## 1 Introduction  
Salinity is a worldwide problem that affects a large percentage of the earth's surface, in which salts gradually accumulate in the soil, eventually transforming fertile soil to barren soil [1]. In this process, water-soluble salts are deposited in the soil to an extent that impacts crop productivity, agricultural economics, and the ecosystem [2]. Currently, salt-affected soils cover over 15 percent of the world's cultivated land [3]. Despite this critical factor that imposes severe constraints on the ecosystem, there is a type of plant able of growing in these salt-affected areas; they are called salt-tolerating plants or halophyte plants [4]. Halophyte plants can grow in extreme conditions of drought, temperature, and salinity (NaCl concentrations above 200 mM) since they respond to salt stress at three levels, e.g., cellular, tissue, and whole plant level [5]. In this context, halophyte plants are a potential solution for degraded soil, freshwater scarcity, and coastal area utilization [6]. Therefore, these plants have been considered alternative crops (biosaline and soilless agriculture) for sustainable use of natural resources. In Portuguese territory, the halophytes grow along the country's coast salt marshes, and some companies are already producing some edible species in salt-affected areas using a soilless cultivation system (SCS) to improve their productivity and marketing, assuring their safety and quality. In this cultivation system, nutrients and salt are added to the halophytes through the cultivation media, and these plants are irrigated by flooding, simulating tides, under controlled temperature, and humidity [7]. Regarding food safety, salt marshes ecosystems are natural deposits of heavy metals near a polluted area. As the metals spread along with the tides and periodic floods, they interact with soil and the biotic community [8]. In this way, the halophytes may accumulate large amounts of these contaminants in their aerial and belowground organs, leading to potential impacts on human health and safety [9]. Portugal has become an important producer of edible halophytes. So far there are few studies carried out with cultivated halophytes using a SCS that report their nutraceutical value, as well as their benefits on human health when consumed in equilibrated diets. Therefore, studies involving halophyte species are crucial. In a previous study, the halophyte (_Sarcocornia fruticosa_ L.) cultivated using a SCS showed higher nutrient contents (ash, proteins, and fat contents), antioxidant activity, and total phenolic compound content than wild plants [7]. Halophytes are used traditionally as herbs and vegetables and some species are appreciated in gourmet cuisine as a promising substitute for table salt because of their characteristic salty taste. These plants are attracting attention for being sources of phenolic acids, flavonoids, coumarins, vitamins, and carotenoids, which are reported to be health promoters due to their antioxidant properties [10; 11; 12]. These natural antioxidants are produced by halophytes to maintain their cellular functioning under oxidative stress conditions (e.g., high ionic content, waterlogging, and submersion) [13; 14]. Studies show that the regular consumption of phenolic acids and flavonoids exerts cardiovascular protective effects and may reduce the onset or progression of cardiovascular diseases, particularly hypertension [15; 16]. In this context, some studies have demonstrated that extracts from halophyte species could be used for the prevention and treatment of heart disease and hypertension (angiotensin-converting enzyme (ACE)-inhibitory activity) due to the presence of polyphenols and bioactive compounds [17; 18; 19].