Sea vegetable

Edible seaweed are algae that can be eaten and used in the preparation of food. They typically contain high amounts of fiber and are a complete protein. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae.

Seaweeds are also harvested or cultivated for the extraction of alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.

Most edible seaweeds are marine algae whereas most freshwater algae are toxic. Some marine algae contain acids that irritate the digestion canal, while some others can have a laxative and electrolyte-balancing effect.

The dish often served in western Chinese restaurants as 'Crispy Seaweed' is not seaweed but cabbage that has been dried and then fried.

Seaweeds are used extensively as food in coastal cuisines around the world. Seaweed has been a part of diets in China, Japan, and Korea since prehistoric times. Seaweed is also consumed in many traditional European societies, in Iceland and western Norway, the Atlantic coast of France, northern and western Ireland, Wales and some coastal parts of South West England, as well as Nova Scotia and Newfoundland. The Māori people of New Zealand traditionally used a few species of red and green seaweed.

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Wikipedia