[Contents of various nutrients, minerals and seasonal fluctuations in Porphyra columbina, an edible marine algae from the Argentine Patagonian++ coast].

Porphyra columbina (Rodophyta Bangiales), one of the most important edible seaweeds, grows abundantly in the southern Argentine coast. Their mineral content and seasonal fluctuations were determined because there is no national data about their nutritional value. Samples were collected from April 1993 to February 1994 from Golfo San Jorge (30 Km South of Comodoro Rivadavia). Algae were washed with sea water and dried at room temperature (20-2 degrees C) for 24 hs, following the local processing procedure. Moisture and ashes were determined according to A.O.A.C. After mineralization with nitric acid sodium and potassium were determined by flame photometry; calcium, magnesium and iron by atomic absorption spectrophotometry (AAS); and phosphorus by Gomori's method. The results, expressed per 100 g dry algae showed the following values: moisture content: 7.03 to 11.00 g/100 g; ashes: 16.18 to 22.70 g/100 g; sodium: 3.18 to 6.41 g/100 g; potassium 1.24 to 1.96 g/100 g; magnesium: 600 to 836 mg/100 g; phosphorus: 78 to 276 mg/100 g; calcium: 63 to 108 mg/100 g and iron: 3.9 to 26.4 mg/100 g. The results of composition of algae as manufactured in the region showed important seasonal differences, with the highest values of ashes, sodium, potassium and magnesium in winter season (June and July).