Percorrer por autor "Vasco, Elsa"
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- Abordagem holística em avaliação de risco de contaminantes alimentares: a utilização de metodologias probabilísticasPublication . Assunção, Ricardo; Martins, Carla; Vasco, Elsa; Nunes, B.; Alvito, PaulaApresentação a utilização de metodologias probabilísticas na abordagem holística que assume uma importância crescente na avaliação de risco de contaminantes em alimentos.
- Aditivos AlimentaresPublication . Vasco, ElsaArtigo de opinião sobre aditivos alimentares. O Instituto Nacional de Saúde Doutor Ricardo Jorge é a entidade em Portugal responsável pela avaliação da ingestão de aditivos alimentares, estando em curso a implementação de um sistema de monitorização em meio escolar.
- Aditivos Alimentares em géneros alimentíciosPublication . Vasco, Elsa; Ravasco, Francisco; Brazão, Roberto; Oliveira, Luísa; Fernandes, Paulo; Tomé, Sidney; Lopes, Andreia; Dias, Maria da GraçaNa União Europeia, todos os aditivos alimentares estão regulamentados, são identificados por um código constituído pela letra E seguida de um número composto por 3 ou 4 algarismos e são sempre incluídos nas listas de ingredientes dos alimentos em que são utilizados. Os rótulos dos géneros alimentícios devem identificar a função do aditivo no alimento acabado (por exemplo, cor, conservante) e a substância específica utilizada, referindo-se ao código E ou ao seu nome (por exemplo, E 954 ou sacarina).
- Adoçantes – uma alternativa saudávelPublication . Vasco, ElsaComunicação sobre o consumo de adoçantes, na perspectiva de Saúde Pública.
- Análise de nitratos e nitritos em alimentos à base de carne: otimização de um método de HPLCPublication . Carvalho, Cláudia; Serra, Maria Celeste; Vasco, ElsaObjetivo: Este estudo teve como objetivo a otimização de um método com base na norma europeia EN 12014-4 para determinar nitratos e nitritos em alimentos à base de carne por HPLC.
- Analytical determination of nitrates in vegetablesPublication . Laia, Ana; Serra, Maria; Vasco, ElsaIntroduction: Nitrate compounds are common in the nature and widely found in food, water and soil. Generally, the nitrate compounds from vegetables are considered to be the main source of dietary nitrate intake. When consumed in excessive quantities, nitrate can be harmful to health because it could cause carcinogenesis and metahemoglobinemia. However, vegetables have an essential nutritional function and play an important role in health protection. In this way, to assess the dietary exposure of the population to these compounds, it is important to know the nitrate contents in vegetable products as they are consumed. As the nitrate concentration in vegetables varies according to season it is also important to study the effect of seasonality on the nitrate content.
- Applicability of an in vitro model to assess the bioaccessibility of food contaminantsPublication . Alvito, Paula; Vasco, Elsa; Martins, Carla; Dupont, D.In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants either caused by industrial or environmental contamination or as a result of production processes. The total amount of an ingested contaminant (intake) doesn´t always reflects the amount that is available to the body, because only a certain amount of the contaminant is bioavailable1. Studies in animals and humans show that oral bioavailability of compounds from food can be significantly different depending on the food source (food product), food processing or food preparation1. In vitro digestion models are widely used to study the structural changes, digestibility, and release of food components under simulated gastrointestinal conditions. In these digestion models, the most frequently used biological molecules are digestive enzymes, bile salts, and mucin. A digestion temperature of 37ºC and a time of 2h are predominantly employed2. However there are considerable differences in the type of experimental parameters measured in the various digestion models. INFOGEST (COST Action FA1005) aims at improving the current scientific knowledge on how foods are disintegrated during digestion and promotes the harmonization of currently used digestion models3. The present study aims to gather and discuss data on the bioaccessibility values of food contaminants (mycotoxins and nitrates) occurring in foodstuffs marketed in the region of Lisbon4,5 in order to contribute to estimate the toxicological risk associated with the consumption of contaminated foodstuffs. Samples were digested using an in vitro digestion model1 and food contaminants analyzed by HPLC before and after the digestion process. Patulin (mycotoxin) bioaccessibility was determined in an artificially contaminated apple juices with bioaccessibility ranging from 19% to 47%. Nitrates (natural contaminant) bioaccessibility was determined in 17 vegetable-based baby foods revealing bioaccessibility ranging from 42% to 159%. These large differences in the bioaccessibily of food contaminants could be attributed to differences in the composition of food matrix. More studies for food contaminants in different food matrix need to be performed to estimate the variability in bioaccessibility and its impact on food toxicology and risk assessment.
- Application of mathematical models to mycotoxins children risk assessment: a case study of Portuguese children exposure to co-occurring mycotoxins in processed cereal-based foodsPublication . Assunção, Ricardo; Vasco, Elsa; Nunes, Baltazar; Loureiro, S.; Martins, Carla; Alvito, PaulaPeople, animals and the environment can be exposed to multiple chemicals at once from a variety of sources, but current risk assessment is usually carried out based on one chemical substance at a time. In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, a wide group of fungal secondary metabolites that are known to potentially cause toxicity and carcinogenic outcomes. Mycotoxins are commonly found in a variety of foods including those intended for consumption by infants and young children and have been found in processed cereal-based foods available in the Portuguese market. The use of mathematical models, including probabilistic approaches using Monte Carlo simulations, constitutes a prominent issue in human health risk assessment in general and in mycotoxins exposure assessment in particular. The present study aims to characterize, for the first time, the risk associated with the exposure of Portuguese children to single and multiple mycotoxins present in processed cereal-based foods (CBF). Portuguese children (0-3 years old) food consumption data (n=103) were collected using a 3 days food diary. Contamination data concerned the quantification of 12 mycotoxins (aflatoxins, ochratoxin A, fumonisins and trichothecenes) were evaluated in 20 CBF samples marketed in 2014 and 2015 in Lisbon; samples were analyzed by HPLC-FLD, LC-MS/MS and GC-MS. Daily exposure of children to mycotoxins was performed using deterministic and probabilistic approaches. Different strategies were used to treat the left censored data. For aflatoxins, as carcinogenic compounds, the margin of exposure (MoE) was calculated as a ratio of BMDL (benchmark dose lower confidence limit) to the aflatoxin exposure. The magnitude of the MoE gives an indication of the risk level. For the remaining mycotoxins, the output of exposure was compared to the dose reference values (TDI) in order to calculate the hazard quotients (ratio between exposure and a reference dose, HQ). For the cumulative risk assessment of multiple mycotoxins, the concentration addition (CA) concept was used. The combined margin of exposure (MoET) and the hazard index (HI) were calculated for aflatoxins and the remaining mycotoxins, respectively. 71% of CBF analyzed samples were contaminated with mycotoxins (with values below the legal limits) and approximately 56% of the studied children consumed CBF at least once in these 3 days. Preliminary results showed that children exposure to single mycotoxins present in CBF were below the TDI. Aflatoxins MoE and MoET revealed a reduced potential risk by exposure through consumption of CBF (with values around 10000 or more). HQ and HI values for the remaining mycotoxins were below 1. Children are a particularly vulnerable population group to food contaminants and the present results point out an urgent need to establish legal limits and control strategies regarding the presence of multiple mycotoxins in children foods in order to protect their health. The development of packaging materials with antifungal properties is a possible solution to control the growth of moulds and consequently to reduce mycotoxin production, contributing to guarantee the quality and safety of foods intended for children consumption.
- Are breakfast cereals safe to consumption by children? A preliminary exposure assessment approachPublication . Assunção, Ricardo; Vasco, Elsa; Nunes, Baltazar; Martins, Carla; Alvito, PaulaIn human health risk assessment, ingestion of food is considered a major route of exposure to mycotoxins, metabolites that cause toxic outcomes in humans and infants are a particularly vulnerable population group. This study aims to characterize the risk associated with the consumption of breakfast cereals (BC) concerning the exposure of Portuguese children to mycotoxins. Portuguese children (< 3 years old, n=103) food consumption data of BC were obtained using a 3 days food diary in a pilot study performed at a Primary Health Care Unit. Fourteen BC samples were purchased from supermarkets in Lisbon region and the occurrence of aflatoxin B1 (AFB1) and ochratoxin A (OTA) were detected according to EN15851, with slight modifications, followed by HPLC-FLD analysis. Daily exposure of children to mycotoxins was performed using deterministic and probabilistic approaches. Different strategies had been considered to treat the left censored data. The output of exposure was compared with dose reference values. The analytical method showed a good performance with LOD of 0.003 and 0.006 µg.kg-1, LOQ of 0.009 and 0.019 µg.kg-1 and recoveries of 73 and 71 %, for AFB1 and OTA, respectively. Approximately 71% and 86% of BC samples were contaminated with AFB1 and OTA, respectively. Approximately 23 % of the studied children consumed BC at least one time in these 3 days. Both approaches showed that children exposure to single mycotoxins present in BC were well below the dose reference values. This study concerns the first risk assessment of Portuguese children to single mycotoxins in BC.
- Are Portuguese children exposed to mycotoxins through infant foods? A preliminary approachPublication . Assunção, Ricardo; Vasco, Elsa; Nunes, Baltazar; Alvito, PaulaMycotoxins are a wide group of fungal secondary metabolites that cause toxic and carcinogenic outcomes in humans exposed to them. The major foodborne mycotoxins of public health interest are the aflatoxins, fumonisins, trichothecene and ochratoxin A (OTA)1,2. Infants have a more restricted diet and they generally consume more food on a body weight basis than adults thus they are a particularly vulnerable population group to food contaminants as mycotoxins. In Portugal, Alvito et al. had reported the presence of aflatoxin B1 (AFB1) and M1 (AFM1) and OTA in baby foods3 and no data are available until now concerning the exposure assessment of Portuguese children to these mycotoxins. Exposure assessment, which evaluates the degree of intake of a certain contaminant, is one of the four steps included in risk assessment. Although several scientific reports have been published in order to propose the best methodologies for the exposure assessment framework, to date harmonization is far from being achieved4. The aim of the present study was to estimate the exposure of Portuguese children to mycotoxins due to infant foods ingestion, based on a probabilistic approach, using a risk analysis software (@Risk 6 for Excel, Palisade). The mycotoxin occurrence3 of AFB1, AFM1 and OTA in infant foods and consumption data for children until 3 years old were modeled. Consumption data were based on preliminary results recently obtained during a pilot study performed at Primary Health Care Unit from Cascais under the Mycomix Project. Different strategies had been considered to treat the left censored data.