Characterization of seaweed extract produced on the Southern Coast of the Rio de Janeiro State

Abstract

Brazil has a considerable developmental potential in the mariculture by the seaweed cultivation. The extract derived from Kappaphycus alvarezii (Doty) L.M. Liao has shown promising results in agricultural applications. Nonetheless, studies have indicated disparities in the physicochemical composition of extracts produced in different locations. This study aimed to characterize the K. alvarezii extract produced from commercially cultivated seaweed in Angra dos Reis (RJ/ Brazil). The average yield of the produced extract was 0.64 ± 0.05 L kg-1, with the resulting solid fraction measuring 319 ± 35 g kg-1. Potassium (K2O) emerged as the most relevant macroelement in the sample, with a concentration of 19.5 g L-1, followed by Nitrogen at 0.24 g L-1 and Phosphorus at 0.1 g L–1. Among the secondary macroelements, Magnesium was the most prominent at 0.41 g L-1, followed by Calcium at 0.29 g L-1, and Sulfur at 0.16 g L-1. In addition, the microelements Iron (5.25 mg L-1) and Zinc (2.5 mg L-1), and the element Sodium (2.85 g L-1) also presented significant contributions. The extract of K. alvarezii produced in this study exhibited intrinsic characteristics, showed disparities in elemental composition regarding others extracts reported in the literature.