Caracterização de elementos inorgânicos em macroalgas do litoral cearense

Abstract

Macroalgae have historically been present in the diet of the world's population, especially in Japan. Interest in these organisms is growing because they contain substances with biochemical properties that are attractive to industries in a wide range of areas. In Ceará, the consumption of algae follows the growing trend in the rest of the world. However, information on the inorganic composition of macroalgae from this region is still scarce. In this work, we studied the inorganic composition of 7 species of macroalgae from the Ceará coast (Hypnea musciformis, Gracilaria birdiae; Solieria filiformis, Bryothamnion triquetrum, Sargassum vulgare, Caulerpa racemosa and Ulva lactuca). The analytes (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sr, V and Zn) were quantified in the dry and rainy seasons of 2022 using ICP-OES, after digestion in acidic media, except for Hg which was quantified by direct analysis using DMA. Certified reference material (CD-200) was analyzed, showing recoveries greater than 95%. The macroalgae species showed different inorganic composition profiles, with a predominance of the elements Ca, K Na, Mg and P. Sargassum vulgare stood out for its concentration of Hg and As (1.479 ± 0.005 mg kg-1 and 172 ± 6 mg kg-1, both in the rainy season). Ulva lactuca had a high concentration of V (46.4 ± 3.4 mg kg-1, during the rainy season). In general, the concentration levels of the elements in the macroalgae samples were higher in the rainy season. However, long-term studies should be carried out to understand the effect of seasonality on the composition and/or elemental concentration profile of these macroalgae from the Ceará coast.