Spirulina (Blue Green Algae) A Protein Treasure (70% of Protein)

Spirulina (Blue Green Algae) A Protein Treasure (70% of Protein)

 

Spirulina

Spirulina are multicellular and filamentous blue-green microalgae. Arthrospira platensis is the most common and widely available spirulina grows in water, can be harvested and processed easily and has significantly high macro- and micronutrient contents. It is used as human food as an important source of protein and is collected from natural water, dried and eaten.

        Spirulina is a primitive organism originating some 3.5 billion years ago that has established the ability to utilize carbon dioxide dissolved in seawater as a nutrient source for their reproduction. It is a photosynthesizing cyanophyte (blue-green algae) that grows vigorously in strong sunshine under high temperatures and highly alkaline conditions.

       In 1967 spirulina was established as a “wonderful future food source” in the International Association of Applied Microbiology (Sasson, 1997). Analysis of the nutritional properties of spirulina showed first and foremost an exceptionally high protein content, of the order of 60–70 percent of its dry weight; it also showed the excellent quality of its proteins (balanced essential amino acid content).

The spirulina Contains:

Protein: Spirulina contains unusually high amounts of protein, between 55 and 70 percent by dry weight, depending upon the source (Phang et al., 2000). It is a complete protein, containing all essential amino acids, though with reduced amounts of methionine, cystine, and lysine, as compared to standard proteins such as that from meat, eggs, or milk; it is, however, superior to all standard plant protein, such as that from legumes.

Essential fatty acids: Spirulina has a high amount of polyunsaturated fatty acids (PUFAs), 1.5–2.0 percent of 5–6 percent total lipid. In particular spirulina is rich in γ-linolenic acid (36 percent of total PUFAs), and also provides γ-linolenic acid (ALA), linoleic acid (LA, 36 percent of total ), stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (AA). Spirulina has high quality protein content (59–65 percent), which is more than other commonly used Plant sources such as dry soybeans (35 percent), peanuts (25 percent) or grains (8–10 percent). A special value of spirulina is that it is readily digested due to the absence of cellulose in its cell walls.

Vitamins: Spirulina contains vitamin B1 (thiamine), B2 (riboflavin), B3 (nicotinamide), B6 (pyridoxine), B9 (folic acid), B12 (cyanocobalamin), vitamin C, vitamin D and vitamin E.

β-carotene: Spirulina contains large amounts of natural β-carotene and this β-carotene is converted into vitamin A. According to the findings of the National Cancer Institute, United States of America, an intake of 6.0 mg β-carotene daily may be effective in minimizing the risk of cancer.

Minerals: Spirulina is a rich source of potassium, and also contains calcium, chromium, copper, iron, magnesium, manganese, phosphorus, selenium, sodium and zinc.

Amino acids: Spirulina protein has a balanced composition of amino acids, with concentrations of methionine, tryptophan and other amino acids (Lysine, Phenylalanine, Tyrosine, Leucine, Glutamic acid, Aspartic acid, Cystine, Serine, Arginine, Histidine, Threonine, Proline, Valine, Isoleucine, Alanine and Glycine ) almost similar to those of casein.

Applications of Spirulina

Immune system enhancement: The Academy of Chinese Military Medical Sciences showed that spirulina could effectively improve the survival rate of mice after exposure to a lethal dose of radiation, prolong their survival time, and improve their immunity and activity of superoxide dismutase (SOD). Proved to be effective in lowering blood lipid, combating fatigue and increasing the level of immunoglobulin A (IgA) and immunoglobulin M (IgM). Phycocyanin of Spirulina platensis inhibits the growth of human leukemia K562 cells when supplemented with diet (Liu et al., 2000).

Nutritional supplement: Spirulina is rich in high quality protein, vitamins, minerals and many biologically active substances (Becker, 1994). Its cell wall consists of polysaccharide which has a digestibility of 86 percent, and could be easily absorbed by the human body. Spirulina is well known to have a very high iron content, it was tested against a typical iron supplement, iron sulfate. Spirulina-fed rats absorbed 60 percent more iron that rats fed the iron supplement. This study suggested that there is a highly assimilable form of iron in spirulina. A study also showed that it was effective in correcting anaemia in rats. A study showed the blood hemoglobin content increased from 10.9 to 13.2 (±21 percent) for human (female), a satisfactory level no longer considered anaemic (Henrikson, 1989). Spirulina significantly reduced the blood glucose level of both male and female.

Food source: when the algal cells or filaments of spirulina are transformed into powder it can provide the basis for a variety of food products, such as soups, sauces, pasta, snack foods, instant drinks and other recipes. Spirulina can be used as a partial supplementation or complete replacement for protein in aquafeeds.

Use as fertilizer:  blue-green algae replacing chemical fertilizers and rebuilding the structure of depleted soils (FAO, 1981)

Protein supplement in poultry and livestock feeds:

Fishmeal, groundnut meal and soybean meal can be partially replaced by spirulina in the preparation of diets of fish, poultry, cattle and domestic animals (Venkataraman, Somasekaran and Becker, 1994; El- Sayed, 1994; Britz, 1996).

Colorant in food products:

The blue-green colour of spirulina is due to two pigments: phycocyanin (blue) and chlorophyll (green). These two pigments are combined with another group of pigments known as carotenoids (red, orange and yellow). This phycocyanin extracted from spirulina was first marketed in 1980 by the Dainippon Ink & Chemicals Inc. under the brand name “Lina Blue-A”. This was mainly used as a food colourant, as an edible dye in ice creams and as a natural dye in the cosmetics industry. However, as the pigment was light sensitive, special care must be taken in protecting it from bleaching (Vonshak, 1990).

 REFERENCES

    Banerjee, M. & Deb, M. 1996. Potential of fly ash and Spirulina combination as a slow release fertilizer for rice field. Cientifica Jaboticabal, 24: 55–62.

    Becker, E.W. 1988. Microalgae for human and animal consumption. In M.A. Borowitzka & L.

    Borowitzka, eds. Micro-algal Biotechnology, pp. 222–256. Cambridge, Cambridge University Press.

    Becker, E.W. 1994. Microalgae. In Nutrition. pp. 196–249. Cambridge, Cambridge University Press.

    Belay, A., Yoshimichi, O., Miyakawa, K. & Shimamatsu, H. 1993. Current knowledge on potential health benefits of Spirulina. J. Appl. Phycol., 5: 235–241.

    M. Ahsan, B. Habib, Mashuda Parvin, FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS, Rome, 2008. A review on culture, production and use of spirulina as food for human and feed for domestic animal and fish.