Prof.Shorog Alotaiby
School of Food Science and Nutrition, University of Leeds, UK Department of Chemistry, College of Science, Princess Nourah Bint Abdul Rahman University,84428 Riyadh, Saudi Arabia
Title: Extraction, isolation, purification, and characterization of bioactive pigments from spirulina and evaluation of their pro and antioxidant activity.
Biography
Biography: Prof.Shorog Alotaiby
Abstract
Spirulina is a type of blue-green algae of the genus Arthrospira that grows in tropical and subtropical regions. Spirulina has been used in developing regions of the world as a food source for centuries and in 1974 the United Nations classified spirulina as “one of the best foods of the future”. Nowadays spirulina is grown all over the world for its nutritional properties, moreover spirulina has gained wide commercial interest as a dietary supplement due to its richness in minerals, vitamins, proteins, and its high content of photosynthetic pigments. Our approach allows the isolation of these pigments on the gram scale per 100g of from the source of Spirulina based on their water solubility in two successive steps and using synergy system between freezing - thawing -Ultrasonication as a green extraction technique. First the phycocyanin is extracted, followed by the extraction of chlorophyll and carotenoids. Evaluation of the crude chlorophylls extract revealed chlorophyll a as dominant pigment compared to chlorophyll b. This extract was purified chromatographically, the various pigments were obtained whose purity was investigated by HPLC, these pigments are as follows: β-carotene (87%) pheophorbide a (96.79%) of pheophytin a (95.89%) and lutein (72.26%). For the crude phycocyanin extract, a single step for precipitation using (NH4)2SO4 was performed as isolation and purification strategy. The antioxidant capacity of the pigments was evaluated using various assays such as radical scavenging activity (DPPH), iron-reducing antioxidant (FRAP) and Trolox equivalent antioxidant capacity (TEAC). Comparative analysis of in vitro radical scavenging properties showed that chlorophyll derivatives gave the highest radical scavenging ability, while phycocyanin gave the lowest radical scavenging ability. The pro-oxidant capacity of dyes was evaluated under visible light illumination conditions, chlorophyll derivatives but not phycocyanin, were able to produce singlet oxygen.