Identification of the physicochemical characteristics of peptides that influence their hydrolysis by pepsin

Changing the structure of foods can modulate their nutritional quality by modifying the digestion process, a complex process that is still imperfectly understood. In particular, digestion dynamics have been poorly studied, although it can has significant metabolic consequences. The objective of this study is to model the proteolytic cascade by pepsin, and to highlight a potential "structural effect". Egg white is an interesting model to meet this dual objective, as it offers the possibility of obtaining gels with different structures. In a probabilistic modeling approach of the peptide cleavage dynamics, we sought to identify leverages for the cleavage of a peptide after a given digestion time. For this purpose, peptides are identified and quantified at different time points in an in vitro digestion experiment. A Generalized Additive Modeling of the probability of a cleavage based on the physicochemical profile of peptides is proposed, considering either all kinds of cleavages made by the pepsin or only those made on preferential peptide bonds. The most significant variables are related to the length of the peptide and its location on the ovalbumin sequence. These results suggest that the action of pepsin depends more on structural criteria than on the presence of specific cleavage sites