Effects of konjac glucomannan on the water distribution of frozen dough and corresponding steamed bread quality.

ABSTRACT

The influences of konjac glucomannan (KGM) on the water distribution of frozen dough and steamed bread quaility made from frozen dough were addressed in this study. Low Field Nuclear Magnetic Resonance (LF-NMR) analysis demonstrated that the less tightly bound water of the dough was transferred to tightly bound water with the increase of KGM. Differential Scanning Calorimetry (DSC) showed that the freezable water of the frozen dough was transferred to non-freezable water with increasing the amount of KGM. DSC and LF-NMR results indicated the water state in the frozen dough was consistent. The addition of KGM enhanced the height and whiteness of steamed bread, but it decreased springiness, cohesiveness and resilience of steamed bread. As the KGM substitution rate increased, the hardness of steamed bread first decreased and then increased. The steamed bread with 1.5% of KGM showed the best quality.