Percorrer por autor "Portmann, Reto"
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- INFOGEST static in vitro simulation of gastrointestinal food digestionPublication . Brodkorb, André; Egger, Lotti; Alminger, Marie; Alvito, Paula; Assunção, Ricardo; Ballance, Simon; Bohn, Torsten; Bourlieu-Lacanal, Claire; Boutrou, Rachel; Carrière, Frédéric; Clemente, Alfonso; Corredig, Milena; Dupont, Didier; Dufour, Claire; Edwards, Cathrina; Golding, Matt; Karakaya, Sibel; Kirkhus, Bente; Le Feunteun, Steven; Lesmes, Uri; Macierzanka, Adam; Mackie, Alan R.; Martins, Carla; Marze, Sébastien; McClements, David Julian; Ménard, Olivia; Minekus, Mans; Portmann, Reto; Santos, Cláudia N.; Souchon, Isabelle; Singh, R. Paul; Vegarud, Gerd E.; Wickham, Martin S.J.; Weitschies, Werner; Recio, IsidraDeveloping a mechanistic understanding of the impact of food structure and composition on human health has increasingly involved simulating digestion in the upper gastrointestinal tract. These simulations have used a wide range of different conditions that often have very little physiological relevance, and this impedes the meaningful comparison of results. The standardized protocol presented here is based on an international consensus developed by the COST INFOGEST network. The method is designed to be used with standard laboratory equipment and requires limited experience to encourage a wide range of researchers to adopt it. It is a static digestion method that uses constant ratios of meal to digestive fluids and a constant pH for each step of digestion. This makes the method simple to use but not suitable for simulating digestion kinetics. Using this method, food samples are subjected to sequential oral, gastric and intestinal digestion while parameters such as electrolytes, enzymes, bile, dilution, pH and time of digestion are based on available physiological data. This amended and improved digestion method (INFOGEST 2.0) avoids challenges associated with the original method, such as the inclusion of the oral phase and the use of gastric lipase. The method can be used to assess the endpoints resulting from digestion of foods by analyzing the digestion products (e.g., peptides/amino acids, fatty acids, simple sugars) and evaluating the release of micronutrients from the food matrix. The whole protocol can be completed in ~7 d, including ~5 d required for the determination of enzyme activities.
- The effects of matrix proteins on the aflatoxinM1 bioacessibility and the Caco-2 intestinal transportPublication . Tavares, Ana Maria; Egger, Charlotte; Portmann, Reto; Alvito, PaulaMycotoxins are fungal natural contaminants commonly found in food products that cause severe effects in human health, especially children. The mycotoxins occur in a great variety of foods, and can form complexes with the food matrix with a significant impact on their bioaccessibility. The bio-accessible fraction of the food contaminant contributes to the effective internal exposure depending on the contamination level, food matrix and the way the food is contaminated (spiked or naturally)1. To our knowledge, until now no studies were performed to disclose the possible role of milk proteins in the bioacessibility of aflatoxin M1 (AFM1), a mycotoxin commonly found in milk products. On behalf of a Short Term Scientific Mission within the Infogest COST action and of the project Mycomix (FCT, Portugal), a collaboration study between the National Health Institute Doutor Ricardo Jorge (Portugal) and Agroscope Liebefeld-Posieux (Switzerland) was established. The recently submitted harmonized in vitro digestion protocol2 was for the first time applied to study the bioaccessibility of AFM1 in artificially contaminated infant formula and the protein profile of the samples analysed by LC-MS/MS. The results revealed a good performance of the harmonized method, showing a successful digestion of the proteins into smaller peptides. However, the presence of aflatoxin M1 contamination was not detected before and after digestion, suggesting an interaction with the food matrix. Moreover, in the transport assays, the presence of AFM1 did not impair the Caco-2 cells membrane integrity as shown by the Transepithelial Electrical Resistance. Further assays including an optimized AFM1 extraction medthod are in progress to evaluate toxin bioaccessibility and its presence in basolateral, apical cell media and cell cytoplasm.
- The harmonized INFOGEST in vitro digestion method: From knowledge to actionPublication . Egger, Lotti; Menard, Olivia; Delgado-Andrade, Cristina; Alvito, Paula; Assunção, Ricardo; Balance, Simon; Barberá, Reyes; Brodkorb, Andre; Cattenozh, Thomas; Clemente, Alfonso; Comi, Irene; Dupont, Didier; Garcia-Llatas, Guadalupe; Lagarda, María Jesús; Le Feunteun, Steven; JanssenDuijghuijsen, Lonneke; Karakaya, Sibel; Lesmes, Uri; Mackie, Alan R.; Martins, Carla; Meynier, Anne; Miralles, Beatriz; Murray, Brent S.; Pihlanto, Anne; Picariello, Gianluca; Santos, Claudia N.; Simsekm, Sebnem; Recio, Isidra; Rigby, Neil; Rioux, Laurie-Eve; Stoffers, Helena; Tavares, Ana; Tavares, Lucelia; Turgeon, Sylvie; Ulleberg, Ellen K.; Vegarud, Gerd E.; Vergères, Guy; Portmann, RetoWithin the active field of in vitro digestion in food research, the COST Action INFOGEST aimed to harmonize in vitro protocols simulating human digestion on the basis of physiologically inferred conditions. A harmonized static in vitro digestion (IVD) method was recently published as a primary output from this network. To validate this protocol, inter-laboratory trials were conducted within the INFOGEST network. A first study was performed using skimmilk powder (SMP) as amodel food and served to compare the different in-house digestion protocols used among the INFOGEST members. In a second inter-laboratory study applying the harmonized protocol, the degree of consistency in protein hydrolysis was investigated. Analysis of the hydrolyzed proteins, after the gastric and intestinal phases, showed that caseins were mainly hydrolyzed during the gastric phase, whereas β- lactoglobulin was, as previously shown, resistant to pepsin. Moreover, generation of free amino acids occurred mainly during the intestinal phase. The study also showed that a few critical steps were responsible for the remaining inter-laboratory variability. The largest deviations arose from the determination of pepsin activity. Therefore, this step was further clarified, harmonized, and implemented in a third inter-laboratory study. The presentwork gives an overviewof all three inter-laboratory studies, showing that the IVD INFOGEST method has led to an increased consistency that enables a better comparability of in vitro digestion studies in the future.