Percorrer por autor "Castanheira, Isabel"
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- Bioaccessibility and cytotoxicity of arsenic and mercury in cooked seafood : implications for food safety and human health riskPublication . Ventura, Marta; Assunção, Ricardo; Matos, Beatriz; Coelho, Inês; Delgado, Inês; Gueifão, Sandra; Santiago, Susana; Castanheira, Isabel; Martins, MartaSeafood is an important component of healthy dietary patterns. However, it can also serve as a dietary source of toxic elements that bioaccumulate in aquatic environments and biomagnify through the food web. This study quantified arsenic (As) and mercury (Hg) in cooked seafood, assessed their bioaccessibility, and evaluated the cytotoxic potential of the bioaccessible fractions using the human intestinal HT-29 cell line. The highest As concentrations were found in bivalves (3.7 ± 0.2 mg kg−1), and the highest Hg concentrations in scabbardfish (0.57 ± 0.01 mg kg−1). The bioaccessibility of As was substantially higher (ranging from 91 ± 2% to 127 ± 6%) than that of Hg (ranging from 4.8 ± 0.3% to 24 ± 8%). The highest bioaccessibility was observed in fresh tuna, 127 ± 6% and 24 ± 8% for As and Hg, respectively. Cytotoxicity assays at 24 h, 48 h, and 72 h indicated that bioaccessible Hg concentrations remained below cytotoxic thresholds. These results highlight the importance of integrating bioaccessibility and toxicological indicators into the evaluation of seafood safety.
- Commercial baby foods aimed at children up to 36 months : are they a matter of concern?Publication . Santos, Mariana; Matias, Filipa; Loureiro, Isabel; Rito, Ana Isabel; Castanheira, Isabel; Bento, Alexandra; Assunção, RicardoProper nutrition in infancy and early childhood is crucial to ensuring optimal child development, growth, and better health outcomes later in life. The nutrient profile model proposed by WHO/Europe aims to assess the nutritional quality and promotional/marketing aspects of commercial baby foods aimed at children up to 36 months. We used commercial data from 191 baby foods collected between March 2021 and July 2021, from eight supermarket chains in the Lisbon Metropolitan area. According to the model specifications and the NOVA classification system, we assessed the nutritional quality and promotion aspects and the degree of processing, respectively. The presence of at least one sugar-contributing ingredient was found in 34.0% of the products; 13.9% of products listed sugars and 15.0% listed fruit juices or concentrates as an ingredient. The claim “No added sugar” was present in 69.6% of products. Only 35.1% of products comply with all the nutritional requirements of the model. Concerning processing classification, 61.8% of products were ultra-processed, and about 57.0% were indicated for children < 12 months. These findings reinforce the importance of implementing measures to ensure that commercial foods for infants are marketed appropriately and to promote foods with a lower degree of processing.
- Measuring minerals in pseudocereals using inductively coupled plasma optical emission spectrometry : what is the optimal digestion method?Publication . Nascimento, Ana C.; Motta, Carla; Rego, Andreia; Delgado, Inês; Santiago, Susana; Assunção, Ricardo; Matos, Ana Sofia; Santos, Mariana; Castanheira, IsabelPseudocereals have gained attention due to their adaptability to different climates, high nutritional value, and suitability for gluten-free and plant-based diets. However, a challenge lies in the necessary adaptations in the diet pathways, mainly due to the lack of matrix-matching metrological tools. To address this problem, we developed a classification system to support laboratory decisions without shaped Proficiency Testing (PT) or Certified/Standard References Material. This system evaluates method performance through limit of detection (LOD), maximum uncertainty, and statistical comparison. For that matter, the mineral contents (Cu, Mn, Fe, Zn, Mg, P, Ca, K, and Na) of quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus), and buckwheat (Fagopyrum esculentum) were determined, using three different digestion methods, including dry-ashing, microwave, and graphite block acid digestion. A decision was reached concerning the optimal digestion method to be employed, with the results classified into three categories: (i) “rejected if results failed in two categories; (ii) “use with caution” if results were not satisfactory in one category; or (iii) “accepted”, if the results passed in all the categories. The system efficacy was exemplified by the effectiveness of dry-ashing and graphite block acid digestion by comparison with microwave digestion. Neither dry-ashing nor graphite block acid digestion can be recommended as an alternative method to the microwave digestion method when all the prioritized nutrient minerals are understudied. Although the microwave method is preferable for multi-elemental analysis, it is possible to obtain, with caution, comparable results from all the digestion methods if a higher relative combined uncertainty is defined (target uncertainty < 11%) under the assumption that this is suitable for the study.
- Studying iodine intake of Portuguese children school mealsPublication . Delgado, Inês; Ventura, Marta; Gueifão, Sandra; Assunção, Ricardo; Coelho, Inês; Bento, Alexandra; Silva, José Armando L.; Castanheira, IsabelIodine is an essential trace element, and its nutritional importance is well established. The iodine content of school meals of Portuguese children aged between 6 and 10 years (collected in the metropolitan area of Lisbon) was analyzed by ICP-MS. The samples were cooked with and without iodized salt and additionally some complementary foods were purchased as supplements to the main meals or to the other meal along the day. The results report six meals per day and they suggest that at least one main meals (lunch or dinner) prepared with iodized salt is enough to reach the recommended daily iodine intake (AI), 90 µg/day, not exceeding the tolerable upper intake (UL) level of 300 µg/day. When both main meals are cooked without iodized salt, 11 % of the hypotheses present an iodine content less than 90 µg/day. However, when lunch and dinner are prepared with iodized salt, 1 % exceeds the value of the UL. The food groups with the highest levels of iodine are daily products and fish. These results presuppose a balanced diet without any dietary restrictions. So, for ideological or medical reasons, special attention must be paid to diets with some limitations, such as vegetarian, lactose or high content of proteins free diets.