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Edible algae are a natural source of nutrients, including iodine, and can also contain nitrogen in the form of nitrate (NO3−) and nitrite (NO2−) as they can fix nitrogen from seawater. This study aimed to analyse the NO3−, NO2−, and iodine concentrations in eighteen macroalgae and five microalgae species commercially available in the United Kingdom. NO3− and NO2− concentrations were measured using high-performance liquid chromatography (HPLC), and iodine was determined using inductively coupled plasma mass spectrometry (ICP-MS). NO3− and iodine concentrations in macroalgae (NO3−: 4050.13 ± 1925.01 mg/kg; iodine: 1925.01 ± 1455.80 mg/kg) were significantly higher than in microalgae species (NO3−: 55.73 ± 93.69 mg/kg; iodine: 17.61 ± 34.87 mg/kg; p < 0.001 for both). In the macroalgae group, nori had the highest NO3− (17,191.33 ± 980.89 mg/kg) and NO2− (3.64 ± 2.38 mg/kg) content, as well as the highest iodine content. Among microalgae, Dunaliella salina had the highest concentration of NO3− (223.00 ± 21.93 mg/kg) and iodine (79.97 ± 0.76 mg/kg), while Spirulina had the highest concentration of NO2− (7.02 ± 0.13 mg/kg). These results indicate that commercially available edible algae, particularly macroalgae species, could be a relevant dietary source of NO3− and iodine. [ABSTRACT FROM AUTHOR]

In the first study focusing on the Red Sea's Tabuk coast, six edible species of the most common algae were collected to evaluate their approximate composition using AOAC methods, amino acids using ion-exchange chromatography, minerals using atomic absorption spectroscopy, phenolic compounds using the Folin–Ciocalteu method, and ferric-reducing antioxidant power. All the data were significantly (p < 0.05) different among all the studied species. The data indicated that the protein content ranged from 9.25% for A. nodosum to 20.06% for H. musciformis. C. racemosa had the highest lipid content of 7.57%. Phosphors varied from 68.2 mg/100 g for A. nodosum to 406 mg/100 g for D. simplex. The largest amounts of calcium (2458 mg/100 g) and iron (29.79 mg/100 g) were found in C. racemosa. The total essential amino acids ranged between 38.16 and 46.82% for A. nodosum and D. simplex, respectively. F. vesiculosus had the maximum content of phenolic compounds (11.06 mg GAE/g). A. nodosum had the highest antioxidant capacity (1.78 mg TE/g). The research concluded that algae are the main effort toward sustainable agriculture to meet the world's food needs. that algae may be used to improve food naturally. To satisfy the criteria for sustainable food, which is one of the pillars of NEOM, numerous studies are required to investigate the natural products available in the Red Sea. [ABSTRACT FROM AUTHOR]

Foods enriched with nutritional compounds and biological activities, especially antioxidants, are considered healthier for human and/or animal consumption. Seaweeds are rich sources of biologically active metabolites and are used as functional foods. In this study, proximate compositions, physicobiochemical characteristics and oil oxidative stability were analyzed for 15 abundant tropical seaweeds (four green—Acrosiphonia orientalis, Caulerpa scalpelliformis, Ulva fasciata, Ulva lactuca; six brown—Iyengaria stellata, Lobophora variegate, Padina boergesenii, Sargassum linearifolium, Spatoglossum asperum, Stoechospermum marginatum; and five red—Amphiroa anceps, Grateloupia indica, Halymenia porphyriformis, Scinaia carnosa, Solieria chordalis). All seaweeds were analyzed for the proximate composition, including moisture content, ash content, total sugar content, total proteins, total lipids, crude fiber, carotenoid content, total chlorophyll content, proline, iodine content, nitrogen-free extract, total phenolic content and total flavonoid content. Green seaweeds showed higher nutritional proximate composition, followed by brown and red seaweeds. Among the different seaweeds, Ulva, Caulerpa, Sargassum, Spatoglossum and Amphiroa showed high nutritional proximate composition compared to other seaweeds. High cation scavenging, free radical scavenging and total reducing activities were observed for Acrosiphonia, Caulerpa, Ulva, Sargassum, Spatoglossum and Iyengaria. It was also observed that 15 tropical seaweeds contained negligible amounts of antinutritional compounds, including tannic acid, phytic acid, saponins, alkaloids and terpenoids. Nutritionally, green and brown seaweeds provided higher sources of energy (150–300 calories per 100 g) compared to red seaweeds (80–165 calories per 100 g). Additionally, this study also confirmed that tropical seaweeds improved the oxidative stability of food oils and, therefore, might be recommended as natural antioxidant additives. The overall results confirm that tropical seaweeds are potential sources of nutrition and antioxidants and may be explored as functional food, dietary supplementation or animal feed. Additionally, they may also be explored as food supplements for fortifying food products, as food toppings or for garnishing and seasoning foods. However, a human or animal toxicity analysis is required before any conclusive recommendation for daily food or feed intake can be made. [ABSTRACT FROM AUTHOR]

Food resources are limited in arid countries such as the United Arab Emirates (UAE); the salinity of the groundwater, together with a lack of natural fresh water sources and arable land, force the country to import most of its food. However, seaweed could play an important role in providing a locally available food resource, as it does not require fresh water and arable land to grow. The traditional use of several seaweed species as food sources has been documented in Asia and the Americas, where their nutritional composition has been well reported. Although the UAE's aquatic environment is quite harsh due to high water salinity (over 40 g/L) and high surface water temperatures (over 35 °C), its native seaweed species could play a role as a food source in this arid region, thereby bolstering the country's level of food security. To evaluate its potential in this context, fresh samples of the native Ulva intestinalis seaweed were collected in the shallow waters of Abu Dhabi Emirate, UAE. These samples were calculated to contain 34.38 ± 0.24 kcal, with a biomass composition of 5.185 ± 0.04% carbohydrate, 3.32 ± 0.14% protein, and 0.04 ± 0.01% fat (by dry matter). Of all the minerals present in the biomass, potassium had the highest concentration (7947 ± 319.5 ppm), followed by magnesium (3075.9 ± 1357 ppm) and sodium (756.3 ± 478 ppm). The water-soluble vitamins B1, B2, B3, B6, and C were below the detection limit in the samples. The rich concentration of essential minerals such as potassium, magnesium, iron and zinc in Ulva intestinalis makes it a promising novel food source. To the best of our knowledge, this is the first experimental study to examine the feasibility of using seaweed that is native to the UAE as a nutritional and sustainable food source in order to address the challenge of food security currently being faced by the country. [ABSTRACT FROM AUTHOR]

Antioxidants play an important role as Reactive Oxygen Species (ROS) chelating agents and, therefore, the screening for potent antioxidants from natural sources as potential protective agents is of great relevance. The main aim of this study was to obtain antioxidant-enriched fractions from the common seaweed Fucus spiralis and evaluate their activity and efficiency in protecting human cells (MCF-7 cells) on an oxidative stress condition induced by H2O2. Five fractions, F1-F5, were obtained by reversed-phase vacuum liquid chromatography. F3, F4 and F5 revealed the highest phlorotannin content, also showing the strongest antioxidant effects. The cell death induced by H2O2 was reduced by all fractions following the potency order F4 > F2 > F3 > F5 > F1. Only fraction F4 completely inhibited the H2O2 effect. To understand the possible mechanisms of action of these fractions, the cellular production of H2O2, the mitochondrial membrane potential and the caspase 9 activity were studied. Fractions F3 and F4 presented the highest reduction on H2O2 cell production. All fractions decreased both caspase-9 activity and cell membrane depolarization (except F1). Taken all together, the edible F. spiralis reveal that they provide protection against oxidative stress induced by H2O2 on the human MCF-7 cellular model, probably acting as upstream blockers of apoptosis. [ABSTRACT FROM AUTHOR]