*1.1.1 Brown seaweeds*

Brown algae also known as phaeophyta are the seaweeds mainly grow in cold waters at Northern Hemisphere. Marine is their main habitat and it plays a great role in their properties. Macrocystic is a kelp which grows underwater forests and may extend 60 m (200 ft) in length and has high level of biodiversity [14, 15]. Sargassum, another brown algae is an example of singular floating mats of seaweed in tropical waters. Many other brown algae grow along rocky shores and they have been used as food by humans since 2000 years [14].

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*Major Natural Vegetation in Coastal and Marine Wetlands: Edible Seaweeds*

Brown algae is a great source of iodine and is the most commonly used alginates. They have thickening property, which is greatly used in food products such as salad dressings, in oil industry for oil-drilling muds and in coatings. The color of brown algae is from green and yellow pigments coming from xanthophyll and chlorophyll, respectively. The ranges of colors in brown algae species are due to the variable blending of these two pigments [13, 16, 17]. Some example of brown seaweeds are

Red algae are also classified as phylum Rhodophyta. They are the most abundant and commercial value of sea algae. The term Rhodophyta refers to the algae group with red pigments due to phycoerythrin and phycocyanin. These pigments mask chlorophyll a, which do not contain chlorophyll b, β-carotene and a number of

Red algae are found on rocky shores. Some species are much deeper than brown or green algae. It is known that there are 550 species of red seaweed in the world and so they are the largest seaweed group [13, 17]. Two of them are shown in **Figure 2**. For example, a total of 128 varieties of red algae had been recorded in Red Sea so far [13, 16]. The main reserves in red seaweeds are typically floridean starch, and floridoside. The walls of these algae are made of cellulose and agar and carrageenans, both of which are long chained polysaccharides. Cellulose, agar and carrageenans are widely used commercially and have a large number of uses. Some red algae cells are different because, they are not good enough in amoeboidly, but none of the

The green algae are classified in the phylum Chlorophyta and are usually grown in the intertidal zone which has the high and low water marks, and in shallow water where there is plenty of sunlight. Due to the similarity of pigments, it is thought that they are the most closely related algae. Many types of green algae found on the surface of the ocean or near rocky surfaces. Some species of green seaweeds, *Halimeda macroloba*, *Ulva lactuca*, *Enteromorpha clathrata* and *Caulerpa trifara* are shown in **Figure 3** [13]. Approximately 140 species were recorded on the shores of the world. On the coast of Eritrea, there are about 50 species in the Red Sea.

Sea lettuce is one of the most widely known species. Green algae with bright green leaves up to 30 cm are called sea lettuce (*Ulva lactuca*). Green algae are deeply bound to the lower layers and are not usually cast by waves on the beach. Sometimes exceptionally, some green algae can tear through their substrate during storms and

Seaweed as a fundamental diet matter are known in Asia since prehistoric times. Some 21 species are used in daily cuisine in Japan and even six of them have been used since the eighth century. Kaiso, one of the edible seaweeds, accounted for 10% of the Japanese cuisine until recently. Using seaweeds in the kitchens extend an average of 3.5 kg per household in 1973, an increase of 20% over 10 years [19–22]. The 12 largest countries, using seaweeds in the kitchens in the world, are China, France, UK, Japan, Chile, Philippines, Korea, Indonesia, Norway, USA, Canada and Ireland. The seaweed production and the health of the sea algae is growing

*DOI: http://dx.doi.org/10.5772/intechopen.88303*

shown in **Figure 1**.

*1.1.2 Red seaweeds*

*1.1.3 Green seaweeds*

with heavy wave motion.

**1.2 Edible seaweeds**

unique xanthophylls [13, 18].

algae contain flagella, so none can swim quickly [13, 17].

**Figure 1.** *Some example of brown seaweeds [13].*

*Major Natural Vegetation in Coastal and Marine Wetlands: Edible Seaweeds DOI: http://dx.doi.org/10.5772/intechopen.88303*

Brown algae is a great source of iodine and is the most commonly used alginates. They have thickening property, which is greatly used in food products such as salad dressings, in oil industry for oil-drilling muds and in coatings. The color of brown algae is from green and yellow pigments coming from xanthophyll and chlorophyll, respectively. The ranges of colors in brown algae species are due to the variable blending of these two pigments [13, 16, 17]. Some example of brown seaweeds are shown in **Figure 1**.

### *1.1.2 Red seaweeds*

*Plant Communities and Their Environment*

of 1.4 kg seaweed per person consumption.

called pepsin [10, 12].

**1.1 Marine seaweeds**

*1.1.1 Brown seaweeds*

in different section in this review.

been used as food by humans since 2000 years [14].

macroalgae have higher biomass sells in comparison with seaweeds. Seaweeds are mostly cultivated in near shores in China, Philippines and Japan [7, 8]. The total aquatic production in 2004 passed 15.36 million tons while 93% of the contribution belonged to seaweeds. Among this, 6000 species of seaweeds are harvested which fall into three categories as, green (Chlorophytes), brown (Phaeophytes) and red (Rhodophytes). Regarding the abundancy, the human consumption is mainly on brown algae (66.5%), red algae (33%), and green algae (5%) in Asia [2, 9]. The main producers in Asia are focusing on specific algae such as, in China, Japan and Korea are Nori (Porphyra, red algae), Konbu (Laminaria, brown algae) and Wakame (Undaria, brown algae). Among 6000 species discovered about 150 species are known as food source and 100 for phycocolloid production. The total revenue for edible algae passed 1 billion US dollars only in Japan and this estimation is the value

Marine algae, in addition of being used in food, dairy, pharmaceutical, cosmetic and medicine industries, they can also be used in biodiesel, bioethanol, and hydrogen gases preparation. They can also be applied as antioxidant, antibiotics, and virostatic agents [10, 11] application of algae in food industry either for human or animal consumption has brought some negative perspectives due to some toxic elements such as cadmium or fucotoxins. The amount of toxin in algae is related to the contents of fiber and bioactive compounds present. This has direct impact on digestibility and application in food industry. Digestibility has connections mainly with the nitrogen consumption before and after digestion by using specific enzymes

Three main categories of marine seaweeds are Chlorophyta (green algae), Rhodophyta (red algae) and Phaeophyta (brown algae) [13]. Each class is explained

Brown algae also known as phaeophyta are the seaweeds mainly grow in cold waters at Northern Hemisphere. Marine is their main habitat and it plays a great role in their properties. Macrocystic is a kelp which grows underwater forests and may extend 60 m (200 ft) in length and has high level of biodiversity [14, 15]. Sargassum, another brown algae is an example of singular floating mats of seaweed in tropical waters. Many other brown algae grow along rocky shores and they have

**192**

**Figure 1.**

*Some example of brown seaweeds [13].*

Red algae are also classified as phylum Rhodophyta. They are the most abundant and commercial value of sea algae. The term Rhodophyta refers to the algae group with red pigments due to phycoerythrin and phycocyanin. These pigments mask chlorophyll a, which do not contain chlorophyll b, β-carotene and a number of unique xanthophylls [13, 18].

Red algae are found on rocky shores. Some species are much deeper than brown or green algae. It is known that there are 550 species of red seaweed in the world and so they are the largest seaweed group [13, 17]. Two of them are shown in **Figure 2**. For example, a total of 128 varieties of red algae had been recorded in Red Sea so far [13, 16]. The main reserves in red seaweeds are typically floridean starch, and floridoside. The walls of these algae are made of cellulose and agar and carrageenans, both of which are long chained polysaccharides. Cellulose, agar and carrageenans are widely used commercially and have a large number of uses. Some red algae cells are different because, they are not good enough in amoeboidly, but none of the algae contain flagella, so none can swim quickly [13, 17].

### *1.1.3 Green seaweeds*

The green algae are classified in the phylum Chlorophyta and are usually grown in the intertidal zone which has the high and low water marks, and in shallow water where there is plenty of sunlight. Due to the similarity of pigments, it is thought that they are the most closely related algae. Many types of green algae found on the surface of the ocean or near rocky surfaces. Some species of green seaweeds, *Halimeda macroloba*, *Ulva lactuca*, *Enteromorpha clathrata* and *Caulerpa trifara* are shown in **Figure 3** [13]. Approximately 140 species were recorded on the shores of the world. On the coast of Eritrea, there are about 50 species in the Red Sea.

Sea lettuce is one of the most widely known species. Green algae with bright green leaves up to 30 cm are called sea lettuce (*Ulva lactuca*). Green algae are deeply bound to the lower layers and are not usually cast by waves on the beach. Sometimes exceptionally, some green algae can tear through their substrate during storms and with heavy wave motion.

### **1.2 Edible seaweeds**

Seaweed as a fundamental diet matter are known in Asia since prehistoric times. Some 21 species are used in daily cuisine in Japan and even six of them have been used since the eighth century. Kaiso, one of the edible seaweeds, accounted for 10% of the Japanese cuisine until recently. Using seaweeds in the kitchens extend an average of 3.5 kg per household in 1973, an increase of 20% over 10 years [19–22]. The 12 largest countries, using seaweeds in the kitchens in the world, are China, France, UK, Japan, Chile, Philippines, Korea, Indonesia, Norway, USA, Canada and Ireland. The seaweed production and the health of the sea algae is growing

**Figure 2.** *Some species of red seaweeds [13].*

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*Major Natural Vegetation in Coastal and Marine Wetlands: Edible Seaweeds*

**Kelps Fucales Ectocarpales**

*canaliculata*)

*fusiforme*)

*echinocarpum*)

Arame (*Eisenia bicyclis*) Bladderwrack (*Fucus vesiculosus*) Mozuku (*Cladosiphon* 

Hijiki or Hiziki (*Sargassum* 

Thongweed (*Himanthalia elongata*)

*okamuranus*)

minerals and proteins and fatty acids but not great efforts have been allocated on the research of these plant like organisms [10, 25, 26]. Seaweeds are considered as source of soluble dietary fibers, proteins, minerals, vitamins, antioxidants, phytochemicals, and polyunsaturated fatty acids, with low caloric value. These nutrient factors are directly influenced by external environmental factors such as geographic location, temperature and season [27, 28]. Although their main application is gelling agent, thickened and stabilizers in food industries but currently studies are focused on medicinal usage and their anticancer, diabetes, inflammation, obesity and other ailments treatments [27]. Edible seaweeds are fundamental part of the cuisine for people living by the seas in areas such as Asia, Hawaii, South America and Africa, as well as marine products obtained from the sea, which are the source of protein from the sea, and in recent years a focus of interest in Europe and America due to the increasing interest in healthy nutrition. Edible seaweeds are a very good source of vitamins such as A, B1, B2, B6, B12, niacin and C and also rich in iodine, potassium, iron, magnesium and calcium. They are nutritious as a component in food [4, 13, 21, 22, 29–32].

*The list of the common edible Brown algae types (Kelps, Fucales and Ectocarpales).*

In addition to being source of food, seaweeds have antibacterial, antiviral and antifungal properties [2, 33]. In ancient researches, there are tracks of seaweed applications specially in 2500 years old Chinese literature [34, 35]. For instance, Japanese were using seaweed as one of the main ingredients in recipe for Nori in addition to raw fish and sticky rice. It is also well known in Europe and North America that seaweeds have therapeutic powers in treatment of tuberculosis, arthritis, colds and influenza. Very early discovery in 1990s, marine bacteria, invertebrates and algae were used in bioactive compounds [34, 36]. Major milestone in pharmaceutical industries during 1980–1995 was research on seaweed [34, 37]. The discoveries showed that many types of seaweed have anti-inflammatory and anti-microbial agents. These agents are able to be used in treatment of wounds, burns and rashes and some evidences have suggested the algae have been used in

treatment of breast cancer in ancient Egypt [38, 39].

*DOI: http://dx.doi.org/10.5772/intechopen.88303*

Cochayuyo (*Durvillaea* 

Sea palm (*Postelsia palmaeformis*)

luetkeana*)*

*latissima*)

**Table 1.**

Sea whip (Nereocystis

Sugar kelp (*Saccharina* 

Wakame (*Undaria pinnatifida*) Hiromi (*Undaria undarioides*)

*antarctica*)

Badderlocks (*Alaria esculenta*) Channelled wrack (*Pelvetia* 

*Ecklonia cava* Limu Kala (*Sargassum* 

Oarweed (*Laminaria digitata*) Spiral wrack (*Fucus spiralis*)

Kombu (*Saccharina japonica*) *Sargassum*

**Figure 3.** *Some species of green seaweeds [13].*

increasingly important, the world seaweed production in 2000, including wild and softened, has reached about 10 million tons [21, 22].

As it was mentioned above, seaweeds are categorized into three classes of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) marine macroalgae. Some reported common edible Brown algae (Phaeophycae) are divided as Kelp, Fucales and Ectocarpales, given in **Table 1** [23]. Common edible Red algae (Rhodophyta) are Carola (*Callophyllis* spp.), Carrageen moss (*Mastocarpus stellatus*), Dulse (*Palmaria palmata*), *Eucheuma* (*Eucheuma spinosum* and *Eucheuma cottonii*), Gelidiella (*Gelidiella acerosa*), Ogonori (*Gracilaria*), Grapestone *Mastocarpus papillatus*, *Hypnea*, Irish moss (*Chondrus crispus*), Laverbread (*Porphyra laciniata*/*Porphyra umbilicalis*), Gim (*Pyropia*, *Porphyra*) and Nori (*Porphyra*) [23]. Common edible Green algaes are Chlorella (*Chlorella* sp.), Gutweed (*Ulva intestinalis*), Sea grapes or *green caviar* (*Caulerpa lentillifera*), Sea lettuce (*Ulva* spp.) [23].
