Seaweed
Varieties
Seaweed has no leaves, stems, or roots; the plant body of seaweed, which consists of nonvascular tissue, is referred to as the "thallus," a term derived from the Greek word thallos, meaning, "green shoot." These perennial or annual plants grow in warm, temperate or cold water. Their size and shape are determined by their habitat. The plants found in warm seas are grasses or bushes that rarely grow to heights of more than 30 centimetres, while seaweed that grows in colder waters is quite lush and can measure anywhere from 1 - 10 metres in length.
Like plants that grow on land, seaweed photosynthesises organic compounds by means of pigments such as chlorophyll. The texture and flavour of seaweed vary greatly from one species to another; for example, it can be rubbery, tender, or crisp. There are almost 25,000 different species of seaweed, only a very small number of which have a pleasant taste (between 40 - 50 species). These edible varieties belong to one of four groups - brown algae (Pheophyceae), green algae (Chlorophyceae), red algae (Rhodophyceae), and blue-green algae (Cyanophyceae).
Several species of seaweed are cultivated by placing spore-bearing shoots, plastic tubes, or ropes in temperature-controlled reservoirs of seawater, or in the sea itself. Each class of seaweed has particular characteristics.
Brown algae are the most abundant and most commonly used variety. It is brown in colour because yellow and brown pigments known as xanthophylls mask the green chlorophyll. The species of brown seaweed harvested in Japan include arame, hijiki, kombu, and wakame. Kelp is the most common variety of brown seaweed. Brown seaweed grows at moderate depths.
Other pigments do not mask the chlorophyll in green algae. Among the plants classified, as green algae are those comprising the Ulva and Caulerpa genuses. Certain species belonging to the Ulva genus are referred to as "sea lettuce," and Caulerpa algae are known as "sea grapes" due to their grapelike shape (they too taste like lettuce). Green seaweed grows to be 5 - 10 centimetres long and generally has a delicate taste and texture.
Red algae is coloured by a red pigment known as phycoerythrin, which masks the green chlorophyll. The numerous plants classified as red algae include the 30 species comprising the Porphyria genus, dulse (Palmaria palmata), and carrageen (Chondrus crispus). Galactose, a simple sugar found in red algae, combines with other monosaccharide's to form various viscous polysaccharides. These are extracted from several different species of seaweed to produce agar-agar and carrageen, substances used in the food industry as gelling, emulsifying, and stabilizing agents.
Blue-green algae are primitive microscopic plants that are sometimes classified as bacteria. These include spirulina, which is often consumed as a nutritional supplement.
The proteins in seaweed are comprised of a better balance of amino acids than those found in plants that grow on gut are not as well balanced as animal proteins. Most varieties of seaweed are deficient only in sulphuric amino acids.
Carbohydrates are a major component of seaweed, usually comprising from 40% to 60% of their total weight. Most of carbohydrates are complex organic compounds; in fact, only 5°% to 10% of them are simple sugars. Relatively little research has been done on the digestibility of the carbohydrates found in seaweed, but they are known to be quite difficult to digest, which means that seaweed is not very fattening. However, it appears that when people eat seaweed on a regular basis, their digestive systems develop enzymes that are better able to assimilate the polysaccharides.
Seaweed is low in fat and calories. It is an excellent source of minerals (which comprise approximately 5% to 10% of the total weight of dried seaweed), especially calcium and iodine. It also contains significant quantities of several vitamins, including vitamin A (in the form of beta-carotene), certain B-complex vitamins (especially thiamine, riboflavin and niacin), and vitamin C.
Seaweed is thought to have numerous medicinal properties, The ailments seaweed is reputed to alleviate or cure include arteriosclerosis, hypertension, obesity, constipation, hyperthyroidism, tumours, bacterial infections and intestinal worms. Unfortunately, much research remains to be done concerning the actual impact of seaweed on some of these conditions. Therapies involving seawater and seaweed baths make use of the medicinal properties of seaweed, as do certain pharmacological preparations. The medications containing seaweed include anticoagulants, vermifuges and drugs used to treat high blood pressure.
Dried seaweed can be rehydrated or eaten as is as a snack. Seaweed can be used in a variety of ways. It is used as a food additive, fertilizer, and fodder, as well as to develop photographs and to make glue, paper, rubber, cement, paint, fabric, gunpowder, glass, toothpaste and cosmetics.
Like plants that grow on land, seaweed photosynthesises organic compounds by means of pigments such as chlorophyll. The texture and flavour of seaweed vary greatly from one species to another; for example, it can be rubbery, tender, or crisp. There are almost 25,000 different species of seaweed, only a very small number of which have a pleasant taste (between 40 - 50 species). These edible varieties belong to one of four groups - brown algae (Pheophyceae), green algae (Chlorophyceae), red algae (Rhodophyceae), and blue-green algae (Cyanophyceae).
Several species of seaweed are cultivated by placing spore-bearing shoots, plastic tubes, or ropes in temperature-controlled reservoirs of seawater, or in the sea itself. Each class of seaweed has particular characteristics.
Brown algae are the most abundant and most commonly used variety. It is brown in colour because yellow and brown pigments known as xanthophylls mask the green chlorophyll. The species of brown seaweed harvested in Japan include arame, hijiki, kombu, and wakame. Kelp is the most common variety of brown seaweed. Brown seaweed grows at moderate depths.
Other pigments do not mask the chlorophyll in green algae. Among the plants classified, as green algae are those comprising the Ulva and Caulerpa genuses. Certain species belonging to the Ulva genus are referred to as "sea lettuce," and Caulerpa algae are known as "sea grapes" due to their grapelike shape (they too taste like lettuce). Green seaweed grows to be 5 - 10 centimetres long and generally has a delicate taste and texture.
Red algae is coloured by a red pigment known as phycoerythrin, which masks the green chlorophyll. The numerous plants classified as red algae include the 30 species comprising the Porphyria genus, dulse (Palmaria palmata), and carrageen (Chondrus crispus). Galactose, a simple sugar found in red algae, combines with other monosaccharide's to form various viscous polysaccharides. These are extracted from several different species of seaweed to produce agar-agar and carrageen, substances used in the food industry as gelling, emulsifying, and stabilizing agents.
Blue-green algae are primitive microscopic plants that are sometimes classified as bacteria. These include spirulina, which is often consumed as a nutritional supplement.
History
Plants that grow in, or near, salt water or fresh water, seaweed has been eaten since ancient times in certain parts of the world, mainly by the inhabitants of coastal regions in north-western Europe (Scotland, Ireland, Norway, Iceland), Hawaii, South America, the Pacific islands, New Zealand, and Asia (especially in Japan, China, and Korea). Archaeological evidence found in Japan suggests that seaweed has been part of the human diet for at least 10,000 years. The Japanese eat more seaweed per capita than people of any other nationality, and Japan is the world's leading producer and exporter of seaweed; this explains why individual varieties of seaweed are often referred to by their Japanese names (kombu, wakame, hijiki, arame, etc.)Nutritional Value
The nutritional value of seaweed depends on the species, as well as on where it is grown and when it is harvested. Spirulina is exceptionally rich in protein: 100 grams of dried spirulina contains 54 to 65g of protein.The proteins in seaweed are comprised of a better balance of amino acids than those found in plants that grow on gut are not as well balanced as animal proteins. Most varieties of seaweed are deficient only in sulphuric amino acids.
Carbohydrates are a major component of seaweed, usually comprising from 40% to 60% of their total weight. Most of carbohydrates are complex organic compounds; in fact, only 5°% to 10% of them are simple sugars. Relatively little research has been done on the digestibility of the carbohydrates found in seaweed, but they are known to be quite difficult to digest, which means that seaweed is not very fattening. However, it appears that when people eat seaweed on a regular basis, their digestive systems develop enzymes that are better able to assimilate the polysaccharides.
Seaweed is low in fat and calories. It is an excellent source of minerals (which comprise approximately 5% to 10% of the total weight of dried seaweed), especially calcium and iodine. It also contains significant quantities of several vitamins, including vitamin A (in the form of beta-carotene), certain B-complex vitamins (especially thiamine, riboflavin and niacin), and vitamin C.
Seaweed is thought to have numerous medicinal properties, The ailments seaweed is reputed to alleviate or cure include arteriosclerosis, hypertension, obesity, constipation, hyperthyroidism, tumours, bacterial infections and intestinal worms. Unfortunately, much research remains to be done concerning the actual impact of seaweed on some of these conditions. Therapies involving seawater and seaweed baths make use of the medicinal properties of seaweed, as do certain pharmacological preparations. The medications containing seaweed include anticoagulants, vermifuges and drugs used to treat high blood pressure.
Buying
Fresh seaweed should be dark and richly coloured, not pale or discoloured. Dried or fresh seaweed is available in health-food stores.Storage
Most varieties of fresh seaweed can be refrigerated for a few days. Store dehydrated seaweed in a tightly sealed container (such as a glass jar) in a cool, dry, dark place. Cooked seaweed should be refrigerated, and most varieties of seaweed can be frozen, with the notable exception of kelp.Preparing
Seaweed should be washed before it is used because it often contains sand and small shells. Dried seaweed is almost always soaked before it is eaten or cooked (for 5 - 60 minutes or longer). The water in which it is soaked can be used to make broths or sauces and to cook pasta or grains.Cooking
Seaweed can be eaten either hot or cold and is used as a seasoning, garnish, or nutritional supplement (as a powder or flakes, or in capsules or tablets). Prepared in a variety of ways, it can be boiled, roasted, steamed, fried, sauteed, or marinated in vinegar or tamari.Using
It can be served as an appetizer, a vegetable side dish, or a dessert, and can also be used to make tea. It is often added to hors d'oeuvres, soups, salads, and pasta dishes. Sea lettuce is a common ingredient in salads and soups.Dried seaweed can be rehydrated or eaten as is as a snack. Seaweed can be used in a variety of ways. It is used as a food additive, fertilizer, and fodder, as well as to develop photographs and to make glue, paper, rubber, cement, paint, fabric, gunpowder, glass, toothpaste and cosmetics.
