Evaluation of the Elemental Composition, Identification and Quantification of Major Phenolic Compounds and Fatty Acids in Perennial Salicornia Species

Perennial Salicornia species are promising halophytic food resources, but comparative information on their mineral and bioactive composition remains limited. We characterized elemental composition, total phenolic content, individual phenolic compounds in aerial tissues and seeds, fatty acid profiles, and seed morphology in selected taxa from seven perennial Salicornia species collected across Mediterranean, Atlantic, and inland saline habitats. Elemental composition was assessed by ICP-MS in 68 samples from 18 sites. Na, K, Mg, and Ca dominated the elemental profile, while species-related differences were detected for K, Ca, Fe, Ni, and Ba; fruiting samples showed lower Fe, As, Sr, Ba, and Pb concentrations. Total phenolic content ranged from 2.579 to 3.924 mg GAE/g DW. Several glycosylated flavonoids were identified: isoquercetin and rutin were the major forms, whereas luteolin-7-O-glucoside and apigenin-7-O-glucoside occurred only sporadically. In seeds, rutin and isoquercetin together accounted for 65.1–96.2% of quantified phenolics. Eleven fatty acids were identified, with substantial contributions of linoleic and α-linolenic acids in several samples. These results expand the compositional and taxonomic knowledge of perennial Salicornia and support their potential as alternative food resources.