Introduction: In modern days, there have been numerous applications of microalgae: from human and animal nutrition to cosmetics and the production of highly valuable molecules (e.g., fatty acids, pigments, proteins, etc.). Spirulina and Chlorella algal meals are traditionally consumed in China, Japan, India, America and Africa South. Scientific studies suggest that one tea spoon of microalgae dry powder daily promotes weight loss, lowers serum cholesterol and glucose levels, helps boosting the immune system etc. Microalgae are characterized by high protein and low lipid content. Nevertheless, algal lipids are comprised of large amounts of essential unsaturated fatty acids. The aim of the present study is to analyse total lipids and lipid classes, unsaturated fatty acids and cholesterol content in two commercial microalgae dietary products from the Bulgarian market.
Materials and methods: Total lipids were extracted according to the Bligh and Dyer method. They were separated into neutral lipids, glycolipids and phospholipids by means of solid-phase extraction and thin-layer chromatography. Lipid classes were transmethylated and subjected to gas chromatography coupled with mass spectrometry. Cholesterol was analysed by high-performance liquid chromatography after alkaline saponification with methanolic potassium hydroxide. Ultraviolet detector was used for cholesterol detection.
Results: Total lipids accounted: 3.8 g per 100 g dry Spirulina powder and 5.1 g per 100 g Chlorella powder. Glycolipids were the main lipid class in Spirulina, while lipids in Chlorella were represented predominantly by neutral lipids. In both species polyunsaturated fatty acid presented 50% of total lipids.
Conclusions: The presented results showed that Spirulina and Chlorella powders produced in Bulgaria contain high amounts of unsaturated fatty acids and low cholesterol levels which could confirm the high nutritional value of both microalgal species.
