Have you ever wondered what spacemen eat when they go on day- and week-long expeditions beyond the skies? What do the inhabitants aboard the International Space Station munch on to stay fit in zero-gravity? The answer is 'magical blue-green algae.' Commonly known as spirulina, the blue-green micro algae is one of the most nutrient-rich foods. The biomass of cynobacteria has been here before humans and dinosaurs and is one of the oldest life forms on earth.
Nutritionists suggest the blue-green algae, which are storehouses of omega-3 fatty acids, are effective food supplement for astronauts. Other members of the algae family are also of prime importance in a healthy diet plan, according to nutritionists.
The green plants on earth are mainly divided into algae, bryophytes, pteridophytes, gymnosperms and angiosperms. Algae constitute the plant world in the water bodies which is present on two-thirds of the earth. Unlike the plants which grow on land, algae do not have the transport tissues like xylem and phloem in their bodies. Algae lack the various structures that characterise the land plants like the root, leaves, stem and other organs. From microorganisms that are invisible to the naked eye to vastly spread green carpet on the ocean bed, algae are found in diverse forms.
Importance of algae
Algae or seaweed are photosynthetic organisms that provide food for the various species of aquatic life. The food chain of the aquatic life mostly begins at the different varieties of algae. About 30% -50% of the oxygen content in the water bodies which sustains the aquatic life is in fact exhaled by the algae. The crude oil and the natural gas which are widely extracted today are also formed from the algae that have been turned into fossils at the bottom of the ocean.
Countries like Japan, China and Korea are known for the large-scale production of seaweed for consumption. Almost 70 varieties of alga, including porphyra, ulva, laminaria, undaria and sargassum, are edible. Corella which has 53 -65% fat content is widely used as a food supplement.
Algae in food items
The phycocolloids like alginates, carrageenan and agar, which are extracted from the cells of ocean algae or seaweed, are commonly used in cakes, dairy products, ice creams, syrups, candy bars, tinned food, cosmetic products, medicines etc. The nitrogen and mineral rich seaweed is also used by farmers as an excellent fertilizer.
Some algae are rich source of omega-3 fatty acid, which helps the growth and development of the brain cells and protects the human body from the free radicals. Though we depend on fishes like salmon, sardines, mackerel and tuna for our daily dose of omega-3 fatty acids, the rapid decline in the fish population has prompted the scientists to turn to algae like crypthecodinium, ulkenia and schizochytrium for the steady supply of omega-3 fatty acids.
Cooking oil from algae
Studies have revealed that high-quality cooking oil can be made from algae as well. Some micro-algae contain unsaturated oil. The industrial production of such seaweed can be done even on lands that are generally unfit for cultivation. About 35% of the dry weight of these algae constitutes oil, fats and other minerals.
(With inputs from Sreerangam Jayakumar)
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