Browsing by Author "Nobre, Daniela"
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- Evaluation of iodine content in Portuguese primary school meals after mandatory iodization programPublication . Delgado, Inês; Coelho, Inês; Nobre, Daniela; Castanheira, Isabel; Calhau, Maria A.Clinical studies in Portugal have demonstrated the existence of a generalized deficiency in iodine of pregnant women and with school-age children. A general lack of awareness within the Portuguese population about the importance of iodine in the diet has also been identified. Thus, in this work we report the program underway in country to monitor the real content of iodine in school meals.
- Evaluation of iodine content in Portuguese primary school meals after mandatory iodization programPublication . Delgado, Inês; Coelho, Inês; Nobre, Daniela; Castanheira, Isabel; Calhau, Maria AntóniaThe National Legislation refer the use of iodized salt and consumption of fish and seafood, the supplementation of pregnant and lactating women in the form of potassium iodide (guidance from the DGS: iodine intake in preconception, pregnant and breastfeeding women 2013) and the use of iodized salt in school canteens (circular: Guidelines on school menus and cafeterias - 2013/2014.2013).
- Evaluation of iodine content in Portuguese primary school meals after mandatory iodization programPublication . Delgado, Inês; Coelho, Inês; Nobre, Daniela; Castanheira, Isabel; Calhau, Maria AntóniaClinical studies in Portugal have demonstrated the existence of a generalized deficiency in iodine of pregnant women and with school-age children. A general lack of awareness within the Portuguese population about the importance of iodine in the diet has also been identified. Thus, in this work we report the program underway in country to monitor the real content of iodine in school meals. Collection of foods from schools was designed to represent school meal program in place. Foods were organized into three groups. One hundred and forty four samples cooked with iodization salt (soup and main course) were collected from primary schools across Lisbon District (Group I). Twelve samples were used as reference of real iodine content from a pilot school (Group II). One hundred and forty four samples composed according consumption data were used as reference of minimum iodine value (Group III). A total of three hundred samples were analysed in pooled or single corresponding to thirty six laboratory samples and analysed in triplicate. The iodine contents were determined by inductively coupled plasma-mass spectrometry (ICP-MS) after alkaline extraction with TMAH (tetramethylammonium hydroxide) in a graphite block system during 3 hours at 90 °C, under the frame of ISO/EN 17025:2005 and EN 15111:2007. Laboratory performance was demonstrated through a successfully participated in Proficiency Testing Schemes launched by accredited provider. The concentration of iodine in analysed samples showed a wide range of levels varying according to the group. Group I from 9.9 µg/100g in chicken to 23.2 µg/100g in fish. Group II the highest value (32.3 µg/100g) was found in soup. The lowest value (below limit of quantification) was found in meat of Group III. The ratio between Group I and Group III was used to estimate effectiveness of the program, and the biggest difference was found in fish and narrowest was determine in chicken. The distance between iodine content in Group I and Group II was used to monitoring bias due to pooled samples. The major difference was observed in turkey. Sodium content is discussed as a contribution to clarify the iodine differences. Cooking procedure, iodization salt absorption, and operator performance were identified as main factors contributing to the differences between real and prescribed content. Iodization salt content determined in foods as consumed is an appropriate approach to evaluate fortification program and risks of both inadequate and excess iodine intake.
- Iodine and Selenium contents in Portuguese foods as consumedPublication . Delgado, Inês; Ventura, Marta; Gueifão, Sandra; Coelho, Inês; Rego, Andreia; Moreira, Tiago; Sanches, Diana; Nobre, Daniela; Castanheira, IsabelIntroduction: Selenium and iodine are micronutrients essential for thyroid hormone synthesis and function. There is also some evidence that low plasma selenium and iodine levels increase the risk of autoimmune thyroid diseases. Plasma levels of these oligoelements are related with dietary intake. Since foods are their main natural sources we investigated iodine and selenium content in foods as consumed collected in Portuguese TDS pilot study as representative of diet in the country. Objective: This work aims to evaluate the contents of Se and I in foods collect during the Portuguese Total Diet Study (TDS). Methodology: Samples (n=1020) were collected according to sampling plan from local markets and analyzed as pooled (n=85) of twelve samples each. The iodine and selenium contents were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after alkaline (iodine) or acid (selenium) digestion assisted by microwave. To guarantee the accuracy of the laboratory results matrix matching reference materials and successfully participation in proficiency test schemes were chosen as metrological parameters. The analytical results were expressed by the average of three replicates. Cluster analysis (CA), Principal Component Analysis (PCA) and Spearman correlation were applied to evaluate the statistical significance of analytical data. Main Findings: Selenium content ranged from 109±10.85 μg/100g (fresh tuna) to 1.82±0.16 μg/100g (milk with cereals). Iodine values were found from 157±5.8 μg/100g (cockles and clams) to 0.27±0.014 μg/100g (lupine). CA classified samples into four main groups on the basis of the iodine and selenium content. PCA and CA analysis are in agreement. Spearman positive correlation (p≤ 0.05) was achieved between iodine and selenium contents. Conclusion: Application of chemometric methods to analytical data is useful to group food samples when iodine/selenium ratio is necessary to suppress iodine deficiency.
- Iodine content in food: comparison between Azores and continental PortugalPublication . Delgado, Inês; Coelho, Inês; Nobre, Daniela; Castanheira, Isabel; Calhau, Maria AntóniaIodine is an essential trace element for the synthesis of thyroid hormones, important for pregnant women and children. Clinical studies in Portugal have demonstrated the existence of a generalized deficiency in iodine of pregnant women and with school-age children particular severity in the archipelago of Azores. Foods are the main iodine source. Thus, in this work we report the characterization of iodine in foods produced and consumed by population from Azores and continental Portugal. Samples of dairy products, fruits and vegetables from both regions were selected. In total, 110 samples were analyzed in triplicate. Iodine contents were determined using inductively coupled plasma-mass spectrometry (ICP-MS) after alkaline digestion assisted by microwave. Milk had higher iodine content in continental Portugal (255μg/l) than in Azores (133μg/l). For cheese, it was also found in continental Portugal that the highest iodine content was 275μg/kg when compared to the Azores, 117μg/kg. Vegetables collected in the Azores had higher iodine contents than those from continental Portugal, with the exception of carrots. For all fruits values below the limit of quantification were found. Results showed that dairy products analyzed are a good source of iodine and should be part of the diets of deficient populations. Proficiency test schemes and certified reference materials were important to guarantee the accuracy of the laboratory results. Analytical data are also in line with recent studies, evidencing that foods rich in iodine represent a clear benefit in the daily intake of this micronutrient, for the general population.
- Iodine content in food: comparison between Azores and continental PortugalPublication . Delgado, Inês; Coelho, Inês; Nobre, Daniela; Castanheira, Isabel; Calhau, Maria AntóniaBackground and objective(s): Iodine is an essential trace element for the synthesis of thyroid hormones, in particularly for pregnant women and children. Clinical studies in Portugal have demonstrated the existence of a generalized deficiency in iodine of pregnant women and with school-age children particular severity in the archipelago of Azores. The main cause of iodine deficiency is low levels of iodine in foods. A general lack of awareness within the Portuguese population about the importance of iodine in the diet has also been identified. Thus, in this work we address the characterization of iodine in foods available in Azores and continental Portugal to promote the consumption of iodine rich foods. Materials and methods: A total of 110 samples 60 from Azores (Az) and 50 from Portugal (cPT) were analyzed as consumed. The iodine content in dairy products, fruits and vegetables was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results: Analysed foods showed large variation in iodine content, with values of 255μg/l (cPT) and 133μg/l (Az) for milk, 275μg/kg (cPT) and 117μg/kg (Az) for cheese. However vegetables collected in Azores presented higher iodine content than those purchased in continental Portuguese supermarkets. Discussion and conclusion(s): All results are sound supported in metrological tools and aligned with other studies published in the literature. This is a premise to estimate the iodine intake of Azores and Continental population and a contribution to understand the role of this intake in the risk of Iodine Deficiency Disorders observed mainly in Azores region.