Effects of thermal-induced konjac glucomannan-protein interaction on structural and rheological properties of wheat dough

This work is dealt with how structural changes induced by konjac glucomannan (KGM) interacting with wheat protein contribute to dough properties upon the heating stage. It comparatively investigated the effects of KGM on gluten thermal-polymerization process from molecular weight, free sulfhydryl content, secondary structure and thermal stability, and then analyzed KGM-induced changes of structural and rheological properties of wheat dough with heating temperature increased. Results showed that KGM increased the average molecular weight, the β -sheet/ β -turn ratio and denaturation temperature of gluten protein while decreased the content of free sulfhydryl groups. It was likely that KGM promoted the formation and stability of gluten networks upon heating by interfering sulfydryl interchange reactions and thermal denaturation. Dough structure was thus strengthened to a compact network and presented the increased elasticity and the raised resilience, springiness, cohesiveness and chewiness of textural properties by heating treatment. • KGM induced sulfydryl interchange, hydrophobic interaction and protein denaturation. • KGM prompted thermal aggregation and stability of gluten structure. • Dough structure was strengthened by KGM-intensified gluten-water interaction. • Dough with KGM showed reinforced elasticity and textural properties.