• New & Renewable Energy
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• v.7 no.3
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• pp.6-16
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• 2011

In order to study the utilization of seaweeds as an alternative renewable feedstock for bioethanol production, their properties of hydrolysis and fermentation were investigated. The seaweeds were well hydrolyzed with diluted sulfuric acid. The weight loss of seaweeds reached 75-90%, but only 12-51% of them was converted into reducing sugars after the acid-hydrolysis at $130^{\circ}C$ for 4-6h. The yield of reducing sugars increased with increasing the hydrolysis time up to 4h and then decreased thereafter. In contrast, the ethanol yield from the hydrolysates increased with hydrolysis time except for green seaweeds maximizing at 4h. Optimal fermentation time by Saccharomyces cerevisiae (ATCC 24858) varied with seaweeds; 48h for green seaweeds, 96h for brown and red seaweeds. The ethanol yield from the hydrolysate reached 138${\pm}$37mg/g-dry for green seaweeds, 258${\pm}$29mg/g-dry for brown seaweeds, and 343${\pm}$53mg/g-dry for red seaweeds, which correspond to approximately 1.5-4.0 times more than the theoretical yield from total reducing sugars in the hydrolysates. The results obtained indicate clearly that the non-reducing sugars or oligosaccharides dissolved in the hydrolysate played an important role in producing bioethanol. Considering the productivity and production cost of each seaweed, brown seaweeds such as Laminaria japonica and Undaria pinnatifida seem to be a promissing feedstock for bioethanol production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.16-22
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• 2006

Mineral and heavy metal contents were determined in three brown edible seaweeds (sea mustard, Undaria pinnatifida; seaweed fusiforme, Hizikia fusiforme; sea tangle, Laminaria japonica) collected from Gijang and Wando in Korea, and two green seaweeds (sea lettuce, Enteromorpha prolifera; green laver, Monostroma nitidum) collected from Gijang. Seaweeds contained high proportions of ash (13.8-24.8%) and sulfate (1.08-3.25%). In brown seaweeds, ash contents (24.5-24.8%) were higher than in green seaweeds (13.8-15.2%). The differences of mineral contents were remarkable in both Gijang and Wando and in 5 various kinds of seaweeds. Brown seaweeds contained higher amounts of both macro-minerals (657-13,947 mg/100 g; Ca, Mg, Na, K) and trace elements (0.27-12.98 mg/100 g; Fe, Al, Zn, Mn, Cr, Cu, Ni), and green seaweeds also had relatively higher amounts of both macro-minerals (233-5,279 mg/100 g) and trace elements (0.26-10.61 mg/100 g).

• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.141-151
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• 2000

Over-grown seaweeds in Donghae(east sea of Korea peninsula) may impedes ocean environment, however, they can be a good nutrient resources for poultry feeds if they are utilized properly. In this study, seaweeds powder were tested for laying hens\` ration to investigate the effects on egg production rate, egg quality and calcium phosphorus excretion. One hundred 65wks-old brown layers were fed for 5 weeks alotted with seaweeds powder addition to experimental diet by 0(control), 0.5, 1.0 and 2.0%, respectively, and obtained following results; 1. Seaweeds proved a mid-protein low-energy feed resources with planty of K, Na, Ca, Mg, Sr and Fe. 2. Seaweeds addition by 0.5% and 1.0% improved egg production rate and egg-mass output markedly(p<0.05) than control. Seaweeds addition did not alter cholesterol level of yolk and yolk index, however egg shell thickness showed increasing trend by increasing seaweeds addition level. 3. Protein absorption and digestibility in seaweed addition treatments were significantly higher(p<0.05) than control group and protein contents of excreta in 0.5% and 1.0% treatments were reduced(p<0.05), which suggests effective protein metabolism for egg production. Increasing seaweeds addition reduces Ca and P contents in rectum and excreta, suggesting Ca and P utilization improvement in laying hens and lessening soil pollution. 4. In conclusion, seaweeds addition in layers' diet by 1.0% level improves egg-mass production and might be egg quality by increasing metabolism of protein, calcium and phosphorus.

• Preventive Nutrition and Food Science
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• v.4 no.3
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• pp.180-183
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• 1999

Seaweeds is a rich sources of dietary fibers exerting a number of physiological properties. However, the reported dietary fiber contents of seaweeds are not consistent and vary widely. Also. a limited number of studies on the biological effects of specific seaweeds have been reported. In this study, water-holding capacity, viscosity and antixidantive activity of major dietary seaweeds were measured to assess their physiological effects. Results showed that total dietary fiber contents ranged from 28 to 51% of dried weight, and large proportions of dietary fiber were insoluble fibers. Water-holding capacity was highest in sea mustard being 1310% , while laver, sea tangle, and green laver exhibited 943, 854 and 815%, respectively. The viscosity of seaweed samples was 20 to 40 cP in sea mustard and sea tangle, while laver and green laver possessed much lower values. All seaweed samples revealed a weak, albeit significant electron donating ability. Also, lipid peroxidation was reduced by 7 to 18%. However, there was no difference in antioxidative activity among seaweeds and sample concernations used. These results imply that most commonly used seaweeds possibly exert parts of their physiological effects through their water-holding, gel-forming , and/or antioxidative activities.

• Fisheries and Aquatic Sciences
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• v.21 no.7
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• pp.19.1-19.11
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• 2018

Background: Traditionally, East-Asians (Korea, Japan, and China) utilize seaweeds as a food source and ingredient in traditional medicine. Korea is one of the biggest seaweed producer and consumer in the global trade. Especially, side dishes made from seaweeds are very popular in the traditional Korean cuisines. Seaweeds are popular as fresh vegetable salads and soup or eaten as snacks. Main body: Seaweeds are rich in essential nutrients, minerals, and vitamins as well as a promising source of novel bioactive compounds. The compounds (polysaccharides, polyphenols, and sterols) present in the edible Korean seaweeds possess important bioactive properties such as antioxidant, anti-inflammation, anticancer, anti-diabetic, and anticoagulant properties. Thus, the long-term consumption of seaweed has a potential to reduce the risk of cancer, diabetes, obesity, and inflammation-related complications. However, seaweed consumption is limited to the small population around the globe. Thus, it is important to increase the awareness of the health benefits of seaweeds consumption among the general population. Short conclusion: In the present study, we discussed some popular green and red edible Korean seaweeds and their health-promoting properties. This study might be useful to increase the public awareness of the consumption of seaweed as a food source.

• Journal of Marine Bioscience and Biotechnology
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• v.5 no.4
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• pp.33-39
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• 2011

As a rapid and quick bioactive compound evaluation technique, we utilized an automatic system of high throughput screening (HTS) to investigate ${\alpha}$-glucosidase inhibitory efficacy of seaweeds, collected from Jeju Island in Korea. In this study, different extracts with methanol at $20^{\circ}C$ and $70^{\circ}C$ from 23 species of brown seaweeds and 22 species of red seaweeds and 9 species of green seaweeds were subjected to HTS. Of the brown seaweeds tested, Myelophycus simplex (20B3), Ishige sinicola (20B5, 70B5), Colpomenia sinuosa, (20B14, 70B14), Hizikia fusiforme (20B21), Ishige okamurai (70B22) and Ecklonia cava (70B23) showed significantly high ${\alpha}$-glucosidase inhibitory activity with 96.52%, 98.34%, 98.37%, 80.49%, 96.16%, 76.32%, 98.32% and 98.12%. Schizymenia dubyi (20R15), Gelidium amansii (20R16) and Polysiphonia japonica (70R22) amomng the red seaweeds showed remarkable ${\alpha}$-glucosidase inhibitory activity more than 95%. On the other hand, the green seaweeds showed poor ${\alpha}$-glucosidase inhibitory activities (less the10%) at 1 mg/ml.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.303-310
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• 2008

Heavy metal concentration of Fe, Zn, Cu, Cd and Pb were analysed from seaweeds (Ulva pertusa, Sargassum thunbergii, Caulacanthus okamurae), sediments and seawater at the two experimental sites of Daebul and Sabjin industrial complex in Mokpo coastal area with a control site (Heugsando). Highest values of heavy metals were found at two experimental sites influencing by various pollution sources such as industrial drains, sewage and harbours. In contrast, the lowest concentrations was observed at the control site without any pollution source. The concentration levels of accumulated heavy metals were in the following order: seaweeds > sediments > seawater. Similar spatial distribution patterns were observed at the seaweeds, sediments and seawater for the highest mean values of the different heavy metals. This result show that seaweeds could be used as a biomonitors of heavy metals at coastal region.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.89-96
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• 1996

This study was conducted to analyze dietary fiber content of 113 common Korean foods. Content of total dietary fiber(TDF) in vegetables, mushrooms, fruite, and seaweeds was determined by enzymatic-gravimetric method developed by Prosky et al. and adopted by AOAC. The average TDF content of the foods analyzed was 3.62$\pm$2.09% for green vegetables, 5.90$\pm$7.61% for light vegetables, 14.27$\pm$18.11% for mushrooms, 3.02$\pm$4.48% for fruits, and 11.39$\pm$12.68% for seaweeds. The foods containing the highest TDF values in the food groups were boiled radish leaves(10.84%) in green vegetables, dried braken(38.36%) in light vegetables, dried juda's ear(18.18%) in mushrooms except dried manna lichen(52.87%), dried persimon(17.73%) in fruits and dried sea mustard(37.77%) in seaweeds. Dried Seaweeds such as sea mustard (37.77%), sea tangle(29.30%), and laver(31.36%) were good sources of dietary fiber. When we consider the health and therapeutic benefits of dietary fiber, it is recommended to continue to consume traditional Korean diet which are mainly composed of vegetables rather than animal foods and to increase consumption of dried mushrooms and seaweeds which contain high content of TDF.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.111-117
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• 2021

The study was aimed at developing an alternative therapeutic agent against acne vulgaris, one of the most common skin diseases, to meet the continuing demand for new therapies. Acne vulgaris is often associated with the acne-causing bacteria such as Cutibacterium acnes. To investigate the safety of agents against acne vulgaris, we evaluated the potential antibacterial activities of edible seaweeds against C. acnes in Korea. Forty-one edible seaweeds, including the brown, green, and red varieties, were selected for the antibacterial test. In comparison with other seaweeds, 70% ethanolic extracts of brown seaweeds, such as Cladophora wrightiana var. minor, Eisenia bicyclis, Ecklonia cava, Ishige foliacea, Ishige okamurae, Sargassum filicinum, and Sargassum miyabei Yendo, exhibited potential antibacterial activity against C. acnes with minimum inhibitory concentrations ranging between 64 and 128 ㎍/mL. To investigate the active anti-acne agents and to enhance our understanding of the antibacterial activities against C. acnes, further solvent-fractionation experiments are warranted. The findings imply that brown seaweeds can be a potential source of natural agents against acne vulgaris.

• Fisheries and Aquatic Sciences
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• v.27 no.7
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• pp.468-473
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• 2024

The tyrosinase inhibition effects of 23 marine-derived seaweeds harvested in Korea were screened to determine their potential as skin-whitening agents. Of the 23 species initially screened, the total phenolic (TP) content of brown, green, and red seaweeds were 7.62-280.11, 5.24-62.37, and 0.63-28.76 phloroglucinol equivalents (PGE) mg/g, respectively. Brown seaweed extracts exhibited much stronger inhibitory activities than green and red seaweed extracts. Among the brown seaweeds, Ecklonia cava had the highest TP content (280.11 PGE mg/g) and the strongest tyrosinase inhibitory effect with a half maximal inhibitory concentration (IC₅₀) value of 4.38 ㎍/mL. The kinetics of tyrosinase inhibition, analyzed by Lineweaver-Burk plots, found E. cava extract to be a non-competitive inhibitor. This study's results indicated that E. cava's inhibition of tyrosinase may have potential applications in the cosmetic industry.