn were highly detected from the seaweeds of Ulsan area. The mean levels of trace metals were high in the order of Zn $(48.02\pm41.20{\mu}g/g)\;>\;Mn (34.63\pm38.95{\mu}g/g)\;>\;Cu(6.29\pm6.52{\mu}g/g)\;>\;Ni(2.17\pm4.00{\mu}g/g)\; >\;Cr(1.61\pm2.35{\mu}g/g)\;>\;Pb(1.28\pm2.37{\mu}g/g)\;>\; Cd(0.67\pm0.75{\mu}g/g)\;>\;Hg(0.02\pm0.02{\mu}g/g)$. Zn was consistently most abundant metal in all samples, followed by Mn and Cu, which are very important for human health. There were higher contents of Hg and Cd in brown algae, the contents of Cr, Cu, Mn, Ni and Pb in green algae, the content of Zn in red algae among them. Additionally, significant linear correlations were observed between a total 28 different pairs of metals, of them, the correlation factor between Cr and Ni showed the highest (r=0.374, p<0.001). The trace metal contents of seaweeds varied with habitats and kinds of samples, nevertheless they showed very safe level in edible seaweeds tested. Scytosiphon lomentaria, which has been known as a little use of food, have shown a clear selectivity for Cr and Pb. Among non-edible seaweeds, Sargassum thunbergii for both Cd and Mn, Lomentaria hakodatensis for Ni and Grateloupia prolongata for Zn have shown a clear selectivity, respectively. Therefore, these seaweeds could be useful as bioindicator for each trace metal pollution.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.144-151
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• 2012

In the course of this study aimed at the development of functional food ingredients from seaweeds, the in vitro antimicrobial activities of methanol extracts prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta) were determined against food-borne diseases and pathogenic microorganisms including multi-drug resistant (MDR) Pseudomonas sp. and Candida sp. Based on disc-diffusion assays at 500 g/disc concentration of the methanol extracts, Ishige okamurai, I. foliacea, Sargassum confusum, and S. yamade exhibited strong antibacterial activities in a broad-spectrum, except against Pseudomonas aeruginosa. In addition to the latter four seaweeds, Ecklonia stolonifera, E. cava and Eisenia bicyclis also demonstrated antifungal activity against C. albicans. Among these 8 selected seaweeds, I. okamurai, I. foliacea, and S. yamade exhibited strong hemolytic activity (55-93%) at 500 g/ml against human RBC. Organic solvent sequential fractions using hexane, ethylacetate and butanol, and water residues were prepared from the 8 selected seaweeds and their anti-Candida sp. activities were further determined. The ethylacetate and butanol fraction of I. okamurai, and the hexane fraction of I. foliacea demonstrated antifungal activity against MDR-pathogenic Candida sp. Although the solvent fractions had no activity against MDR-Pseudomonas sp., our results suggest that seaweeds, especially Ishige okamurai, I. foliacea, S. confusum, and S. yamade could be developed as broad-spectrum antimicrobial ingredients.

• Journal of Life Science
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• v.21 no.4
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• pp.576-583
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• 2011

In the course of study for the development of functional food ingredients from seaweeds having useful biological activities, the in-vitro antioxidant and nitrite scavenging activities of the methanol extracts prepared from 35 different seaweeds (17 phaeophyta, 11 rhodophyta and 7 chlorophyta) were determined. At $500\;{\mu}g/ml$ concentration of the methanol extracts, Ecklonia cava, Ecklonia stolonifera, Eisenia bicyclis (Kjellman) Setchell, Ishige foliacea, I. okamurai, Sargassum confusum, S. fulvellum, S. yamade and Zostera marina showed 60% more DPPH and ABTS scavenging activity. The exceptions were found in I. okamurai and Z. marina, which showed 45% and 53% ABTS scavenging activity, respectively. The correlation coefficient between DPPH and ABTS scavenging activities was 0.855, suggesting that the 9 different seaweeds extracts could scavenge anion and cation radicals concurrently. In reducing power, only E.cava, E.stolonifera and E.bicyclis showed above 0.88 ($Abs_{700}$). In a while, in nitrite scavenging activity at $100\;{\mu}g/ml$ concentration of the methanol extracts, 19 different seaweeds extracts including I. foliacea, I. okamurai, S. confusum, S. fulvellum, and S. yamade showed 60% more activity. Calculation of $IC_{50}s$ of DPPH, ABTS and nitrite scavenging activities of 9 different seaweeds extracts further showed that I. foliacea and S. yamade, besides E.cava, E.stolonifera and E.bicyclis, have strong antioxidant and nitrite scavenging activity. These results suggest that the selected 9 different seaweeds could be developed as functional food ingredients and I. foliacea and S. yamade have potential as novel natural sources of antioxidant and nitrite scavenger.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.348-353
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• 1997

The antimutagenic and cancer cell growth inhibitory effects of methanol extracts from 9 kinds of seaweed were studied in the Ames assay and cell culture systems, respectively. The methanol extracts from the seaweeds of sea lettuce, chlorella, sea tangle, sea mustard, sporophyll of sea mustard, fusiforme, seaweed papulosa, purple laver and ceylon moss showed antimutagenicities against aflatoxin B₁(AFB₁) and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in the Salmonella typhimurium TA100. These extracts revealed relatively higher antimutagenicity against AFB₁(indirect mutagen) than MNNG(direct mutagen). Sporophyll of sea mustard and seaweed papulosa exhibited strong antimutagenic activity against AFB₁, and sporophyll of sea mustard, sea tangle and ceylon moss also reduced the mutagenicity induced by MNNG. The sporophyll fo sea mustard exerted the highest antimutagenic activity among the samples treated. The methanol extracts from 9 kinds of seaweed inhibited the growth of two cancer cell lines, AGS human gastric adenocarcinoma cells and HT-29 human colon carcinoma cells. Sea tangle, sea mustard and sporophyll of sea mustard inhibited the growth of cancer cells significantly. These results suggest that various seaweeds show not only antimutagenic activity but also growth inhibitory effect of some cancer cells.

• Journal of Nutrition and Health
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• v.26 no.2
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• pp.196-201
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• 1993

In this study, dietary fiber contents in vegetables and seaweeds were determined by Mongeau-Brassard method and the AOAC official method. The average total dietary fiber(TDF) contents by AOAC official method were 6% for vegetables, and 33% for seaweeds. The average ratios soluble dietary fiber (SDF) contents to TDF contents were 47% for vegetables and 57% for vegetables except bellflower root and 1.0% - 8.0% for seaweeds. TDF$\pm$error boundary values by Mongeau-Brassard method were a little higher than those by AOAC official method. But, F/Fc of all samples were lower than 1.0. Therefore, Mongeau-Brassard method was evaluated as precisely as AOAC official method.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.361-363
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• 2012

We investigated ultraviolet (UV) absorption materials from Russian seaweeds. First, the UV absorptivities of five seaweeds Gloiopeltis fucatas, Mazzaella sp., Mastocarpus pacificus, Laminaria cichorioides, Saccharina japonica were evaluated by a UV spectrometer. Of these seaweeds, Gloiopeltis fucatas and Mazzaella sp. showed high levels of UV absorption. Column chromatography of active 50% aqueous ethanol extracts from Gloiopeltis fucatas and Mazzaella sp. resulted in the purification of two known compounds. Spectroscopic techniques identified their structures as shinorine and palythine. These materials exhibited UV absorptive capabilities at wavelengths of 333 and 320 nm, respectively. These results suggest that Gloiopeltis fucatas and Mazzaella sp. may be useful as natural cosmeceutical sources.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.75-81
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• 2000

A matrix modification was studied for the determination of trace manganese in several seaweeds by electrothermal atomic absorption spectrophotometry(ETAAS). The type and quantity of modifiers were investigated to realize the efficient modification. Palladium was chosen as a single modifier. By the addition of palladium(5$\mu\textrm{g}$/$m\ell$) to 2ng/$m\ell$ manganese solution, the temperatures were raised from 1,00$0^{\circ}C$ to 1,20$0^{\circ}C$ for the charring and from 2,10$0^{\circ}C$ to 2,20$0^{\circ}C$ for the atomization as well as the sensitivity and reproducibility were improved. With such optimum conditions, the trace amount of manganese in several seaweeds(laver, tangle and brown seaweed) could be determined by a calibration curve method, and good recoveries of more than 965 were also obtained in the samples in which a given amount of manganese was spiked. The detection limit of this method was about 0.048ng/$m\ell$.