Search

Algae are an underexploited source of natural bioactive compounds in Western countries, so an increasing interest in the valorization of these marine organisms has emerged in recent years. In this work, the effect of extracting solvent on the extraction yield, phenolic content, antioxidant capacity, and antimicrobial activity of nine brown macroalgae species (Ascophyllum nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissima, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum, and Fucus spiralis) was assessed. Total phenolic content (TPC) and the antioxidant properties of extracts by different assays: radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) were performed. The antimicrobial activity of extracts was studied against six different foodborne microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa. The highest extraction yield was achieved in ethanolic extracts. However, the highest TPC and FRAP values were obtained on the ethyl acetate extracts, especially from A. nodosum. Concerning algal species, the highest TPC and FRAP values were found in A. nodosum, while the highest DPPH-RSA values were achieved in the hexane extracts of B. bifurcata. The antimicrobial activity of algal extracts varied according to the solvent and alga selected, suggesting the species- and solvent-dependent behavior of this property, with B. bifurcata extracts showing the highest results for a wide range of bacteria. Our results provide insight on the characterization of widespread brown algae in the coasts of the North-Western region of the Iberian Peninsula, reflecting multiple health-enhancing properties which may lead to their exploitation in food, pharmacological, and cosmetic industries. European Commission | Ref. UP4HEALTH (H2020-BBI-JTI-2019) n. 888003 Programa Iberoamericano de Ciencia y Tecnología | Ref. CYTED— AQUA-CIBUS, P317RT0003 European Commission | Ref. ERA-NET ERA-HDHL (H2020) (n 696295) Fundação para a Ciência e a Tecnologia | Ref. PTDC / OCE-ETA / 30240 / 2017 Fundação para a Ciência e a Tecnologia | Ref. POCI-01-0145-FEDER-030240 Fundação para a Ciência e a Tecnologia | Ref. UIDB / 50016/2020 Ministerio de Ciencia e Innovación | Ref. RYC-2017-22891 Xunta de Galicia | Ref. ED431F 2020/12 Xunta de Galicia | Ref. ED481A- 2019/295

Seaweed consumption has increased considerably in Europe as a result of new trends in food. The macroelement (Na, Ca, K, Mg) and trace element (B, Ba, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sr, V, Zn) levels in different species of edible brown seaweeds were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). European Himanthalia elongata species had the highest recorded concentrations of K (57480 mg/kg dry weight). Asian Undaria pinnatifida species had the highest Fe content (58.8 mg/kg dw). Five grams/day of dehydrated seaweed of the Asian U. pinnatifida species mainly contributes to the admissible daily intake of Mg (9.32% adults) and Na (7.05% adults). In any case which exceeds the maximum intake values of any of the elements analyzed, the macro- and trace element levels can vary considerably in a short period of time, so it is necessary to assess the toxic risk in edible seaweeds.

10 Pág. Departamento de Tecnología de Alimentos​​, Edible seaweeds Chondrus crispus, Codium fragile, Himanthalia elongata, Ulva lactuca and Undaria pinnatifida, without any treatment (control seaweeds), were stored at 4 °C for 15, 30, 60, 15 and 30 days, respectively, until microbial counts exceeded 7 log cfu/g. High pressure processed (HPP) seaweeds, treated at 400 or 600 MPa for 5 min on day 2 after collection, were held at 4 °C until day 180. At the start of storage, 133 volatile compounds were detected in control seaweeds, with 89, 31, 45, 79 and 69 compounds found in C. crispus, C. fragile, H. elongata, U. lactuca and U. pinnatifida, respectively. Chemical groups including the highest number of compounds were aldehydes (24), alcohols (23), ketones (18), hydrocarbons (17) and benzene compounds (14). At the end of storage, 131 compounds were detected in control seaweeds, including 18 aldehydes, 28 alcohols, 23 ketones, 14 hydrocarbons and 13 benzene compounds, and 164 compounds in HPP-treated seaweeds, including 23 aldehydes, 31 alcohols, 19 ketones, 23 hydrocarbons and 15 benzene compounds. Increases in the levels of alcohols, benzene compounds and S-compounds and decreases in hydrocarbons, aldehydes and acids were recorded during storage of some control seaweeds, and increases in the levels of alcohols, acids and N-compounds and decreases in aldehydes, ketones and furans during storage of some HPP-treated seaweeds. Odour acceptance fell below rejection threshold as early as on day 15 for control U. lactuca while it remained acceptable until day 60 for control H. elongata and until day 180 for all the HPP-treated seaweeds. HPP treatment at 400 to 600 MPa for 5 min, in combination with refrigerated storage, is a useful tool for seaweed preservation, given its beneficial effects on microbial quality and sensory characteristics., This research was supported by project AGL2013-42911-R (Ministerio de Economía y Competitividad, Spain). The courageousness and camaraderie from Ana del Olmo during the performance of this study is acknowledged by the rest of authors

Algae are a complex, polyphyletic group of organisms, affordable and naturally rich in nutrients, but also valuable sources of structurally diverse bioactive substances such as natural pigments. The aim of this work was to evaluate the polar and non-polar pigment contents of different commercial dried algae (brown: Himanthalia elongata, Undaria pinnatifida, Laminaria ochroleuca, red: Porphyra spp., and a blue-green microalga: Spirulina spp.). The pigment extraction was carried out using different solvents (100% methanol, 100% methanol acid free, 100% ethanol, 90% acetone, N,N-dimethylformamide, dimethyl sulfoxide-water (4:1, v/v) and pH 6.8 phosphate buffer), selected according to their affinity for each class of pigments. Acetone proved to be an efficient solvent to extract chlorophylls from brown and red algae, but not from Spirulina spp. Porphyra spp. presented considerably higher levels of all pigments compared to brown algae, although Spirulina spp. presented significantly higher (p &lt, 0.05) levels of chlorophylls, carotenoids and phycobiliproteins, compared to all macroalgae. The content of fucoxanthin extracted from the three brown algae was highly correlated to the carotenoid content. Within this group, Himanthalia elongata presented the highest fucoxanthin/total carotenoids ratio. Although the yield of extraction depended on the solvent used, the algae studied herein are an interesting source of pigments of great value for a wide range of applications.

WOS:000569919500022; This study was focused on the phenolic content and associated cosmetic activities of seven brown marine macroalgae:Alaria esculenta,Ascophyllum nodosum,Bifurcaria bifurcata,Fucus serratus,Halidrys siliquosa,Himanthalia elongata, andLaminaria ochroleuca, selected for their abundance in Brittany and their phlorotannin production. Phlorotannins were extracted by maceration followed by a liquid/liquid purification to obtain fractions enriched in phlorotannins. Seasonal and yearly variations in phenolic contents were investigated thanks to the Folin-Ciocalteu assay to find the best harvesting season for each species.H-1 nuclear magnetic resonance (NMR) was used to validate the presence of phenolic compounds and to compare the species in terms of phenolic signals, as they produce different phlorotannin molecules. Activities required for cosmetic applications (i.e., radical scavenging, antioxidant, photoprotective, and anti-aging activities) were assessed by in vitro tests. Fucales, especiallyA. nodosum,F. serratus,H. elongata, andH. siliquosa, showed higher phenolic contents than Laminariales.Temporal variations were apparent for five seaweeds with the highest phenolic content, notably in autumn. The phenolic content was high regardless of the season and antioxidant and photoprotective activities were similar to those of commercial molecules, allowing year-round algal harvesting. The anti-aging activity ofA. nodosumandF. serratusfractions was higher than the active tea flavonol, epigallocatechin gallate. These results are promising for the use of abundant marine macroalgae as a source of natural active ingredients for cosmetic applications.

The effect on the biochemical characteristics of Iberico semi-hard cheese supplemented with Himanthalia elongata (HE), Laminaria ochroleuca (LO), Porphyra umbilicalis (PU), Ulva lactuca (UL) or Undaria pinnatifida (UP) seaweeds was investigated. Addition of 1% dehydrated seaweed to curd increased total free amino acids in LO cheese and decreased them in HE and UP cheeses at 60 days with respect to control cheese. Lipolysis was markedly enhanced in UL cheese, which showed on day 60 a 6.0-fold higher concentration of total free fatty acids than control cheese. Seventy-six volatile compounds were detected in cheeses with seaweeds and 54 in control cheese. Aldehydes and alcohols reached higher levels in the control cheese, esters and ketones in PU cheese, acids and sulphur compounds in UL cheese, hydrocarbons in HE and PU cheeses, and furans in HE and UP cheeses.

15 Pág. Departamento de Tecnología de Alimentos​​, Seaweeds are highly perishable foods due to their richness in nutrients. High pressure processing (HPP) has been applied for extending the shelf life of fresh seaweeds but there is no information on the effect of HPP on the bacterial diversity of seaweeds. The culturable bacteria of six species of fresh edible seaweeds (green seaweeds Codium fragile and Ulva lactuca, brown seaweeds Himanthalia elongata, Laminaria ochroleuca and Undaria pinnatifida, and red seaweed Chondrus crispus) were investigated and compared to those of HPP-treated (400 and 600 MPa for 5 min) seaweeds, at the start and end of their refrigerated storage period. A total of 523 and 506 bacterial isolates were respectively retrieved from untreated and HPP-treated seaweeds. Isolates from untreated seaweeds belonged to 18 orders, 35 families, 71 genera and 135 species whereas isolates from HPP-treated seaweeds belonged to 13 orders, 23 families, 43 genera and 103 species. HPP treatment significantly reduced the number of isolates belonging to 6 families and greatly increased the number of Bacillaceae isolates. At the end of storage, decreases in bacterial diversity at the genus and species level were observed for untreated as well as for HPP-treated seaweeds., This study was supported by project AGL 2013-42911-R (Ministerio de Economía y Competitividad, Spain).

The main nutritional/bioactive compounds (protein; aminoacids, AA; fucose; minerals; vitamins B12 and C; and total phenolic content, TPC) of nine commercial algae powders, used as food supplements, were studied. Undaria pinnatifida showed the highest protein/aminoacid contents (51.6/54.4 g 100 g–1). Among brown macroalgae, Himanthalia elongata showed the highest fucose content (26.3 g kg−1) followed by Laminaria ochroleuca (22.5 g kg−1). Mineral contents of 15–24% were observed in the algae, being particularly excellent sources of iodine (69.0–472.0 mg kg−1). Porphyra spp. and Palmaria palmata showed the highest vitamin B12 contents (667–674 µg kg−1). Vitamin C ranged among 490.4–711.8 mg kg–1. H. elongata showed the highest total phenolic content (14.0 g kg–1). In conclusion, the studied algae are excellent sources of protein, AA, minerals, vitamin C and some of them presented particularly high vitamin B12 and fucose contents, which may have a potential use as food supplements.

Seaweed habitats are characterised by constantly fluctuating environmental conditions which can influence the biochemical composition of species. To quantify the natural variability in concentrations and composition of pigments and fatty acids, a seasonal and spatial analysis of ecologically and economically important seaweed species (Fucus serratus, Ascophyllum nodosum, Himanthalia elongata, Laminaria digitata and Palmaria palmata) from Ireland was undertaken. Results revealed both common and species-specific patterns in seasonal and spatial algal composition. Generally, pigment concentrations decreased during summer months and were associated with a higher ratio of xanthophylls to chlorophylls. A similar response was observed regarding the proportions of polyunsaturated fatty acids (PUFA) which also decreased during summer. Concentrations in total fatty acids (TFA) revealed two distinct patterns in the five species investigated. In the two fucoid species, an increase in TFA during summer months was positively correlated with high proportions of monounsaturated fatty acids, implying an accumulation of storage lipids; in the remaining three species, proportions of PUFA were highest during winter and generally followed the seasonal trends of TFA. On a larger, geographical, scale, results demonstrated an influence of sampling location on pigments and fatty acids. Results highlight the complexity of interacting seasonal, spatial and species-specific drivers determining the biochemical composition of seaweeds which influences their value as food source and should be considered when natural stocks are harvested for high-value commercial applications.

The volatile fraction of dehydrated edible seaweeds belonging to seven species (Himanthalia elongata, Laminaria ochroleuca, Palmaria palmata, Porphyra umbilicalis, Saccharina latissima, Ulva lactuca and Undaria pinnatifida) was analyzed by gas chromatography–mass spectrometry, after solid-phase microextraction of samples. Thirty-six hydrocarbons, 34 ketones, 28 aldehydes, 23 alcohols, 8 carboxylic acids, 6 halogenated compounds, 4 furans, 3 esters, 2 sulphur compounds, 2 pyrazines, 1 pyridine and 1 amine were detected among the 151 volatile compounds found in seaweeds. There were significant differences between seaweed species for all the volatile compounds. Hydrocarbons reached their highest levels in U. pinnatifida, ketones in P. umbilicalis, aldehydes in P. palmata and P. umbilicalis, alcohols in P. umbilicalis, carboxylic acids in S. latissima, and halogenated compounds in L. ochroleuca and S. latissima. Sensory analysis revealed that P. palmata, U. lactuca and H. elongata were the seaweeds showing the most potent seafood odour and seaweed odour characteristics. © 2016 Elsevier Ltd

Lipophilic compounds present in dichloromethane extracts of five brown macroalgae from the Portuguese coast were analyzed by gas chromatography-mass spectrometry (GC-MS). Their dicarboxylic acids, long-chain aliphatic alcohols, and monoglyceride profile are reported for the first time. Additionally, other new compounds were also first reported: 24-methylene-cholesterol in Himanthalia elongata, Laminaria ochroleuca, and Undaria pinnatifida; desmosterol and brassicasterol in H. elongata, L. ochroleuca, Sargassum muticum, and U. pinnatifida; fucosterol and campesterol in S. muticum; and cholest-5-en-3-ol-(3 beta)-3-phenyl-2-propenoate in Cystoseira tamariscifolia. Brown macroalgae dichloromethane extracts are mainly composed of fatty acids (463.4-3089.0 mg kg(-1) of dry material) and sterols (75.5-442.7 mg kg(-1) of dry material). High amounts of polyunsaturated fatty acids were found, with the omega-6/omega-3 ratios of all species lower than 3. Cystoseira tamariscifolia, H. elongata, and S. muticum showed to be also promising sources of fucosterol. These results seem to uphold the incorporation of these macroalgae in a more balanced diet, as well as their use in the nutraceutical industry, as long as they are coupled with sustainable management of these natural resources.

A protein extract from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray was prepared and its functional properties, colour and amino acid composition were assessed for its potential future use by the food industry. The total content of amino acids was determined as 54.02 ± 0.46 g amino acids/kg dry weight, with high levels of the essential amino acids lysine and methionine. SDS-PAGE showed 5 protein bands with molecular weights of 71.6, 53.7, 43.3, 36.4 and 27.1 kDa. The water holding capacity and oil holding capacity were determined as 10.27 ± 0.09 g H2O/g and 8.1 ± 0.07 g oil/g respectively. Foaming activity and stability were higher at alkaline pH values. The emulsifying capacity and stability of the extract varied depending on the pH and oil used. These results demonstrate the potential use of Himanthalia elongata protein extract in the food industry. NutraMara – Marine functional foods research initiative

In the present work, a comprehensive methodology to carry out the screening for novel natural functional compounds is presented. To do that, a new strategy has been developed including the use of unexplored natural sources (i.e., algae and microalgae) together with environmentally clean extraction techniques and advanced analytical tools. The developed procedure allows also estimating the functional activities of the different extracts obtained and even more important, to correlate these activities with their particular chemical composition. By applying this methodology it has been possible to carry out the screening for bioactive compounds in the algae Himanthalia elongata and the microalgae Synechocystis sp. Both algae produced active extracts in terms of both antioxidant and antimicrobial activity. The obtained pressurized liquid extracts were chemically characterized by GC-MS and HPLC-DAD. Different fatty acids and volatile compounds with antimicrobial activity were identified, such as phytol, fucosterol, neophytadiene or palmitic, palmitoleic and oleic acids. Based on the results obtained, ethanol was selected as the most appropriate solvent to extract this kind of compounds from the natural sources studied. © 2009 Elsevier B.V. All rights reserved.

Induced chemical defense reactions are widespread in marine brown algae. Despite the evidence that the biosynthesis of defense metabolites can be up-regulated upon herbivory, we do not know how this regulation of biosynthetic pathways to secondary metabolites is achieved in brown algae. In higher plants, the phytohormone jasmonic acid (JA) is crucial for the mediation of induced chemical defenses, and several findings of this metabolite from marine sources have been reported. We tested the hypothesis that JA or related metabolites play a role in induced brown algal defense. Quantification of oxylipins with a detection limit around 20 ng g(-1) algal tissue did not reveal the presence of JA in the seven examined brown algal species Dictyota dichotoma, Colpomenia peregrina, Ectocarpus fasciculatus, Fucus vesiculosus, Himanthalia elongata, Saccharina latissima (formerly Laminaria saccharina), and Sargassum muticum. Moreover, treatment with ecologically relevant concentrations of JA and methyl jasmonate did not lead to a significant change in the profile of medium- and non-polar metabolites of the tested algae. Only when high concentrations ofor =500 microg ml(-1) medium of the phytohormones were applied that a metabolic response which could be attributed to unspecific stress was observed. Bioassays with D. dichotoma that focused on medium- and non-polar compounds confirmed the lack of a biological role of JA and methyl jasmonate in the induction of algal induced chemical defenses. The phytohormone-treated samples did not exhibit any increased defense potential towards the amphipod Ampithoe longimana and the isopod Paracerceis caudata. JA and related phytohormones, known to be active in higher plants, thus appear to play no role in brown algae for induction of the defense chemicals studied here.

The identity of five macroalgae used as sea vegetables or food ingredients has been determined by amplification of the ribosomal DNA ITS region and RFLP analysis. This allows the detection of specificity patterns for each species and provides an alternative method, when morphological or biochemical methods fail, for control of their use as food ingredients. Alga-specific PCR primers have been used to determine the ITS rDNA sequences of DNAs extracted from dried and ground algae up to 5 years old. The seaweeds studied were the red algae Palmaria palmata (dulse), Porphyra umbilicalis (nori), and Chondrus crispus (pioca) and the brown algae Himanthalia elongata (sea spaghetti) and Laminaria sp (konbu). Total genomic DNA suitable for amplification was extracted from the alga powder following the CTAB method. This methodology allowed the sequencing of the amplified product and the drawing of theoretical restriction maps useful in the choice of restriction enzymes for RFLP analysis. Enzymes that appeared useful included Mbo I and Alu I. Cutting with a single enzyme was sufficient to obtain characteristic patterns for the red algae P palmata, P umbilicalis and C crispus. For the two brown algae H elongata and Laminaria sp the ITS rDNA sequence showed a lack of suitable restriction site, contrary to other species for which characteristic patterns were obtained. © 2003 Society of Chemical Industry

Different studies have already demonstrated a direct relationship between seaweed consumption and the prevention and/or improvement in the treatment of diseases related to oxidative stress. Algae have been used, therefore, in the investigation of bioactive compounds, with the aim of developing new medicines and healthy foods. This article presents the results of the analysis of vitamin C, vitamin E, fucoxanthin, chlorophyll a, pheophytin a, lutein, β-carotene, total polyphenol content, and antioxidant activity in Himanthalia elongata dehydrated, hydrated by immersion, boiled, and steamed. These results contribute to a better understanding of the bioactive compounds’ behavior when subjected to different culinary methods and reaffirms the potential of H. elongata as interesting food in our diet Diferentes estudios han demostrado una relación directa entre el consumo de algas y la prevención y/o mejora en el tratamiento de enfermedades relacionadas con el estrés oxidativo. En las algas se ha investigado la presencia de compuestos bioactivos, con el objetivo de desarrollar nuevos medicamentos y alimentos para la salud. Este trabajo presenta los resultados del análisis de vitamina C, vitamina E, fucoxantina, clorofila a, feofitina, luteína, β-caroteno, contenido total de polifenoles y actividad antioxidante en Himanthalia elongata deshidratada, hidratada por inmersión, hervida y al vapor. Estos resultados contribuyen a una comprensión mejor del comportamiento de los compuestos bioactivos cuando la H. elongata se somete a diferentes métodos culinarios y confirma su interés potencial como alimento de nuestra dieta This work was financed under project no. 09TAL023203PR from Xunta de Galicia SI

Seasonal variations and the effect of reproductive development on resource acquisition by two intertidal fucoid species, the iteroparous Fucus serratus L. and the semelparous Himanthalia elongata (L.) S. F. Gray were examined. The oxygen-exchange characteristics of vegetative apical tissue of both non-fertile and fertile plants and receptacle tissue were compared at monthly intervals throughout reproductive development. Respiratory rates in non-fertile F. serratus varied seasonally between 1.5 and 8.0 μmol g−1 fresh wt h−1; in fertile plants the receptacle had a significantly lower respiratory rate than the vegetative tissue. The respiratory rate of the vegetative button of fertile H. elongata displayed less seasonal variation and was lower than that of the receptacle, which varied from a maximum of 9.5 μmol g−1 fresh wt h−1 at receptacle initiation in October to a minimum of 2.0 μmol g−1 fresh wt h−1 in February. The maximum photosynthetic rate (P max) of non-fertile plants of both species did not vary in a distinct seasonal manner (∼60 μmol g−1 fresh wt h−1 for F. serratus and ∼12 μmol g−1 fresh wt h−1 for H. elongata). In fertile plants, the P max of the receptacle tissue was (∼50% lower in F. serratus, and at its peak three times higher in H. elongata, than that of vegetative tissue. The stable carbon-isotope ratio (δ13C) did not differ between different tissue types in F. serratus, but values did vary seasonally, being less negative in the summer than in the winter (−13.5‰ compared to −18‰). The receptacle tissue of H. elongata also displayed a distinct seasonal variation in δ13C values (−12‰ in summer, −16‰ in winter), whilst the δ13C of the vegetative button did not vary seasonally. The rate of uptake of inorganic nitrogen by the vegetative thallus was lower in H. elongata than in F. serratus. The receptacle tissue of F. serratus had lower uptake rates than the vegetative tissue, whilst the uptake rate by H. elongata receptacle tissue was higher than that of the vegetative button.

Polysaccharides present in several seaweeds (Kappaphycus alvarezii, Calliblepharis jubata, and Chondrus crispus—Gigartinales, Rhodophyta; Gelidium corneum and Pterocladiella capillacea—Gelidiales, Rhodophyta; Laurencia obtusa—Ceramiales, Rhodophyta; Himanthalia elongata, Undaria pinnatifida, Saccorhiza polyschides, Sargassum vulgare, and Padina pavonica—Phaeophyceae, Ochrophyta) are analyzed by spectroscopic techniques. The nature of the polysaccharides (with extraction and without any type of extraction) present in these seaweeds was determined with FTIR-ATR and FT-Raman analysis of extracted phycocolloids and ground dry seaweed.

This is the first report about the arrival of the encrusting cheilostomatid bryozoan Watersipora subtorquata on floating seaweeds in German coastal waters of the North Sea. During summer 2012, drifting or stranded thalli of the non-indigenous brown macroalga Himanthalia elongata were investigated on the island of Helgoland showing numerous benthic species covering the holdfast of Himanthalia. Out of the 120 basal structures investigated, 8.3% had viable colonies of the invasive, non-native W. subtorquata attached to them. Himanthalia and W. subtorquata have both their nearest origin reported to be in the English Channel (La Manche), approximately 800 km away from Helgoland. Now we found W. subtorquata as a rafting species in the eastern part of the North Sea, showing its ability to distribute easily over very large distances using floating algae as a natural transport vector. This event might constitute the first step in the potential introduction of this alien species into German coastal waters.

The in vitro degradation of dietary fibre from three brown seaweeds (Himanthalia elongata, Laminaria digitata and Undaria pinnatifida) was studied, using human faecal flora. Two sets of fibre were tested: (1) total algal fibres extracted from the whole algae, mainly composed of alginates, and (2) purified fibres (sulphated fucans, Na-alginates and laminarans) representative of those contained in the whole brown algae. Mannuronate, one algal component, was also investigated. Substrate disappearance and short-chain fatty acid (SCFA) production were monitored after 6, 12 and 24 h fermentation. Gas production was followed hourly during the first 9 h and then at 12 and 24 h. Sugarbeet fibre was used as a fermentation reference substrate. According to the fermentative indices used, most of each of the total algal fibres disappeared after 24 h (range 60-76%) but, unlike the reference substrate, they were not completely metabolized to SCFA (range 47-62%). Among the purified algal fibres, disappearance of laminarans was approximately 90% and metabolism to SCFA was approximately 85% in close agreement with the fermentation pattern of reference fibres. Sulphated fucans were not degraded. Na-alginates exhibited a fermentation pattern quite similar to those of the whole algal fibres with a more pronounced discrepancy between disappearance and production of SCFA: disappearance was approximately 83% but metabolism was only approximately 57%. Mannuronate was slowly fermented but its metabolism corresponded to its disappearance from the fermentative medium. Thus, the characteristic fermentation pattern of the total fibres from the three brown algae investigated was attributed to the peculiar fermentation of alginates, and mannuronate was shown not to be directly involved.

Summary The brown alga Himanthalia elongata (L.) Gray, commonly known as the sea bean, is beginning to be used as human food in Europe. Large quantities are also exported from Europe to Japan where this Pheophyceae is particularly appreciated. The purpose of this work was to determine the food value of this species by studying the variations in its main chemical constituents during the harvesting period (March or June) with respect to different parts of the thallus. We considered variations in nitrogen and protein content, the presence of the main amino acids, the percentage of alginic acid and lipids and the concentrations of mineral salts, soluble and insoluble fibers and fat- and water—soluble vitamins. Except for alginic acid and fibers, the fertile parts of the plant were richer than the sterile parts. This alga has greater food value at the beginning than at the end of spring, and lipid concentrations are higher than those of other food algae.

Extracts of marine algae have been tested to determine their ability to cleave DNA. The species producing positive results wereAscophyllum nodosum, Fucus serratus, F. spiralis, F. vesiculosus, Halidrys siliquosa andHimanthalia elongata. Partial purification of each extract by dialysis against water revealed that the active compounds in each species were high molecular weight polyphenols.

Phycocolloids present in three brown (Himanthalia elongata, Bifurcaria bifurcata, Saccharina latissima) and five red edible seaweeds (Mastocarpus stellatus, Gigartina pistillata, Chondracanthus acicularis, Nemalion helminthoides and Dumontia contorta) were studied by FTIR-ATR spectroscopy. Infrared spectra of polysaccharide standards (alginate, agar, iota-, kappa- and lambda-carrageenan) were obtained for comparison. The main polysaccharide found in brown seaweeds was alginate, a linear copolymer of mannuronic (M) and guluronic acid (G). Alginate M/G ratio was tentatively estimated from specific absorption bands (808/787cm-1 and 1030/1080cm-1) in infrared spectra, suggesting higher values of mannuronic than guluronic acid blocks (M/G>1) for brown seaweeds. According to their infrared spectra, all the red seaweeds studied were mainly carrageenan producers. Thus, M. stellatus showed absorption bands at 929.0, 844.7 and 803.2cm-1 of a typical hybrid kappa/iota/mu/nu-carrageenan, meanwhile G. pistillata and C. acicularis, showed the characteristic broad band (830-820cm-1) of lambda-type carrageenan. Moreover, when the second-derivative was obtained to improve resolution of overlapped bands in the original FTIR spectra, this band was divided into several sharper signals, indicating the presence of lambda-/theta-/xi-carrageenans. Accordingly with their FTIR spectra, N. helminthoides contained sulphated polysaccharides, such as carrageenan or mannans, while D. contorta produced lambda- with lesser amounts of kappa-carrageenan. Therefore, FTIR-ATR spectroscopy is proposed as a useful tool for the food, pharmaceutical and cosmetics industry to check the phycocolloid quality of a raw seaweed material by a quick and non-destructive method. © 2011 Elsevier Ltd.

The effects of three different types of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis) added at two concentrations (2.5% and 5% dry matter) on the physicochemical and morphological characteristics of gel/emulsion systems were evaluated. The addition of seaweeds improved (P < 0.05) water- and fat-binding properties except in the case of Nori added at 2.5%. Hardness and chewiness of the cooked products with added seaweed were higher (P < 0.05), and springiness and cohesiveness were lower (P < 0.05) than in control samples. Colour changes in meat systems were affected by the type of seaweed. The morphology of sample differed depending on the type of seaweed added, and this is the result of differences in physical and chemical characteristic of the seaweed powder used. In general, products formulated with the brown seaweeds (Sea Spaghetti and Wakame) exhibited similar behaviour, different from that of products made with the red seaweed Nori. © 2007 Elsevier Ltd. All rights reserved., This research was supported under project AGL2005-07204-CO2-02, Plan Nacional de Investigación Científica, Desarrollo e Innovación Technológica (I+D+I).

International audience; The soluble and insoluble dietary fibre contents of seven marine algae ('sea vegetables'): wakame (Undaria pinnatifida), hijiki (Hijiki fusiformis), sea spaghetti (Himanthalia elongata), arame (Eisenia bicyclis), sea lettuce (Ulva lactuca), A O nori (Enteromorpha spp), and nori (Porphyra tenera) were determined by the gravimetric method of Prosky et al (J Assoc Anal Chem 1988, 71 1017-1023) following some adaptations. These seaweeds are particularly rich in dietary fibres with total dietary fibre contents varying between 32.7 and 74.6% (on a dry weight basis) of which 51.6 to 85.0% are water soluble. Marine algae appear to be good sources of fibres presenting great chemical, physico-chemical and rheological diversities that may be beneficial in nutrition.

Summary Radioisotopes ( 86 Rb or 32 P) injected or applied during short periods of time to different marine algae show by means of autoradiographic method, that a rapid component of translocation exists in these plants (several m · h -1 ). The larger the species (or more convenient for autoradiography with a thin thallus such as Himanthalia elongata or Chorda filum ), the higher are the experimental values obtained. Similarly, the shorter the transport time (between 2 and 10 min), the higher is the value of the speed obtained (extrapolated values may reach 20 to 25 m · h -1 ). In conclusion, the size of the sample, the sensitivity of the method and the experiment time appear to be the limiting factors for a better demonstration of a rapid component of long distance transport.

The growth of epiphytes (plant and animal) was investigated at various stages in the development of the low littoral alga Himanthalia elongata . The vegetative thallus, or button, is very resistant to the settlement of epiphytes on its upper surface, but susceptible to extensive coverage on its lower surface and stalk, especially by Bryozoa and spirorbid worms. The receptacles or straps are invaded by a microforest of filamentous algae, which in turn provides accommondation and in many cases food for many invertebrates, including gastropods, amphipods and larval Diptera. Spirorbid worms on the underbuttons are confined to sites sheltered from strong water currents and wave action, but other epiphytes of the underbuttons show little regard for these features. Microfores and its associated fauna are restricted to sheltered sites. Perspex discs set up as imitation Himanthalia buttons were colonized by the same epiphytes as real Himanthalia buttons, but on both sides, indicating the existence of a special protective mechanism for the upper surfaces of real Himanthalia buttons.

Changes in the intracellular concentration of the hexitols mannitol and altritol have been monitored in plants of Himanthalia elongata (L.) S.F. Gray maintained in a range of hyposaline and hypersaline media for up to 3 days. Altritol forms the major component of the low-molecular-weight organic solute fraction in H. elongata , decreasing in hyposaline media and increasing under hypersaline conditions. This is the first direct evidence that altritol may be involved in osmotic adjustment in H. elongata . Intracellular mannitol levels also varied as a direct function of the external salinity, showing a greater proportional change than altritol. Changes in intracellular hexitol concentration were shown to be independent of the rate of net photosynthesis, indicating osmotic, rather than respiratory, control of internal mannitol and altritol levels.

From an acetylated fraction of Himanthalia elongata extract, an eight-ring phenolacetate was isolated and its structure elucidated with the aid of field desorption mass spectrometry and other spectroscopic methods.

A method is described for the separation and quantification of a range of low-molecular-weight organic solutes, which are major osmolytes, in crude ethanolic extracts of marine algae. The method relies on the use of a silica amine modified column and refractive index detection. The acetonitrile to water ratio was varied to maximise separations. The method is suitable for the detection of simple carbohydrates, amino acids and their derivatives and is particularly suitable for the separation of the isomeric hexitols, altritol and mannitol, found in the brown alga Himanthalia elongata .

Twenty-eight brown seaweeds contain agglutinins that show activity against animal and human erythrocytes. Three brown seaweeds are described whose hemagglutinic activity has not been previously reported: Ectocarpus confervoides, Giffordia granulosa and Cutleria multifida. Hemagglutinic activity against different erythrocytes is as follows: rabbit, 100%; sheep, 71%; chicken, 64%; guinea-pig, 39%; human, 38%; horse, 25% and calf, 21%. The highest agglutinic activity was found with rabbit erythrocytes, with maximum titres of: Fucus serratus (218), Laminaria saccharina (217) and Himanthalia elongata (217). The species Giffordia granulosa showed certain specificity against human erythrocytes. In general, the hemagglutinic activity of these brown seaweeds seems to be of a polyphenolic nature. Agglutinic activity of some of these brown seaweeds can be used as a taxonomic index.

The distribution of altritol (talitol), an isomer of the hexitol, mannitol, was studied in species thought to be closely related to Himanthalia elongata, in which it is already known to occur. Natural abundance 13C nuclear magnetic resonance (NMR) spectroscopy has shown its existence in a further four species endemic to the southern hemisphere: Notheia anomala, Hormosira banksis and Xiphophora chondrophylla, from Australia, and Bijurcariopsis capensis from South Africa. H. banksis, X. chondrophylla and B. capensis all exhibit ‘primitive’ fucalean characters. N. anomala has also been shown to have characteristics common to some members of the Fucales. Therefore the distribution of altritol supports recent views on the relationships between these species and the origin of the Fucales.

It is possible to obtain approximately 0.2% (relative to dry weight) phenols soluble in ethyl acetate from HIMANTHALIA ELONGATA. After removal of a fraction containing high-molecular weight substances, a total of 17 oligomeric phlorotannins with 2 to 8 aromatic rings can be isolated from the mixture of the acetylated phenol fraction. Apart from 2 derivatives belonging to the fucol group, diphlorethol and a tetraphlorethol not yet fully identified, all the other substances are fucophlorethols. Amongst these substances, a phenoxylated therphenyl derivative and several fucophlorethols with two-fold phenoxy-substituted biphenyl moieties were identified for the first time.

Natural abundance 13 C NMR spectroscopy has shown that altritol (talitol) is a major constituent within vegetative and reproductive tissues of Himanthalia elongata . Quantitative GC studies have confirmed that altritol concentrations are 80–160% higher than for the hexitol mannitol (which occurs throughout the Phaeophyta). The data suggest an osmotic role for altritol.