Browsing by Author "Navalho, João"
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- Algae as food in Europe: an overview of species diversity and their applicationPublication . Mendes, Madalena; Navalho, Sofia; Ferreira, Alice; Paulino, Cristina; Figueiredo, Daniel; Silva, Daniel; Gao, Fengzheng; Gama, Florinda; Bombo, Gabriel; Jacinto, Rita; Aveiro, Susana; Schulze, Peter S.C.; Gonçalves, Ana Teresa; Pereira, Hugo; Gouveia, Luisa; Patarra, Rita F.; Abreu, Maria Helena; Silva, Joana L.; Navalho, João; Varela, João; Galileu Speranza, LaisAlgae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.
- Biotecnologia de Dunaliella salina para produção de B carotenoPublication . Navalho, João; Cancela, LeonorO presente trabalho teve como objectivo a optimização do processo produtivo de (3 caroteno pela microalga Dunaliella salina, numa estratégia de produção em duas fases. Na primeira fase do processo, fase de optimização da produção de biomassa num sistema de cultivo em semi-contínuo, foram obtidas produtividades celulares de 170 000 cel/ml/dia para condições de final de Inverno e 470 000 cel/ml/dia em condições de Verão. Os valores de nitrato residual obtidos nas culturas da primeira fase. foram conpatíveis com a utilização directa das culturas como inoculo na segunda. Na fase de carotenogénese. realizada num sistema de "feed-batch", foram obtidas^produtividades de (3 caroteno de 477 mg/nr/dia para condições de final de Inverno e 621 mg/nr/dia em condições de Verão, o controlo da concentração de nitrato nas culturas mostrou-se eficaz na indução de síntese do pigmento e o teor em (3 caroteno e clorofila das culturas da primeira fase, mostrou ser um factor preponderante à obtenção de culturas de elevada relação (3 caroteno/clorofila na segunda.
- Diel biochemical and photosynthetic monitorization of Skeletonema costatum and Phaeodactylum tricornutum grown in outdoor pilot-scale flat panel photobioreactorsPublication . Maia, Inês Beatriz; Carneiro, Mariana; Magina, Tânia; Malcata, F. Xavier; Otero, Ana; Navalho, João; Varela, João; Pereira, HugoDiatoms are currently considered valuable feedstocks for different biotechnological applications. To deepen the knowledge on the production of these microalgae, the diel pattern of batch growth, photosystem II performance, and accumulation of target metabolites of two commercially relevant diatoms, Phaeodactylum tricornutum and Skeletonema costatum, were followed outdoors in 100-L flat panel photobioreactors. S. costatum presented a higher light-to-biomass conversion resulting in higher growth than P. tricornutum. Both fluorescence data and principal component analysis pointed to temperature as a limiting factor for the growth of P. tricornutum. Higher protein and carbohydrate contents were found in P. tricornutum, whereas S. costatum fatty acids were charac-terized by a higher unsaturation degree. Higher productivities were found at 1 p.m. for protein, lipid, and ash in the case of S. costatum. Overall, S. costatum showed great potential for outdoor cultivation, revealing a broader temperature tolerance and increased biomass productivity than P. tricornutum.
- Drying microalgae using an industrial solar dryer: a biomass quality assessmentPublication . Schmid, Benjamin; Navalho, Sofia; Schulze, Peter S.C.; Van De Walle, Simon; Van Royen, Geert; Schüler, Lisa M.; Maia, Inês Beatriz; Bastos, Carolina; Baune, Marie-Christin; Januschewski, Edwin; Coelho, Ana; Pereira, Hugo; Varela, João; Navalho, João; Rodrigues, Alexandre Miguel CavacoMicroalgae are considered a promising resource of proteins, lipids, carbohydrates, and other functional biomolecules for food and feed markets. Competitive drying solutions are required to meet future demands for high-quality algal biomass while ensuring proper preservation at reduced costs. Since often used drying methods, such as freeze or spray drying, are energy and time consuming, more sustainable processes remain to be developed. This study tested an indirect and hybrid solar dryer as an alternative to conventional freeze drying of industrially produced Tetraselmis chui and Nannochloropsis oceanica wet paste. The effects of the drying method on biomass quality parameters, including biochemical profiles, functional properties, and microbial safety, were assessed. No significant differences were found between the applied drying technologies for total proteins, carbohydrates, lipids, and fatty acid profiles. On the other hand, some pigments showed significant differences, displaying up to 44.5% higher contents in freeze-dried samples. Minor differences were also registered in the mineral profiles (<10%). Analyses of microbial safety and functional properties of the solar-dried biomass appear adequate for food and feed products. In conclusion, industrial solar drying is a sustainable technology with a high potential to preserve high-quality microalgal biomass for various markets at expected lower costs.
- Fucoxanthin production from Tisochrysis lutea and Phaeodactylum tricornutum at industrial scalePublication . Pereira, Hugo; Sá, Marta; Maia, Inês Beatriz; Rodrigues, Alexandre; Teles, Iago; Wijffels, Rene H.; Navalho, João; Barbosa, MariaFucoxanthin is a xanthophyll carotenoid with high market value. Currently, seaweeds are the primary source for fucoxanthin industrial production. However, marine microalgae reach 5 to 10 times higher concentrations (2.24 to 26.6 mg g-1 DW) and are considered a promising feedstock. In this work, two marine microalgae were produced at industrial scale to evaluate biomass and fucoxanthin production: Phaeodactylum tricornutum for autumn/winter and Tisochrysis lutea for spring/summer. Both strains were grown in 15 m3 tubular flow-through photobioreactors; for 170 consecutive days of semi-continuous cultivation regime. The average volumetric biomass productivities of P. tricornutum and T. lutea were 0.11 and 0.09 g DW L-1 day-1. P. tricornutum reached higher maximum biomass concentration (2.87 g DW L-1) than T. lutea (1.47 g DW L-1). P. tricornutum fucoxanthin content ranged between 0.2 and 0.7% DW, while T. lutea between 0.2 and 0.6% DW. The fucoxanthin content was correlated with the irradiation (MJ m-2) and biomass concentration in the photobioreactor (g L-1). This is the first work in literature reporting a long-term industrial production of T. lutea. Overall, we showed possible scenarios for fucoxanthin production from microalgae, increasing the window to supply the industry with steady production throughout the year.
- Optimisation of biomass production and nutritional value of two marine diatoms (Bacillariophyceae), Skeletonema costatum and Chaetoceros calcitransPublication . Bastos, Carolina R. V.; Maia, Inês Beatriz; Pereira, Hugo; Navalho, João; Varela, JoãoS. costatum and C. calcitrans are two cosmopolitan high-value centric diatoms, with a rich nutritional profile. The following work optimised the culture medium of S. costatum and C. calcitrans cultures, respectively, in a stepwise process as follows: 2.4 mM and 1.2 mM of silicate, 4 mM of nitrate, 100 µM of phosphate, 20 and 80 µM iron, and 0.5 mL L−1 of micronutrients. The results that were obtained revealed an increase in biomass productivity with a 1.8- and 3.2-fold increase in biomass that was produced by S. costatum and C. calcitrans, respectively. The biochemical profile showed an increase in high-value PUFAs such as 2.6-fold and 2.3-fold increase in EPA for S. costatum and C. calcitrans, respectively, whilst a 2.6-fold increase in DHA was detected in S. costatum cultures. The present work provides the basic tools for the industrial cultivation of S. costatum and C. calcitrans with enhanced productivity as well as improved biomass quality, two factors which are highly relevant for a more effective application of these diatoms to aquaculture and nutraceutical production.
- Phaeodactylum tricornutum in finishing diets for gilthead seabream: effects on skin pigmentation, sensory properties and nutritional valuePublication . Ribeiro, Ana Ramalho; Gonçalves, Amparo; Barbeiro, Mónica; Bandarra, Narcisa; Nunes, Maria Leonor; Carvalho, Maria Luisa; Silva, Joana; Navalho, João; Dinis, Maria Teresa; Silva, Tome; Dias, JorgeMicroalgal biomasses are known to play a major role in fish pigmentation, which is particularly important in farmed fish, since colour and external appearance are the first cue for customers when choosing seafood. A study was undertaken to assess the potential of microalgae biomass from the diatom Phaeodactylum tricornutum as a functional ingredient for gilthead seabream (Sparus aurata) feeds. Three experimental diets were designed: a control diet (CTRL), this same diet supplemented with 2.5% of P. tricornutum wild strain (diet MA20); and a third diet with 2.5% of P. tricornutum biomass (diet MA37) cultivated under different temperature and light regimes that resulted in higher levels of fucoxanthin. Microalgae diets led to a reduction (P < 0.05 in MA37) of whole-body fat and lower lipid retention (P < 0.05 in MA20 and MA37). Microalgae did not impact odour, flavour, whiteness, and fatness perception in cooked fillets. Overall, colour analysis showed that P. tricornutum biomass led to significant differences compared to control in specific areas: the MA37 diet induced a significantly (P < 0.05) lighter and more vivid yellow colouration of seabream operculum (Delta E* approximate to 5) perceptible to the human eye; ventral skin lightness was also affected by the dietary treatments (P = 0.040), being higher for microalgae-fed groups, though this difference was not perceptually strong (Delta E* approximate to 1.7). Phaeodactylum tricornutum biomass can be used as a functional ingredient, improving external pigmentation and thus contributing to meet consumer expectations in relation to farmed gilthead seabream.