Comparative study on composite buckwheat dough and steamed bread modified by transglutaminase and ascorbic acid

Summary The effects of transglutaminase (TGase) and ascorbic acid (AA) on the processing properties of composite buckwheat dough (CBD) and composite buckwheat steamed bread were investigated in this study. Both TGase and AA significantly enhanced the peak and trough viscosity of CBD. With the addition of TGase or AA, storage modulus (G′) and viscous modulus (G″) of CBD increased first and then decreased, which was corroborated by data on protein secondary structure. Results revealed TGase and AA promoted protein crosslinking, and that TGase led to a more continuous, smoother dough structure than did AA. TGase and AA strongly affected hardness, adhesiveness and cohesiveness of CBD with a positive aspect. Compared with the steamed bread made with pure buckwheat, that made with composite buckwheat flour with TGase or AA had significantly lower hardness and gumminess rates within 30–60 min but no significant results were noted within 0–30 min. Buckwheat compound flour was prepared from buckwheat, SPI, sesame and soybean in this study and the effects of vitamin C and transglutaminase on the nutritional and processing qualities of compound buckwheat dough and steamed bread were investigated.