A Review with Special Focus on the Iberian Peninsula
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Send Orders for Reprints to [email protected] Current Organic Chemistry, 2014, 18(7), 896-917 Bioproducts from Seaweeds: A Review With Special Focus On The Iberian Peninsula Susana M. Cardosoa,*, Loïc G. Carvalhob, Paulo J. Silvab, Mara S. Rodriguesc, Olívia R. Pereiraa,c and Leonel Pereirab aCERNAS, School of Agriculture, Polytechnic Institute of Coimbra, Bencanta, 3045-601 Coimbra, Portugal; bIMAR (Institute of Marine Research), Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Apartado 3046, 3001- 401 Coimbra, Portugal; cDTDT, School of Health Sciences, Polytechnic Institute of Bragança, Av. D. Afonso V, 5300-121 Bragança, Portugal Abstract: Seaweeds, i.e. macroalgae that occupy the littoral zone, are a great source of compounds with diverse applications; their types and content greatly determine the potential applications and commercial values. Algal polysaccharides, namely the hydrocolloids: agar, alginate and carrageenan, as well as other non-jellifying polysaccharides and oligosaccharides, are valuable bioproducts. Likewise, pig- ments, proteins, amino acids and phenolic compounds are also important, exploitable compounds. For the longest time the dominant market for macroalgae has been the food industry. More recently, several other industries have increased their interest in algal-derived products, e.g. cosmetics, pharmaceuticals and more recently, as a s ource of feedstock for biorefinery applications. This manuscript re- views the chemical composition of dominant macroalgae, as well as their potential added-value products and applications. Particular at- tention is devoted to the macroalgal species from the Iberian Peninsula. This is located in the Southwest of Europe and is influenced by the distinct climates of the Mediterranean Sea and the Atlantic Ocean, representing a rich spot of marine floral biodiversity. Keywords: Seaweeds, macroalgae, hydrocolloids, phenolic compounds, proteins, bioactives, fucoidans, ulvans, laminarans. 1. INTRODUCTION drugs of marine origin and the concomitant, exponential investiga- tion fo cusing that issue is p erhaps d elivering its first fruits. This is Seaweeds ( or m acroalgae) ar e aquatic, phot osynthetic or gan- the case for the beneficial properties o f various kelps (Laminaria isms belonging to the Eukaryota Domain and the Kingdoms Plantae spp. a nd Saccharina sp p.) for th e t reatment o f g oiter, w hich ar e (the gree n a nd r ed al gae) and t he Chr omista ( the br own a lgae). now known to be due to the relatively high iodine levels in these Although classification systems have changed over time, it is gen- macroalgae [4]. erally accepted that: a) the green algae are included in the phylum Chlorophyta and their pigmentation is identical to that of terrestrial Today, seaweeds are used in many countries for very different plants (i.e. chlorophylls a, b a nd carotenoids); b) the red algae be- purposes, i ncluding t heir di rect c onsumption a s f ood or s upple- long to the phylum Rhodophyta and their photosynthetic pigments ments (by animals and humans), as feedstock for the extraction of are chlorophyll a and the phycobilins ( i.e. R -phycocyanin and R- phycocolloids, or for their bioactive components and as biostimu- phycoerythrin) and carotenoids, mostly -carotene, lutein and zeax- lants and biofertilizers. Notably, direct use as food has strong roots anthin and c) the brown algae are included in the Phylum Ochro- in the East Asia, whereas the West seems to be more committed to phyta ( or t he H eterokontophyta), C lass Pha eophyceae and t heir the extraction of the h ydrocolloids, namely carrageenan, agar and pigments include the chlorophylls a and c, as well as carotenoids, alginate ( European re gistration nu mbers - E407, E406 a nd E40 0, dominated by fucoxanthin [1, 2]. respectively) [3, 5]. In addition, m any seaweeds are receiving in- creasing a ttention as a potential, r enewable sources f or t he f ood Seaweeds are fundamental to the food chain of all aquatic eco- industry, as a feed for livestock and as food directly [6]. Industrial- systems. A s pri mary pr oducers t hey pr oduce oxyge n a nd or ganic ized countries are currently increasing efforts regarding the manu- compounds which serve as the basic trophic level or food for many facturing of hi gh-value p roducts der ived fr om algae, since t hese other living beings. They have also found a role of great importance contain chemical components (e.g. polysaccharides, proteins, lipids to mankind. Indeed, coastal communities have been using macroal- and pol yphenols) w ith a w ide ra nge of bi ological ac tivities. Thi s gae in th e p reparation o f h ome medicines fo r th e treatment o f d is- range of activities l eads t o pr omising a pplications i n nut raceuti- tinct ailments for centuries. Green algae are useful as anthelmintics, cal/functional food, cosmetic, and pharmaceutical industries [7-9]. astringents and to treat gout, while brown algae are commonly used (Table 1) reviews t he seaweed or ders reported from t he I berian in th e tr eatment o f rh eumatic p rocesses, arteriosclerosis, m enstrual Peninsula with some known bioactivities. disorders, hype rtension, gas tric ul cers, goi ter, s kin di seases a nd syphilis. In tu rn, r ed alg ae can b e u sed a s an ticoagulants, anti- Moreover, as world energy demands continue to rise and fossil helmintics and for treating gastritis and diarrhea [3]. These applica- fuel resources are increasingly reduced, macroalgae have attracted tions are ba sed on t he em pirical know ledge of m any ge nerations attention, as a possible renewable feedstock to biorefinery applica- and, in m ost cases, the bioactive compounds and their respective tions, for the production of multiple streams of commercial interest mechanisms of action remain unknown. Still, the recent interest for including biofuels such as bioethanol and biogas [10-12], p articu- larly because they have considerable contents of carbohydrates. In this field, macroalgae have several advantages over terrestrial bio- *Address c orrespondence t o t his a uthor a t t he CERNAS - E scola S uperior A grária, mass, primarily because of their potentially high yields, no competi- Instituto Politécnico de Coimbra, Bencanta, 3045-601 Coimbra, Portugal; Tel: +351 239 802940; Fax: +351 273 239 802979; E-mail: [email protected] tion with food crops for the use of arable land and fresh water re- 1385-2728/14 $58.00+.00 © 2014 Bentham Science Publishers 897 Current Organic Chemistry, 2014, Vol. 18, No. 7 Cardoso et al. Table 1. Sytematics of ord ers of I berian P eninsula s eaweeds w ith [6]. The farming of seaweeds has expanded rapidly as demand has some documented bioactivity (after [2]). outstripped the supply available from natural resources. Com mer- cial har vesting oc curs i n a bout 35 c ountries, s pread be tween t he Phylum/Class Order Genera Species Northern and Southern Hemispheres, in waters ranging from cold, through temperate, to tropical [17]. The consumption and utilization Chlorophyta Bryopsidales 4 13 of seaweed worldwide are associated with a myriad of products that Dasycladale 1 1 generate n early U S$ 8 billion p er y ear [6]. A lmost 9 0 p ercent are food pr oducts for hum an consumption; t he re mainder i s for t he Siphonocladales 1 1 hydrocolloid industry focused on a gar, carrageenan and alginates. Cladophorales 2 9 Macroalgae for direct or indirect consumption (i.e. coloring, flavor- Ulvales 2 8 ing agents and biologically active compounds sold as dietary sup- plements) have been gaining market share, mainly due to the recog- Ulotrichales 1 1 nition of Man´s seaweed traditional uses in their daily lives. Rhodophyta 1.1. The Macroalgal Biodiversity of the Iberian Peninsula Bangiales 2 4 Ahnfeltiales 1 1 The Ib erian P eninsula is lo cated in the warm temperate, Medi- terranean-Atlantic r egion a nd t he I berian c oasts ar e unde r uni que Bonnemaisoniales 2 3 circumstances, receiving climatic influences from the North Atlan- Ceramiales 22 29 tic O cean ( western, nor th c oasts, a nd a djacent i slands) a nd t he Mediterranean Sea (southern, eastern coasts, and adjacent islands), Corallinales 7 14 thus generating a sharp latitudinal gradient in the macroalgal flora. Gelidiales 3 7 Along the coastline, rocky shores are separated by e xtended areas Gigartinales 18 22 of sandy beaches. Most of the beaches from the western coasts are very exposed and the algae which do occur in the intertidal zone are Gracilariales 2 5 mainly found closest to the low tide level. The intertidal algal flora Halimeniales 1 2 of the northern zone is similar to that of the coast of Central Europe i.e. Nemaliales 5 6 ( B rittany, Fr ance and t he southern pa rts of the B ritish I sles), while the intertidal algal flora of southwestern and eastern coasts is Neamatomales 1 1 very different, responding to a marked influence from the Mediter- Palmariales 2 2 ranean and th e North West African C oast species. T emperate spe- cies gra dually dec line in num ber s outhwards along t he W estern Plocamiales 1 1 Iberian coast, where some taxa have their southern limit [18, 19]. Rhodymeniales 5 5 The intertidal flora of the northwestern zones are dominated by Heterokontophyta/ Ascophyllum nodosum, Bifurcaria bifurcata, Himanthalia elongata, Phaeophyceae Saccorhiza polyschides ( Phaeophyceae, Fuc ales), Gelidium cor- neum, Gelidium pulchellum ( Rhodophyta, G elidiales), Chondrus Cutleriales 2 2 crispus, Mastocarpus stellatus, Calliblepharis jubata, Gigartina Desmarestiales 1 2 pistillata, Chondracanthus acicularis ( Rhodophyta, Gigartinales), Dictyotales 7 15 Osmundea pinnatifida, Pterosiphonia complanata ( Rhodophyta, Ceramiales) an d Corallina elongata ( Rhodophyta, Cor allinales).