Impact of whey protein addition on wheat bread fermented with a spontaneous sourdough

Summary Wheat bread is consumed in large quantities throughout the world. However, it contains an inadequate amount of proteins. This fact can be improved by adding whey protein concentrate (WPC). Sourdough (S) fermentation generally improves some characteristics and the digestibility of bread. The aim of this paper was to determinate the physicochemical properties and in vitro protein digestibility of bread with 20% of WPC leavened with spontaneous S (WPC 20‐S). To complete the experimental design, bread with S without WPC (WPC 0‐S) and bread with yeast (Y) without and with WPC 20% (WPC 0‐Y and WPC 20‐Y, respectively) were produced. WPC 20‐S bread had higher pH, lower moisture and higher hardness and chewiness, compared with WPC 0‐S. Interestingly, WPC had a negative effect only on the specific volume of bread fermented with Y but not when S was used. For all formulations, WPC improved the protein content and in vitro protein digestibility.