19 Nov Nutritional Advantages
Spirulina is a real food although it is used today in the Western World as a dietary complement.
Extensive analyses and nutritional studies have demonstrated that this microalga expresses a number of features of particular interest from the nutritional standpoint such as a balanced protein composition, and the presence of rare essential lipids, a variety of nutritional minerals and vitamins.
For the estimation of nutritional benefits of Spirulina protein two important nutritional values were determined: The Net Protein Utilisation (NPU) and the Protein Efficiency Ratio (PER).
Protein utilization is determined experimentally by calculating the percentage of nitrogen retained, when the source of proteins under study is the only limiting nutritional factor.
On the other hand, PER is the weight gain of an individual (usually an experimental animal), divided by the weight of proteins ingested using as reference proteins lactalbumin or casein.
Since Spirulina cells do not have cellulose walls, as in the case of plant cells, but a relatively fragile envelope of murein, its proteins show very high digestibility (83-90 per cent as against 95.1 per cent for pure casein.
So, Spirulina does not require cooking to increase the availability of its proteins.
The NPU value of Spirulina is estimated between 53-61 or 85-92 per cent of that of casein.
On the other hand the PER value determined in experimental animals is estimated between 1.8-2.6 as against a PER value of 2.5 for pure casein and PER values of 1.23, 2.2 and 1.15 for maize, rice and wheat respectively (**13, **15).
Spirulina has a very low fat content which is lower than almost all other protein sources. One gram has only 3.6 calories and virtually no cholesterol (0.13 mg).
In contrast, a large egg yields about 300 mg of cholesterol and 80 calories, while providing only the same amount of protein as the tablespoon of spirulina.
Thus, spirulina is a low-fat, low-calorie, cholesterol-free source of protein.
The United Nations World Health Organization (WHO) has confirmed that “Spirulina represents an interesting food for multiple reasons” (**15), while the Food and Drug Administration (FDA) of USA has categorized several Arthrospira dried biomass products as “generally recognized as safe” (GRAS) for human consumption (FDA GRAS Notice No.GRN 000127).
(**) Literature on the subject