Abstract(s)
As microalgas são uma potencial fonte para a obtenção de variados compostos biologicamente activos (carotenóides, ácidos gordos, vitaminas e polissacáridos), com uma eficácia superior à verificada pelas tradicionais culturas vegetais terrestres. São por isso consideradas ingredientes funcionais, o que conduziu ao recente aumento do seu interesse comercial. A produção de microalgas compreende conhecimentos e competências multidisciplinares como: biotecnologia e aspectos nutricionais. Sendo esta última área um campo de pesquisa emergente, pois possibilita a avaliação da biodisponibilidade de diversos compostos. A importância terapêutica dos ácidos gordos polinsaturados n-3 (PUFA n-3) em particular o ácido eicosapentaenóico (EPA; 20:5n-3) e o ácido docosahexaenóico (DHA; 22:6n- 3) é bem conhecida. Actualmente, a maior fonte de EPA e DHA é obtida pelo pescado. Contudo, as microalgas marinhas sintetizam PUFA n-3 em elevadas quantidades, o que as torna atractivas do ponto de vista nutricional. Concomitantemente, a síntese de carotenóides pela maioria das microalgas é uma alternativa viável como suplemento dietético. O trabalho desenvolvido visa avaliar as potencialidades de novos ingredientes funcionais na dieta humana: microalga Diacronema vlkianum, como fonte de ómega-3, e Chlorella vulgaris na sua variante laranja, como fonte de pigmentos antioxidantes. O estudo foi desenvolvido em modelos animais (ratinhos Wistar), e compreendeu a avaliação da bioincorporação de ácidos gordos e carotenóides após a suplementação respectiva com Diacronema vlkianum (2 meses) e Chlorella vulgaris (1 mês). A determinação de ácidos gordos foi feita com recurso à Cromatografia Gás-Líquido com detector de Ionização de Chama (GC – FID). Já, a aferição de carotenóides foi executada através da Cromatografia Líquida de Alta Pressão (HPLC). A suplementação com Diacronema vlkianum revelou ter um impacto na mudança da composição de EPA, DPA e da razão Ʃn-3/Ʃn-6 nos tecidos analisados, indicando assim ser uma boa fonte de ómega-3. A análise da incorporação de carotenóides nos tecidos após suplementação com Chlorella vulgaris não permitiu a obtenção de resultados conclusivos, o que pressupõe uma nova abordagem metodológica no futuro.
Microalgae are considered a potential source of a wide spectrum of biologically active chemicals, such as: carotenoids, fatty acids, vitamins, and polysaccharides with a superior efficacy in relation to the traditional culture of vegetables. These microorganisms have been considered in a near past as potential source of functional food, which increase their commercial value. The production and consumption of microalgae requires multidisciplinary skills: biotechnology and nutritional aspects. This last area is emerging due to the allowance of a better knowledge of the assessment of toxicology and the bioavailability of the biomolecules in research. The importance of the therapeutic value of n-3 polyunsaturated fatty acids (PUFA n-3), especially eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) is well recognised. Nowadays, seafood is the major EPA and DHA dietary source. However, microalgae are also excellent producers of n-3 long chain fatty acids, making them an attractive source of PUFA n-3. Likewise, the majority of microalgae seem to be a viable alternative for carotenoids supply. This work aims to investigate the possible adoption of new functional ingredients in human diet: microalgae Diacronema vlkianum as a source of PUFA n-3, and Chlorella vulgaris (orange) as a font of carotenoids with antioxidant capacity. In order to understand the effect of fatty acid and carotenoid daily supplementation, the study was developed in two different parts. In both parts of the studie Wistar rats were used as an animal model. The tissues and organs collected were analysed by Liquid Chromatography (GC-FID), for determination of fatty acids percentages and by High Pressure Liquid Chromatography (HPLC) for carotenoids quantification in the tissues. The study with D. vlkianum revealed a significative increase of EPA, DPA and Ʃn- 3/Ʃn-6 in the tissues of supplemented rats. The carotenoids incorporation study didn’t reveal any tissue assimilation, which implies a new approach in future studies.
Microalgae are considered a potential source of a wide spectrum of biologically active chemicals, such as: carotenoids, fatty acids, vitamins, and polysaccharides with a superior efficacy in relation to the traditional culture of vegetables. These microorganisms have been considered in a near past as potential source of functional food, which increase their commercial value. The production and consumption of microalgae requires multidisciplinary skills: biotechnology and nutritional aspects. This last area is emerging due to the allowance of a better knowledge of the assessment of toxicology and the bioavailability of the biomolecules in research. The importance of the therapeutic value of n-3 polyunsaturated fatty acids (PUFA n-3), especially eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) is well recognised. Nowadays, seafood is the major EPA and DHA dietary source. However, microalgae are also excellent producers of n-3 long chain fatty acids, making them an attractive source of PUFA n-3. Likewise, the majority of microalgae seem to be a viable alternative for carotenoids supply. This work aims to investigate the possible adoption of new functional ingredients in human diet: microalgae Diacronema vlkianum as a source of PUFA n-3, and Chlorella vulgaris (orange) as a font of carotenoids with antioxidant capacity. In order to understand the effect of fatty acid and carotenoid daily supplementation, the study was developed in two different parts. In both parts of the studie Wistar rats were used as an animal model. The tissues and organs collected were analysed by Liquid Chromatography (GC-FID), for determination of fatty acids percentages and by High Pressure Liquid Chromatography (HPLC) for carotenoids quantification in the tissues. The study with D. vlkianum revealed a significative increase of EPA, DPA and Ʃn- 3/Ʃn-6 in the tissues of supplemented rats. The carotenoids incorporation study didn’t reveal any tissue assimilation, which implies a new approach in future studies.
Description
Tese de mestrado. Biologia (Biologia Humana e Ambiente). Universidade de Lisboa, Faculdade de Ciências, 2010
Keywords
Algas Microalgas Ácidos gordos Antioxidantes Teses de mestrado - 2010