Chemical characterization and nutritional value of Spirulina platensis cultivated in natural conditions of Chichaoua region (Morocco)

Abstract The aim of the current study was to characterize the phytochemical, phytopigments, and nutritional value of Spirulina platensis produced in Chichoua region of Morocco. A natural medium based on well water-wood ash is used instead of an artificial Zarrouk medium. Several analyses including phytochemical screening and antioxidant activity (DPPH and ABTS) were performed in extracts (methanol, ethanol and acetone) of S. platensis. The phytopigments were analyzed by measuring chlorophylls a and b, carotenoids, and phycobiliproteins. The nutritional composition was evaluated through dry matter, lipids, carbohydrates, crude protein, acidic detergent lignin, neutral detergent fiber, acidic detergent fiber, minerals, and vitamins. The methanolic extract showed the highest phenolic contents (7.00±0.07 mg GAEs/g), flavonoids (1.00±0.011 mg QEs/g), and ABTS•+ free radical scavenging activity (38.35±1.68%). Spirulina platensis produced in the well water-wood ash medium is rich in crude proteins (53.29%), c-phycocyanins (18.25±1.81%), and minerals. It also contains a high vitamin concentrations such as pantothenic acid (B5), niacin (B3), riboflavin (B2), and folic acid (B9). The results confirmed that the cultivation of S. platensis under natural conditions, using well water-wood ash medium increases the amounts of some minerals, c-phycocyanin, and water-soluble vitamins. Furthermore, this medium can be profitable for large-scale mass production of S. platensis with yields similar to that obtained from Zarrouk medium.