Nitrosation can occur during meat digestion due to the physicochemical conditions of the stomach (low pH and reducing conditions). The aim of the present study was to elucidate the link between the nitrosation of proteins from beef meat and their digestibility by comparing cooked meat digested with and without the addition of nitrite. To do this, a dynamic in vitro artificial digestive computer-controlled system (DIDGI®) was used to reflect human gastro-intestinal conditions. Peptides and proteins from gastrointestinal digestion were identified by high-resolution LC-MS/MS mass spectrometry. The results showed a dynamic digestion pattern of meat proteins according to their cellular localization. A combined effect of the digestive compartment and the addition of nitrite was established for the first time on peptides profile, linking the nitrosation of proteins and their digestibility.