Five tropical seaweeds (Sargassum wightii, Ulva lactuca, Sargussum turbinaria, Kappaphycus alvarezii, and Gracilaria verrucosa) found in the sea around Sri Lanka were evaluated for the nutritional value that was used as a complementary source of protein, fiber, ash, oil, essential and non-essential trace elements for human and animals. The moisture and ash content in these seaweeds ranged from (79-89)% and (20-60)% respectively in dry weight (d.w). The average highest crude fiber was from S. turbinaria (15.41%) and followed by U. lactuca (13.26%). The total lipid content was ranging from (0.30-1.97)% d/w while the total protein content was from (3-15)% d.w in these seaweeds. The average high protein content (14.38%) was from U. lactuca. The essential trace minerals of seaweeds, including copper (Cu), zinc (Zn) and ferrous (Fe) were ranged from (0.17-135.94) mg/kg, (2.33- 82.00) mg/kg, (26.54-158.62) mg/kg, d.w. The lowest concentration of Cu, Zn, and Fe was observed in K. alvarezii (0.17 mg/kg, 3.80 mg/kg and 83.19 mg/kg). We found the highest Fe content was in U. lactuca (73.64–152.14) mg/kg. Cadmium (Cd) concentration was detected in the range from (0.170 – 2.300) mg/kg in d.w, while mercury (Hg) was not detected (LOD<0.07 mg/kg). These metal concentrations were lower than the European Union (EU) maximum allowable value. The studied seaweeds are the richest sources of minerals, crude lipid, protein and crude fiber and thus can help to address food scarcity and security.

Seaweeds, Nutrition, Protein, Lipid, Trace Elements