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Pimenta J.,Instituto Nacional dos Recursos Biologicos INRB | Pimenta J.,University of Lisbon | Dias F.M.V.,University of Lisbon | Marques C.C.,Instituto Nacional dos Recursos Biologicos INRB | And 10 more authors.
Reproduction in Domestic Animals | Year: 2012

Contents: The function of prion-like protein Doppel was suggested to be related to male fertility. In this study, the importance of ovine Doppel polypeptide on spermatozoa capacitation and fertilization was evaluated. After refolding, recombinant Doppel (rDpl) was supplemented with different concentrations (40, 80 or 190ng/ml) to ovine spermatozoa during the capacitation process. In experiment 1, post-thawed ovine spermatozoa were incubated with different concentrations of rDpl during 1h for swim-up, and changes in sperm motility, concentration, vigour, viability and capacitation were monitored (10 replicates). In experiment 2, the fertilization ability of post-swim-up spermatozoa incubated as above was tested through heterologous fertilization of bovine in vitro matured oocytes (n=423, three replicates). Regardless of dosage, rDpl improved (p≤0.03) spermatozoa viability. Sperm individual motility and vigour were the highest (p≤0.04) for the group receiving 190ng/ml rDpl. Sperm supplemented with the highest doses of rDpl achieved higher (p=0.02) fertilization rates (56.0±3.0%) than control (39.1±2.2%) and 40ng/ml rDpl (39.8±2.7%). Preliminary data suggest that Doppel protein may enhance in vitro spermatozoa fertilizing ability. © 2011 Blackwell Verlag GmbH.


Cardoso C.,Instituto Nacional dos Recursos Biologicos INRB | Ribeiro B.,Instituto Nacional dos Recursos Biologicos INRB | Ribeiro B.,University of Lisbon | Mendes R.,Instituto Nacional dos Recursos Biologicos INRB
European Food Research and Technology | Year: 2012

The production of heat-induced gels from raw materials with poor gelling ability remains a technical challenge, for which new solutions have been proposed. The addition to the gel batters of a cross-linking chemical agent, such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), may present a valuable tool for the improvement of gelling. Accordingly, a response surface methodology was used to optimize the conditions of EDC application, the EDC concentration (0.0-0.5 %, w/w) and the batters' pH (4.5-7.5). Results showed that textural, colour, and water-binding properties of heat-induced hake gels were extremely sensitive to EDC content and pH. It was possible to find an optimal EDC level-pH binary common to the various studied parameters, a pH between 4.0 and 5.0 and an EDC concentration of 0.5 %, w/w. Moreover, this experimental work proved to be feasible the achievement of gel products of acceptable textural quality from frozen hake through EDC incorporation in optimal conditions. © 2012 Springer-Verlag.


Alves S.P.,Instituto Nacional dos Recursos Biologicos INRB | Alves S.P.,University of Lisbon | Santos-Silva J.,Instituto Nacional dos Recursos Biologicos INRB | Cabrita A.R.J.,University of Porto | And 2 more authors.
PLoS ONE | Year: 2013

Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18:2n-6 and 18:3n-3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n-3. © 2013 Alves et al.


Cardoso C.,Instituto Nacional Dos Recursos Biologicos INRB | Ribeiro B.,Instituto Nacional Dos Recursos Biologicos INRB | Ribeiro B.,University of Lisbon | Mendes R.,Instituto Nacional Dos Recursos Biologicos INRB
Journal of Food Engineering | Year: 2012

The effect of microbial transglutaminase (MTGase) and dietary fibre (DF) from pea and chicory on the dynamic rheological properties of protein paste were studied for hake, gilthead seabream, sea bass, and meagre. Meagre and gilthead seabream presented higher storage modulus (G′) and higher transition temperatures marking the various phases of thermal gelling. The incorporation of chicory DF in the formulations reduced G′. It was found that high degree of protein denaturation enhanced gel hardness. On the other hand, low degree of protein denaturation produced gels with high deformability. In accordance to this, the gels of those species with lower protein unfolding at a given temperature benefited most from MTGase addition. © 2012 Elsevier Ltd. All rights reserved.


Garrido S.,University of Lisbon | Murta A.G.,Instituto Nacional dos Recursos Biologicos INRB
Journal of Fish Biology | Year: 2011

Interdecadal variability of the diet composition of horse mackerel Trachurus trachurus was examined through analysis of the stomach contents of fish collected from the north-west and south of Portugal during 1990-1992 and 2005-2006. These decades correspond to periods of high and low feeding intensity of T. trachurus. Dietary composition of adult T. trachurus was assessed by determining the frequency of occurrence and biovolume of identified prey, and these two variables were combined to estimate an index of relative importance of prey. Dietary composition differed between areas, seasons and, in particular, decades. The most important prey in 1990-1992 were euphausiids while in 2005-2006 the most important prey were fishes. Results show that periods of different feeding intensity for T. trachurus are characterized by diets with different dominant prey items, suggesting that a description of the diet of a fish species is not complete if only based on samples collected in a limited space and time period. This result has implications for the study of marine trophic food webs, since a generalist predator may easily and rapidly change its trophic niche, to adapt to different prey abundance and availability. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.


Paiva R.B.,University of Lisbon | Neves A.,University of Lisbon | Sequeira V.,University of Lisbon | Nunes M.L.,Instituto Nacional Dos Recursos Biologicos INRB | And 2 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2012

Little information is available on the maternal-embryonic relationships among sharks. Birdbeak dogfish (Deania calcea) has been described as ovoviviparous, but this term comprises a wide range of forms on how the embryos are nourished including lecithotrophy and matrotrophy. To evaluate the maternal-embryonic relationship in birdbeak dogfish we have analysed chemical features (fatty acid composition and mercury (Hg) levels) and biological characteristics (egg and embryo dry weight variation, uterus characterization). Monounsaturated fatty acids were the dominant fatty acids in eggs while polyunsaturated fatty acids (PUFA) were the dominant fatty acids in both pregnant females and embryos. Significant differences were found among eggs, embryos and pregnant females for all fatty acids groups with the exception of saturated fatty acids for embryos and pregnant females. The principal components analysis revealed that embryos are particularly related to n-6 PUFA and pregnant females with n-3 PUFA. A close relationship exists between the Hg level of pregnant females and the Hg level of their embryos which indicates that there is a transfer of mercury from maternal sources. The comparison of the mean dry weight between eggs and embryos showed a gain of 3.8% obtained in the embryos. Histological sections of the uteri of pregnant females showed a high level of both superficial and inner vascularization in the uterine villi as well as the presence of secretor cells. Until now, the importance of this species maternal contribution and interference for the embryos development has never been documented. However, the biological and chemical results observed in the present work show that there is a matrotrophic strategy for the birdbeak dogfish. © 2011 Marine Biological Association of the United Kingdom.


Alves S.P.,Instituto Nacional dos Recursos Biologicos INRB | Alves S.P.,Abel Salazar Biomedical Sciences Institute | Cabrita A.R.J.,University of Porto | Jeronimo E.,Instituto Nacional dos Recursos Biologicos INRB | And 4 more authors.
Journal of Animal Science | Year: 2011

Two experiments were conducted using laboratory mini-silos to study the effect of ensiling and silage additives on fatty acid (FA) composition, including minor or unusual FA, of ryegrass and corn silages. Ryegrass was ensiled for 12 wk with no additives, with the addition of a bacterial inoculant or formic acid. Corn was ensiled for 9 wk without additives, with the addition of a bacterial inoculant or calcium formate. Ensiling affected both total FA content and FA composition of ryegrass silages. Total FA concentration increased (P < 0.001) during ryegrass ensiling. The proportions (g/100 g of total FA) of the major unsaturated FA, 18:3n-3 and 18:2n-6, were not affected (P > 0.05) by ensiling. However, their concentration (mg/g of DM) in silages was greater (P = 0.017 and P = 0.001, respectively) than in fresh ryegrass. Two 18:2 FA (trans-11,cis-15 and cis-9,cis-15) that were not originally present in the fresh ryegrass were detected in silages. Silage additives affected the FA composition of ryegrass silages, mostly by increasing the proportions of SFA, but not on total FA concentration. Ensiling did not affect (P = 0.83) total FA content of corn silages; however, FA composition was affected, mostly by decreasing the proportions of 18:2n-6 and 18:3n-3. Silage additives had no effect on corn silage FA composition. Exposing corn silages to air resulted in no oxidation of FA or reduction in total FA content or composition. © 2011 American Society of Animal Science. All rights reserved.


Silva F.V.M.,University of Auckland | Silva F.V.M.,Instituto Nacional dos Recursos Biologicos INRB | Gibbs P.A.,Leatherhead Food International
Trends in Food Science and Technology | Year: 2010

The increasing consumption of minimally processed chilled foods poses new risks in terms of public safety and foodborne infections. Thermal pasteurization (65-95 °C) reduces the numbers of unwanted vegetative cells of pathogenic and spoilage microorganisms in foods, extending food shelf-life, promoting food safety, and allowing the reduction and elimination of added chemical preservatives to foods. With respect to low-acid foods, microbial spores surviving pasteurization must be controlled, by using cold storage and transportation (1-8 °C), and a limited shelf-life. A review on the heat resistance of most common contaminant microbial flora in low-acid chilled foods is presented and a new strategy for the design of pasteurization processes based on the non-proteolytic psychrotrophic Clostridium botulinum spores thermal resistance will be approached. © 2009 Elsevier Ltd. All rights reserved.


PubMed | Instituto Nacional dos Recursos Biologicos INRB
Type: Journal Article | Journal: Journal of animal science | Year: 2011

Two experiments were conducted using laboratory mini-silos to study the effect of ensiling and silage additives on fatty acid (FA) composition, including minor or unusual FA, of ryegrass and corn silages. Ryegrass was ensiled for 12 wk with no additives, with the addition of a bacterial inoculant or formic acid. Corn was ensiled for 9 wk without additives, with the addition of a bacterial inoculant or calcium formate. Ensiling affected both total FA content and FA composition of ryegrass silages. Total FA concentration increased (P < 0.001) during ryegrass ensiling. The proportions (g/100 g of total FA) of the major unsaturated FA, 18:3n-3 and 18:2n-6, were not affected (P > 0.05) by ensiling. However, their concentration (mg/g of DM) in silages was greater (P=0.017 and P=0.001, respectively) than in fresh ryegrass. Two 18:2 FA (trans-11,cis-15 and cis-9,cis-15) that were not originally present in the fresh ryegrass were detected in silages. Silage additives affected the FA composition of ryegrass silages, mostly by increasing the proportions of SFA, but not on total FA concentration. Ensiling did not affect (P=0.83) total FA content of corn silages; however, FA composition was affected, mostly by decreasing the proportions of 18:2n-6 and 18:3n-3. Silage additives had no effect on corn silage FA composition. Exposing corn silages to air resulted in no oxidation of FA or reduction in total FA content or composition.

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