Browsing by Issue Date, starting with "2018-06-05"
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- Differences In Antioxidant Activity of Two Varieties of Pine Nut Seeds Grown in PortugalPublication . Ribeiro, Mariana Mendes; Rego, Andreia; Castanheira, IsabelAntioxidants are a field of food science and nutrition which is under close attention - is among the most studied subject in these areas - for their key role in maintaining homeostasis, protecting cellular components and their functions, and reducing oxidative stress (Cömert and Gökmen, 2018). Food can be a source of several compounds with antioxidant activity. There are several studies demonstrating proportionality between the consumption of antioxidant compounds through diet and the decrease in the incidence of certain pathologies. It is known that pine nut seeds are important sources of various antioxidant compounds (Xiao-Yu Su et al., 2009). Comparing to other nut kernels (such as walnut, hazelnut, peanut and almond) pine nut is third with highest antioxidant capacity (Delgado et al., 2010). Two varieties of pine nut seeds (Selected Pine Nut, SPN and Regular Pine Nut, RPN) cultivated in Portugal have been investigated for its antioxidant activity and for its Total Phenolic Content (TPC). The difference between them is that one is announced to be from a higher quality and the other from a regular quality, with a huge difference at the market value. In this work, the total phenols of the pine nut seeds extract were determined by the Folin-Ciocalteu method. The potential of the extract to neutralize reactive species was evaluated by the assay with 2,2-diphenyl-1-picrylhydrazyl (DPPH). The higher antioxidant activity was observed for SPN and the highest phenol content was detected also in this sample. Comparing to other kernel nuts, pine nut demonstrate remarkable antioxidant activity and high content of phenolic compounds (Cömert and Gökmen, 2018). As for the comparison between the different pine nut varieties, the results point out that a more careful manufacture preserves the antioxidant activity and, in this sense, adds functional value to the pine nut seeds. This study demonstrated that pine nuts seeds grown in Portugal exhibit high antioxidant activity with a great potential to be incorporated in food products to promote human health.
- The phytochemical and bioactivity profiles of wild Calluna vulgaris L. flowersPublication . Rodrigues, F.; Moreira, T.; Pinto, D.; Pimentel, F.B.; Costa, A.; Nunes, M.A.; Albuquerque, T.G.; Costa, H.S.; Palmeira-de-Oliveira, A.; Oliveira, A.I.; Sut, S.; Dall'Acqua, S.; Oliveira, M.B.P.P.The nutritional composition of Calluna vulgaris flowers as well as the phytochemical profile, antioxidant (DPPH and FRAP assays), antimicrobial and cytotoxic (in human immortalized non-tumorigenic keratinocyte and fibroblasts) activities of aqueous, hydroalcoholic and ethanolic extracts were evaluated. A high content of fiber and carbohydrates (75%) and the prevalence of α-tocopherol as vitamer deserves attention. Linolenic (35%), linoleic (27%) and palmitic (21%) acids were the most abundant fatty acids. Qualitative and quantitative analysis by LC-MS and 1NMR indicated high levels of quercetin, kaempferol and myricetin derivatives as well as procyanidins. The hydro-alcoholic extract displayed the highest antioxidant activity and total phenolics (TPC) and flavonoid contents (TFC). No adverse effects on cells were observed until a concentration of 100 μg/mL and a good antimicrobial activity was reported against S. epidermidis and S. aureus with the hydro-alcoholic extract. The data obtained demonstrated that wild plants like heather, although not being a common nutritional reference, can be used in an alimentary base as a source of bioactive compounds, namely antioxidants.
- Monitorização do teor açúcares em néctares, sumos e refrigerantesPublication . Jesus, Susana; Rego, Andreia; Motta, Carla; Delgado, Inês; Castanheira, IsabelUm dos nutrientes relevante da dieta humana são os açúcares que podem ser divididos em monossacarídeos (glucose, frutose, galactose, manose), dissacarídeos (sacarose, lactose, maltose) e polióis. Estes compostos são uma fonte de energia alimentar, contudo identificou-se uma relação entre o consumo excessivo dos açúcares na dieta e as complicações de saúde como a obesidade, diabetes mellitus não dependente da insulina, doenças cardiovasculares e cárie dentária (WHO, 1997). Segundo o inquérito alimentar nacional e de atividade física (ian.iaf) os refrigerantes, sumos e néctares contribuem entre 3% e 10% para a ingestão diária de açúcares mono e dissacarídeos (ian.af 2017). Recentemente foi introduzida uma taxa sobre açúcares neste tipo de bebidas, sendo assim importante proceder a uma análise critica comparativa entre os teores de açúcar de refrigerantes antes e depois da publicação do desta taxa de imposto. Deste modo, este trabalho tem como objetivo o desenvolvimento do método da quantificação de açúcares por cromatografia liquida de ultra eficiência acoplada a um detetor de massas (UPLC-MS/MS) e posterior determinação de açúcares em sumos, refrigerantes e néctares de marca branca e comercial recolhidas nas grandes superfícies de Portugal.
- Comparison Between Milk, Yogurt And Non-Dairy Milk Consumed in PortugalPublication . Delgado, Inês; Coelho, Inês; Ventura, Marta; Rodrigues, Sara; Ferreira, Marta; Castanheira, IsabelIodine is an essential trace element and its nutritional importance is well established. It is required for the synthesis of the thyroid hormones thyroxine and its active form T3, as well as the precursor iodotyrosines. The major role of thyroid hormones is related to the growth and development of the body. Iodine deficiency is the most common cause of preventable mental impairment. Chronic iodine deficiency can lead to disorders which include mental impairment and retardation, and formation of goiter (thyroid dysfunction), an enlargement of the thyroid gland which implies inadequate thyroid hormones production (Rohner et al., 2014). Recently EFSA and WHO established 150 µg per day as the adequate iodine daily intake (EFSA Panel on Dietetic Products, 2014; World Health Organisation and Food and Agriculture Organization of the United Nations, 2004). Food is the largest natural source of iodine. Dairy products are one of the major iodine suppliers, because of dairy-farming practices that contribute to its high iodine content (Leufroy et al., 2015). In literature the contribution of dairy products has been estimated between 25 % and 70 % of the daily iodine intake (van der Reijden et al., 2017). Nowadays, several people are substituting dairy products for non-dairy milks. For example, people with allergy or lactose intolerance. This work aims to determine the iodine content in dairy products and compare them with non-dairy milks. Samples of milk, yogurt and non-dairy milk consumed in Portugal were selected. In total, 41 samples were analyzed in triplicate. Iodine contents were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after alkaline extraction assisted by a heating block. The preliminary results show a high variation between brands, ranging from 91.2 to 367 μg/L. Similar results (17 - 365 μg/L) were reported by other authors (Dahl et al., 2003). Comparing between dairy products and non-dairy milks revealed a large variation. Non-dairy milks present about 60 times less iodine than dairy products. These results are in agreement with the literature (Bath et al., 2017). For people with lactose intolerance, allergic to milk, or under voluntary restrictive diets as vegans the alternative to dairy products may be non-dairy milks, with iodine fortification. This fortification is necessary so that the recommended nutrient intake of iodine can be supplied. In conclusion these results combined with consumption data are a contribution to estimate a real intake of dietary iodine of Portuguese population.
- Pêra-Rocha: Influência do Tempo de Cozedura no Conteúdo Fenólicos Totais e Capacidade AntioxidantePublication . Teixeira, Rita G.; Rego, Andreia; Jesus, Susana; Castanheira, IsabelA Pera-Rocha é uma variedade exclusivamente portuguesa produzida na sua maioria na Costa Central Oeste de Portugal. Reconhecida pela União Europeia, a Pera-Rocha do Oeste possui Denominação de Origem Protegida (DOP) e faz parte integrante do Património Cultural Português (Regulamento (CE) 492/2003). Estudos mostram que a Pera-Rocha do Oeste, face a outras variedades, é muito rica em compostos fenólicos totais (Salta et al., 2010). Contudo, nesta variedade, nunca foram estudadas as alterações de compostos fenólicos totais mediante o processamento culinário. Este estudo teve como objetivo estudar o impacto da cozedura na atividade antioxidante em peras com e sem casca, cozidas por períodos de 5, 10 e 15 minutos.
- Evaluation of Antioxidant Activity of ‘Rocha’ PearPublication . Rego, Andreia; Coelho, Inês; Santos, Rui G.; Bordado, João; Castanheira, IsabelThis work allowed to investigate the differences between PDO and non PDO pears in terms of their antioxidant activity.
- Next generation sequencing: a golden tool in mitochondrial diseasesPublication . Nogueira, Celia; Pereira, Cristina; Silva, Lisbeth; Vieira, Luis; Leão Teles, Elisa; Campos, Teresa; Rodrigues, Esmeralda; Martins, Esmeralda; Bandeira, Anabela; Soares, Gabriela; Janeiro, Patricia; Costa, Claudia; Gaspar, Ana; Santos, Helena; Vilarinho, LauraThe development of Next Generation Sequencing (NGS) has revolutionized the diagnostic approach of mitochondrial disorders, particularly in children. The purpose of our project is to develop a NGS strategy to identify the genetic defect in 250 patients, to confirm the clinical diagnosis of the disease.
- FluHMM: a simple and flexible Bayesian algorithm for sentinel influenza surveillance and outbreak detectionPublication . Lytras, Theodore; Gkolfinopoulou, Kassiani; Bonovas, Stefanos; Nunes, BaltazarTimely detection of the seasonal influenza epidemic is important for public health action. We introduce FluHMM, a simple but flexible Bayesian algorithm to detect and monitor the seasonal epidemic on sentinel surveillance data. No comparable historical data are required for its use. FluHMM segments a typical influenza surveillance season into five distinct phases with clear interpretation (pre-epidemic, epidemic growth, epidemic plateau, epidemic decline and post-epidemic) and provides the posterior probability of being at each phase for every week in the period under surveillance, given the available data. An alert can be raised when the probability that the epidemic has started exceeds a given threshold. An accompanying R package facilitates the application of this method in public health practice. We apply FluHMM on 12 seasons of sentinel surveillance data from Greece, and show that it achieves very good sensitivity, timeliness and perfect specificity, thereby demonstrating its usefulness. We further discuss advantages and limitations of the method, providing suggestions on how to apply it and highlighting potential future extensions such as with integrating multiple surveillance data streams.
- Tracing the geographical origin of food products with multielement fingerprinting and chemometrics: the case of Rocha pearPublication . Coelho, Inês; Matos, Ana S.; Teixeira, Rita; Nascimento, Ana; Bordado, João; Donard, Olivier; Castanheira, IsabelThe present work aims to develop a chemical fingerprint of Rocha pears produced within the PDO region based on multielement analysis.