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This work aims to assess the potential of the green seaweed Ulva fasciata Delile as an alternative source of dietary fibre (DF). Total DF content was determined, some of its physico-chemical properties described and the physiological effects of U. fasciata meal on rats fed a hypercholesterolemic diet were investigated. U. fasciata may be considered a potential alternative source of DF with a total content of about 400 g.kg -1 (dry basis) and interesting physico-chemical properties: water retention capacity of 8.74 g/water.g -1 dry sample (seaweed meal) and 0.90 (seaweed carbohydrate extract), lipid adsorption capacity of 4.52 g/oil.g -1 dry sample (seaweed meal) and 5.70 (seaweed carbohydrate extract), intrinsic viscosity of 2.4 dl.g -1 (seaweed carbohydrate extract) and cation exchange capacity of 3.51 Eq.kg -1 (seaweed carbohydrate extract). The diet containing seaweed meal was able to keep rats' total cholesterol (TC) down without causing any undesirable increase in LDL-C fraction. No evidence of toxic and/or antinutritional components in the seaweed meal was detected. Rats showed a fecal volume much greater (13 g) than that fed on cellulose diet (7 g) (p < 0.05). These properties confer on the seaweed the potential to be used in food technology for the acquisition of low-calorie food and might be important in body weight control, reduction of blood TC and LDL-C as well as in prevention of gastrointestinal diseases.

Natural antioxidants found in marine macroalgae are bioactive compounds known to play an important role in the prevention of diseases associated with aging cells protecting them against the oxidative damage. The purpose of this study was to evaluate the antioxidant and cytotoxic activity of ethanolic extracts of two species of red seaweeds, Amansia multifida and Meristiella echinocarpa. In vitro antioxidant activity was determined by DPPH radical scavenging assay, ferric-reducing antioxidant power (FRAP) assay, ferrous ion chelating (FIC) assay, β-carotene bleaching (BCB) assay and total phenolic content (TPC) quantification. Cytotoxicity was evaluated with the brine shrimp Artemia sp. lethality test. The TPC values observed in the present study indicated that both species A. multifida and M. echinocarpa are rich in phenolic compounds, reaching values of 45.40 and 28.46 mg gallic acid equivalent (GAE) g -1 of ethanolic extract, respectively. DPPH radical scavenging and ferrous ion chelating showed values of 60% and 17%, respectively. Both seaweed extracts inhibited β-carotene oxidation by approximately 40%. None of the algal extracts were potentially cytotoxic. The results have showed that extracts of both species of marine red algae exhibit antioxidant potential and low toxicity. They are sources of natural antioxidant compounds.

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CP 6043, Brasil, sakersil@gmail.com *A quem a correspondência deve ser enviada α-, β-caroteno e α-tocoferol em algas marinhas in natura α-and β-carotene, and α-tocopherol in fresh seaweeds Márcia Barbosa de SOUSA 1 , Kelma Maria dos Santos PIRES 1 , Daniel Barroso de ALENCAR 1 , Alexandre Holanda SAMPAIO 1 , Silvana SAKER-SAMPAIO 1 * IntroduçãoAs macroalgas marinhas constituem um grupo heterogêneo de vegetais encontrados abundantemente em todos os ecossistemas. São fonte de uma grande variedade de compostos benéficos para o homem, apresentando diversas aplicações em nutrição animal e humana (URBANO; GOÑI, 2002), indústria de alimentos (MAMATHA et al., 2007), fertilização do solo (BLUNDEN, 1991) e outras áreas biotecnológicas (FARIAS; NAZARETH; MOURÃO, 2001;LIMA et al., 2004). Durante as últimas décadas, a comunidade científica demonstrou interesse crescente pelo estudo dos carotenóides e das vitaminas lipossolúveis, que podem estar associados com a redução de doenças cardiovasculares e outras doenças degenerativas (WILLIS; WIANS-Jr, 2003;JOHNSON, 2004).Os carotenóides são pigmentos naturais que se destacam principalmente devido a sua ampla distribuição nos seres vivos, grande diversidade estrutural e numerosas funções fisiológicas, dentre as quais, a principal é atuar como precursores de vitamina A nos animais (BRITTON; LIAAEN-JENSEN; PFANDER, 1995).A vitamina A dietária dá origem a uma variedade de metabólitos ativos, coletivamente conhecidos como retinóides, compostos por retinóis, retinais e ácidos retinóicos, dependendo do grupo terminal polar (NOY, 2000). A maior parte do β-caroteno e de outros carotenóides provitamina A é convertida em retinol (OLSON, 1989;ARMSTRONG;HEARST, 1996;ARMSTRONG, 1997), mas eles não são considerados micronutrientes essenciais e não existe uma Ingestão Diária Recomendada (IDR) específica. Apesar disso, no cômputo da atividade vitamina A dos alimentos, referida como retinol equivalente (RE), eles são levados em consideração. De acordo com a Resolução de Diretoria Colegiada (RDC) N o 269, de 22 de setembro de 2005, da Agência Nacional de Vigilância Sanitária, do Ministério da Saúde, que trata da IDR de vitaminas, minerais e proteínas para indivíduos e diferentes grupos populacionais, a IDR de vitamina A consiste em 600 µg de RE para adultos. Cada 1 µg de β-caroteno corresponde a 0,167 µg de RE e cada 1 µg de outros carotenóides provitamina A, a 0,084 µg de RE (BRASIL, 2005). AbstractThe aim of this work was to evaluate the potential of 32 marine macro algae species, members of Chlorophyta, Rhodophyta and Phaeophyta, as sources of α-carotene, β-carotene and α-tocopherol. Both β-carotene and α-carotene were found in all species of green macroalgae analyzed. The maximum content of α-carotene was detected in algae belonging to Caulerpa genus and the minimum in Codium decorticatum. The amount of β-carotene found was minimum in Caulerpa mexicana and maximum in Ulva fasciata. Among the Rhodophyta species, eleven contain α-carotene, the maximum content was found in Botryocladia occidental...