• Briard-Bion, Valérie
• Mackie, Alan
• Jardin, Julien
• Dupont, Didier
• Torcello-Gómez, Amelia
• Risse, Kerstin
• Mechoulan, Elodie
• Deglaire, Amélie

Abstract

Evaluating the gastrointestinal (GI) fate of proteins is part of the assessment to determine whetherproteins are safe to consume. In vitro digestion tests are often used for screening purposes in theevaluation of potential allergenicity. However, the current pepsin resistant test used by theEuropean Food Safety Authority, only corresponds to fasted gastric conditions representative of alate phase adult stomach. In addition, these tests are performed on isolated proteins and the effectof the food matrix and processing are not systematically considered. The aim of this research is tocompare three different static in vitro GI scenarios that are physiologically relevant. Namely, aninfant, early phase (fed state) adult and late phase (fasted state) adult model. These protocols areapplied to well-characterised isolated dairy (β-lactoglobulin and β-casein) and egg (lysozyme andovalbumin) proteins and the impact of food matrix/processing on their proteolysis is alsoinvestigated. A combination of SDS-PAGE, LC-MS/MS and spectrometric assay was used for theevaluation of the proteolysis. Results highlight differences across the three GI scenarios whether onisolated proteins or within food matrices. The infant model led to incomplete digestion, leavingintact egg proteins, either isolated or in the food matrix, and intact β-lactoglobulin in the milk. Inaddition, peptides greater than 9 amino acids were found throughout the intestinal phase for allproteins studied, regardless of the scenario. This reinforces the difficulty of linking proteindigestibility to potential allergenicity because many other factors are involved that need furtherinvestigation.

Topics

• impedance spectroscopy
• phase
• liquid chromatography
• liquid chromatography-mass spectrometry