Original article Bifurcaria bifurcata: a key macro-alga as a source of bioactive compounds and functional ingredients Celso Alves, 1 * Susete Pinteus, 1 Tiago Sim~ oes, 1 Andre Horta, 1 Joana Silva, 1 Carla Tecel~ ao 1,2 & Rui Pedrosa 1 1 MARE Marine and Environmental Sciences Centre, ESTM, Instituto Politecnico de Leiria, 2520-641 Peniche, Portugal 2 Instituto Superior de Agronomia, LEAF, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal (Received 5 February 2016; Accepted in revised form 5 April 2016) Summary The aim of this work was to study the proximate composition and the bioactive profile of Bifurcaria bifurcata. It contains 73.31 0.69% of moisture, 8.57 0.11 g per 100 g dry weight (d.w.) of protein, 5.81 0.14 g per 100 g d.w. of lipid content and 30.15 0.00 g per 100 g d.w. of ash. The polyunsatu- rated fatty acids were the most abundant fatty acid (FA), accounting for 2426.56 mg per 100 g which rep- resents 41.77% of the total FA. The methanolic fraction showed high quantity of polyphenols (220.01 0.010 phloroglucinol equivalents g 1 extract), DPPH radical reduction capacity (EC 50 :58.82 lg mL 1 ) and oxygen radical absorbent capacity (3151.35 119.33 lmol Trolox equivalents g 1 extract). The highest antimicrobial effect was observed against Pseudomonas aeruginosa (11.3 1.5 mm) and Sac- charomyces cerevisiae (IC 50 :17.07 lg mL 1 ) induced by methanolic and dichloromethane fractions, respectively. Dichloromethane fraction revealed the highest antitumor activity on Caco-2 and HepG- 2 cells. Bifurcaria bifurcata can be a promising source of bioactive compounds and functional ingredients. Keywords Antimicrobial agents, antioxidant activity, bioassays, fatty acids, natural products, nutrition, seaweeds. Introduction Over recent decades, there has been an increasing demand for natural compounds and functional foods associated with health and welfare of humans, by pharmaceutical, cosmetic and food industries (Panges- tuti & Kim, 2011). Consequently, the marine environ- ment has proved to be one of the most interesting and rich source of natural compounds, many of which exhibit structural/chemical features not found in terrestrial environment (Murray et al., 2013). For many centuries, algae have played an important eco- logical and commercial role in many regions of the world, for food or therapeutic practice, especially in Asian countries such as China, Japan and Korea (Almeida et al., 2011). More recently, the interest in the commercial utilisation of algae has been increas- ing, as these showed to be a rich source of valuable chemical constituents exhibiting different biological activities with applications in food, cosmetic, agricul- tural and horticultural sectors, as well in human health (Stengel et al., 2011). However, Portugal and many other European countries have not benefited conveniently, so far, either from the nutritional point of view or from the adding value associated with the unique compounds that these marine organisms pro- duce. The ability of algae to adapt to extreme environ- mental conditions is directly reflected on the diversity of compounds produced with high biotechnological relevance such as phenolic compounds, terpenes or alkaloids that are related with antioxidant, antimicro- bial, antitumor and other bioactivities (El Gamal 2010). Moreover, due to their low content in lipids, high concentration in polysaccharides, natural richness in minerals, polyunsaturated fatty acids and vitamins (Guschina & Harwood, 2006), algae are referenced as an important source of functional ingredients well recognised due to their valuable health beneficial effects (Pangestuti & Kim, 2011). Macro-algae can be classified into three classes: green algae (Chlorophyta), red algae (Rhodophyta) and brown algae (Ochrophyta) (Guiry & Guiry, 2014). Among the algae groups settled in temperate regions, Phaeophyceae are the most abundant and the species of Sargassaceae and Dictyotaceae families constitute the main producers of bioactive compounds with 2/3 1638 *Correspondent: Fax: +351 262 783 088; e-mail: celso.alves@ipleiria.pt International Journal of Food Science and Technology 2016, 51, 1638–1646 doi:10.1111/ijfs.13135 © 2016 Institute of Food Science and Technology