Edible Halophyte Research Articles

Antinutrients in Halophyte-Based Crops

The cultivation of halophytes is an alternative approach to sustain agricultural productivity under changing climate. They are densely equipped with a diverse group of metabolites that serve multiple functions, such as providing tolerance to plants against extreme conditions, being used as a food source by humans and ruminants and containing bioactive compounds of medicinal importance. However, some metabolites, when synthesized in greater concentration above their threshold level, are considered antinutrients. Widely reported antinutrients include terpenes, saponins, phytate, alkaloids, cyanides, tannins, lectins, protease inhibitors, calcium oxalate, etc. They reduce the body's ability to absorb essential nutrients from the diet and also cause serious health problems. This review focuses on antinutrients found both in wild and edible halophytes and their beneficial as well as adverse effects on human health. Efforts were made to highlight such antinutrients with scientific evidence and describe some processing methods that might help in reducing antinutrients while using halophytes as a food crop in future biosaline agriculture.

Salinity Tolerance Mechanism of Crithmum maritimum L.: Implications for Sustainable Agriculture in Saline Soils

Edible halophytes are attracting attention due to their potential for agriculture in saline and marginal areas. The salt tolerance mechanism was analyzed in Crithmum maritimum L., based on ionic, osmotic, and redox homeostasis strategies under salt stress. The methodology involved growing C. maritimum seeds in pots under controlled greenhouse conditions and exposing them to different NaCl concentrations (0, 100, 200, and 300 mM) for five months. High salinity levels decreased plant length and biomass, but the shoot-to-root length and biomass ratio increased significantly. Photosynthetic pigments (chlorophyll and carotenoids) were quantified using spectrophotometric analysis, while macro- and micro-nutrient contents were determined via the Kjeldahl method, flame photometry, and atomic absorption spectrophotometry. Osmolyte accumulation, including proline and glycine betaine, was analyzed using specific biochemical assays, and antioxidant enzyme activities (SOD, CAT, and POX) were measured to assess redox homeostasis. Photosynthetic pigments in C. maritimum leaves slightly increased at 100 mM NaCl, but significantly declined at 200 and 300 mM NaCl. A high Na content in the shoots indicated no restriction in mineral uptake in the roots. Nitrogen and phosphorus slightly decreased under high salinity. The cation content in the shoots varied: potassium decreased, while calcium and magnesium increased with salinity, although the Mg+2/Na+ and K+/Na+ ratios showed similar declining patterns. The micro-nutrients iron and manganese increased in the shoots, while copper remained unchanged. The content of osmolytes proline and glycine betaine significantly increased under the 200 and 300 mM NaCl treatments. Antioxidant enzyme activities (SOD, CAT, and POX) decreased at 100 and 200 mM NaCl, but were strongly induced at 300 mM NaCl. The total antiradical activity of the leaves increased with higher salinity levels. Our results indicated that the facultative halophyte characteristics of C. maritimum emerged after exposure to 200 mM NaCl. Increased calcium content may be a key factor in salinity tolerance. We concluded that C. maritimum employs strong osmotic adjustment and redox homeostasis mechanisms, making it a promising candidate for cultivation in saline environments.

Phenolic profile, cytotoxicity and in vitro antioxidant and enzyme inhibitory properties of the edible halophyte Sarcocornia fruticosa from southeastern Tunisia

This work aims to boost the sustainable valorization of the edible halophyte Sarcocornia fruticosa (L.) A.J. Scott (Amaranthaceae) from Southern Tunisia by assessing its potential as a source of bioactive components. To achieve this, hydroethanolic extracts of S. fruticosa, collected from two distinct Tunisian biomes (Zarzis: SFZ and Djerba: SFDJ), were profiled for total phenolic, flavonoid, and condensed tannin contents, as well as for individual phenolic composition by HPLC-ESI-MS. Then, the extracts were evaluated for in vitro antioxidant properties via complementary methods and for in vitro inhibition of enzymes related to Alzheimer's disease (acetylcholinesterase: AChE, and butyrylcholinesterase: BuChE), type 2 diabetes (α-glucosidase and α-amylase), and hyperpigmentation and food oxidation (tyrosinase). Finally, they were assessed for acute in vitro toxicity. Our findings identified thirteen phenolic compounds, with rutin being the predominant compound and its content being nearly twice as high in SFZ than in SFDJ (1224.51 and 643.61 mg/kg DW, respectively). Salvianolic acid B was also reported for the first time in Sarcocornia genus. The extracts exhibited notable ferric reducing antioxidant power (FRAP), with SFZ displaying an effective median concentration (EC50) value of 0.97 mg/mL. They also showed promising inhibitory effects on acetylcholinesterase (>40%) and tyrosinase (>50%), without any cytotoxicity. The Zarzis ecotype in particular displayed superior bioactive properties, making it an excellent candidate for future cultivation trials under saline conditions, with potentially valuable economic outcomes for the region. These findings highlight the potential of S. fruticosa as a source of functional ingredients with nutraceutical and therapeutic applications.

Evaluation of direct and transgenerational influences of salinity on germination and early seedling growth in an edible halophyte, Crithmum maritimum.

Crithmum maritimum is a wild, edible halophyte with large potential as a cash crop for salinized soils. However, the tolerance during seed germination appears to be highly site-specific and contradictory, whereas little is known on salinity tolerance during early seedling growth. This study was aimed at characterizing variation in the responses of germination and early seedling growth in diverse C. maritimum populations along the Iberian Southwest coast. Specifically, we sought to distinguish between direct salinity effects and those influenced by the salinity of maternal environments. Physicochemical properties, including salinity of maternal environments, were assessed across diverse habitats. A total of 3480 seeds from 58 mother plants were utilized. Seeds were subjected to germination assays under various salinity treatments (0-500mM NaCl), with subsequent monitoring of germination parameters. Non-germinated seeds were tested for recovery germination, and viability was assessed using the tetrazolium test. Of germinated seeds, 1160 seedlings were monitored for survival and early growth metrics. General Linear Models were employed to analyze the effects of salinity and maternal environmental influence on germination and early growth. Despite reduced and delayed germination under salinity, seeds showed remarkable tolerance up to 150mM, surpassing prior reports, with consistent viability up to 500mM, indicating substantial salinity-induced dormancy. Seedling growth was more sensitive to continued treatment; no plants survived above 150mM. The salinity experienced by maternal plants had only a marginal effect on germination but significantly contributed to reduce seedling biomass production, both above and below ground. This study highlights the significance of maternal salinity on early growth in C. maritimum, emphasizing the species' resilience to salt stress during germination and recovery. These insights are crucial for optimizing cultivation techniques and informing research on other halophytes in saline environments.

Comparing the nutritional, phytochemical, and anti-microbial potential of wild and cultivated Tetragonia decumbens mill.: A promising leafy vegetable for bio-saline agriculture in South Africa

Tetragonia decumbens is a neglected edible halophyte that grows naturally in coastal areas of South Africa. Its underutilisation is due to the limited literature on its nutraceutical potential. So, this research was designed to assess the nutritional value, secondary metabolites, and anti-microbial potential of wild and greenhouse cultivated T. decumbens to further support its consumption and potential medicinal use. Samples of T. decumbens were collected from three coastal areas (Strand beach, Muizenberg beach and Blouberg beach) during the dry and wet seasons in Cape Town, and the greenhouse cultivated were subjected to varying salinity doses (0, 50, 100, 150, 200 and 250 mM). Results revealed a considerable increase in minerals (N, P and Mg) and proximate composition (Ash, moisture, and carbohydrates) in greenhouse cultivated plants subjected to 50 mM of salinity while the highest crude fat and neutral detergent fibre were recorded in wild samples. Moreover, heavy metal accumulation (Zn and Fe), phytochemicals, anti-nutrients and anti-microbial activities were more pronounced in wild plants than in cultivated samples. Wild plants collected at Blouberg beach had more heavy metals, anti-nutrients, phytochemicals, and anti-microbial activity. These findings validate for the first time, the relevance of nutritional quality of T. decumbens in assessing its suitability as a source of nutrients and antioxidants with possible medicinal value as shown by the inhibition of harmful bacteria and fungal strains.

A Comparative Study of the Influence of Soil and Non-Soil Factors on Seed Germination of Edible Salt-Tolerant Species

Cultivating edible salt-tolerant plants (halophytes) for human consumption is increasingly important due to climate change and soil salinization, and offers sustainable agricultural solutions. Optimizing seed germination, the crucial initial stage of crop growth, is essential for enhancing crop production. This study aimed to optimize the germination of edible halophytes under greenhouse conditions, focusing on select soil (salinity and substrate) and non-soil-related factors (chemical and mechanical treatments). The target species were selected for their commercial value and included Mesembryanthemum crystallinum L. (crystalline iceplant), Salicornia ramosissima J. Woods (sea asparagus), Medicago marina L. (sea medick), Ammophila arenaria (L.) Link (European beachgrass), Portulaca oleracea L. (common purslane), and Atriplex halimus L. (Mediterranean saltbush). Salinity negatively impacted germination rates (GRs) and delayed mean germination time (MGT) across species. P. oleracea had the highest GR (95.6%) in coco peat under freshwater irrigation, and the shortest MGT (5.2 days). A. halimus did not germinate under the tested conditions. Scarification with sulfuric acid improved the GR of M. marina by 42.2%, while scarification with ultrasounds improved the GR of A. arenaria by 35.5%. Our results indicate that the choice of substrate and the application of specific treatments like scarification can significantly improve the germination of certain halophyte species under variable saline conditions.

Effects of drought and increased temperature on phytochemical traits of the edible halophyte Crithmum maritimum: Perspectives for future climatic scenarios

Climate change, characterised by drought events and rising temperatures, exerts a significant threat to crop productivity and global food security. Halophytes, known for their resilience in harsh conditions, offer promising options for sustainable cultivation alternatives. Our study focused on Crithmum maritimum, commonly known as sea fennel, an edible halophyte with potential in the food and nutraceutical industries, to explore the impacts of drought and increased temperatures on its nutritional and antioxidant profiles. Different C. maritimum populations displayed high nutritional qualities, suitable for consumption despite appearing slight differences among localities. While both drought and increased temperatures affected plant growth and phytochemical profiles, their impact on nutritional value was minor. Surprisingly, drought induced an unexpected decline in phenolic content, challenging the assumption of increased antioxidants in response to water scarcity. Different rates of decrease in leaf production were observed among C. maritimum populations under drought, yet overall, they maintained similar levels, suggesting potential suitability for cultivation in environments with limited water availability. Diverse population-specific responses under climatic treatments revealed different alterations in amino acid and oxidative stress profiles, suggesting diverse adaptive strategies. These findings provide critical insights into C. maritimum adaptability to climate-driven changes, offering valuable information for future agricultural practices

Isopimpinellin inhibits UVA-induced overproduction of MMPs via suppression of MAPK/AP-1 signaling in human dermal fibroblasts.

Corydalis heterocarpa is an edible halophyte and an ingredient in traditional Korean medicine. In the present study, isopimpinellin (IPN), a bioactive coumarin, was isolated from the medicinal halophyte C. heterocarpa, and the effects of IPN against UVA-induced photoaging were investigated in human dermal fibroblasts. Photoaging is a skin disorder that manifests itself as premature skin aging due to chronic exposure to UV radiation. The symptoms of photoaging mainly arise from degraded skin connective tissue produced by overly expressed matrix metalloproteinases (MMPs). IPN treatment decreased the UVA-induced formation of reactive oxygen species and decreased MMP-1, MMP-3, and MMP-9 collagenases at the protein level. The UVA-mediated suppression of tissue inhibitors of MMP-1 and -2 was attenuated with IPN. The presence of 10μM IPN inhibited the MAPK-mediated phosphorylation of c-Fos and c-Jun. In conclusion, the overall result of the current study indicated that IPN inhibited the UVA-induced overexpression of MMPs via blocking the MAPK/AP-1 pathway.

Combined genome and transcriptome provides insight into the genetic evolution of an edible halophyte Suaeda salsa adaptation to high salinity.

Suaeda salsa L. is a typical halophyte with high value as a vegetable. Here, we report a 447.98 Mb, chromosomal-level genome of S. salsa, assembled into nine pseudomolecules (contig N50 = 1.36 Mb) and annotated with 27,927 annotated protein-coding genes. Most of the assembled S. salsa genome, 58.03%, consists of transposable elements. Some gene families including HKT1, NHX, SOS and CASP related to salt resistance were significantly amplified. We also observed expansion of genes encoding protein that bind the trace elements Zn, Fe, Cu and Mn, and genes related to flavonoid and α-linolenic acid metabolism. Many expanded genes were significantly up-regulated under salinity, which might have contributed to the acquisition of salt tolerance in S. salsa. Transcriptomic data showed that high salinity markedly up-regulated salt-resistance related genes, compared to low salinity. Abundant metabolic pathways of secondary metabolites including flavonoid, unsaturated fatty acids and selenocompound were enriched, which indicates that the species is a nutrient-rich vegetable. Particularly worth mentioning is that there was no significant difference in the numbers of cis-elements in the promoters of salt-related and randomly selected genes in S. salsa when compared with Arabidopsis thaliana, which may affirm that plant salt tolerance is a quantitative rather than a qualitative trait in terms of promoter evolution. Our findings provide deep insight into the adaptation of halophytes to salinity from a genetic evolution perspective.

Elemental uptake and antioxidant activity in edible Mediterranean halophytes from Tinto River

A complete survey is presented on elemental composition, selected amino acids and antioxidant capacity in edible halophytes from Spain. We include materials from the Iberian Peninsula: littoral-coastal Tinto River basin areas (SW Spain: Huelva province) and mainland territories (NW and central Spain: Zaragoza). The aim of this contribution is to characterize the relation between nutritional content compounds and their key role in antioxidant capacity in stress environments. Using analytical techniques such as ICP-MS, DPPH, FRAP and TBARS our results revealed the importance of different antioxidant responses in edible halophytes and their relations between elemental inorganic nutrients and stronger accumulation of some bioactive compounds like phenolic acids, flavonoids and amino acids. These molecules may be the key to the survival of these species in extreme saline environments located in Spain.

DFT, GC-MS analysis and biological evaluation of Limbarda crithmoides L. Dumort essential oil; an important edible halophyte grown in Pakistan

Antimicrobial resistance is a major health burden in Pakistan, and therefore new herbal medicine-based therapeutic regimens are being largely investigated. Limbarda crithmoides essential oil was extracted by using hydrodistillation method. Chemical profiling of essential was evaluated by using FTIR and GC-MS analysis. A total of 20 components were identified including, p-xylene, o-xylene, β-linalool, acetophenole and 3-isopropylphenyl methylcarbamate. The HOMO and LUMO analysis in DFT investigations presented that 3-isopropylphenyl methylcarbamate, p-xylene and o-xylene posess a substantial capacity to transfer charge through molecules. The antimicrobial potential of essential oil showed moderate inhibition against E. coli (MIC = 6.25 mg/mL), whereras a significant inhibition Staphylococos aureus was recorded (MIC = 3.12 mg/mL). Further, significant antioxidant activities were recorded in DPPH radical scavenging (IC50 = 80.5 µg/mL), H2O2 (64 ± 1.2%) and FRAP (60.3 µg ferrous equivalents) assays. It was therefore concluded that Limbarda crithmoides essential oil has potential antioxidant and anti-antimicrobial properties and can be used for further investigations.

Protective properties of the edible halophyte Carpobrotus edulis (L.) N.E.Br. towards neoformed food contaminants-related oxidative stress and genotoxicity

Carpobrotus edulis (L.) N.E.Br. is an edible halophyte native to South Africa, where it has been traditionally consumed as food, revealing its nutritional value, and used in the treatment of human diseases probably due to the accumulation of bioactive compounds such as polyphenols. These compounds have potential to display valuable biological activities that could bring several benefits to the human being, including the mitigation of toxicity induced by food contaminants. Therefore, this study investigated biological activities with health-promoting potential of a C. edulis ethanol extract (CEE), such as antioxidant, antigenotoxic, and antimutagenic. CEE was shown by LC-DAD-ESI/MSn to be composed of 16 polyphenols. The extract exhibited antioxidant properties by protecting Saccharomyces cerevisiae viability and improving the redox state of HepG2 cells under oxidative stress. Antigenotoxicity of CEE against H2O2-induced oxidative damage was detected in HepG2 and Caco-2 cells by comet assay and subsequently observed in the dominant deletion assay in S. cerevisiae. Antigenotoxicity and antimutagenicity of CEE towards the neoformed contaminant benzo[a]pyrene was found in HepG2 and Caco-2 cells by comet assay and in Salmonella typhimurium using the Ames test, respectively. The disclosed antigenotoxic and antimutagenic properties of C. edulis further advance its potential for application in food and nutraceutical industries for health benefits.

Salinity effects on germination of Portulaca oleracea L.: A multipurpose halophyte from arid rangelands

Salt resistance studies have, unfortunately, mainly been focused on conventional crops, with very few studies being conducted on the potential of available halophytes as new crops in the future. Portulaca oleracea L. has been listed as one of the most used medicinal plants by the World Health Organization as an edible halophyte. It is a fast-growing herbaceous annual with high nutritional relevance. The present work was designed to determine the effect of six soluble salts (NaCl, Na2SO4, KCl, CaCl2, CaCO3, and MgCl2) on germination of P. oleracea seeds. The effect of salinity was tested on final germination percentage (FGP%), and germination tolerance index (GTI%) using five concentrations (0, 200, 300, 400, and 600 mM) of each salt. In addition, laboratory experiments were conducted to assess the effects of salinity on germination recovery from high saline conditions (600 mM). Salinity level and salt composition significantly influenced germination attributes. P. oleracea seeds were non-dormant, exhibited approximately 100% germination in distilled water. Both FGP and GTI gradually decreased with increasing salinity. This study showed that seeds of P. oleracea can germinate under 300 mM in all tested salts. The salts causing germination inhibition exhibited specificity, with an increasing trend observed in the following sequence: MgCl2 > Na2SO4 > NaCl > KCl > CaCl2 > CaCO3. Transferring ungerminated seeds from 600 mM to distilled water recovered their germination ability. Based on these results, we can conclude that P. oleracea is a high salt-tolerant species that can tolerate a variety of salts found in soil. Therefore, P. oleracea may be considered a promising species for improving ecological balance in saline soils.

Phytochemical Diversity and Related Bioactivity of Ethyl Acetate Fraction from Different Organs and Provenances of the Edible Halophyte Crithmum Maritimum L.

Sea fennel (Crithmum maritimum L.) is a facultative halophyte from the Apiaceae family. The variation of phenolic compounds, the antioxidant and antibacterial activities of different extracts of different organs of sea fennel were investigated. The roots, stems, leaves and seeds were collected from three bioclimatic stages of Tunisia. Solvent fractionation method (using aqueous acetone, petroleum ether and ethyl acetate) was adopted to separate the extract ingredient and to concentrate phenolics. Total phenolics, total flavonoids, and condensed tannins significantly varied between organs and localities. In leaves, the highest level of phenols was detected in the upper and sub-humid zones. However, in stems the high amounts of phenols were observed in semiarid climate. The antioxidant activity was evaluated through four different methods and the antimicrobial activity was assessed against five human pathogenic bacteria and a fungal strain. Multivariate analysis showed significant effect of organ and locality on the antioxidant properties. Results of the antibacterial activities showed significant differences among extracts and was reflected by a large spectrum of activity ranging from totally not active (Zones of inhibition (zi) < 1 mm) to very high activity (zi >16 mm). Combined statistical results allowed to select the more potent fraction to be analyzed using reversed-phase HPLC (RP-HPLC). The flavanol epigallocatechin was identified as a major phenolic compound which contributed greatly to the antioxidant capacity. The results established in this study highlighted the importance of this halophyte cash crop in the human diet as natural source of active components.

Arthrocnemum Moq.: Unlocking Opportunities for Biosaline Agriculture and Improved Human Nutrition.

(1) Background: This study provides novel insights into the elemental content and biomineralization processes of two halophytic species of the genus Arthrocnemum Moq. (A. macrostachyum and A. meridionale). (2) Methods: Elemental content was analyzed using ICP-MS, while biominerals were detected through electron microscopy (SEM and TEM) and X-ray diffraction. (3) Results: The elemental content showed significant concentrations of macronutrients (sodium, potassium, magnesium, and calcium) and micronutrients, especially iron. Iron was consistently found as ferritin in A. macrostachyum chloroplasts. Notably, A. macrostachyum populations from the Center of the Iberian Peninsula exhibited exceptionally high magnesium content, with values that exceeded 40,000 mg/kg d.w. Succulent stems showed elemental content consistent with the minerals identified through X-ray diffraction analysis (halite, sylvite, natroxalate, and glushinskite). Seed analysis revealed elevated levels of macro- and micronutrients and the absence of heavy metals. Additionally, the presence of reduced sodium chloride crystals in the seed edges suggested a mechanism to mitigate potential sodium toxicity. (4) Conclusions: These findings highlight the potential of Arthrocnemum species as emerging edible halophytes with nutritional properties, particularly in Western European Mediterranean territories and North Africa. They offer promising prospects for biosaline agriculture and biotechnology applications.

Valorization of Salicornia patula Duval-Jouve Young Shoots in Healthy and Sustainable Diets.

The revalorization of natural resources in food production is increasing, and the effect of climate change is negatively affecting the production of conventional crops. In recent years, edible halophytes have received more attention due to their ability to tolerate a wide range of salinities. Thus, the use of halophytes that require less water and are strongly adapted to high-salinity soil and coastal areas can provide sustainable agriculture in certain areas. In addition, there is growing interest in the study of the possibilities that these species offer as foods due to their excellent nutritional profile and antioxidant properties. For that reason, the exploitation of plants adapted to these areas is nowadays even more important than in the past to guarantee food security in arid or semiarid salinized territories. The available data about the nutrients and bioactive compounds composition of many non-cultivated edible vegetables traditionally used in the Mediterranean area, such as Salicornia edible young shoots, are still scarce. With the aim of improving the knowledge on their nutritional value, the present study provides new data about the content of some compounds with biological activity, such as fiber and organic acids, in eight samples of young shoots of S. patula Duval-Jouve gathered in great mainland and coastal salt marshes in Southwest and Central Spain. Results showed that this vegetable can be considered a healthy food and a very good source of dietary fiber (4.81-6.30 g/100 g fw total fiber). Its organic acid profile showed oxalic, malic, citric and succinic acids. Oxalic acid was the major one, with mean values of 0.151-1.691 g/100 g fw. From the results obtained in this study, S. patula shoots could be recommended as an alternative source of fiber for healthy and sustainable diets in the general adult population with no risk of renal disease.

Commercial Cultivation of Edible Halophytes: The Issue of Oxalates and Potential Mitigation Options

Saline agriculture, including the commercial cultivation of edible halophytes, is expanding rapidly to address the increase in salinised soil due to natural and man-made causes, the decline in availability of fresh water, the increased use of poor-quality water, and increasing food insecurity. Halophytes, as food crops, offer an innovative new opportunity in agriculture, many being highly nutritious and containing bioactive compounds. However, the commercial production of edible halophytes to meet emerging consumer demands faces several challenges. This review examines the market potential for the expansion of edible halophyte crops and the challenges of consumer acceptance and production capacity beyond wild harvest. In addition to beneficial compounds, halophytes are known to contain several anti-nutrient compounds, which can have negative health consequences. In edible halophytes, oxalates are of particular concern. However, research has shown that there are ways to mitigate the accumulation of oxalate through processing, agronomic practice, and genetic engineering. These approaches are presented as potential strategies that can be used in commercial farming systems to reduce the levels of this compound.

Australian indigenous edible halophytes — nutritious and functional for a sustainable future: antioxidant capacity and antimicrobial properties

In recent years, edible halophytes have received more attention due to their ability to tolerate a wide range of salinities. Furthermore, halophytes have long been used for food, feed and medicinal purposes. However, available information on their nutritional profile (including antioxidant compounds) and bioactivity is still very limited. Therefore, the present study investigated the antioxidant capacity and antibacterial activity of three important Australian indigenous edible halophytes, <i>Sesuvium</i> sp. (Seapurslane), <i>Suaeda</i> sp. (Seablite) and <i>Atriplex</i> sp. (Saltbush), to assess their bioactive properties and potential to be used as functional food ingredients. The antioxidant capacity was determined by total phenolic content (TPC), total flavonoid content (TFC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and the antimicrobial activity was evaluated using the agar well diffusion method. The methanolic extract of Seapurslane showed the highest TPC (12.5 mg GAE/g DW), TFC (4.3 mg QE/g DW) and DPPH (102.6 μM TE/g DW), followed by Seablite and Saltbush. The ethanolic extract of Seapurslane had antimicrobial activity against Gram positive <i>Staphylococcus aureus</i> bacterium, a predominant food pathogen causing gastroenteritis and other health issues. These initial results are very promising and indicate that Australian-grown halophytes may have the potential to be utilised as novel sources of antioxidant and antimicrobial compounds for different food applications.

Growth, Physiology and Nutritional Quality of C4 Halophyte Portulaca oleracea L. Grown Aeroponically in Different Percentages of Artificial Seawater under Different Light-Emitting Diode Spectral Qualities.

Edible halophyte Portulaca oleracea L., known as purslane, was grown in two percentages of artificial seawater (ASW) under two combined red (R) and blue (B) LED spectra. High salinity (40% ASW) negatively affected shoot productivity and leaf growth of purslane compared to those grown in 10% ASW. Photosynthetic pigment and total reduced nitrogen concentrations were significantly higher in purslane grown in 10% ASW than in 40% ASW. However, LED spectral quality did not markedly influence these parameters. Grown in 10% ASW under R/B 2.2, purslane had the highest maximum nitrate reductase activity, while those in 40% ASW under R/B 2.2 had the highest activation state. Under both light qualities, purslane had a sevenfold increase in proline concentration in 40% ASW than in 10% ASW. Total phenolic compounds' concentration was the highest in 10% ASW under R/B 0.9, while there were no significant differences in the accumulation of total soluble sugars and ascorbic acids among all plants. Antioxidant enzymes activities were lower in 40% ASW under R/B 2.2 compared to the other conditions. In conclusion, salinity affected the yield, physiology and nutritional quality of purslane. The impacts of LED spectral quality on purslane were only reflected by certain physiological and nutritional parameters.

Comprehensive characterization of selected phytochemicals and minerals of selected edible halophytes grown in saline indoor farming for future food production

Sustainable and resilient agri-food systems are needed to ensure food security in the face of increasing urbanization, water scarcity and climate change. Saline indoor farming offers a flexible use of urban production areas with resource-saving water management. Salt-tolerant plants (halophytes) are crops that can be grown in saline environments, have excellent nutritional properties, such as being rich in minerals and phytochemicals. The aim of this study was to evaluate plant performance and selected nutritional properties of five halophyte species (glasswort, quinoa, garden orache, scurvy grass and palm kale) in saline indoor farming with different salinities. In particular, we evaluated morphological parameters, as well as, carotenoids, chlorophylls, glucosinolates, plant hormones by LC-MS, and anion composition by IC. The five halophyte species showed differences in plant growth performance and nutritional properties depending on the salinity level. For example, we found a total carotenoid content ranging from 1581.4 ± 180.4 ng mg-1 DW (scurvy grass) to 188.3 ± 48 ng mg-1 DW (glasswort; no salt) and a 40-times higher increase of β-carotene (200 mM salt) for glasswort, compared to the other halophytes. In summary, we observed that the phytochemical content varied with salinity and that halophytes require species-specific growing conditions to enhance valuable metabolites.