• 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.

• 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.

• KSBB Journal
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• v.29 no.6
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• pp.414-420
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• 2014

The seaweeds with high carbohydrate ratio Gelidium amansii, Saccharina japonica and Enteromorpha intestinalis were used as red, brown, and green seaweeds, respectively. Thermal acid hydrolysis, enzymatic saccharification and fermentation were carried out using those seaweeds to produce ethanol. The ethanol concentrations from red, brown and green seaweed were 14.8 g/L, 11.6 g/L and 9.9 g/L, respectively. After the production of ethanol, the seaweeds were reused to absorb heavy metal. The maximum biosorption ratio was Cu(II) (89.6%), Cr(III) (82.9%), Ni(II) (66.1%). Cu(II) had the highest affinity with 3 waste seaweeds. Red seaweed was verified the most effective substrates to both process.

• 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.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.63-68
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• 2003

Effective alginate extraction from waste-brown seaweeds was studied. The waste-brown seaweeds almost consist of stems of seaweeds. Alginate could be obtained from the stems as well as leaves of seaweed. Ultrasonic vibration(47kHz) facilitated filtering step in the alginate extraction process. Among various alkalies for alginate extraction, $NaHCO_3$ was most appropriate concerning use of dealginates. The yield of alginate extraction using $NaHCO_3$ 2wt% solution was 19.3% at $60^{\circ}C$. The dealginates from $NaHCO_3$-extraction process have been found most suitable food for red-worms.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.3
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• pp.170-177
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• 2006

As a rapid and quick bioactive compound evaluation technique, in this study we utilized a automatic system of High Throughput Screening (HTS) to investigate DPPH radical scavenging efficacy of seaweeds, collected from Jeju Island in Korea. In this study, 6 species of green seaweeds, 18 species of brown seaweeds and 22 species of red seaweeds extracted with methanol at $20^{\circ}C$ and $70^{\circ}C$ were subjected to HTS. Of the green seaweeds tested, Enteromorpha compressa (20G6) of the green seaweeds showed DPPH radical scavenging activity of over 60%. On the other hand, the other green seaweeds showed poor DPPH radical scavenging activities (lees than 40%) at 1 mg/ml. Sargassum siliquastrum (20B17, 70B17), Dictyota dichotoma (70B1), Sargassum coreanum (70B16) and Ecklonia cava (70B26) among the brown seaweeds showed significantly high DPPH radical scavenging activity with 96%, 97%, 92%, 92%, 87%. Polysiphonia japonica (20R24), Schizymenia dubyi (20R17), Gelidium amansii (20R18) and Acrosorium flabellatum (20R23) among the red seaweeds showed remarkable DPPH radical scavenging activity of over 90%.

• Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.181-187
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• 2023

The control of intestinal α-amylase and α-glucosidase is an effective therapeutic strategy for prevention of post-prandial hyperglycemia associated with diabetes mellitus. The objective of this study was to evaluate the anti-diabetes activities of Korean edible seaweed against α-amylase and α-glucosidase, two carbolytic enzymes involved in serum glucose regulation. Of the 41 species initially screened, Cladophora wrightiana var. minor, Eisenia bicyclis, Ecklonia cava, Ishige foliacea, and Ishige okamurae exhibited the strongest inhibitory activities from brown seaweeds. Asparagopsis taxiformis showed the strongest inhibitory effects from red seaweeds. The results of this study suggest that the crude brown seaweed extracts (C. wrightiana var. minor, E. bicyclis, E. cava, I. foliacea, and I. okamurae) and crude red seaweed extracts (A. taxiformis) may have beneficial effects suppressing the rise in postprandial hyperglycemia through the inhibition of α-amylase and α-glucosidase.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.252-259
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• 2006

Extracts which were prepared by four different extractions - 80% methanol extracts (ME) at high ($70^{\circ}C$) and a room temperature ($20^{\circ}C$), respectively and aqueous extracts (AE) at both temperatures with the residue after the methanol extracts - of 10 green, 19 brown and 25 red seaweeds collected in Jeju Island coast were examined for their DPPH free radical scavenging activity using a ESR (electron spin resonance) spectroscopy. A variety of the extracts showed positive scavenging effect against DPPH free radical (except the green seaweeds). Among the extracts, the brown seaweed extracts exhibited the highest scavenging activity. Especially, Sargassum spp. of the brown seaweeds have remarkable scavenging activities - both methanolic and aqueous at the both temperatures ($20^{\circ}C$ and $70^{\circ}C$). On the other hand, ME showed better scavenging activity than AE in the red seaweed extracts. These results indicate that autogenous seaweeds in Jeju will be potential natural antioxidants for functional food compounds.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.38-52
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• 2003

Seaweeds are large algae that grow in a saltwater or marine environment. There are over 400 species of seaweeds in the bay of Korea. Most seaweeds are divided into three groups according to their color : the green seaweeds(division Chlorophyta), the brown(Phanphyta) and the red(Rhodophyta), Seaweeds have been harvested for use as food, fertilizer, animal feed and medicines for thousands years. In the past decade, there has been increasing interest in using seaweeds for animal feedstuffs and feed supplements as their health qualities are becoming better known. In this review some perspectives on nutritional values and the role of functionality ingredients of various seaweeds will be also discussed. Ecklonia cava kjellman(EC), a perennial seaweed, is one of the main components of the marine forests along the East and South coasts of Korea. We conducted three experiments to evaluate the nutritional values of EC and the crude lectin extracted residues from EC(LEEC) and to investigate their dietary effects on productivity and immunocompetence in poultry. The crude protein content of EC was relatively low(about 10 ％) and its amino acids were poorly available. But, the results of our study suggested that EC can be used into broiler feed up to 3 ％ without any adverse effect, if its nutritional values are well evaluated prior to use. Similar results of dietary LECC up to 1.0 ％ level on egg production and egg quality have been obtained in layers. The concentrations of serum TNF-${\alpha}$ after Salmonella challenge were rapidly increased in accordance with the level of LEEC. These results indicated that LEEC can be used as a feed additives for enhancing of immunocompetence in poultry.