Browsing by Author "Rodrigues, A."
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Dairy cattle-slurry treatment technologies: towards an integrating approach of crop production, animal feeding and environmental impactsPublication . Rodrigues, A.; Gomes, A.; Ferreira, L.; Trindade, H.; Fonseca, A.; Pereira, J.Dairy cattle farms have a well-known environmental impact that affects all ecological compartments: air, soil, water and biosphere [1]. Dairy cattle farming are a significant source of anthropogenic gases from enteric fermentation, manure storage and land application, mainly ammonia (NH3), nitric oxide (NO), nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4). The emission of such gases represents not only an environmental problem but also leads to energy and nitrogen (N) losses in ruminant production systems [2-5]. Several efforts are required on the development of new technologies and strategies that mitigate gaseous emissions, N losses and improve the efficiency of the energy and N cycles [6, 7]. In the Northwest of Portugal, dairy cattle production has a major impact on the economy, with strong repercussions at national scale. Therefore, our Ph.D. thesis project aims to: a) Study natural supplements as additives in the dairy cattle diet towards a decrease in GHG emissions from feeding operations; b) Compare commercial dairy cattle diets with and without additives on gaseous emissions from manure deposited in a simulated concrete floor; c) Assess the concentrations and emissions of NH3 and greenhouse gases from commercial dairy cattle facilities; d) Evaluate the effects of different additives on lowering gaseous emissions from dairy cattle excreta, using a laboratory system simulating a dairy house concrete floor.
- Development and characterization of a ewe’s creamy cheese with aromatic plantsPublication . Guiné, R. P. F.; Teixeira-Lemos, Edite; Ribeiro, P.; Ferreira, M.; Oliveira, A. M.; Teixeira, A. R.; Castro, B.; Rodrigues, R.; Santos, S.; Rodrigues, A.; Santos, A.This work aimed at developing a new dairy product, made of ewe’s milk that cannot be used for making the Serra da Estrela cheese (with Protected Designation of Origin) for not filling the exact specifications. In this way are allied economic with environmental advan- tages. Because this unusable milk represents econom- ic loss for the producers while at the same time increas- ing the volume of effluents that need treatment, this alternative usage allies economic with environmental advantages. A total of 19 samples were produced, and these de- veloped creamy cheeses were evaluated according to formulation and conservation properties, and then submitted to a sensory evaluation and finally analysed in terms of physico-chemical microbiological and nu- tritional properties. The 19 formulations were tested to optimize formulations that would be acceptable in organoleptic terms as well as conservation capac- ity, under refrigeration, for an observational period of 3 weeks. This essay allowed selecting 5 versions of the product that showed best conservation capacity, which were then submitted to sensory evaluation. The sensory analyses involved two types of tests: de- scriptive sensory profile and preference test, and the obtained results allowed selecting the 2 best formu- lations as those most appreciated and with potential for commercialization: a control cheese and one with oregano, which were then analysed. Microbiological analyses were undertaken to verify if the products met the legally established microbiological limits, name- ly for assessing the presence of coagulase-positive staphylococci (Staphylococcus aureus) and Escherichia coli. Moisture, protein, lipids, salt and carbohydrates were analysed by Fourier transform near-infrared (FT- NIR) spectroscopy method and antioxidant activity was evaluated by reaction with the 2,2-diphenyl-1-pic- rylhydrazyl (DPPH) radical. Chemical composition revealed two similar products, but the sample with oregano had higher antioxidant activity as compared with control (70.96 ± 0.36 and 64.99 ± 2.74 mg/L TE, respectively). From the microbi- ological point of view both products were considered safe, with values of staphylococci and E. coli under the applicable regulation limits. In terms of nutritional val- ue, both sample shave high protein content (11.9 and 11.4 g/100 g, respectively for control and sample with oregano) but also high fat (13.9 and 12.3 g/100 g, re- spectively for control and sample with oregano) while being low in sugars (3.4 and 3.8 g/100 g), fiber (< 1%) or salt (< 1%). Energy of both samples was found to be 186 kcal/100 g for the control and 172 g/100g for sam- ple with oregano. In conclusion, in nutritional terms the samples could be considered safe High Protein content foods. More- over, as dairy products contain almost all the essential nutrients, the developed creamy cheeses should be consumed as part of a balanced diet. Finally, the production of these products allows the utilization of the milk that otherwise would have to be discarded, so bringing economic profit while at the same time mini- mizing the need to process it as effluent.
- Effects of biochar inclusion on in vitro rumen fermentation parametersPublication . Rodrigues, A.; Maia, M.; Cabrita, A.; Oliveira, H.; Bernardo, M.; Fonseca, I.; Trindade, H.; Pereira, José Luís; Fonseca, A.
- Healthy bread as an alternative to traditional breadPublication . Rodrigues, A.; Loureiro, J.; Baptista, L.; Guiné, Raquel; Correia, P.Today, bread is part of the culture and eating habits of most people and can be considered one of the most consumed foods in the world. The bread is made from a simple mixture of flour, water, salt and yeast, and it is an extremely versatile food and with a very good digestibility. Since it was first produced for thousands of years, it has undergone changes both in terms of production methods and in terms of its constitution, thus giving place nowadays to a wide variety of breads available on the market. The objectives of this study were to compare the sensory and nutritionally attributes of a special healthier bread, ―Pão São‖, which is a recent product in the Portuguese market. Nutritionally this type of bread turned out to be a food with high nutritional value, with a low salt content (0.4%, about half of traditional bread), and being a good source of omega-3 (0.67%), fibre and protein when compared with the traditional bread. These differences are mainly due to the wide variety of raw materials selected to the preparation of this bread, including the mixture of flour (wheat flour type 150 and 65 and rye flour type 70), oatmeal, sunflower and linseed seeds, soy, fish oil extracts rich in omega 3, malt and milk protein. From the results of the sensory analysis, conducted by a panel of 40 untrained tasters aged 7 to 63 years, it was found that the traditional breads from the region closest to the marketing of healthy bread were preferred by the tasters, especially for their wood and bread flavour, as well as elasticity. The healthy bread was evaluated as a denser bread, with a more intense fermented flavour. With this work it was concluded that the healthy bread is a nutritious and healthy bread, being currently recommended by the Portuguese Foundation of Cardiology. However from the sensory point of view, consumers still slighly prefer the traditional bread.
- Prevalence of hepatitis E virus antibodies in workers occupationally exposed to swine in PortugalPublication . Teixeira, J.; Mesquita, J. R.; Pereira, S. S.; Oliveira, R. M. S.; Abreu-Silva, Joana; Rodrigues, A.; Myrmel, M.; Stene-Johansen, K.; Øverbø, J.; Gonçalves, G.; Nascimento, M. S. J.The concept of zoonotic hepatitis E in industrialized countries has emerged with the discovery of swine strains of hepatitis E virus (HEV) genotype 3, closely related to human HEV. Different routes of zoonotic HEV transmission have been recognized, including contact with infected pigs. Workers occupationally exposed to swine (WOES) have been considered a risk group for HEV infection, but contradictory results have been reported. In the present study, we searched for anti-HEV IgG in WOES (butchers, slaughterhouse workers, veterinarians and pig farmers; n = 114) and in the general population (n = 804) in order to investigate the potential occupational risk of zoonotic HEV infection in this work group. A significantly higher (p = 0.008) anti-HEV IgG seroprevalence was found in WOES (30.7 %) when compared with the general population (19.9 %). Multivariate analysis showed that having professions with exposure to pigs for more than 16.5 years was a risk factor for being positive for anti-HEV IgG (aOR of 5.4, 95 % CI 1.9-15.6, p = 0.002). To our knowledge, this is the first study on the prevalence of anti-HEV IgG in WOES in Portugal, also showing increased probability for infection in this group.