Abstract
Wheat germ (WG), a nutrient-rich by-product of wheat milling, contains high levels of protein, lipids, fibre, and bioactive compounds but is often underutilized due to its susceptibility to rancidity. This study explored the potential of incorporating WG into sourdough (SD) fermentation to produce nutrient-dense sandwich bread. The research objectives included evaluating the physicochemical properties of WG, assessing its impact on SD fermentation, analyzing bread texture and structure, and conducting sensory and nutritional assessments. At a 25 % substitution level, WG promoted lactic acid bacteria growth, reduced pH, and increased organic acid content during fermentation. SD bread with fermented WG exhibited a lower pH, higher organic acid content, and improved dough rheology. Compared to industrial yeast bread, SD bread exhibited a denser structure, darker crust colour due to increased Maillard reactions, and a more complex flavour profile. Sensory evaluation revealed that while consumers appreciated the nutritional benefits, the characteristic sour taste was less preferred. Nutritional analysis revealed higher protein and fibre content, making the product suitable for health-conscious consumers. The findings highlight the feasibility of valorizing WG in SD bread production, offering a sustainable approach to reducing food waste and supporting the circular economy.
