In vitro protein and starch digestion kinetics of individual chickpea cells: from static to more complex in vitro digestion approaches

Attention has been given to more (semi-)dynamic <em>in vitro</em> digestion approaches ascertaining the consequences of dynamic <em>in vivo </em>aspects on <em>in vitro </em>digestion kinetics. As these often come with time and economical constraints, evaluating the consequence of stepwise increasing the complexity of static <em>in vitro </em>approaches using easy-to-handle digestion set-ups has been the center of our interest. Starting from the INFOGEST static <em>in vitro </em>protocol, we studied the influence of static gastric pH <em>versus </em>gradual gastric pH change (pH 6.3 to pH 2.5 in 2 h) on macronutrient digestion in individual cotyledon cells derived from chickpeas. Little effect on small intestinal proteolysis was observed comparing the applied digestion conditions. Contrary, the implementation of a gradual gastric pH change, with and without the addition of salivary α-amylase, altered starch digestion kinetics rates, and extents by 25%. The evaluation of starch and protein digestion, being co-embedded in cotyledon cells, did not only confirm but accounted for the interdependent digestion behavior. The insights generated in this study demonstrate the possibility of using a hypothesis-based approach to introduce dynamic factors to <em>in vitro</em> models while sticking to simple and cost-efficient set-ups. The data used for the graphs in the paper: K. Pälchen, D. Michels, D. Duijsens, S. T. Gwala, A. K. Pallares Pallares, M. Hendrickx, A. Van Loey and T. Grauwet, Food Funct., 2021, DOI: 10.1039/D1FO01123E