Chemical composition and functional properties of Ulva lactuca seaweed collected in Tunisia

The chemical composition and some functional properties of the dried “Ulva lactuca” algae, collected from the littoral between the Taboulba and Sayada area, were determined. The dried “U. lactuca” algae were investigated for their soluble, insoluble and total dietary fibre content, mineral amount, amino acid and fatty acid profiles, swelling capacity (SWC), water holding capacity (WHC) and oil holding capacity (OHC). Results showed that “U. lactuca” alga powder was characterised by a high content of fibres (54.0%), minerals (19.6%), proteins (8.5%) and lipids (7.9%). The neutral fibres contain hemicellulose (20.6%), cellulose (9.0%) and lignin (1.7%). The proteinic fraction analysis indicated the presence of essential amino acids, which represent 42.0% of the total amino acids. The fatty acids profile was dominated by the palmitic acid, which represents about 60.0% of the total fatty acids, followed by oleic acid (16.0%). The study of the functional properties proved that SWC, WHC and OHC of this alga varied with temperatures and that were comparable to those of some commercial fibre rich products.