Effect of baked wheat germ on the rheology and fermentation properties of steamed bread dough

Effect of baked wheat germ (BWG) on the extensional properties, water mobility, and fermentation properties of steamed bread dough was investigated. The extensograph properties analysis revealed that dough containing BWG exhibited a decreasing trend (p < .05) in extensibility and resistance to extension, indicating that the structure of the gluten network was weakened. Analysis of water mobility revealed that the T-22 and T-23 dramatically reduced as the level of BWG increased, decreasing water availability to the gluten matrix and reducing gluten strength. The analysis of fermentation properties showed that the presence of BWG decreased the maximum dough height, indicating that added BWG destroyed the continuous starch-gluten matrix and prevented the free expansion of wheat dough during the proofing stage. However, the total gas production of dough containing BWG was significantly higher than that of the wheat dough, revealing that the increase in levels of BWG facilitated yeast activity for the production of CO2. Novelty Impact Statement We investigated the external properties, water mobility, and fermentation properties of BWG-enriched dough. The results showed that BWG decreased the extensibility and water availability, resistance to extension of dough by forming weakened gluten network structure, causing a small steamed bread volume. Our ultimate aim was to improve the utilization of wheat germ and the nutrition of BWG-enriched steamed bread.