Enhancing the nutritional profile of regular wheat bread while maintaining technological quality and adequate sensory attributes†
Plant proteins, and legume proteins in particular, have become the centre of attention moving towards a more sustainable and, therefore, more plant-based human diet. Especially hybrid products, containing wheat and legume proteins, promise a balanced amino acid composition and an upgraded nutritional value of both protein sources. This study investigates a high-protein hybrid bread (HPHB) formulation, where wheat flour was partially replaced by high-protein ingredients from faba bean, carob and gluten. In addition to a detailed characterisation of technological quality and sensory profile, also the formulation's nutritional value was examined in comparison to regular wheat bread. Therefore, macronutrient composition, antioxidant potential, amino acid profile and contents of antinutritional compounds were analysed. Furthermore, protein digestibility was determined in an in vitro model and in vivo. Dough analysis revealed significant differences of the HPHB formulation compared to regular wheat dough. However, results obtained for bread quality characteristics prove HPHB to be equal to regular wheat bread and sensory results and the determined sensory attributes suggest high consumer acceptance. Nutritional analyses of HPHB showed a more favourable macronutrient composition in comparison to regular wheat bread; as well as low contents of antinutritional compounds and high antioxidant potential linked to high levels of phenolics. Also an improved amino acid profile, increased nitrogen utilisation rate (by 69%) and higher protein efficiency ratio were determined, which are associated with enhanced protein quality. This suggests HPHB, and similar formulations of its kind, as a valuable and healthy food choice, which can contribute to adequate protein supply in predominantly plant-based diets.