Impact of the dairy matrix structure on milk protein digestion kinetics: Mechanistic modelling based on mini-pig [i]in vivo[/i] data
Résumé
The present study is based on the recent mini-pig in vivo results of Barbé et al. [1] and aims at better understanding and modeling the effect of the matrix structure on the digestion kinetics of dairy solutions and gels. The experimental results considered for the modelling are related to the digestion of six differently structured dairy matrices by the mini-pigs (2 milks, 2 acid gels, 2 rennet gels), and consist in plasmatic amino acid concentrations as well as dry matter contents and chromium concentrations (a marker of the liquid phase of the meal) of samples collected at the stomach exit. The model is based on a compartmental approach and is adjusted using a Monte-Carlo Markov-Chain algorithm. It accounts for the main digestive events but also for phenomena that can occur within the stomach (milk clotting and aggregate syneresis).[br/] The model provides a good fitting of all the experimental data and enables recovering good estimates of the model variables as well as simulated physiological parameters (such as stomach volume, gastric secretions or emptying rates) that are consistent with the available literature. This study shows that the great differences in the kinetics of amino acid absorption that were observed experimentally can be fully understood by considering the behaviour of the dairy matrices within the stomach. It also illustrates how a modeling approach can be of great help to unravel the complexity of the mechanisms involved during the digestion process