Grain proteins of wheat (Triticum aestivum) are composed of albumins-globulins and storage proteins, gliadins and glutenins. Gliadins and glutenins form the gluten polymeric network conferring dough rheological properties. Therefore, their content and composition strongly influence the aptitude for processing of wheat cultivar. Wheat is a staple food for human and mainly consumed as bread, after milling grains into flour. However, wheat grain proteins are partially resistant to gastrointestinal enzymes and are associated to several health issues. In this context, our study aims at identifying phenotypic traits linked to bread protein hydrolysis during bread in-vitro digestion. Grains from 17 cultivars grown at two locations in France were phenotyped. Grain hardness, thousand-kernel-weight and grain nitrogen content were measured. Protein composition was determined by Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). Flour polymers were characterised by Asymmetric Flow Field Flow Fractionation (AF4). Dough and gluten technological properties were evaluated by a Chopin alveograph and a Glutomatic system, respectively. For each cultivar, breads were baked according to a standardized yeast-leavened method and digested in vitro with a dynamic gastrointestinal system TIM-1. After two hours of digestion, a nitrogen balance was performed on samples from the stomach compartment and the small intestine (ongoing digestion fractions), the ileal effluents (undigested fraction evacuated towards the colon), and the post-jejunum and post-ileum dialysates (digested fractions), allowing to evaluate the quantity of nitrogen in the digested, ongoing digestion and non-digested fractions. After construction of a synthetic variable reflecting proteolysis at two hours of digestion, multivariate analyses were conducted. Some phenotypic variables appeared to influence partial protein digestibility.