Spirulina is a microscopic, multicellular, filamentous blue-green alga (cyanobacterium). It is nature’s richest and complete source of organic nutrition. The chemical composition of Spirulina reflects its potential as human food, animal feed and as a source of vitamin B-12, vitamin-E, Beta-carotene (provitamin A), antioxidants, Gamma Linoleic Acid (GLA), chlorophyll, biochelated organic iron and complete high biological value protein (65-75%).
The important types of Spirulina commercially available are S.platensis, S.fusiformis and S.maxima.
Spirulina can grow rapidly, reaching high filament densitities in warm, shallow, brackish lakes, marshes, sea water and fresh water. It is capable of adaptation to very different habitats and colonizes certain environments in which life for other microorganisms is very difficult.
Uses of Spirulina:
*Veterinary: Protein supplement in feeds for poultry, cattle, pig, silkworm, fish, shrimps and prawns.
*Industry: The
algal powder as unique ingredient in recipes and products and used in fermented foods. Used as food coloring agent, in drugs and cosmetics, in dyeing industry.
*Agriculture: Used as an antiviral agent against the silkworm Nuclear Polyhedrosis Virus (NPV)
Spirulina is available in powder form capsule form, tablet form, flakes and as broth.
Spirulina Production:
High alkalinity is mandatory (pH8.3-11.0). Temperature to be maintained between 25C and above 35C.Enough lighting is essential.
Continuous agitation and aeration is not recommended and the temperature should not be let below 20C and above 40C.
A major difficulty in developing commercial micro-algal production is the process of
harvesting the
biomass and concentrating it. The difficulty in harvesting is to some extent alleviated with Spirulina, since its filaments are long enough to be removed from the growth medium by filtration. In some production plants today, a vibrating screen is used for harvesting Spirulina biomass. This machine however causes some cell damage due to bruising of the delicate cells. It should be stressed that when the harvesting process is accompanied by even a relatively small amount of cell breakage, the returning flow is sufficiently enriched in organic matter to provide an advantage to myxotrophic or heterotrophic competitors. Thus, the best mode of harvesting the algal biomass should meet two criteria: all the biomass should be removed from the harvested volume and no cell breakage should take place. Such a harvesting system is not yet available to the Spirulina industry.
In commercial Spirulina production,
drying poses a problem, of major economic importance, in that it may constitute about 30% of the production cost. The various systems for drying differ both in the extent of capital investments, and have a marked effect on the food value and the taste of the product. Experience with Spirulina production is that the harvested slurry should be well rinsed in acid water at pH4.0 to remove the adsorbed carbonates. It can then be stored at 0 to 2C for several days, or frozen to -18C for an indefinite time. The usual method for drying of Spirulina is spray-drying, which yields a very good product from which pills may readily be formed. Direct drying of the Spirulina slurry in the
sun is also feasible. Sun drying is not recommended for preparing an algal product intended for human consumption for two reasons:
(1)A rather unpleasant odor is associated with sun-drying due to the slowness of the dehydration process, which enables degradation processes to set in before drying complete.
(2) Sun-drying does not include exposure to high heat (up to 120C for a few seconds as in drum drying) and may thus exhibit a higher bacterial count.
More abstracts about the Spirulina