Display omitted •Maillard reaction occurs during thermal processing of tomato based sauces in the presence of dried pepper.•Accumulation of Amadori compounds in tomato based sauces have no effect on contents of carotenoids and on Z-isomerization of lycopene.•Accumulation of Amadori compounds in tomato based sauces have no effect on contents phenolic compounds and capsaicinoids.•Amadori compounds are bioaccessible in intestinal phase but not stable in digestive chyme.•Bioaccessibility of different Amadori compounds are highly variable depending on amino acid constituents. Amadori compounds (ACs), the first stable products of Maillard reaction, are detected in various products of fruits and vegetables, and show an antioxidant activity which can be related to beneficial effects in human health. In order to optimize the nutritional quality of a multi-ingredient tomato sauce (tomato puree – onion – olive oil – dried pepper), the fate of ACs during processing (drying, heating) and gastrointestinal digestion of a model meal was assessed as well as that of other microconstituents, i.e. carotenoids, phenolic compounds and capsaicinoids. The drying at 50 °C of fresh pepper induced the formation and accumulation of ACs after 6 days. During the heat treatment by microwave of multi-ingredient tomato sauce, Maillard reaction occurs in presence of dried pepper and the content in ACs in the tomato-based sauces increased (+33% to + 53%) depending of quantities of dried pepper added. The bioaccessibility of total ACs was 24–31% in duodenal phase and 18–22% in jejunal phase. Individual ACs have shown variable bioaccessibility, e.g. very high for Fru-Arg (50.8% to 71.3%), and very low for Fru-Met (1.8% to 2.2%). The kinetic monitoring of ACs in digestion medium showed that ACs are not stable (-46% in gastric phase, −49 % in intestinal phase) which indicated their potential degradation in the digestive tract. The presence of ACs in the multi-ingredients tomato sauces had no effect on the content of the other bioactive compounds monitored in the study and even promoted the bioaccessibility of total lycopene (+30%) but decreased the bioaccessibility of total phenolic compounds.