Search

CONSTRUÇÃO 2012, Universidade de Coimbra, Dez. 2012 As argamassas são um material de grande relevância na construção. Estas são aplicadas no assentamento de alvenarias, em rebocos e ainda para assentamento de revestimentos de acabamento aderidos. As argamassas são muito utilizadas na construção e grande parte do parque imobiliário nacional necessita de intervenções de reabilitação e manutenção que envolvem a sua aplicação. Daí a importância da sua caracterização, assim como o estudo de materiais alternativos para a sua composição. Aliando este material construtivo ao conceito da construção sustentável, é possível e vantajosa a introdução de resíduos industriais na sua produção. No presente artigo apresenta-se um estudo, realizado no âmbito dos projetos financiados pela FCT METACAL e LIMECONTECH, a argamassas de traço volumétrico 1:3, em que o traço de ligante é constituído por cal hidráulica natural NHL3.5 de produção nacional, ou essa cal e resíduo de granulometria fina de cerâmica de barro vermelho e/ou de metacaulino, e o traço de agregado é constituído sempre pela mesma mistura de areias siliciosas lavadas e calibradas. Foram realizadas diversas composições de argamassas, variando as percentagens de resíduo e de metacaulino empregues em substituição de massa equivalente da cal hidráulica natural. Os ensaios foram realizados em provetes prismáticos, cujas dimensões são 160x40x40 (mm). Os provetes foram sujeitos a três condições de cura até à idade de ensaio, aos 28 dias: húmida, a 90±5% de humidade relativa (HR), de referência segundo a norma EN 1015-11: 1999, a 65±5% de HR, e nestas últimas condições mas com aspersão diária com água durante os primeiros dias de cura, sempre a 20±3°C de temperatura. A campanha experimental apresentada inclui os seguintes ensaios aos provetes: módulo de elasticidade dinâmico, resistência à flexão, resistência à compressão, absorção de água por capilaridade, secagem e porosidade aberta. Em relação aos resultados obtidos constata-se que as argamassas sujeitas a cura com aspersão nos primeiros dias (mais facilmente reprodutível em obra), apresentam valores de resistência mecânica adequados à aplicação na reabilitação de edifícios. As argamassas sujeitas a cura húmida e principalmente as com substituição de cal por metacaulino apresentam as resistências mecânicas mais elevadas, possíveis de adotar em suportes mais recentes. Em relação à absorção capilar e à secagem, o comportamento das argamassas foi adequado, não apresentando valores piores devido à substituição da cal pelo resíduo cerâmico.

Total fat and fatty acids profile are important factors for the nutritional evaluation of nuts and oilseeds. In the last years, several studies have reported the importance of consumption nuts and oilseeds to promote health benefits, especially those related with cardiovascular diseases. This is due to its high content of fat, which is mainly composed of unsaturated fatty acids. The overall objective of this study was to compare the total fat content and fatty acids profile of seven types of nuts and five types of oilseeds. Thereby, samples were randomly collected at supermarkets and herbal shops from Lisbon region, and three composite samples were prepared, in order to provide accurate data that covers all the possible variations among samples. For the lipid profile of oilseeds and nuts, either accredited methods or methods for which the laboratory has shown a successful participation in Proficiency testing schemes were used. Total fat determination was performed with an acid hydrolysis method followed by extraction using a Soxhlet apparatus with petroleum ether, as the extraction solvent (AOAC 948.15, 2000). Preparation of FA methyl esters was carried out by a combined method of methylation and transesterification. Chromatographic analysis was performed with a gas chromatograph equipped with a mass spectrophotometer detector. A HP-88, fused silica capillary column (100 m x 0.25 mm i.d., 0.25 mm) was used for FA determination. Samples were analyzed in triplicate. The applied GC-MS method allows separation and identification of more than fifty FA, including some trans-FA and ω3 or ω6 FA. Total fat content ranged between 39.8 ± 1.15 and 66.6 ± 0.11 g/100 g of edible portion, for brown flaxseeds and Brazil chestnuts, respectively. Linoleic acid was the major fatty acid found in sunflower seeds and walnuts. Sesame seeds, pumpkin seeds, roasted peanuts and salted peanuts have similar quantities of oleic and linoleic acid. For brown and golden flaxseeds, the major fatty acid was linolenic acid (18.3 ± 1.99 and 21.8 ± 1.03 g/100 g of edible portion, respectively). Cashew, peeled almonds and salted pistachio have similar fatty acids profile with oleic acid being the major fatty acid. Nuts and oilseeds are rich sources of fat, specially unsaturated fatty acids which are related with several health benefits, namely cardiovascular diseases. In Portugal, circulatory system diseases still remain the leading cause of death. Therefore, increasing the consumption of nuts and oilseeds in Portugal is extremely required. With this study we intend to provide accurate data on nuts and seeds lipid profile to enhance its consumption based on its nutritional quality and related health benefits. Further studies will be carried out with respect to phytosterols composition, carotenoids and liposoluble vitamins.

In the last years, there has been an increased consumers interest and demand for traditional foods, which have an important role in the diets. Traditional foods can also be a valuable contribution to the development and economic sustainability of rural areas and the preservation of biodiversity. The aim of this study was to determine the proximate composition in traditional vegetable and fruit based recipes from Black Sea Area countries, in the frame of the European Project BaSeFood. The determination of the nutritional composition of selected traditional foods from Bulgaria, Georgia, Romania, Russian Federation, Turkey and Ukraine is being carried out within the frame of the BaSeFood Project. Six foods from the vegetables group were analysed: Ukrainian borsch; Transcarpathian green borsch; Nettle sour soup; Nettles with walnut sauce; Rodopian dried beans and Kale soup. From the fruits group, five traditional foods were analysed: Uzvar; Plums jam; Churchkhela; Rose jam and Fruit of the evergreen cherry laurel. Water content, ash, total protein, total fat, total sugars and total dietary fibre are being determined at an accredited laboratory by ISO/IEC 17025 or by successful participation in Proficiency testing schemes. Most vegetable based foods have water and ash content higher than fruits. The values for water ranged from 14.2 to 92.4 g/100 g for Rose jam and Nettle sour soup, respectively. With respect to total fat content, generally fruit based foods have lower levels (< 0.15 g/100 g) than vegetables (5.02 g/100 g). For total protein, Nettles with walnut sauce presented the highest content (9.6 g /100 g) and Rose jam the lowest content (0.3 g/100 g). For total dietary fibre, the values varied between 0.3 and 6.44 g/100 g. All analytical values are expressed per 100 g of edible portion. The proximate composition of the selected traditional foods from Black Sea Area Countries is important in order to elucidate their role in the dietary pattern of populations. The analysed samples present a high moisture content and low fat content. Foods with high water content are usually low in calories. Therefore, vegetable and fruit based traditional foods are not energy dense foods, while they are considered rich in other essential nutrients. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n.º 227118.

Within the frame of the European Project BaSeFood (Sustainable Exploitation of Bioactive Components Black Sea Area traditional foods), thirty-three traditional foods from six Black Sea Area Countries (Bulgaria, Georgia, Romania, Russian Federation, Turkey and Ukraine) were selected and prepared according to the traditional recipe, ingredients and traditional preparation methods. The aim is to promote and preserve traditional foods and to produce new and reliable data of the overall nutritional composition. Water content is being determined by gravimetric method, using a dry air oven at 101 °C ± 2 °C for 2 h, until constant weight. Total fat is being performed with an acid hydrolysis method followed by extraction using a Soxhlet with petroleum ether, as the extraction solvent. The obtained residue is dried for 1 h 30 min at 101 °C ± 2 °C, until constant weight, according to the acid hydrolysis method. Total dietary fibre, ash and total protein content are being determined by the AOAC official methods 985.29, 945.46 and 991.20, respectively. Total nitrogen for protein content is being determined by the Kjeldahl method in combination with a copper catalyst using a block digestion system. To assure the quality of analytical results, methods used in the laboratory are accredited by ISO/IEC/17025 or successful participation in proficiency testing schemes. Herbs, spices, aromatic plants and fermented products are those which presented the highest water content. In contrast, products from oilseeds have the lowest water content (3.94 g/100 g) and the highest total fat (58.2 g/100 g), total protein (20.8 g/100 g), ash (3.25 g/100 g), total sugars (45.8 g/100 g) and total dietary fibre (11.3 g/100 g) contents. For cereals and cereals based foods, a great variability in the water content was found (5.99 to 75.8 g/100 g). All results are given per 100 g of edible portion. Traditional foods from the same group have generally similar proximate analysis pattern. In the products from oilseeds, the highest content in macronutrients was found, except for water content. The proximates composition will be useful to include new nutritional data into national food composition databases. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n.º 227118.