## 3 Results and Discussion
### Volatile Compounds Profile
fruticosa_ contained a higher content of protein, ash, salt, chlorides, minerals (Na, K, Fe, Mg, Mn, Zn, Cu), and flavonoids. In contrast, _S. ramossissima_ presented a higher content of phenolic acids and polyunsaturated fatty acids. Considering the phenolic profile of the plants, _S. fruticosa_ and _M. nodiforum_ showed the most distinct profiles, with a relatively higher abundance of hydroxycinnamic acids in _S. fruticosa_, and a relatively higher abundance of flavonoids in _M. nodiforum_ and _S. ramossissima_ showed the highest content of hydroxycinnamic and hydroxybenzoic acids. The most abundant flavonoids class, especially in _S. fruticosa_, was the flavonoids, namely, the compound tentatively identified, for the first time in this species, as rhametin hexosyl pentoside. The phytochemical diversity of the studied halophytes clearly indicates the advantages of consuming these species in the diet as a strategy to enhance the diet's nutraceutical value and, consequently, their antioxidant activity and anti-hypertensive effect. Future work is mandatory in order to increment the knowledge about these halophytes and the relationship between their bioactive composition and possible health effects. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/antiox12061161/s1](https://www.mdpi.com/article/10.3390/antiox12061161/s1)]([https://www.mdpi.com/article/10.3390/antiox12061161/s1](https://www.mdpi.com/article/10.3390/antiox12061161/s1)), Figure S1: Correlation matrix (Pearson's R values from \(-\)1 to 1) between the phenolic composition and the bioactivity measured by in vitro antioxidant and anti-hypertensive activities. ACE inhibition expressed as inverse values for the anti-hypertensive activity. Table S1: Individual phenolic compounds quantified in the different halophyte species. Results are expressed as mean \(\pm\) standard deviation (n = 2), \(\mu\)g/g of fresh weight (FW). The hydroxycinnamic acids (HCA) and their derivatives were quantified as a 3-O-caffeoylquinic acid equivalent (CQAE), flavonoids were quantified as quercetin-3-glucose equivalent (QGE), and hydroxybenzoic acids (HBA) were quantified as a gallic acid equivalent (GAE). Table S2: References [153-240] are cited in the Supplementary Materials. Conceptualization, S.C.O.-A., A.T.S. and M.R.B. ; methodology, S.C.O.-A., F.A., J.S., A.B.-S., B.D., I.C. and M.S. ; formal analysis, S.C.O.-A., F.A., J.S., A.B.-S. and B.D. ; investigation, S.C.O.-A., F.A., J.S, A.B.-S., B.D. and I.C. ; data curation, S.C.O.-A., E.M., F.A. and J.S. ; writing--original draft preparation, S.C.O.-A., E.M., F.A. and J.S. ; writing--review and editing, S.C.O.-A., E.M., B.D., I.C., M.S., A.T.S. and M.R.B. ; supervision, S.C.O.-A., A.T.S. and M.R.B. ; project administration, S.C.O.-A., A.T.S. and M.R.B. ; funding acquisition, A.T.S. and M.R.B. All authors have read and agreed to the published version of the manuscript. This study was funded by (i) iNOVA4 Health (UIDB/04462/2020 and UIDP/04462/2020) and MARE (UIDB/04292/2020 and UIDP/04292/2020), a program financially supported by Fundacao para a Ciencia e Tecnologia/Ministerio da Ciencia, Tecnologia e Ensino Superior, through national funds and the Associate Laboratories LS4 FUTURE (LA/P/0087/2020) and ARNET (LA/P/0069/2020); (ii) Fundacao para a Ciencia e Tecnologia through the recovery of antioxidant compounds from halophyte plants using green technologies: application on food and cosmetic industries, ReHAlAntiOx project (Reference EXPL/ASP-AGR/1655/2021); (iii) the INTERFACE Programme through the Innovation, Technology, and Circular Economy Fund (FITC); (iv) the Portuguese Mass Spectrometry Network (Rede Nacional de Espectrometria de Massa--RNEM; LISBOA-01-0145-FEDER-402-022125); and (v) B.D. was supported by a researcher contract (2022.01746.CEECIND). Not applicable. The data supporting the findings of this study are available within the article and its supplementary material.