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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]

The purpose of this study was to examine the growing demand for healthy functional dairy products by investigating the incorporation of Spirulina platensis into concentrated yoghurt and evaluating its impact on starter cultures and product properties. A comprehensive analysis demonstrated the potential of spirulina to enhance bifidobacteria growth, acidity, PUFA content, and antioxidant activity in yoghurts, indicating its potential to improve the nutritional quality and oxidative stability of dairy products. The study investigated the impact of different Spirulina ratios on the activity of yoghurt starter cultures, including Lb. casei, Lb. plantarum, Lb. acidophilus, and Bifidobacterium mix. Three concentrated yoghurt samples were prepared, including a control, a probiotic sample, and a sample incorporating Spirulina powder. The findings suggest that while Spirulina did not significantly affect lactic acid bacteria, it noticeably stimulated the growth of Bifidobacterium. Treated samples showed increased acidity and TVFAs, with pH values displaying an inverse trend compared to the control. Clear differences in colour parameters and sensory evaluations distinguished control from treated samples. Additionally, Spirulina supplementation demonstrated a pronounced effect in enhancing antioxidant activity, as observed through DPPH radical scavenging activity, and influencing the peroxide value, reflecting improved oxidative stability in the yoghurt. This successful utilisation of Spirulina suggests its potential application in diverse edible algae in the food sector, especially in dairy products, enhancing both nutritional and sensory aspects, as well as contributing to improved oxidative stability

A water-soluble polysaccharide (EP) was purified from edible algae Enteromorpha prolifera. Gel permeation chromatography (GPC), ion chromatography (IC), and fourier transform infrared (FT-IR) were performed to characterize its structure. EP was defined as a low molecular weight (6625 Da) composed of rhamnose, glucose, glucuronic acid, xylose, galactose, arabinose, and mannose. Moreover, it was a sulfated polysaccharide with a degree of substitution (DS) of 1.48. Then, the high-fat diet/streptozotocin (HFD/STZ) induced diabetic mouse model was established to support evidence for a novel hypoglycemic mechanism. Results showed that blood glucose (47.32%), liver index (7.65%), epididymal fat index (16.86%), serum total cholesterol (26.78%) and triglyceride (37.61%) in the high-dose EP (HEP) group were significantly lower than those in the HFD group. Noticeably, the content of liver glycogen in the HEP group was significantly higher (62.62%) than that in the HFD group, indicating the promotion of glycogen synthesis. These beneficial effects were attributed to significantly increased protein kinase B (AKT) phosphorylation and its downstream signaling response. Further studies showed that diabetic mice exhibited excessive O-GlcNAcylation level and high expression of O-linked β-D-N-acetylglucosamine transferase (OGT), which were decreased by 62.21 and 30.43% in the HEP group. This result suggested that EP had a similar effect to OGT inhibitors, which restored AKT phosphorylation and prevented pathoglycemia. This work reveals a novel hypoglycemic mechanism of EP, providing a theoretical basis for further studies on its pharmacological properties in improvement of T2DM. [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]

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.

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]

Abstract Background Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions. Methods We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice. Results The treatments inhibited the degranulation of RBL-2H3 cells and immunoglobulin E (IgE) production, suggesting anti-asthma effects in vitro. The in vitro anti-asthma effects in cells were confirmed in mice following the induction of asthma by alumina and chicken egg ovalbumin (OVA). Oral administration of the bioprocessed Ecklonia cava and purified fractions suppressed the induction of asthma and was accompanied by the inhibition of inflammation- and immune-related substances, including eotaxin; thymic stromal lymphopoietin (TSLP); OVA-specific IgE; leukotriene C4 (LTC4); prostaglandin D2 (PGD2); and vascular cell adhesion molecule-1 (VCAM-1) in bronchoalveolar lavage fluid (BALF) and other fluids and organs. Th2 cytokines were reduced and Th1 cytokines were restored in serum, suggesting the asthma-induced inhibitory effect is regulated by the balance of the Th1/Th2 immune response. Serum levels of IL-10, a regulatory T cell (Treg) cytokine, were increased, further favoring reduced inflammation. Histology of lung tissues revealed that the treatment also reversed the thickening of the airway wall and the contraction and infiltration of bronchial and blood vessels and perialveolar inflammatory cells. The bioprocessed Ecklonia cava/mushroom mycelia new functional food showed the highest inhibition as compared with commercial algae and the fractions isolated from the bioprocessed product. Conclusions The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections.

The use of seaweed and algal derived products in the food industry has grown rapidly in recent times. Major areas of expansion have been in Western countries where algae derived commodities are being utilised as edible foods or sources of high value ingredients. However, studies focused on potential allergenicity attributed to these food items, prevalence of allergenicity, and public health awareness are limited. Therefore, the current research summarises the existing literature focused on algal induced allergy in humans. Of the available literature, a total of 937 titles were identified, and 33 articles underwent subsequent full-text screening. Most research focused on prevalence and were derived from studies conducted in Europe (58%), North America and Canada (33%), and the remainder Australia and South Korea (9%). No studies addressed the need for public education or labelling of algal products. Our review reports that the available evidence identified points to algal derived products as being potential sources of allergens in the human food chain. Several components have been characterised that are shown to induce allergic responses in humans. Few studies have assessed the prevalence of algal allergenicity in the general population and as such further research is warranted given the increased usage of these products in the food industry. [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.

Background: Ecklonia cava is an edible marine brown alga harvested from the ocean that is widely consumed in Asian countries as a health-promoting medicinal food The objective of the present study is to evaluate the anti-asthma mechanism of a new functional food produced by bioprocessing edible algae Ecklonia cava and shiitake Lentinula edodes mushroom mycelia and isolated fractions. Methods: We used as series of methods, including high performance liquid chromatography, gas chromatography, cell assays, and an in vivo mouse assay to evaluate the asthma-inhibitory effect of Ecklonia cava bioprocessed (fermented) with Lentinula edodes shiitake mushroom mycelium and its isolated fractions in mast cells and in orally fed mice. Results: The treatments inhibited the degranulation of RBL-2H3 cells and immunoglobulin E (IgE) production, suggesting anti-asthma effects in vitro. The in vitro anti-asthma effects in cells were confirmed in mice following the induction of asthma by alumina and chicken egg ovalbumin (OVA). Oral administration of the bioprocessed Ecklonia cava and purified fractions suppressed the induction of asthma and was accompanied by the inhibition of inflammation- and immune-related substances, including eotaxin; thymic stromal lymphopoietin (TSLP); OVA-specific IgE; leukotriene C4 (LTC4); prostaglandin D2 (PGD2); and vascular cell adhesion molecule-1 (VCAM-1) in bronchoalveolar lavage fluid (BALF) and other fluids and organs. Th2 cytokines were reduced and Th1 cytokines were restored in serum, suggesting the asthma-induced inhibitory effect is regulated by the balance of the Th1/Th2 immune response. Serum levels of IL-10, a regulatory T cell (Treg) cytokine, were increased, further favoring reduced inflammation. Histology of lung tissues revealed that the treatment also reversed the thickening of the airway wall and the contraction and infiltration of bronchial and blood vessels and perialveolar inflammatory cells. The bioprocessed Ecklonia cava/mushroom mycelia new functional food showed the highest inhibition as compared with commercial algae and the fractions isolated from the bioprocessed product. Conclusions: The in vitro cell and in vivo mouse assays demonstrate the potential value of the new bioprocessed formulation as an anti-inflammatory and anti-allergic combination of natural compounds against allergic asthma and might also ameliorate allergic manifestations of foods, drugs, and viral infections. [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.

Seaweed aquaculture is one of the fastest growing marine sectors with 31.2 million tonnes year–1 of harvest worth over 11.7 billion USD. Commercial operations still rely on traditional techniques but innovative strategies are essential for future expansion. The present paper reports on a simple device that could effectively segregate non-fused haploid gametes from diploid zygotes in the green alga Ulva lactuca. The differential phototactic behaviour of gametes and zygotes was used for their separation. Approximately 56.2% non-fused haploid gametes and 5.3% diploid zygotes were separated after 5 min and after 1 hr and 2 hr, the composition of gametes was 26.6 and 8.8%, respectively while that of zygotes 32.7 and 57.4%, respectively. The effects of extrinsic abiotic factors, including light, temperature, salinity, photoperiod, dehydration and thallus fragmentation, on the induction of gametogenesis was found to be limited at 35°C (13.33 ± 5.77%) and a short day 9:15 h light:dark photoperiod (20 ± 4.08%), while dehydration treatments enhanced spore induction. This study demonstrated the efficient and cost-effective utilisation of locally available materials in producing a simple, small, precise, durable and easy to use system, which also saved on energy. The effective segregation of non-fused gametes from zygotes aids in cytological preparation, bio-chemical characterisation investigations as well as breeding and hybridisation all of which have direct implications on the future farming of Ulva and other species of seaweeds with similar life phases.

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]

Understanding the physiological responses of kelp to environmental parameters is essential for the conservation of natural kelp beds and increased cultivation yield. We investigated the effects of photosynthetically active radiation (PAR) and temperature on photosynthesis of a subarctic edible brown alga, Saccharina sculpera (Laminariales), using pulse amplitude modulation (PAM)–chlorophyll fluorometry and optical dissolved oxygen sensors. Photosynthesis–PAR experiments at 8 °C, 15 °C, and 22 °C revealed the highest net photosynthetic rates at 22 °C. Values for compensation (Ec) and saturation (Ek) indicated a high affinity for a light environment that reflected the natural vertical habitat of this alga. The photosynthetic response of S. sculpera to temperature indicated that the optimum temperature for oxygenic photosynthesis ( K o p t G P ) was 22.9 °C, which was consistent with the highest seawater temperature in Japanese distribution range for this subarctic species. The alga survived for 168 h at 24 °C in darkness. Continuous 6 h exposure to PAR of 100 µmol (low) and 1000 µmol (high) photons m–2 s–1 at 8 °C, 15 °C, and 22 °C induced chronic photoinhibition in the alga, with greater declines in effective quantum yields of photosystem II (ΦPSII). Failure to recover Fv/Fm after dark acclimation at low and high PAR was observed, except for low PAR at 8 °C. The physiological performance of S. sculpera indicates an affinity for a low light environment. We expect that our results will lead to an improvement in aquaculture techniques through the regulation of cultivation depth. [ABSTRACT FROM AUTHOR]

To clarify the presence of algal-susceptible indigenous bacteria (SIB) in the gut, ICR mice were fed high-sucrose (50% w/w) diets containing either no fibre (NF), 5% brown alga "arame", Eisenia bicyclis; 5% red alga "tsunomata", Chondrus ocellatus; 5% (w/w) green alga "hitoegusa", Monostroma nitidum; or 5% (w/w) cyanobacterium "blue-green alga", Aphanizomenon flos-aquae for 14 days. Faecal frequency and weight were the highest in mice fed M. nitidum. Plasma cholesterol was the lowest in the mice fed C. ocellatus. The caecal microbiome was examined by 16S rDNA (V4) amplicon sequencing. Principal component analysis of operational taxonomical units (OTUs) revealed that the edible algae altered the microbiome. An increase in abundance levels of OTUs by E. bicyclis (Bacteroides acidifaciens-, Bacteroides intestinalis-, Bifidobacterium pseudolongum-like), C. ocellatus (Bacteroides vulgatus- and Escherichia coli-like), M. nitidum (Faecalibaculum rodentium- and Muribaculum sp.-like), and A. flos-aquae (Muribaculum sp.) was detected. Abundance of Lactobacillus johnsonii was the lowest in mice fed the algal diets. Bacteria that increased in numbers were identified as algal SIBs. SIBs might have different effects on host health depending on the food material consumed. From the algal SIBs, B. pseudolongum, B. vulgatus, F. rodentium, and L. johnsonii were isolated using blood-liver agar and identified with the 16S rDNA BLAST search. Future studies should be focused on isolation of other SIBs. [ABSTRACT FROM AUTHOR]

Edible algae are rich in high-value nutrient active substances, such as polysaccharides, high-unsaturated fatty acids, taurine, carotenoids and alfalfa. Whether as daily food or extracting active substances as medicines, edible algae are of great benefit to people. Therefore, there is an increasing demand for edible algae products. However, the conventional processing techniques used in food industry for edible algae will bring issues about the deterioration of the quality of algae food, the loss of aroma flavor, incomplete extraction, and low efficiency. In this review, the recent development in novel processing techniques for edible algae could improve the efficiency, save energy, improve quality. This review discussed advantages and disadvantages of currently available efficient techniques about drying and sterilization of edible algae, including ultrasound, infrared radiation, microwave, radio frequency. Extraction techniques in edible algae were also discussed in this review, including microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and pulsed electric field-assisted extraction (PEF). Currently, the processing of edible seaweed is mainly concentrated on three aspects of drying, sterilization and extraction. In future research, it is necessary to consider application of more processing methods to maintain the characteristics of edible algae. For example, RF and artificial intelligence can be combined to improve the efficient processing of edible algae. • The significance of edible algae processing is discussed in detail. • Pointed out the shortcomings of traditional processing technologies. • Focus on the application of high-efficiency technologies in the sterilization, drying and extraction of edible algae. • Compare the advantages and disadvantages of different efficient processing technologies. • Discussed and compared different efficient extraction technologies. [ABSTRACT FROM AUTHOR]

Seaweed (edible algae) is not a staple food in the Western diet, despite occasional use as a traditional ingredient in coastal areas. High nutritional value, combined with the expansion of the health-food industry, has led to a resurgence of seaweed in the British diet. While seaweed could be useful in tackling dietary iodine insufficiency, consumption of some species and sources of seaweed has also been associated with risks, such as toxicity from high iodine levels, or accumulation of arsenic, heavy metals and contaminants. The current retail level of seaweed and edible algae in the UK market, either as whole foods or ingredients, was evaluated with particular focus on labelling and iodine content. Seaweed-containing products (n = 224) were identified. Only 22 products (10%) stated information regarding iodine content and another 40 (18%) provided information sufficient to estimate the iodine content. For these products, the median iodine content was 110 μg/g (IQR 21–503) and 585 μg per estimated serving (IQR 105–2520). While calculations for iodine exposure per serving relied on assumptions, 26 products could potentially lead to an iodine intake above the (European) tolerable adult upper level of 600 μg/day. In the context of the data presented, there is scope to improve product labelling (species, source, processing, content).

The mineral and saccharide contents, and antioxidant properties in aqueous extract solutions of eleven dried algal products obtained from the Boso Peninsula, Japan, were investigated. Potassium content was high in the brown alga Sargassum fusiforme . Polysaccharides content and viscosity were high in the red algae Gloiopeltis furcata , Chondrus ocellotus and C. elatus. Total phenolic compound content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity, and Fe-reducing power were high in brown algae Eisenia bicyclis , S. fusiforme and the red alga Pyropia sp. Superoxide anion (O 2 − ) radical-scavenging capacity was high in G. furcata , C. ocellotus , C. elatus and the green alga Monostroma nitidum. Lactobacillus plantarum strains isolated from the coast could ferment G. furcata , C. elatus and M. nitidum . The O 2 − radical-scavenging capacities of the red algae were increased by fermentation. These results suggest that some macroalgal beach-cast brown algae without fermentation and red algae with fermentation can be utilized as natural resources for functional foods. [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]

To clarify the anti-oxidant and anti-glycation properties of traditional edible algae, aqueous extract solutions (AESs) from eight dried algal products that were commercially available in the Miura Peninsula of Japan were prepared. AESs of the red alga, Pyropia sp. (nori), demonstrated strong Fe-reducing power with a high total phenolic compound content. On the other hand, the sporophyll of the brown alga Undaria pinnatifida (mekabu) exhibited high superoxide anion radical-scavenging capacity. Anti-glycation activity in bovine serum albumin (BSA)-fructose (Fru) and in BSA-methylglyoxal (MGO) was high for nori and the stem of Sargassum fusiforme (naga-hijiki). The results of the BSA-MGO model agreed with those of the phenolic content and Fe-reducing power. Anti-glycation activities of mekabu, Sargassum horneri (akamoku), naga-hijiki, the frond of U. pinnatifida (wakame), and Gelidium elegans (tengusa) in the BSA-Fru model were clearly increased by fermentation with Lactobacillus plantarum Miura-SU1 isolated from the Miura Peninsula. The results of the present study suggest that, once fermented with lactic acid bacteria (LAB), akamoku and other edible algae will have a potential role in preventing diabetes- and aging-related glycation. [ABSTRACT FROM AUTHOR]

The antioxidant and anti-glycation properties in aqueous extract solutions (AESs) of 11 dried algae products were investigated. AESs of brown algae Ecklonia kurome (kurome) and Ecklonia stolonifera (tsuruarame) showed a strong DPPH radical-scavenging capacity and Fe-reducing power with high total phenolic compound content. On the other hand, superoxide anion radical-scavenging capacities of Porphyra sp. (iwanori, red alga), sporophyll of Undaria pinnatifida (mekabu, brown alga), and Gelidiaceae sp. (tengusa, red alga) were also high. Anti-glycation activities in BSA-fructose and BSA-methylglyoxal glycation were also high in kurome, while iwanori showed high activity. Results of the BSA-fructose model agreed with those of superoxide anion radical-scavenging. On the other hand, those of the BSA-methylglyoxal model agreed with those of the phenolic content, DPPH radical-scavenging capacity, and Fe-reducing power. Anti-glycation activities of iwanori, U. pinnatifida (wakame), and mekabu in the BSA-fructose model were clearly increased by fermentation with Lactobacillus plantarum AN6. [ABSTRACT FROM AUTHOR]

Chlorella vulgaris has gained popularity in recent years as a functional food ingredient with its highly nutritious profile. In this study, we have explored the effects of baking at 125 °C for 15 min to C. vulgaris CCAP 211/11b on the biomass's water soluble carbohydrate and protein contents, total lipids, and soluble vitamins (B1, B2, B3, B5, B7, B9, B12 and C). Control (raw) and experimental (baked) groups' average soluble carbohydrate content varied between 26 and 27%, soluble proteins 21–23%, and total lipids 7–9% of dried cell weight indicating no significant effects of baking process on C. vulgaris. Results of liquid chromatography-mass spectrometer (LC-MS/MS) showed that baking also had no significant effect on vitamins except B3. Vitamins B1, B2, and B3 were higher in baked samples compared to the control group. Overall, C. vulgaris deemed suitable for addition to functional food recipes with short baking durations considering the durability of main biochemical components as well as water soluble vitamins. • Effects of baking (125 °C, 15 min) on biochemical composition of Chlorella vulgaris • Soluble carbohydrates, proteins, total lipids content were not affected by baking • Soluble vitamins were not impacted by baking and retained composition [ABSTRACT FROM AUTHOR]

Edible seaweed consumption is a route of exposure to arsenic. However, little attention has been paid to estimate the bioaccessibility and/or bioavailability of arsenosugars in edible seaweed and their possible degradation products during gastrointestinal digestion. This work presents first use of combined inductively coupled plasma mass spectroscopy (ICP-MS) with electrospray ionization tandem mass spectrometry (ESI-MS/MS) with two-dimensional HPLC (size exclusion followed by anion exchange) to compare the qualitative and quantitative arsenosugars speciation of different edible seaweed with that of their bioavailable fraction as obtained using an in vitro gastrointestinal digestion procedure. Optimal extraction conditions for As species from four seaweed namely kombu, wakame, nori and sea lettuce were selected as a compromise between As extraction efficiency and preservation of compound identity. For most investigated samples, the use of ammonium acetate buffer as extractant and 1 h sonication in a water bath followed by HPLC-ICP-MS resulted in 40-61% of the total As to be found in the buffered aqueous extract, of which 86-110% was present as arsenosugars (glycerol sugar, phosphate sugar and sulfonate sugar for wakame and kombu and glycerol sugar and phosphate sugar for nori). The exception was sea lettuce, for which the arsenosugar fraction (glycerol sugar, phosphate sugar) only comprised 44% of the total extracted As. Interestingly, the ratio of arsenobetaine and dimethylarsinic acid to arsenosugars in sea lettuce extracts seemed higher than that for the rest of investigated samples. After in vitro gastrointestinal digestion, approximately 11-16% of the total As in the solid sample was found in the dialyzates with arsenosugars comprising 93-120% and 41% of the dialyzable As fraction for kombu, wakame, nori and sea lettuce, respectively. Moreover, the relative As species distribution in seaweed-buffered extracts and dialyzates was found to be very similar. Collection of specific fractions from the size-exclusion column to be analysed using anion-exchange HPLC-ESI-MS/MS enabled improved chromatographic selectivity, particularly for the less retained arsenosugar (glycerol sugar), facilitating confirmation of the presence of arsenosugars in seaweed extracts and dialyzates. Using this approach, the presence of arsenobetaine in sea lettuce samples was also confirmed. [ABSTRACT FROM AUTHOR]

Abstract: Twelve commercially available edible marine algae from France, Japan and Spain and the certified reference material (CRM) NIES No. 9 Sargassum fulvellum were analyzed for total arsenic and arsenic species. Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126μgg−1. Arsenic species in alga samples were extracted with deionized water by microwave-assisted extraction and showed extraction efficiencies from 49 to 98%, in terms of total arsenic. The presence of eleven arsenic species was studied by high performance liquid chromatography–ultraviolet photo-oxidation–hydride generation atomic–fluorescence spectrometry (HPLC–(UV)–HG–AFS) developed methods, using both anion and cation exchange chromatography. Glycerol and phosphate sugars were found in all alga samples analyzed, at concentrations between 0.11 and 22μgg−1, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2μgg−1). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (<0.9μgg−1) and generally high arsenate (As(V)) concentrations (up to 77μgg−1) were found in most of the algae studied. The results obtained are of interest to highlight the need to perform speciation analysis and to introduce appropriate legislation to limit toxic arsenic species content in these food products. [Copyright &y& Elsevier]

Microalgae are natural sources of proteins and bioactive compounds and can be used as a functional ingredient to improve the nutritional quality of gluten-free (GF) bread. Several strategies have been applied to aid processing and enhance GF bread properties. This study evaluated the partial replacement of pea flour by Chlorella sorokiniana biomass powder to increase the nutritional quality of GF bread. The bread was enriched with 2.5 g (M2.5) or 5.0 g (M5.0) of microalga powder per 100 g of the blend of rice flour and corn starch in substitution of pea flour. For the evaluation of the carotenoid profile and fatty acids composition, two baking temperature-time binomials were tested (220 °C/12 min and 180 °C/15 min). Comparing the control and the M5.0 bread, the microalga addition increased the protein content from 67 mg g−1 to 85 mg g−1 and the lutein content from 1.6 μg g−1 to 57.5 μg g−1. Furthermore, the omega-3 content in the fatty acids increased from 5.0% to 6.1%. Sensory analysis revealed that the M2.5 bread had an acceptance rate greater than 70%. No impact on the texture, neither on the specific volume, was induced by the C. sorokiniana addition. • Highligths • The bread with 2.5% of microalga had an acceptance rate higher than 70%. • The protein content increased 26% for the bread with a high content of microalga. • The baking process did not affect the β-carotene content of the microalga enriched bread. • The combination of high temperature and short baking time generates lower lutein degradation. • For both baking conditions, the bread with 5% of microalga can be classified as a high-lutein functional food.. [ABSTRACT FROM AUTHOR]

Algae CO 2 biofixation provides a promising opportunity due to earn carbon credits and valuable end uses. For balancing technology, energy and economy issues in practical utilization, this approach quantitively interprets the contradictions from upstream CO 2 source with a wide range of initial concentration to downstream CO 2 biofixation product including edible algae and algal biomass. The influence of upstream CO 2 deliverable on algal quantity and quality have been assessed, and the influence of CO 2 concentration on CO 2 transport mode choice has been also assessed coupling the transportation distance. In downstream algal fixation, quantitively relationship of algal growth have been established. The assessment discovered that direct energy consumptions complied with logarithmic relationship with specific productivities while both direct energy and indirect energy consumption complied with linear relationship with protein content. According to sensitive uncertainty analysis, initial CO 2 concentration is a critical parameter to influence significantly energy consumption in upstream CO 2 deliverables and algal quality while the contents of protein and specific productivity are the critical sensitive parameters in downstream algae deliverables. Potential modification systems are achieved for significantly reducing energy consumption by improving specific productivity and carbon abundance with low protein content in algae. Unlabelled Image • Establish quantitively relationship of algal growth and CO 2 fixation efficiency • Correlation of upstream flue gas and downstream CO 2 biofixation product choice • Effects of algae growth rate and protein contents on energy consumption • Effects of initial CO 2 concentration on algal products quality • Key impact factors extracted by the sensitive uncertainty analysis [ABSTRACT FROM AUTHOR]

Seaweed (edible algae) is not a staple food in the Western diet, despite occasional use as a traditional ingredient in coastal areas. High nutritional value, combined with the expansion of the health-food industry, has led to a resurgence of seaweed in the British diet. While seaweed could be useful in tackling dietary iodine insufficiency, consumption of some species and sources of seaweed has also been associated with risks, such as toxicity from high iodine levels, or accumulation of arsenic, heavy metals and contaminants. The current retail level of seaweed and edible algae in the UK market, either as whole foods or ingredients, was evaluated with particular focus on labelling and iodine content. Seaweed-containing products ( n = 224) were identified. Only 22 products (10%) stated information regarding iodine content and another 40 (18%) provided information sufficient to estimate the iodine content. For these products, the median iodine content was 110 μg/g (IQR 21-503) and 585 μg per estimated serving (IQR 105-2520) . While calculations for iodine exposure per serving relied on assumptions, 26 products could potentially lead to an iodine intake above the (European) tolerable adult upper level of 600 μg/day. In the context of the data presented, there is scope to improve product labelling (species, source, processing, content).