After thousands of years, seaweeds continue to be a source of food and valuable extracts for various industry applications. Nutritional benefits from seaweed include iodine, fiber, fats, and vitamins and minerals. Active constituents, such as phlorotannins, function as antioxidants, and have hypotensive and anti-inflammatory effects in the human body. Seaweed provides a natural source for human nutrition as well as a renewable source for industrial applications.(1)
Fig.1 Fresh Laminaria Japonica
Kombu comes from brown seaweeds that are a natural source of macro minerals such as magnesium, iodine, calcium, iron, and zinc. Certain bioavailable trace elements such as chromium, cobalt, manganese and vanadium have been identified in seaweed. (3) Vitamin B 12, which is not synthesized in plants, is also found in algae.(9) Brown seaweeds have high antioxidant capacity. (9) The compounds that “are responsible for antioxidant activity in seaweed include vitamin E, carotenoids, vitamin C as ascorbic acid, and partially vitamin B1 and niacin.” (9)
The three main compounds of extracted components from seaweed are polyphenols, peptides, and polysaccharides. (5) Polyphenols are minor compounds found in seaweed along with carotenoids, minerals, and fatty acids.(7) Peptides and polysaccharides are a part of the major seaweed compounds that can be extracted. Polyphenols and bioactive peptides both have antioxidant properties. Polyphenols contribute to disrupting free radical chain reactions and deters the generation of reactive oxygen species.(11) These phytochemicals function together as co-antioxidants and also for vitamin regeneration. (11)
Bioactive peptides can be derived from protein sources by different methods, such as hydrolysis by proteolytic enzymes. (6) The beneficial purpose for bioactive peptides is of interest in the pharmaceutical market for finding binding sites compatible in vivo (6).
“Fucan, fucoidan, galactan sulphate, carrageenan, xylomannan sulphate, sodium alginate, fucoxanthin, porphyran, and alginic acid are some bioactive polysaccharides from seaweed.”(8) Kombu’s indigestible fiber content comes from large amounts of polysaccaharides in the cell walls. (2) Kombu from the Laminaria sp. contains alginate and fucoidan fibers.(3) Fucoidan from algae contribute to different functions in the human body. Research with fucoidans has included anticoagulant, antioxidant, antivirus, and antitumor studies. (4) The anticoagulant properties are due to interaction with antithrombin III and blocking coagulant factors. (5) Fucoidans also enhance the activation of splenocytes, lymphocytes, and macrophages, all of which help boost the immune system. Anti-inflammatory properties of fucoidan can be contributed to disenabling Cox-2 gene expression and LPS-induced iNOS. (5)
Other valuable extracts from seaweed that are used in the food industry are fucoxanthin and fucosterol. (3) Brown seaweed identifiably features fucoxanthin. Fucoxanthin is a xanthophyll and is the most abundant carotenoid. Fucosterol is the dominant sterol from marine brown algae. The content of fucosterol is estimated between 83 and 97%.(10) Fucosterol is valued for its use in diabetic medications and in the prevention for cardiovascular disease. (10)
Fig.1 Chemical compound of Fucoxanthin
Uses for Kombu
Kombu is mainly used as food and in food supplements. Kombu contains up to 60 minerals,which is appealing for the food industry. Seaweed is 15 to 20% ash content. Seaweed is used as fertilizer and as a feed supplement for both plants and animals. Seaweed has a range of other industrial uses in the pharmaceuticals, cosmetics, and textiles industries.(12)
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2. Ruperez, P.; Toledano, G., 2003: Indigestible fraction of edible marine seaweeds. Journal of the Science of Food and Agriculture 83(12)
3. Miyuki Shirosaki, Tomoyuki Koyama. Chapter 15 – Laminaria japonica as a Food for the Prevention of Obesity and Diabetes. Advances in Food and Nutrition Research, Volume 64, 2011.
4. Vishchuk OS, Ermakova SP, Zvyagintseva TN. The fucoidans from brown algae of Far-Eastern seas: Anti-tumor activity and structure-function relationship.
Food Chem. 2013 Nov 15;141(2):1211-7. Epub 2013 Mar 26.
5. You-Jin Jeon, W.A.J.P. Wijesinghe, Se-Kwon Kim. Chapter 12 – Functional Properties of Brown Algal Sulfated Polysaccharides, Fucoidans
Advances in Food and Nutrition Research, Volume 64, 2011, Pages 163-178 .
6. Samarakoon K., Jeon Y.J. Bio-functionalities of proteins derived from marine algae—A review. Food Res. Int. 2012;48:948–960. doi: 10.1016/j.foodres.2012.03.013.
7. A. Jiménez-Escrig, E. Gómez-Ordóñez, P. Rupérez. Chapter 26 – Seaweed as a Source of Novel Nutraceuticals: Sulfated Polysaccharides and Peptides
Advances in Food and Nutrition Research, Volume 64, 2011, Pages 325-337.
8. Mohamed S., Hashim S.N., Rahman H.A., 2012, Seaweeds: a sustainable functional food for complementary and alternative therapy, Trends Food Sci.Tech.
9. Soňa Škrovánková. Chapter 28 – Seaweed Vitamins as Nutraceuticals Advances in Food and Nutrition Research, Volume 64, 2011, Pages 357-369
10. Barrow, Colins James. (2007). Nutraceutical Science and Technology, Volume 7 : Marine Nutraceuticals and Functional Foods. Boca Raton: CRC Press.P.
11. Paliyath, G., Bakovic, M., Shetty, K., & ebrary, I. (2011). Functional foods, nutraceuticals, and degenerative disease prevention. Chichester, West Sussex, UK ; Ames, Iowa: Blackwell.
12. Venugopal, V. 1., & ebrary, I. (2009). Marine products for healthcare: Functional and bioactive nutraceutical compounds from the ocean. Boca Raton: CRC Press/Taylor & Francis.