The impact of air-drying at 25 °C, brining at 25%, and dry-salting (at 28% and 40%) on the quality and nutritional parameters of Ulva rigida were evaluated over six months of storage. Overall, the main changes occurred in physical aspects during storage time, with U. rigida intensifying its yellow/browning tones, which were more evident in salt-treated samples. The force necessary to fracture the seaweed also increased under all the preservative conditions in the first month. Conversely, the nutritional parameters of U. rigida remained stable during the 180 days of storage. All processed samples showed a high content of insoluble and soluble fibers, overall accounting for 55%-57% dw, and of proteins (17.5%-19.2% dw), together with significant amounts of Fe (86-92 mg/kg dw). The total fatty acids pool only accounted for 3.9%-4.3% dw, but it was rich in unsaturated fatty acids (44%-49% total fatty acids), namely palmitoleic (C16:1), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), and stearidonic (18:4) acids, with an overall omega 6/omega 3 ratio below 0.6, a fact that highlights their potential health-promoting properties.
Keywords: Ulva sp.; air-drying; brining; color; dry-salting; fatty acids; minerals; nutritional; sea lettuce; texture.