| Spirulina is considered a traditional food in the Mexican and African cultures. It is a planktonic blue-green algae (from Cyanobacterium gender) found in alkaline water of volcanic lakes. Spirulina has a 62% amino acid content being the world’s richest natural source of vitamin B12, it also contains a whole spectrum of natural mixed carotene and xanthophyll phytopigments. Spirulina has a soft cell wall made of complex sugars and proteins. Actually it is gaining more attention because of its nutritional and various medicinal properties.
The use of Spirulina’s pigments as colorants has been explored by the pharmaceutical and food industries mainly because the new world trends towards the substitution of synthetic colorants by natural ones. The first experimental plant for S. platensis production was developed during the 60’s in the Institut Francaise du Peetrole. Nowadays, Japan and United States of America have industrial scale production and more than 40 kind of products derived from this algae are available on the market.
Supercritical fluid extraction (SFE) is a well-recognized alternative to conventional solvent-based extraction techniques. SFE has the main advantages of being environmentally benign and available as fully automated systems. CO2 has been the most used supercritical solvent, because the compounds can be obtained without contamination by toxic organic solvents and without thermal degradation, and it requires mild conditions to become a supercritical fluid. Nevertheless, due to its poor solvating power sometimes is necessary the use of polar modifiers. In the present work, ethanol was selected as modifier due to its GRAS (Generally Recognized As Safe) character that makes it suitable to be used for food ingredients production.
Possibilities of extracting antioxidant compounds from Spirulina platensis by using an environmentally friendly process (such SFE) are reported. Several extracting conditions were evaluated via an experimental design and the extracts obtained were chemically and functionally characterized using LC-DAD and ß-carotene bleaching test, respectively. Results obtained demonstrated the interest of the SFE as a clean technique to selectively isolate different type of compounds, with different activities, from natural sources such microalgae.
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