Escola Superior de Turismo e Tecnologia do Mar
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Browsing Escola Superior de Turismo e Tecnologia do Mar by Field of Science and Technology (FOS) "Ciências Agrárias::Agricultura, Silvicultura e Pescas"
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- Bioproducts from forest biomass II. Bioactive compounds from the steam-distillation by-products of Cupressus lusitanica Mill. and Cistus ladanifer L. wastesPublication . Tavares, Cláudia S.; Martins, Alice; Miguel, M. Graça; Carvalheiro, Florbela; Duarte, Luís C.; Gameiro, José A.; Figueiredo, A. Cristina; Roseiro, Luísa B.Obtaining essential oils and hydrolates from underutilized biomass is an economic and sustainable way for production of these high added-value bioproducts. However, this process still generates large amounts of residues as the by-products obtained during distillation, which can be a concern for the environment, but also adequate substrates for other applications. Considering this fact, the waste distilled by-products remaining after steam-distillation of underutilized biomass from Cupressus lusitanica and Cistus ladanifer, were evaluated as a natural source of other high value products with biological activities, namely, phenolic compounds. Thus, the remaining extracted solid residues (ESRs) were characterized and subject to further treatments by ultrasound-assisted extraction (UAE) with ethanol and 70 % acetone, in order to prepare phenolic-rich extracts thereof: ESRs(EtOH) and ESRs(70 % Ace). Together with the distiller condensation waters (DCWs), these extracts were characterized for their phenolic content (total phenols, tannins and flavonoids). Their antioxidant activity was also evaluated by different methodologies. The phenolic profile of DCWs, ESRs(EtOH) and ESRs(70 % Ace) from both waste species was obtained by capillary zone electrophoresis (CZE) and phenolic compounds were tentatively identified. Results obtained for C. lusitanica biomass are here disclosed for the first time. Generally, all samples revealed to be rich in phenolic compounds, being C. ladanifer biomass the one with higher phenolic content. DCWs presented values of 140 mgGAE/g for C. lusitanica and 210 mg GAE/g for C. ladanifer, from which ca. 60 % were tannins. Extracts obtained with 70 % acetone were the ones with the highest results, except for the antioxidant activity by xanthine oxidase and superoxide inhibition, which was higher in DCWs. Catechins were the major compounds found for both species, but gallocatechins and gallic acid were only identified in C. ladanifer. Hydroxycinnamic acid derivatives and salicylic acid were also identified in C. ladanifer, partly justifying the anti-inflammatory effect referred for this species.
- Characterization of Selected Wild Mediterranean Fruits and Comparative Efficacy as Inhibitors of Oxidative Reactions in Emulsified Raw Pork Burger PattiesPublication . Ganhão, Rui; Estévez, Mario; Kylli, Petri; Heinonen, Marina; Morcuende, DavidIn the present study, water, ethanolic, and methanolic extracts from seven selected wild fruits originally from the Mediterranean area, namely, strawberry tree (Arbutus unedo L., AU), azarole (Crataegus azarolus L., CA), common hawthorn (Crataegus monogyna L., CM), blackthorn (Prunus spinosa L., PS), dog rose (Rosa canina L., RC), elm-leaf blackberry (Rubus ulmifolius Schott, RU), and rowan (Sorbus aucuparia L., SA), were analyzed for the total amount and profile of phenolic compounds and for the in vitro antioxidant activity against the DPPH and ABTS radicals (study 1). The seven fruits showed different chemical compositions, which consequently led to different antioxidant potentials. Among the seven fruits initially analyzed, AU, CM, RC, and RU had the highest amount of phenolic compounds and displayed the greatest antioxidant activity in vitro. Extracts from these four fruits were tested as inhibitors of lipid oxidation in raw pork burger patties subjected to refrigerated storage at 2 °C for 12 days (study 2). The quantitative measurements of thiobarbituric acid reactive substances (TBA-RS), hexanal content, and color stability were used as indicators of oxidative reactions. The four selected fruits displayed intense antioxidant activity against lipid oxidation, which highlights the potential usage of these fruits as ingredients for the manufacture of healthy meat products. Among them, RC and AU were particularly efficient as their protective effect against lipid oxidation was more intense than that displayed by quercetin (230 mg/kg of burger patty).
- Evaluating the Potential of the Defatted By-Product of Aurantiochytrium sp. Industrial Cultivation as a Functional FoodPublication . Reboleira, João; Félix, Rafael; Félix, Carina; Melo, Marcelo M. R. de; Silva, Carlos M.; Saraiva, Jorge A.; Bandarra, Narcisa M.; Teixeira, Bárbara; Mendes, Rogério; Paulo, Maria C.; Coutinho, Joana; Lemos, Marco F. L.While Aurantiochytrium sp. is an increasingly popular source of polyunsaturated fatty acids (PUFAs), its extraction generates high amounts of waste, including the spent, defatted residue. The composition and bioactivities of this by-product could prove to be a major part of the sustainable valorisation of this organism within the framework of a circular economy. In this study, the defatted biomass of commercial Aurantiochytrium sp. was nutritionally characterised, and its amino acid profile was detailed. Additionally, the antioxidant and prebiotic potentials of an enzymatically digested sample of defatted Aurantiochytrium sp. were evaluated under a set of miniaturised in vitro assays. The nutritional profile of the spent Aurantiochytrium biomass revealed a protein and dietary-fibre rich product, with values reaching 26.7% and 31.0% for each, respectively. It also held high concentrations of glutamic and aspartic acid, as well as a favourable lysine/arginine ratio of 3.73. The digested samples demonstrated significant Weissela cibaria and Bifidobacterium bifidum growth-enhancing potential. Residual ferric reducing antioxidant power (FRAP) activity was likely attributed to antioxidant amino acids or peptides. The study demonstrated that some of the nutritional and functional potential that reside in the defatted Aurantiochytrium sp. waste encourages additional studies and the development of food supplements employing this resource’s by-products under a biorefinery framework.
- Feeding habits of Solea senegalensis in earthen ponds in Sado estuaryPublication . Castelo Branco, Maria Ana; Arruda, Marco A.; Gamito, SofiaThe senegale sole, Solea senegalensis Kaup, 1858, is a commercially valuable fish and it is beginning to be cultured in a semi-intensive way in fish farms in southern European countries. The present study was initiated to investigate the diet of S. senegalensis under semi-extensive conditions. The feeding habits of sole were studied in two earthen ponds of a fish farm in the Sado estuary. In one earthen pond, artificial fish ration was given. S. senegalensis feeds on few prey items, its diet is mainly composed of insect larvae (Chironomus salinarus) and polychaeta (Hediste diversicolor). The diet composition of this species suggests feeding specialization, by consuming mainly annelids and insect larvae and by avoiding other items, extremely abundant in the environment, such as gastropods. In the water reservoir where ration was given, some fish consumed simultaneously benthic organism together with ration. However, benthic organisms seem to be the most important component of S. senegalensis diet.
- Growth Performance after Agouti-Signaling Protein 1 (Asip1) Overexpression in Transgenic ZebrafishPublication . Godino-Gimeno, Alejandra; Sánchez, Elisa; Guillot, Raúl; Rocha, Ana; Angotzi, Anna Rita; Leal, Esther; Rotllant, Josep; Cerdá-Reverter, José MiguelThe melanocortin system is a key structure in the regulation of energy balance. Overexpression of inverse agonists, agouti-signaling protein (ASIP), and agouti-related protein (AGRP) results in increased food intake, linear growth, and body weight. ASIP regulates dorsal-ventral pigment polarity through melanocortin 1 receptor (MC1R) and overexpression induces obesity in mice by binding to central MC4R. Asip1 overexpression in transgenic zebrafish (asip1-Tg) enhances growth, yet experiments show fish overexpressing Asip1 do not develop obesity even under severe feeding regimes. Asip1-Tg fish do not need to eat more to grow larger and faster; thus, increased food efficiency can be observed. In addition, asip1-Tg fish reared at high density are able to grow far more than wild-type (WT) fish reared at low density, although asip1-Tg fish seem to be more sensitive to crowding stress than WT fish, thus making the melanocortin system a target for sustainable aquaculture, especially as the U.S. Food and Drug Association has recently approved transgenic fish trading.
- Spatio-temporal structure of diatom assemblages in a temperate estuary. A STATICO analysisPublication . Mendes, Susana; Fernández-Gómez, Maria José; Resende, Paula; Pereira, Mário Jorge; Galindo-Villardón, Maria Purificación; Azeiteiro, Ulisses MirandaThis study examines the spatio-temporal structure of diatom assemblages in a temperate estuary (Ria de Aveiro, Western Portugal). Eighteen monthly surveys were conducted, from January 2002 to June 2003, at three sampling sites (at both high and low tide) along the estuarine salinity gradient. The relationship of diatom assemblages and environmental variables was analysed using the STATICO method, which has been designed for the simultaneous analysis of paired ecological tables. This method allowed examination of the stable part of the environment-diatom relationship, and also the variations of this relationship through time. The interstructure factor map showed that the relationship between the 11 environmental variables and the abundance of the 231 diatom species considered was strongest in the months May and September 2002 and January, February and May 2003. The stable part of the species-environment relationships mainly consisted of a combined phosphate, chlorophyll a and salinity gradient linked to a freshwater-marine species gradient. A more pronounced gradient was observed in January, February and May 2003. Diatom assemblages showed clear longitudinal patterns due to the presence of both marine and freshwater components. May and September 2002 had the least structured gradients with marine-estuarine species appearing in the freshwater side of the gradient. The most complete gradient in February 2003 could be considered, in terms of bio-ecological categories, as the most structured period of the year, with a combination of strong marine influence in the lower zone and freshwater influence in the upper. The best-structured gradients were during periods of a diatom bloom. Stable diatom assemblages (with a strong structure and a good fit between the diatoms and environment) are described and characterized. This study shows the efficiency of the STATICO analysis. The inclusion of space-time data analysis tools in ecological studies may therefore improve the knowledge of the dynamics of species-environmental assemblages.
- Tryptophan Depletion and Formation of α-Aminoadipic and γ-Glutamic Semialdehydes in Porcine Burger Patties with Added Phenolic-Rich Fruit ExtractsPublication . Ganhão, Rui; Morcuende, David; Estévez, MarioThe effect of added fruit extracts on the oxidation of muscle proteins in porcine burger patties subjected to cooking and chill storage was studied. Extracts from arbutus berries (Arbutus unedo L., AU), common hawthorns (Crataegus monogyna L., CM), dog roses (Rosa canina L., RC), and elmleaf blackberries (Rubus ulmifolius Schott, RU) were prepared, characterized, added to burger patties (3% of total weight), and evaluated as inhibitors of protein oxidation. Negative (no added extract, C) and positive control (added quercetin, 230 mg/kg, Q) groups were also included in the design. Protein oxidation was assessed by means of tryptophan loss using fluorescence spectroscopy (FS) and formation of the specific protein carbonyls αaminoadipic (AAS) and y-glutamic semialdehyde (GGS) using liquid chromatography and mass spectroscopy (LC-MS). Both advanced methodologies (FS and LC-MS) were found to be reliable and specific protein oxidation measurements that allow us to gain chemical insight into protein oxidation. The mechanisms likely involved In the oxidative reactions affecting proteins during cooking and storage of burger patties are profusely discussed. Phenolic-rich fruit extracts protected tryptophan residues against oxidation and Inhibited the formation of both semialdehydes In burger patties during cooking and subsequent chill storage. In general, RC, RU, and AU were the most effective inhibitors of protein oxidation, with this effect being more intense than that of pure polyphenols like quercetin. These fruit extracts could be considered functional ingredients as their antioxidant actions contribute to the enhancement of the nutritional value of the meat products.
- A warming decade unveils changes in the chaetognath Parasagitta friderici and appendicularian Oikopleura dioica abundance in a coastal system of the Iberian PeninsulaPublication . Dolgner, Nuno; Marques, Sónia Cotrim; Monteiro, Marta; Primo, Ana Lígia; Pardal, Miguel A.; Azeiteiro, Ulisses M.The influence of multiscale processes such as climate, hydrodynamic and biological alterations on two coastal and estuarine gelatinous zooplankton groups were assessed under a warming decade from 2003 to 2012. At three sampling stations on the Mondego estuary, zooplankton and water samples were collected, evaluating the abundance of chaetognaths and appendicularians. P. friderici and O. dioica were the most prominent species from each gelatinous zooplankton group, occurring in 87% and 86% from all the samples analysed, respectively. Both species displayed higher abundances during summer–autumn months and presented similar seasonal peaks whose densities increased after the first half of the study period. Statistical analysis showed that water temperature, salinity and copepods abundance explained most of the variance in the interannual abundance of both species. This study emphasizes the importance of these less spoken species, which play crucial roles in the ecosystem and points out their resilience to extreme weather events, thriving under future climate change situations.