LAUSR

The present study investigated the biochemical composition of three seaweeds; Ulva fasciata (Chlorophyta), Sargassum linifolium (Phaeophyta) and Corallina officinalis (Rhodophyta). Total chlorophyll content was maximum in U. fasciata (34.06mg/g dry wt.) while carotenoid content was the highest in C. officinalis (3.8 mg/g dry wt.). The uppermost level of carbohydrates was (27.98% of dry wt.) in C. officinalis and proteins were maximum (14.89%) in S. linifolium. Aspartic, glutamic, alanine, leucine and proline were common amino acids in the three tested species. The polyunsaturated ω6 and ω3 essential fatty acids were recorded in S. linifolium (3.28%) and in U. fasciata (3.18%). The results showed that U. fasciata contained the highest amounts of lipids (2.96%), phenols (11.95mgGA/g dry wt.), flavonoid (7.04 mgCA/g dry wt.) and ascorbic acid (4.11mg/100g), respectively. β-Carotene was maximum (3940.12 IU/100 g) in C. officinalis. DPPH antioxidant activities were the highest in U. fasciata (81.3%) followed by S. linifolium (79.8%) then C. officinalis (72.6%). Among the 12 analyzed minerals, most of them were high in S. linifolium in which ion quotient ratio was the smallest (0.343). Since these algal species are common in the Egyptian coastal waters, their biochemical composition and antioxidant activities made them promising candidates for nutritional, pharmaceutical and medicinal applications.