Comparison of a static and a dynamic in vitro model to estimate the bioaccessibility of As, Cd, Pb and Hg from food reference materials Fucus sp. (IAEA-140/TM) and Lobster hepatopancreas (TORT-2) Silvia Torres-Escribano a , Sylvain Denis b , Stéphanie Blanquet-Diot b , Marta Calatayud a , Laura Barrios c , Dinoraz Vélez a, ⁎, Monique Alric b , Rosa Montoro a a Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Apdo. 73, 46100, Burjassot, Valencia, Spain b Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine Auvergne, ERT 18, Conception ingénierie et développement de l'aliment et du médicament, BP 10448, F-63000 Clermont-Ferrand, France c Departamento de Informática Científica (SGAI-CSIC), C/ Pinar 19, 28006 Madrid, Spain abstract article info Article history: Received 3 May 2010 Received in revised form 6 October 2010 Accepted 9 October 2010 Available online xxxx Keywords: Arsenic Cadmium Lead Mercury Bioaccessibility In vitro gastrointestinal digestion models Bioaccessibility, the fraction of an element solubilized during gastrointestinal digestion and available for absorption, is a factor that should be considered when evaluating the health risk of contaminants from food. Static and dynamic models that mimic human physiological conditions have been used to evaluate bioaccessibility. This preliminary study compares the bioaccessibility of arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg) in two food certified reference materials (CRMs) (seaweed: Fucus sp., IAEA-140/TM; Lobster hepatopancreas: TORT-2), using two in vitro gastrointestinal digestion methods: a static method (SM) and a dynamic multicompartment method (TIM-1). There are significant differences (p b 0.05) between the bioaccessible values of As, Cd, Pb and Hg obtained by SM and TIM-1 in the two CRMs. The specific form in which the elements studied are present in the CRM may help to explain the bioaccessibility values obtained. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg) are toxic trace elements, and their concentrations in foods must be controlled by health authorities because of the possible adverse effects on the health that are associated with their dietary intake. In risk assessment, the exposure assessment stage evaluates the extent, duration, frequency and magnitude of exposures to a chemical pollutant (WHO, 2008). The evaluation of the magnitude of exposure to metal (loid)s through food should consider oral bioavailability, i.e. the “fraction of an administered dose that reaches the central (blood) compartment from the gastrointestinal tract” (Wragg and Cave, 2002), also known as absolute bioavailability (ABA). Relative Bioavailability (RBA) is obtained when the bioavailability of a material that is being studied is compared with the bioavailability determined for a reference material (Ruby et al., 1996; Nagar et al., 2009). A conservative tool for evaluating oral bioavailability is oral bioacces- sibility, defined as “the fraction that is soluble in the gastrointestinal environment and is available for absorption” (Wragg and Cave, 2002). Bioaccessibility provides an indication of maximum oral bioavailabil- ity and is therefore an important tool to be used in risk assessment (Intawongse and Dean, 2006). In recent years, the evaluation of bioaccessibility has acquired special importance. Studies of soils have shown the suitability of evaluating gastric, intestinal or gastrointes- tinal bioaccessible metal(loid) concentrations by in vitro assays to predict the in vivo bioavailability of As, Cd and Pb (As: Rodríguez et al., 1999; Juhasz et al., 2007; Nagar et al., 2009; Cd: Schroder et al., 2003; and Pb: Ruby et al., 1996). For food to be absorbed through the intestinal epithelium, first it has to be digested by a mechanical and chemical process that includes salivary, gastric and intestinal phases. Digestion starts in the mouth, where mechanical trituration is produced by mastication and mixing and moistening of the food with saliva, which contains ptyalin. The food then passes to the oesophagus and stomach, where it mixes with gastric juice which contains pepsin and hydrochloric acid. Digestion continues in the small intestine, where the absorption processes take place. In the first part of the duodenum the food is mixed with bile and pancreatic juice, which, together with a wide variety of enzymes secreted by the activity of enterocytes, constitute the intestinal juice. Nutrients and contaminants in the soluble fraction are then ready for absorption into the systemic circulation. Science of the Total Environment xxx (2010) xxx–xxx ⁎ Corresponding author. Tel.: + 34 963 900 022; fax: + 34 963 636 301. E-mail address: deni@iata.csic.es (D. Vélez). STOTEN-12301; No of Pages 8 0048-9697/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.scitotenv.2010.10.021 Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv Please cite this article as: Torres-Escribano S, et al, Comparison of a static and a dynamic in vitro model to estimate the bioaccessibility of As, Cd, Pb and Hg from food reference mate..., Sci Total Environ (2010), doi:10.1016/j.scitotenv.2010.10.021