The algae constitute a large group of‘primitive’ plants – they do not reproduce by seeds as in most medicinal and food plants but rather by spores, and the plant body is not divided into root, stem, and leaf, but is in the form of a relatively undifferentiated ‘thallus’. They are mainly aquatic, being found in freshwater ponds,rivers, and lakes, and are the seaweeds found on shores all over the world.
Total seaweed usage alone amounts to about 3.5 million tons per year. In Western countries seaweeds are harvested from their natural habitats, but in Asia there is quite a good deal of planned cultivation (e.g. see Porphyra below). Although microscopic algae (Chlorella and Spirulina)may be harvested naturally, today they are usually cultivated commercially....
Algae are classified according to their pigments. All algae contain the green
pigment chlorophyll; the group known as the green algae contains only chlorophyll,but other groups have pigments in addition to chlorophyll. In the brown algae(seaweeds) the additional pigment is fucoxanthin.
In the red algae (seaweeds) it is phycoerythrin (red) and phycocyanin (blue)the relative quantities vary, so different species vary in colour from red to bluish green; in the blue-green algae the only extra pigment is phycocyanin. There is also great variation in size between species of the algae. Some are microscopic (unicellular and filamentous), whereas some seaweeds attain a length of 50 m (165 ft).
A microscopic, fresh-water alga found as corkscrew-like filaments. In the sixteenth century Spanish explorers found Aztecs harvesting a ‘blue mud’, probably consisting
of Spirulina, from Lake Texaco (Mexico). This was dried and turned into chips and loaves. Similarly, the alga has been collected by local people from Lake Chad (Africa).
Spirulina is still harvested from freshwater sources, but it is also cultured commercially in California, Thailand, India, and China. Presumably, it should be easier to produce a purer harvest from cultured material, rather than a natural source where other algae might be present.
The commercial product (the alga has been dried) contains:
(a) 60–70% protein with a good amino acid profile;
(b) 16–20% carbohydrate;
(c) 2–3% fat;
(d) 7–9% water;
(e) 5–8% minerals, including iron, calcium, and many others;
(f) vitamins: beta-carotene (provitamin A) and some of the B complex, including, as reported, B12, E, and K.
The ironpresent is easily absorbed by humans, which is not always the case with iron from other plant sources. Vitamin B12is not normally found in plant foods, only animal sources – a possible problem for vegetarians and vegans. However, as with
Chlorella and seaweeds, there is considerable doubt about the nutritional significance of B12recorded for Spirulina. Spirulina presents a good nutritional profile, but it is far more expensive than some animal foods (e.g. meat, milk),
which may not worry vegetarians.
Chlorella (a green alga)A microscopic unicellular alga, up to about 10 µm (1 µm = 0.001 mm) in diameter. In many other respects it is similarto Spirulina. Commercial cultivation takes place, and its nutritional profile is roughly the same. Both Spirulina and Chlorella are available as tablets in health food shops.
Total seaweed usage alone amounts to about 3.5 million tons per year. In Western countries seaweeds are harvested from their natural habitats, but in Asia there is quite a good deal of planned cultivation (e.g. see Porphyra below). Although microscopic algae (Chlorella and Spirulina)may be harvested naturally, today they are usually cultivated commercially....Algae are classified according to their pigments. All algae contain the green
pigment chlorophyll; the group known as the green algae contains only chlorophyll,but other groups have pigments in addition to chlorophyll. In the brown algae(seaweeds) the additional pigment is fucoxanthin.
In the red algae (seaweeds) it is phycoerythrin (red) and phycocyanin (blue)the relative quantities vary, so different species vary in colour from red to bluish green; in the blue-green algae the only extra pigment is phycocyanin. There is also great variation in size between species of the algae. Some are microscopic (unicellular and filamentous), whereas some seaweeds attain a length of 50 m (165 ft).
A microscopic, fresh-water alga found as corkscrew-like filaments. In the sixteenth century Spanish explorers found Aztecs harvesting a ‘blue mud’, probably consisting
of Spirulina, from Lake Texaco (Mexico). This was dried and turned into chips and loaves. Similarly, the alga has been collected by local people from Lake Chad (Africa).
Spirulina is still harvested from freshwater sources, but it is also cultured commercially in California, Thailand, India, and China. Presumably, it should be easier to produce a purer harvest from cultured material, rather than a natural source where other algae might be present.
The commercial product (the alga has been dried) contains:
(a) 60–70% protein with a good amino acid profile;
(b) 16–20% carbohydrate;
(c) 2–3% fat;
(d) 7–9% water;
(e) 5–8% minerals, including iron, calcium, and many others;
(f) vitamins: beta-carotene (provitamin A) and some of the B complex, including, as reported, B12, E, and K.
The ironpresent is easily absorbed by humans, which is not always the case with iron from other plant sources. Vitamin B12is not normally found in plant foods, only animal sources – a possible problem for vegetarians and vegans. However, as with
Chlorella and seaweeds, there is considerable doubt about the nutritional significance of B12recorded for Spirulina. Spirulina presents a good nutritional profile, but it is far more expensive than some animal foods (e.g. meat, milk),
which may not worry vegetarians.
Chlorella (a green alga)A microscopic unicellular alga, up to about 10 µm (1 µm = 0.001 mm) in diameter. In many other respects it is similarto Spirulina. Commercial cultivation takes place, and its nutritional profile is roughly the same. Both Spirulina and Chlorella are available as tablets in health food shops.
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