Browsing by Author "Dupont, D."
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- 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.
- MycoMix and risk assessment: a contribute to improve risk analysisPublication . Alvito, Paula; Assunção, Ricardo; Borges, T.; Dupont, D.; Leal, S.; Loureiro, S.; Louro, H.; Martins, Carla; Nunes, Baltazar; Pinhão, M.; Koroušic Seljak, B.; Silva, M.J.; Silva, E.; Vasco, Elsa; Calhau, Maria AntóniaRisk analysis, is a powerful tool for including science-based knowledge in a systematic approach to food safety problems. The use of risk analysis can promote ongoing improvements in public health and provide a basis for expanding international trade in foods. Within risk analysis, the risk assessment results are quantitative or qualitative expressions of the likelihood of harmful effects associated with exposure to a chemical (WHO, 2010). Human risk assessment of combined exposure to multiple chemicals (chemical mixtures) poses several challenges to scientists, risk assessors and risk managers, namely the complexity of the terminology and problem formulation, the diversity of chemical entities, and the toxicological profiles and exposure patterns in test species and humans (EFSA, 2013). Mycotoxins are natural contaminants produced by fungi and its frequent co-occurrence in food poses a threat to human health, mainly to vulnerable population groups as children. MycoMix is an ongoing national project (2013-15) that explores the toxic effects of mixtures of mycotoxins in infant food and its potential health impact. This project aims to study the occurrence of multiple mycotoxins and toxicity interactions in infant foods and cereals consumed by Portuguese children and try to answer several questions: 1) Are children exposed daily to mycotoxins through food? 2) What are the quality and quantity that characterize this exposure? 3) Can this exposure bring harm to children? Answering these questions will raise novel approaches to: 1) apply new techniques on mycotoxin multiple detection, 2) understand the toxicity responses upon multiple mycotoxin exposures, and 3) implement new methodologies to characterize hazard and risk for children exposure to mycotoxins. A multidisciplinary team has been developing, for the first time in Portugal, i) a liquid chromatography (LC) method coupled with tandem mass-spectrometry (LC-MS/MS) for multimycotoxin detection in infant food developed and applied to study infant food consumed by Portuguese children, ii) cito and genotoxic assays to assess the toxicity of binary mixtures of mycotoxins detected in analyzed infant foods associated with the MIXTOX tool to assess the interactive effects, iii) in vitro methodologies to simulate the digestive and intestinal absorption processes of binary mixtures of mycotoxins, iv) a web-based dietary assessment and diet planning platform, the “OPEN Portugal”, to record infant food consumption data allowing simultaneously the assessment of the nutritional profile of the inquired children, and v) a set of deterministic, probabilistic (@RISK) and cumulative risk assessment approaches that allow the exposure assessment and risk characterization of Portuguese children to multiple mycotoxins in food. An overview of the results obtained within the MycoMix project will be presented, showing the patterns of the exposure of Portuguese infant to multiple mycotoxins as well as the scientific evidence of the toxic effects of mycotoxin mixtures using in vitro models. Hence,MycoMix outputs contribute for hazard identification and characterization as well as to exposure characterization, contributing for risk analysis.
- A Standardised Static in Vitro Digestion Method Suitable for Food - an International ConsensusPublication . Minekus, M.; Alminger, M.; Alvito, Paula; Ballance, S.; Bohn, T.; Bourlieu, C.; Carrière, F.; Boutrou, R.; Corredig, M.; Dupont, D.; Dufour, C.; Egger, L.; Golding, M.; Karakaya, S.; Kirkhus, B.; Le Feunteun, S.; Lesmes, U.; Macierzanka, A.; Mackie, A.; Marze, S.; McClements, D.J.; Ménard, O.; Recio, I.; Santos, C.N.; Singh, R.P.; Vegarud, G.E.; Wickham, M.S.; Weitschies, W.; Brodkorb, A..Simulated gastro-intestinal digestion is widely employed in many fields of food and nutritional sciences, as conducting human trials are often costly, resource intensive, and ethically disputable. As a consequence, in vitro alternatives that determine endpoints such as the bioaccessibility of nutrients and non-nutrients or the digestibility of macronutrients (e.g. lipids, proteins and carbohydrates) are used for screening and building new hypotheses. Various digestion models have been proposed, often impeding the possibility to compare results across research teams. For example, a large variety of enzymes from different sources such as of porcine, rabbit or human origin have been used, differing in their activity and characterization. Differences in pH, mineral type, ionic strength and digestion time, which alter enzyme activity and other phenomena, may also considerably alter results. Other parameters such as the presence of phospholipids, individual enzymes such as gastric lipase and digestive emulsifiers vs. their mixtures (e.g. pancreatin and bile salts), and the ratio of food bolus to digestive fluids, have also been discussed at length. In the present consensus paper, within the COST Infogest network, we propose a general standardised and practical static digestion method based on physiologically relevant conditions that can be applied for various endpoints, which may be amended to accommodate further specific requirements. A frameset of parameters including the oral, gastric and small intestinal digestion are outlined and their relevance discussed in relation to available in vivo data and enzymes. This consensus paper will give a detailed protocol and a line-by-line, guidance, recommendations and justifications but also limitation of the proposed model. This harmonised static, in vitro digestion method for food should aid the production of more comparable data in the future.
- A standardised static in vitro digestion method suitable for food – an international consensusPublication . Minekus, M.; Alminger, M.; Alvito, Paula; Ballance, S.; Bohn, T.; Bourlieu, C.; Carrière, F.; Boutrou, R,; Corredig, M.; Dupont, D.; Dufour, C.; Egger, L.; Golding, M.; Karakaya, S.; Kirkhus, B.; Le Feunteun, S.; Lesmes, U.; Macierzanka, A.; Mackie, A.; Marze, S.; McClements, D.J.; Ménard, O.; Recio, I.; Santos, C.N.; Singh, R.P.; Vegarud, G.E.; Wickham, M.S.J.; Weitschies, W.; Brodkorb, A.Simulated gastro-intestinal digestion is widely employed in many fields of food and nutritional sciences, as conducting human trials are often costly, resource intensive, and ethically disputable. As a consequence, in vitro alternatives allowing for the determination of a variety of endpoints such as bioaccessibility of nutrients and non-nutrients, or digestibility of macronutrients such as lipids, proteins and carbohydrates, are used for screening and building new hypotheses. Various digestion models have been proposed, often impeding the possibility to compare results across research teams. For example, a large variety of enzymes from different sources such as of porcine, rabbit or human origin have been used, differing in their activity and characterization. Differences in pH, mineral type, ionic strength and digestion time, which alter enzyme activity and other phenomena, may also considerably alter results. Other parameters such as the presence of phospholipids, individual enzymes such as gastric lipase and digestive emulsifiers vs. their mixtures (e.g. pancreatin and bile salts), and the ratio of food bolus to digestive fluids, have also been discussed at length. In the present consensus paper, within the COST Infogest network (Dupont et al., 2011), we propose a general standardised and practical static digestion method based on physiologically relevant conditions that can be applied for various endpoints, which may be amended to accommodate further specific requirements. A frameset of parameters including the oral, gastric and small intestinal digestion are outlined and their relevance discussed in relation to available in vivo data and enzymes. This consensus paper (Minekus et al., 2014) will give a detailed protocol and a line-by-line, guidance, recommendations and justifications but also limitation of the proposed model. This harmonised static, in vitro digestion method for food should aid the production of more comparable data in the future.