Nutritional profiling of the edible seaweeds Gracilaria edulis, Ulva lactuca and Sargassum sp.

In the present study, nutritional composition of the edible seaweeds, Gracilaria edulis (red seaweed), Ulva lactuca (green seaweed) and Sargassum sp. (brown seaweed) were evaluated. Results showed that the seaweeds had protein content of 13.84±3.55 to 18.21±0.00%; fat 0.73±0.001 to 0.93±0.00%, carbohydrate 30.32±0.21 to 43.19±1.75% and total dietary fibre (TDF) content of 53.625±0.18 to 63.175±0.46% on dry weight basis. Among the three seaweeds, Sargassum sp. contained highest protein content (18.21±0.00%) and G. edulis possessed highest TDF (63.175±0.46%). Macronutrients viz., Na, P and Ca and the micronutrients, Fe, Se, Mn, Cu and Zn were present in all three seaweeds. G. edulis had highest Na (423.33±1.15 mg 100 g-1), P (282.5±0.5 mg 100 g-1), Ca (223.33±0.58 mg 100 g-1) and Fe (65.28±0.33 mg 100 g-1), whereas highest Se content was recorded in Sargassum sp (49.82±0.09 mg 100 g-1). Palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2, ω-6) were the most abundant saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively. Fatty acid profile also revealed that small quantity of docosahexaenoic acid (DHA) (C22:6, ω-3) ranging from 0.064 to 0.494% was present in all the three seaweed species but eicosapentaenoic acid (EPA) (C20:5, ω-3) was present only in Sargassum sp. at a concentration of 0.583%. G. edulis had higher vitamin D2 (2.590 mg 100 g-1), vitamin E (1.017 mg 100 g-1) and vitamin K1 (0.714 mg 100 g-1) than Sargassum sp. and U. lactuca. The results clearly indicates that these three seaweeds can be considered as a good source of dietary fibre, protein, minerals and vitamins and can be used for fortifying foods or as components of functional foods.