Mineral composition of seaweeds and seagrasses of the Philippines

Minerals, although required in relatively small amounts, play crucial roles in many vital processes of the human body, and their deficiency can cause several serious health issues. Seaweeds and seagrasses, traditionally consumed as vegetables in coastal areas worldwide, are generally known as a rich source of macro- and microminerals in concentrations much higher than in terrestrial plants. Despite their significant nutritional potential, the mineral composition of most of the seaweeds and seagrasses remains unexplored. In the present study, the concentrations of 23 minerals in nine seaweeds and seagrasses from the Philippines were determined using inductively coupled plasma optical emission spectroscopy. The results showed that some of the species are excellent sources of various essential minerals. Actinotrichia fragilis and Mastophora rosea were the highest in calcium content (21,511 and 14,100 mg/100 g DM, respectively), and, together with Anadyomene plicata, they were richest in copper (2.49-3.77 mg/100 g DM), iron (292-480 mg/100 g DM), manganese (22.3-27.2 mg/100 g DM), and nickel (1.49-2.93 mg/100 g DM). Moreover, M. rosea had the highest content of magnesium (2,093 mg/100 g DM). Other species, such as Enhalus acoroides (phosphorus in flowers and seeds, 277 and 282 mg/100 g DM, respectively), Halophila ovalis (silicon, 13.8 mg/100 g DM), Halymenia dilatata (zinc, 5.51 mg/100 g DM), Halymenia maculata (sulphur, 8,268 mg/100 g DM) and Portieria hornemannii (potassium, 8,985 mg/100 g DM; vanadium, 2.90 mg/100 g DM) can be highlighted as good sources of minerals. All these species have a promising potential as mineral-rich foods and can contribute to food and nutrition security.